Major Topic Abbreviation Major Topic Abbreviation

Adrenal Cortex Adren Cort Fractures Fractures

Anatomy Anat General Information Gen Info

Anesahesia Anesth Grafts Gradfts

Biopsy Biopsy Implants Implants

Disorders/Conditions Disord/Cond Miscellaneous Misc.

Drugs Drugs Temporomandibular Joint TMJ

Exodontia Exo

ORAL SURGERY & PAIN CONTROL Adren Cort

The gold standard test for primary adrenal failure is the:

. Blood glucose test

. ACTH stimulation test

. Serum creatinine level

. BL\ iest

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The ACTH stimulation test is performed to examine the response ofthe adrenal gland

to an exogenously administered dose ofACTH. Normal patients have a doubling oftheserum cortisol level after a dose of ACTH. The serum cortisol level should rise to >20

prg dL ifthere is adequate adrenal function. Art inadequate response suggests adrenal gland

hrpofirnction. Note: Cosyntropin (Cottosyz) is an ACTH analogue that stimulates the ad-

renal gland and its ACTH receptors.

About 20 mg of hydrocortisone is secreted by the adrenal cortex daily. During stress

the cortex can increase the output to 200 rng daily.

Rem€mber: Patients taking steroids or people with disease ofthe adrenals will have de-

creased ability to produce more glucocorticoids (hydrocortisone) in times of stress fejr-

tractions). The reason for this is as follows:

Secretion ofglucocorticoids is stimulated by ACTH, a hormone produced in the anterior

pituitary. The pituitary responds to stress by increasing ACTH output and therefore glu-

cocorticoid production increases. A relative lack ofglucocorticoids will also increase out-

put ofACTH. An overabundance ofcirculating systemic steroids will inhibit production

ofACTH. Patients on large doses ofsteroids repress ACTH production which leads to

atroohv of adrenal cortex.

. Never regain full adrenal cortical function

. Take as much as a year to regain full adrenal cortical function

. Take as little as a week to regain full adrenal cortical function

. Take usually a couple of days to regain full adrenal cortical function

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. Ectopic ACTH Syndrome

. MENS I

. Cushing's syndrome

. Addison's disease

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o

The following guidelines may help determine if a patient's adrenal function is suppressed,however, ifany doubt €xists, consult the patient's physician before performing surgery.

Some Guidelines:. People on smalf doses (5 mg Prednisone/day) will have suppression when they havebeen on the regimen for a month.. People taking equivalence of 100 mg cortisol/day (20-30 mg Prednisone/da1) wrll haveabnormal cortical function in a week.. Short-term therapy (1-3 days) ofeven high dose steroids will not alter adrenal corticalfunction.. A person who has been on suppressiye doses of steroids will take as much as a yearto regain full adrenal cortical function.

Patients with a&enal insu{ficiency are hyperpigmented. This is most noticeable on the buc-cal and labial mucosa, although other areas such as the gingiva may be involved. The hyper-pigmentation is a result of hypersecretion of ACTH, which can stimulate melanocytes toproduce pigment.

Patients rvith decreased adrenal gland hormone production experience weakness, weight loss,

onhostatic hypotension, nausea, and vomiting. Patients with severe adrenal insufficiency can-

not increase steroid production in response to stress and in extreme situations may have car-

diovascular collapse. It is important that an adrenally insufficient patient have adequate

steroid replacement, since the stress oforal surgery can precipitate adrenal crisis.

ln adrenal crisis, an intravenous or intramuscular injection ofhydrccortisone must be givenimmediately. Supportive treatment of low blood pressure with intravenous fluids is usuallynecessary. Hospitalization is required for adequate treatment and monitoring.

Cushing syndrome is a hormonal disorder caused by prolonged exposure ofthe body's tis-sues to high levels ofthe hormone cortisol. This results in characteristic changes in bodyhiatus including moon facies, truncal obesity, muscular wasting, and hirsutism. Some-

times called "hypercortisolism," it is relatively rare and most commonly affects adults

aged 20 to 50. The femaleto-male incidence ratio is approximately 5:1.

Patients with Cushing's syndrome are often h)?ertensive because offluid retention. Long-term glucocorticoid excess can result in decreased collagen production, a tendency tobruise easily, poor wound healing, and osteoporosis. They are often at increased risk forinfection.

Laboratory snrdies may reveal increased blood glucose levels because ofinterference withcarbohydrate metabolism, and examination of the peripheral blood smear may demon-

strate slight decrease in eosinophil and lymphocyte counts.

Important: The patient's cardiovascular status must be evaluated and treated if neces-

sary prior to surgery.

Note: The most common cause ofCushing's syndrome is a tumor in the pituitary ofthehloothalamus.

. Have patient discontinue the Prednisone for two days prior to the extraction

. Give steroid supplementation and remove the tooth with local anesthesia andsedation

. lnstruct the palient to lake 3 grams of amoxicillin one hour prior to extraction

. No special treatment is necessary prior to extraction

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. First molar

. Second premolar

. Second molar

. Canine

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Important: The f€ar here is that the patient may not have sumcient adrenal cort€x secretion (adrenal in-sulJiciency) to withstand the stress of an €xtraction without taking additional steroids. (This holds true

for any palient who has been treatedfor any disease vilh steloid therapy).

Patients with adrenal insufficiency, patients on daily steroid therapy, and patients who have rccently fin-ished a couNe of stercids should receive steroid supplement for dental procedures.

The concems about adrenal insufficiency should be raised on the basis ofclinicrl history. In the majorityofcases, the dentist should ask:

. Is it known that the patient's adrenal glands do not function adequately?

. Is the patient on chronic steroid therapy at doses ofprednisone higher than 15 mg/day?

. Has the patient been on steroid therapy at doses ofprednisone higher than l5 mg/day within the last

2 weeks?*** Ifthe answer to any ofthe above questions is yes, the dentist should assume that the patient willneed stress-dose steroids.

G€neral guidelines for the management ofpatients on steroid therapy:. Steroid supplement in patients who can develop adrenal insulliciency. Early moming appointm€nts. Shoner appointrnents. Minimize stress. Use sedation techniques when appropriate. Modiry dental treatment plan when appropriate. The major goal in these patients is to avoid precipitation ofadrenal insufnciency

Remember: Erythema multiforme is a hypersensitivity syndrome characterized by polyrnorphous

eruption ofskin and mucous membranes. Macules, papules, nodules, vesicles, or bullae and target or("bull's-eye-shaped") lesions aie seen. A sev€re form ofthis condition is known as StevensJohnsonsyndrome, These patients may be receiving moderate doses of syst€mic coficosteroids and thereforemay be unable to withstand the stress ofan extraction. Consultation with theirphysician is absolutely nec-

essary before treating these patients.

The greater palatine foramen is generally located halfway between the gingival margin and mid-line ofthe palate, approximately 5 mm anterior to thejunction ofthe hard and soft palate (vibrat-ing line) distal to the apex ofthe maxillary second molarThe hard palate is perfonted by the following foramina;

. The incisive foramen, posterior to the maxillary incisors, which transmits the nasopalatinenerves and the terminal branches ofthe sphenopalatine artery. The greater palatine foramen, is most Iiequently located distal to the maxillary second molar,which transmits the greater palatine vessels and nerve. The lesser palatine foramen, j ust poste.ior to the greater palatine foramen, which transmits thelesser palatine vessels and nerve

Nerves of the palate:. Sensory Inneryation to lhe palate: is supplied by the m^xillary (CN I/-2) nerve. The ante-rior part ofthe hard palate is supplied by the nasopalatine nerve which passes through the in-cisive foramen. The posterior part ofthe hard palate is supplied by the gr€ater palatine nervewhich passes through the greater palatine foramen. The soft palate is supplied by the lesser pala-tine nerve which passes though the lesser palatine foramen.. Motor Innervation: the tensor veli palatini is innervated by a muscular branch from themandibular division ofthe trigeminal nerve fCN Z/. All othermuscles are innervated by the pha-

ryngeal plexvs (motor pottion from the vagus nerve and cranial part of lhe accessory nene),

The greater palatine block or GP block is useful for dental procedures involving palatal soft tis-sues distal to the maxillary canine. This maxillary block anesthetizes the posterior portion of the

hard palate, anteriorly as far as the maxillary first premolar and medially to the midline.Target area: the gre ater (anterior) palatirre nerve as it passes anteriorly between the sofi tissues and

bone of the hard palate.

The nasopalatine nerve block anesthetizes the anterior portion ofthe hard palate (soft and hardtis.sre,r) from the mesial ofthe right first prcmolar to the mesial of the left fiIst premolar. Targetarea: incisive foramen, beneath the incisive papilla.

. Efferent components only

. Afferent components only

. Both efferent and afferent components

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. Articular fossa

. Anterior band of the articular disc

. Posterior band of the articular disc

. Articular eminence

. Retodiscal tissue

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The facial nerve leaves the cranial cavity by passing through the intemal acoustic meatus,which leads to the facial canal inside the temporal bone. Finally, the nerve exits the skr.rll byway of rhe stylomasloid foramen of the temporal bone.Note: lfyou cut the facial nerve just after its exit from the sylomastoid foramen, it wouldcause a loss of innewation to the muscles of facial expression.

The facial nerve carries an efferent component for the muscles of facial expression and forthe preganglionic parasympathetic innervation ofthe lacrimal gland (relaying in the ptery-gopalatine ganglion) and submandibular and sublingual glands (relar-ing in the submandibu-lar gangliott).

The afferent component serves a tiny patch of skin behind the ear, taste sensation, and the

body ofthe tongue.

Clinical information:l. Bell's palsy: involves unilateral facial paralysis with no known cause, except that thereis a loss ofexcitability ofthe involved facial nerve. The onset ofthis paralysis is abrupt, andmost symptoms reach their peak in 2 days. One theory of its cause is that the facial nervebecornes inflamed within the temporal bone, possibly with a viral etiology.L Trigeminal neurzlgia (tic douloureLLr): also has no known cause but involves the affer-eni nen:es of the trigeminal nerve. It usually involves the maxillary or mandibular nerve

branches but not the ophthalmic branch. One theory is that this lesion is caused by pressure

on ihe sensory root ofthe trigeminal ganglion by area blood vessels. Clinically, the patientfeels excruciating short-term pain f/ic/ when facial trigger zones are touched or when speak-ing or masticating, setting offassociated briefmuscle spasms in the area. The right side ofthe tace is affected more commonly than the left. It is more common in females. Carba-mazepite (Tegretol) is still the mainstay oftreatment.

The articular disc (meniscus) is composed of dense fibrous connective tissue, and it is

positioned in between the condyle and the fossa, thereby dividing the joint into superior and

inferiorjoint spaces.

The articular disc (nteniscus) vaies inthickness; the thinncr ccntral intermediate zone separates

the thicker portions, which are the anterior and posterior bands. The posterior band of the

articular disc is the thickest of the two bands, and it is attached with posterior loose connectivetissues called retrodiscal tissues (bildminar zone; postefiot attachment). The less thick anteriorband of the articular disc is contiguous with the capsular ligament, the condyle, and the superiorbelll ofthe lateral pterygoid muscle.

\ote: The retrodiscal tissue is highly vascularized and innervated, whereas the articular disc forthe nosl part is not. Only the extreme periphery of the afiicular disc is slightly innervated.

. Frontonasal duct

. Bulla ethmoidalis

. Hiatus semilunaris

. Nasolacrimal duct

. Submental artery

. Inferior alveolar artery

. Lingual artery

. Ascending pharyngeal artery

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Unfortunately, this opening lies high up on the medialwall ofthe sinus, so that the sinus readily accu-mulates fluid. Sincc the frontal and anterior ethmoidal sinuses drain into the infundibulum, which intum drains into the hiatus semilunaris, the chance that infection may spread from these sinuses into themaxillary sinus is great.2 tlpes of sinusitisr acute and chronic: common clinical manifestations include sinus congestion, dis-charge, pressure, face pain, and headaches.

Acute Sinusitis: the most common fonn ofsinusitis, typically causcd by a cold that results in inflam-mation ofthe sinus membranes, normally resolves in I to 2 weeks. Sometimes a secondary bactedal in-fection may seftle in the passageways after a cold; bacteria normally located in thc area (Streptococcus

pneutnnide dnd Hdeuophilus influenzae) may begin to increase, producing an acute bacterial sinusitis.Clinical signs ofacute sinusitis include

. Severe pain, constant and localized

. Tendemess to percussion ofthe maxillary posterior teeth

. A mucopurulent exudate

. Any unusual motion orjarring accentuates the pain

. Tendemess over the anterior sinus wall

Chronic sinusitis: an infcction ofthc sinuses that is present for longer than 1 month and requires longer

duration medical therapy. Typically either chronic bacterial sinusitis or chronic noninfectious sinusitis.Chronic bacterial sinusitis is trcatcd with anttbiotics (ampicillin or auqme tin). Chronic noninfectioussinusiris often is treated with steroids (opical o/ oral) and nasal washes.Locations of sinusitis:. \Ie\illary: the most common location for sinusitis; associated with all of the common signs and

s)mproms but also results in tooth pain, usually in the molar region. sphenoid: rarc, but in this location can result in problems with the pituitary gland, cavemous sinus

spdrome, and meningitis. Frontal: usually associated with pain over the forehead and possibly fever. Ethmoid: potential complications include meningitis and orbital cellulitis.

\ote: Thc maxillary sinus is innervated by the maxillary division of the trigeminal nerve (CN l/-2).

Speciiicall-v. the ASA, PSA, and MSA nerves as well as the inliaorbital nervc.

ft loops upward and then passes deep to the posterior border ofthe hyoglossus muscle to

enter the submandibular region. The loop ofthe artery is crossed superficially by the hy-poglossal nene. The lingual artery supplies structures ofthe floor ofthe mouth and the

posterior and inferior surface ofthe tongue. Major branches include the :

. Suprahyoid artery: supplies the suprahyoid muscles

. Doral lingual artery: supplies the tongue, tonsils, and soft palate

. Sublingual artery: supplies the floor ofthe mouth, mylohyoid muscle, and sublin-gual gland. Deep lingual artery: supplies the tongue

Important: The lingual artery does not accompany the conesponding nerve throughoutits course.

Remember: The inferior alveolar nerve, artery, and vein along with the lingual nerve

are found in the pterygomandibular space between the medial pterygoid muscle and the

ramus ofthe mandible. The inferior alveolar nerve passes lateral to the sphenomandibu-

lar ligament. The submandibular duct is crossed twice by the lingual nerve. Ifthe lingualnerve is cut after the chorda tympanijoins, there will be loss ofboth taste and tactile sen-

sation.

Note: The lateral pterygoid muscle forms the roofofthe pterygomandibular space.

. Pterygomandibular raphe

. Mastoid process

. Epicranial aponeurosis

. Genial tubercles on the intemal surface ofthe mandible

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. Facial nerve

. Trigeminal nerve

. Vagus nerve

. Glossopharyngeal nerve

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On each side, the pterygomandibular raphe extends from the hamulus and passes infe-riorly to attach to the posterior end ofthe mandible's mylohyoid line. It is formed by theunion ofthe tendinous ends ofthe superior constrictor ofthe pharynx and the buccinatormuscle. Note: As the mandible moves relative to the hamulus, the length ofthe raphe ispassively increased.

The pterygomandibular raphe is noted in the oral cavity as the pterygomandibular fold.

.--.., . L The buccinator muscle is pierced by the needle when performing an inferior

l Notegll alveolar nerve block.'W 2. The deep tendon of the temporalis muscle and the superior pharyngeal con-

strictor muscle form a V-shaped landmark for an inferior alveolar nerve block.3. When draining purulent exudate from an abscess of the pterygomandibu-lar space from an intraoral approach, the buccinator muscle is most likely tobe incised.

The nerve fibers pass to the otic ganglion via the tympanic branch ofthe glossopharyn-

geal nerve and the lesser petrosal nerve. Postganglionic parasympathetic fibers reach

the parotid gland via the auriculotemporal nerve, which lies in contact with the deep sur-

lace ofthe gland. Note: Postganglionic sympathetic fibers reach the gland as a plexus ofnerves around the extemal carotid artery

The parotid gland is the largest ofthe major salivary glands and is entirely serous in se-

cretion. The parotids are located below andjust anterior to the ear. The gland's capsule isfrom the deep cervical fascia. About 750% or more ofthe parotid gland overlies the mas-

seter muscle. the rest is retromandibular.

The parotid gland is drained by Stenson's duct, which forms within the deep lobe andpasses from the anterior border of the gland across the masseter muscle superficially,through the buccinator muscle into the oral cavity opposite the maxillary second molar.

The external carotid artery and its terminal branches within the gland, namely, the su-perficial temporal and the maxillary arteries, supply the parotid gland. The lymph vessels

drain into the parotid lymph nodes and deep cervical li,mph nodes.

1. Mumps is a viral disease of the parotid gland. Parotitis is the inflammationofthe parotid gland.

2. Von Ebner's glands are the only other adult salivary glands which are purelyserous.

3. Although it passes through the parotid gland, the facial nerve do€s not pro-vide any innervation to it.

. Notoi:, .,::#;{

ORAL SURGERY & PAIN CONTROL

A dentist is performing a routine restoration on the left mandibular first molar,He is giving an inferior alveolar nerve block injection, where he deposits

anesthetic solution right next to the Iingula and mandibuhr foramen.Which ligament is most likely to get damaged?

. Sphenomandibular ligament

. Temporomandibular ligament

. Stylomandibular ligament

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A patient comes into your dental o{fice complaining of chewingdilficulties. When you ask him to protrude his mandiblen the

mandible markedly deviat€s to th€ right. Which muscle,which inserts fibers into the capsule and articular disc of

the TMJ, is most likely damaged?

. Right medial pterygoid muscle

. Lefl medial pterygoid muscle

. Right lateral pterygoid muscle

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Thc sphenomandibular and stylomandibular ligaments are considered to be accessory liga-ments. The former is attached to the lingula of the mandible and the latter at the angle of themandible. These ligaments are responsible for limitation ofmandibular movements (thet linit ex-cessive opening). Note: The sphenomandibular ligament is most oftcn danaged in an inferioralveolar nerve block.

The temporomandibular ligament fabo called the lateral liganert) runs from the articular em-inence to the mandibular condyle. It provides lateral reinlbrcement for the capsule. This ligamentprevents posterior and inferior displacement ofthe condyle (it is the rlain srabilizing liganrentoJ the TMJ). Notei This ligament keeps the head of the condyle in the mandibular fossa if thecondyle is fractured.

Collateraf figaments (medial and lateral) also referred to as "discal ligaments," are Iigaments thatarise from the periphery ofthe disc, are attached to the medial and iateral poles ofthe condyle re-

spectively, and stabilize the disc on the top ofthe condyle. These ligaments rcstrict movement ofthe disc away from thc condyle during function. Note: They arc composed of collagenous con-nective tissuc: thus they do not strelch.

Joint capsLrlesphcnoid bonc

SphcnomandibularIgamcnr Styloid proccss

oftcn)poral bone

Stylonandibularllgamcnt

Anglc ofmandibular

.,{nkylosis ofthe condyle: the most common cause ofTMJ ankylosis is trauma

. A unilateral condylar fracture

The mandible will deviate away from the affected side with:. Condylar hyperplasia: malocclusion is also a common occurrence with this injury

Remember: The lateral pterygoids (right and leJi) acting together are the prime pro-tractors of the mandible. Important: In addition to opening and protruding, the lateralpterygoids move the mandible from side to side, For right lateral excursive movements,

the left lateral pterygoid muscle is the prime mover and vice versa.

A patient who sustained a subcondylar fractare (unilateral condylar fracture) on lheleft side would be unable to deviate the mandible to the right (as stated qbove the

mandible v,ill deviate to the side o/ injury with a unilateral condylar fracture, this patientu'ottlrl not be able to deviate the mqndible to the right) This is normally treated by a closedproc€dure involving intermaxillary fixation. This procedure immobilizes the con-comitant fractures and conects the displacement ofthe jaws associated with the condylarftacture thereby conecting the shift ofthe midline toward the side ofthe fiactured condyle

and the slight prematue posterior occlusion on that side.

The mandible will also deviate toward the side of iniurv with:

. Submental lymph nodes

. Submandibular lymph nodes

. Parotid lymph nodes

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. Sphenopalatine artery

. Greater palatine artery

. Posterior superior alveolar artery

. Infraorbital artery

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The deep cewical lymph nodes ar€ located along the length ofthe intemal jugular vein on each sideofthe neck, deep to the stemocleidomastoid muscle. The deep cervical nodes extend from the baseofthe skull to the root ofthe neck, adjacent to the pharynx, esophagus, and trachea. The deep cer-vical nodes are further classified as to their relationship to the stemocleidomastoid muscle as beinssuperior or inferior.

The deep cervical lymph nodes are responsible for the drainage of most of the circular chain ofnodes, and receive direct efferents from the salivary and thyroid glands, the tongue, the tonsil, thenose, th€ pharynx, and the larynx. All these vessels join together to form the jugular lymphtrunk. This vessel drains into either the thoracic duct on the left, the right lymphatic duct onthe right, or independently drains into either the intemal jugular, subclavian, or brachiocephalicvelns.

Some regional groups of lymph nodes:. Parotid lymph nodes - receive lymph from a strip of scalp above the parotid salivary gland,from the anterior wall ofthe extemal auditory meatus, and from the lateral parts of the eyelidsand middle ear. The efferent lymph vessels drain into the deep cervical nodes.. Submandibular lymph nodes - located between the submandibular gland and the mandible;receive lymph liom the front of the scalp, the nose, and adjacent cheek; the upper lip and lowerlip (ercept the center p.trt); tlrc paranasal sinuses; the maxillary and mandibular teeth ferceplthe mandibular incisorsl; the aDterior two-thirds of the tong\e (except the tip); the floor ofthemouth and vestibule; and the gingiva. The eferent lynph vessels drain into the deep cervicalnodes.. Submental lymph nodes - located behind the chin and on the mylohyoid muscle; receive

lymph from the tip of the tongue, the floor of the mouth beneath the tip of the tongue, the

mandibular incisor teeth and associated gingiva, the center part of the lower lip, and theskin over the chin. The eflerent lymph vessels drain into the subrnandibular and deepcervical nodes.

The externaf carotid artery supplies most ofthe head and neck, except for the brain (the btaingets its blood supply from the internal carotid and the veltebrql arleries). The extemal carotidpasses through the parotid salivary gland and terminates as the maxillary and superficial tenpo-ral arteries. The superficial artery supplies the scalp. The maxillary artery leaves the infratempo-

ral fossa by passing though the pterygomaxillary fissure into the pterygopalatine fossa. Here itsplits up into branches that accompany the branches ofthe maxillary nerve. It supplies the muscles

ofmastication, the maxillary and mandibular teeth, the palate, and almost all ofthe nasal cavity.

The matrdibular t€eth receive blood from the inferior alveolar artery, which is a branch of the

maxillary artery. The maxillary teeth also receive blood from branches ofthe maxillary artery as

follows:. Posterior teeth: from the posterior superior alveolar artery. Anterior teeth: from the anterior and middle superior alveolar artedes.

Remember: The venous return ofboth dental arches is the pterygoid plexus ofveins.

Branches ofthe maxillary artery that accompany the branches ofthe maxillary nerve;

l. The posterior superior alveolar artery descends on the posterior surface ofthe maxilla and

supplies the maxillary sinus and the maxillary molar and premolar teeth.

2. The infraorbital artery ente$ the orbital cavity thrcugh the inferior orbital fissure. lt ends

by emerging on the face with the infraorbital nerve.

3. The greater palatine artery descends through the grcater palatine canal with the greater pala-

tine nerve. tt is distributed to the mucous membrane covering the oral surface ofthe hard palate.

4. Tbe pharyngeal branch passes backward to supply the mucous membrane ofthe roofofthenasopharynx.5. The sphenopalatin€ artery passes thrcugh the sphenopalatine foramen into the nasal cavity.It supplies the mucous membrane ofthe nasal cavity.

. Lingual frenum

. Nasolacrimal duct

. Parotid raphe

. Sublingual caruncle

. Arthrodialjoint

. Ginglymus joint

. Ginglymoarthrodial joint

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,n;4'%#

The submandibular glatds (formerly celled the submaxillary glands) arc located in thesubmandibular triangle ofthe neck and the floor ofthe oral cavity. The submandibular duct(Wharton's duct) is a long duct that travels along the anterior floor of the mouth. The ductopens into the oral cavity at the sublingual caruncle, a small papilla near the midline ofthemouth floor on each side ofthe lingual fienum. Clinically, the gland is effectively palpated in-fe or and posterior to the body of the mandible, moving inward from the inferior border ofthe mandible near its argle as the patient lowers the head. Note: The submandibular gland isa mixed gland, secreting both serous and mucous saliva, but predominantly serous secreting.

The submandibular glands are innervated by efferer,t (paras4pathetly' secretomotor fibersfrom the facial nerve, which run in the chorda tympani and in the lingual newe (branch ofZ-3) and synapse in the submandibular ganglion. Note: This is the same as the sublingualglands. The blood supply comes from branches of the facial and lingual arte es. The veinsdrain into the facial and lingual veins. The lymph vessels drain into the submandibular and

deep cewical lymph nodes.

Important: During its course, Wharton's duct is closely related to the large lingual nerve*.hich eventually crosses over it. This is important because if you incise the mucous mem-branes of the floor of the mouth, depending on where you cut, you may expose the lingualnerve, Wharton's duct, and the sublingual gland.

l. To expose the duct intraorally, only mucous membrane needs to be cut through.2. L).rnphadenopathy is the most common cause ofswelling ofthe tissues in the sub-

mandibular triansle.

Because the TMJ has characteristics ofboth a hinge joint and a gliding joint, it is classified as a gingly-moarrhrodial joint. A unique feature ofthe TMJ is that it is rigidly connected to both the dentition and

the contralateral TMJ.Components ofthe TMJ:

. Mandibular condyle (sometines called the cowlyloid process of the mandible) - the aniculating sur-

face or functioning part of the condyle is located on the superior and anterior sudaces ofthe head ofthe condyle. This surface is covered with a dense layer oflibrous connective tissue.. Articular fossa - this fossa is the anterior three-fourths ofthe laryer mandibular fossa. It is consid-ered to be a notr-functioning portion ofthejoint. Remember: The mandibular fossa (g/enoidfossa)

is rhe remporal component ofthe TMJ; it is bounded in front by the articular eminence, and behind,b-v the tympanic part of the temporal bone, which separates it from the extemal auditory meatus.. Articular eminence (also called the articular tubercle) - is aidge that extends mediolaterallyjustin fiont ofthe mandibular fossa. It is considered to be the functional portion ofthejoint. It is lined$ ith a thick dense layer of librous connective tissue.. -A.rticular disc /a/,ro called the meniscus) - is a biconcave librocartilaginous disc interposed be-

t\|een the condyle ofthe mandible and the mandibtiar (glenoid) fossa ofthe temporal bone which pro-

!ides the gliding surface for the mandibular condyle, resulting in smoothjoint movement. The cenhalpart is avascular and devoid ofnerv€ tissue, only the extreme periphery is slightly innervated.

Postglenoidproccss

Blood vcsscls

Condyle

Uppe. synovialcavity

Arlicular

Joint disc

Lower synovialcaviry

Latcral ptcrygoid musclc

it is usually displaced through the periosteum and locatedto the lateral pterygoid plate and _ to the lateral pterygoid

muscle with displacement.

. medial, inferior

. medial, superior

. lateral, inferior

. lateral, superior

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The carotid sheath contains all of the followlng EXCEPT one,Which one is the I9XCEP?1ON?

. Carotid artery

. Sympathetic trunk

. Jugular vein

. Vagus nerve

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The infratemporal fossa is an irregular space behind the maxilla. Its roof is formed bythe greater wing ofthe sphenoid. The lateral pterygoid plate ofthe sphenoid is medial. La!erally, it is limited by the coronoid process and ramus ofthe mandible. The infratempo-ral fossa communicates with the pterygopalatine fossa through the pterygomaxillaryfissure which is a cleft between the lateral pterygoid plate and the ma,rilla. It communi-cates with the orbit through the inferior ort ital fissure which is between the maxilla and

the greater wing ofthe sphenoid.

The pterygopalatine fossa is a small space behind and below the orbital cavity. It lies be-tween the pterygoid plates ofthe sphenoid and palatine bone below the apex ofthe orbit.

Clinical: Ifthere is good access and adequate light, a single cautious effort to retrieve the

tooth with a hemostai can be made. Ifthe effort is unsuccessful, or ifthe tooth is not vi-sualized, the incision should be closed, the patient should be infonned, and prophylacticantibiotics should be prescribed. A secondary surgical procedure is performed 4-6 weeks

later after lateral and posteroanterior radiographs are taken to locate the tooth in all threeplanes. After adequate anesthesia, a long needle is used to locate the tooth. Careful dis-section is performed along the needle until the tooth is visualized and subsequently re-

moyed. Note: Ifno functional problems exist after displacement, the patient may elect notto have the tooth removed. Proper documentation of this is critical.

***The carotid sheath does not contain the sympathetic trunk, which lies posterior to the

carotid sheath and anterior to the prevertebral fascia.

The carotid sheath is located at lhe lateral boundary ofthe retropharyngeal space at the

level ofthe oropharynx on each side ofthe neck deep to the stemocleidomastoid muscle.

It extends from the base ofthe skull to the first rib and sternum. It contains the carotid ar-

teries, the jugular vein, and the vagus nerve. Within the carotid sheath, the vagus nerve(CN-! lies posterior to the conrnon carotid artery and intemaljugular vein.

The facial vein unites with the retromandibular vein below the border ofthe mandible and

empties into the main venous structure ofthe neck, the internal jugular vein. The in-ternal jugular vein descends through the neck within the carotid sheath and unites be-

hind the sternoclavicular joint with fte subclavian vein to form the brachiocephalicvein. The brachiocephalic veins (ngi t and lefi) unite inthe superior mediastinlun to formthe superior vena cava, which retums blood to the right atrium ofthe heart.

. Posterior superior alveolar nerve

. Glossopharyngeal nerve

. Facial nerve

. Mylohyoid nerve

20Coplaight O 201 l -20 1? - Denial Deck!

r\.

. Intemal carotid artery

. Extemal carotid art€ry

. Cornmon carotid artery

. Aorta

Coplrighr @ 201l-2012 - Dental Decks

After the inferior alveolar nerve exits the mandibular canal, a small branch occurs, calledthe mylohyoid nerve. This newe pierces the sphenomandibular ligarnent and runs inferi-orly and anteriorly in the mylohyoid groove and then onto the inferior surface ofthe my-lohyoid muscle. The mylohyoid nerve serves as an effetent nerve to the mylohyoid muscle

and the anterior belly ofthe digastric muscle. This nerve may in some cases also serve as

an afferent nerve for the mandibular first molar.

The mylohyoid muscle is an anterior suprahyoid muscle that is deep to the digastric mus-

cle. In addition to either elevating the hyoid bone or depressing the mandible, the muscle

also forms the floor ofthe mouth and helps elevate the tongue.Note: The sublingual gland is located superior to the mylohyoid muscle.

. . l. When placing the film for a periapical view of the mandibular molars, it isNote{r the mylohyoid muscle that gets in the way if it is not relaxed.':;t;;i 2- when the floor ofthe mouth is lowered surgically, the mylohyoid and g€-

nioglossus muscles are detached.

3. An injection into the parotid gland (capsule) uthen atlempting to administeran inferior nerve block may cause a Bell's palsy facial expression

-paralysisofthe forehead muscles, the eyelid and ofthe upper and lower lips on the same

side ofthe face that the injection was given. Important: Ifthe parotid capsule

injection happens, care must be taken to protect the eye from injury and dryingusing lubrication and an eye patch.

4. Remember: The bone of the maxilla is more porous than that of the

mandible, therefore, it can be infiltrated anywhere.

The major arterial blood supply to the TMJ is derived from the superficial temporalartery and from the maxillary artery posteriorly, and from smaller masseteric, posteriordeep temporal, and lateral pterygoid arteries anteriorly. The venous drainage is througha diffuse plexus around the capsule and rich venous channels that drain the retrodiscal

rissue. ){ot€: The two terminal branches of the extemal carotid artery are the superficialtemporal artery and the maxillary artery.

The fibrous capsule of the TMJ is innervated from a large branch of the auriculotem-poralrerYe (branch ofV-3).The rnterior region ofthejoint is innervated from the mas-seteric nerve (also a branch of V-3) and from the posterior deep temporal nerve (a/so

a bronch oJ'V-3).The sensory innervation ofthe TMJ is via the trigeminal nerve as well.The nerve fibers prirnarily follow the vascular supply and terminate as free nerve endings.

Thus. the capsule, synovial tissue, and extreme periphery ofthe disc are innervated. The

anicular cartilage and the central part ofthe disc contain no nerv€s. Both myelinated and

nonmyelinated nerves are seen in the TMJ. The retrodiscal bilaminar zone has a rich neu-

rovascular supply and is the source ofproprioception.

Remember: Most synovial joints have hyaline cartilage on their articular surface; how-

ever, a number ofjoints, such as the stemoclavicular, acromioclavicular, and TMJs, are

associated with bones that develoo from intramembranous ossification. These have fi-brocartilage articular surfaces.

Which cranial nerve provides motor innervation to thesternocleidomastoid and trapezius rnuscles?

. Glossopharyngeal (CN lX)

. Yagus (CN ))

. Accessory (CNX1)

. Hypoglossal (Cir'J71)

Copright C 201 l-2012 - Dertal Decks

After a stroke on the right side ofthe brain that affects the rightupper motor neurons, the tongue deviates to the:

. Left on protrusion

. Right on protrusion

. Neither ofthe above, the tongue would not be affected

23Cop)'right O 201 l-2012 - De al Decks

Nerve Site of Exit from Skull Component Function

(cN yr|,Inlcmal acouslic mcatus Specirl s€nsory To thc o.gan of Coni for hcaring

To the semicircular canals lbrbalance

Glossopha.J,DgealcN 14

B.anchial molork p e c ial |irc e ra I eJle r e n t)

(se n etu I y i s c e tu I efer etlt)

k%erat \)isceftt ateren,

G€n€ral s€n$rykenerut somtic .ffercnt)

Special $nsory('peciat ateren,

Supplics de stylophaDngeus muscle

Paraslmprlhctic inncrvation of thc smoolhmusclc rnd gllnds oflhe pharynx. larlnx,and visccra ofthc lhomx and abdomcn

Cadics visccral scnsory inlbrmation fromthc carotid sinus and body

Providcs gcncol scnsalion infomationfrom the skin oflhc cxtemal car, intcmalsurfacc ofthc tympanic membranc.uppcr pharynx. andpostcrior onc-tlird of

Providcs tnstc scnsation from postcriorone-th;d ofthc tonguc

Bramhirl motor---{rrnill

(s p ? c ia | \' i' c e tu I etre r n,

Brrnchial motor----{pinal

(spec i a I viscerul etetenl

Inncrvatcs musclcs ot thc larynx and

Inncflates thc trapezn's andstcmoclcidomasloid musclcs

HFoglossalIC\ XII)

Hyposlossal canal

ke"erut sonntk effercnt)Inncwatcs all of the inrrins;c and mort ofthe exlrinsic musclcs oflhc lon8uc

kenioslase$, ltlloglotsus, antl h\ oglossus

Lesions of the hypoglossal nerve:. Hypoglossal nerve Iesions paralyze the tongue on one side. On protrusion, the tongue deviates to the ipsilateral fsarre/ or contralateral side, de-

pending on the lesion site.

Lower motor neuron lesion:

Lesions to the hypoglossal nerve causes paralysis on the ipsilateral fsame) side:. Tongue deviates to the paralyzed side on protrusion (the paralwed muscles v,illlag. cartsing th? tip to dcviote).. Musculature atrophies on the paralyzed side. Tongue fasciculations occur on the paralyzed sideExample: With a neck wound that cuts the right hypoglossal nerve, the tongue de-

viates to the right on protrusion, and the right half of the tongue will later demon-

strate atrophy and fasciculations

Upper motor neuron lesion:

Causes paralysis on the contralateral side:. Tongue deviates to the side opposite the lesion. Musculature atrophies on side opposite the lesionExample: After a stroke on the right side of the brain that affects the right uppermotor neurons, the tongue deviates to the left on protrusion, and the left half of the

tongue will atrophy

Important: If the genioglossus muscle is paralyzed, the tongue has a tendency to fallback and obstruct the oropharyngeal airway with risk of suffocation.

The sublingual gland is locatsd in the oral cavitybetwe€n the mucosa ofthe oral cavitv and the:

. Masseter muscle

. Mylohyoid muscle

. Buccinator muscle

. Temporalis muscle

24Copt"ighr O 201 1,2012 - Denral Decks

. Superior to the deep lobe ofthe submandibular salivary gland

. Posterior surface ofthe ma-rillary tuberosity ofthe maxilla

. Anterior to the infraorbital foramen ofthe maxilla

. The apex of the petrous part of the temporal bone in the middle cranial fossa

25Copyrighr O 201 1,2012 - D€nral D€cks

The sublingual glands are located in the floor ofthe mouth beneath the tongue, close tothe midline. It lies between the sublingual fossa of the mandible and the genioglossusmuscle ofthe tongue. The mylohyoid muscle supports the individual sublingual glands in-feriorly. Unlike the submandibular gland, which drains via one large duct, the sublingualgland drains via approximately l2-20 small ducts fRivian's ducts),the majority open intothe mouth on the sumrnit ofthe sublingual fold, but a few open into the submandibularduct.

The sublingual gland is ifflervated by parasympathetic secretomotor fibers from the fa-cial nerve, which run in the chorda t)rynpani and in the lingual nerve (branch of V-3) andsynapse in the submandibular ganglion. The blood supply comes from branches ofthefacial and lingual arteries. The veins drain into the facial and lingual veins. The lymph ves-

sels drain into the submandibular and deep cervical lymph nodes.

Important:. The lymph vessels ffom both the sublingual and submandibular glands drain into thesubmandibular and the deep cervical lymph nodes. Bartolin's duct, a common duct that drains the anterior part ofthe sublingual glandin the region ofthe sublingual papilla, may be present. The submandibular duct lies on the sublingual gland. The sublingual gland is a mixed salivary gland, secreting both mucous and serous

saliva, but predominantly mucous-secreting

\ote: Von Ebner's glands are located around the circumvallate papilla ofthe tongue.Their main function is to rinse the food away from the papilla after it has been tasted bythe taste buds. They are purely serous.

The rrigeminal newe emerges from the anterior surface of the pons by a large sensory and a small motorroor. Ihe motor root lying medial to the sensory root. The nerve passes forward out of the postedorcranial fossa, below the superior petrosal sinus, and carries with it a pouch derived from the meningealla)er ofdura mater. On reaching the depression on the apex ofthe petrous part ofthe temporal bone inthe middle cranial fossa, the large sensory rcot expands to form the trigeminal ganglion. The motorrootof rhe rigeminal nerve is situated below the sensory ganglion and is completely separate from it. Theophthalmic, maxillary and mandibular nerves arise from the anterior border ofthe ganglion.Somatic sensory cell bodies ofthe ganglion,s sensory libers enter the:

. Ophthalmic division 1f-1) to supply general sensation to the orbit and skin of face above eyes

. \Iaxillary division (Y-2) to supply general sensation to rhe nasal cavity, maxillary teeth, palate,and skin over maxilla. \landibular division fZ-3) to supply general sensation to the mandible, TMJ, mandibular teeth,floor ofmouth, tongue and skin ofmandible

The axons of rhe neurons gnter the pons through the sensory rcot and terminate in one of the threenuclei ofthe trigeminal sensory nuclear complex:

Typ6 of Ilbere Trigeminal Sen3ory Nucleus

spinal (d€scmdind nucleus

Piincipal (main) mso.y nucleus

\ote: Proprioceptive fibers fiom muscles and the TMJ are found only in the mandibular division. Thecell bodies of proprioceptive first order neurons arc found in the mesencephalic nucleus, not themgeminal ganglion. The TMJ, as is the case with alljoints, receives no motor innervation. The musclesrhat move the joint receive the motor innervation.Branchiomeric motor libers innervate the temporalis, masseter, medial and lateral pterygoid,anterior belly of the digastric, mylohyoid, tensor tympani, and tensor veli pa,latjni (palati).

. Tonsillar branch ofthe facial artery

. Lingual artery

. Vertebral artery

. Ascending pharyngeal artery

Coplright O 201 l -20 12 , Dmtal Deck

. Ophthalmic nerve

. Va,,rillary nerve

. Facial nerve

. Mandibular nerve

Coplrigh! O20ll-2012 - Dental Decl!

The lingual artery arises from the anterior surface ofthe external carotid artery, opposite the

tip ofthe greater comu ofthe hyoid bone. It loops upward and then passes deep to the poste-

rior border ofthe hyoglossus muscle to enter the submandibular region. The loop ofthe arteryis crossed superficially by the hypoglossal nerve. Branches include dorsal lingual artery,suprahyoid artery and sublingual artery (t'hich supplies sublingual gland).lt terrninates as the

deep lingual artery, which ascends between the genioglossus and inferior longitudinal mus-

cles. Note: The floor ofthe mouth also receives its blood supply from the lingual artery

Remember:. Motor innervation: from the hypoglossal nerve /CNf,/,l).

. Sensory innervation: lingual (branch o-f trigeminal CN V-3) supplies the anterior two-thirds. glossopharyngeal (CN1X) supplies the posterior one-third (including vallate papil-lae), vagus /CN X) through the internal laryngeal nerve supplies the area near the

epiglottis.

r-ote: Besides the posterior l/3 of the tongue the glossopharyngeal nerve also supplies

sensory innervation to the tonsil, nasopharynx and pharynx areas.

. Taste: facial (CN VII) via chorda tympani supplies the antedor two-thirds; glossopha-

ryngeal (CN L& supplies the posterior one-third.

Note: The v€rtebral arteries arise from the subclavian arteries andjoin to form the basilar ar-

tery. The basilar artery is the main blood supply to the brainstem and connects to the Circle ofWillis.

Ihe ophthalmic nerve (Vl) enters the middle cranial fossa through the superior orbital fissure and

courses within the lateral wall ofthe cavemous sinus on its way to the trigeminal ganglion. The maxil-lart nerve 4r) enters the middle cranial fossa through foramen rotundum and may or may not pass

!hroueh thc cavemous sinus en route to thc trigeminal ganglion. The mandibular nerve frc/ entets the

middle cranial fossa through foramen ovale, coursing directly into the ttigcminal ganglion. The trigcm-inal ganglion 1n. if. a. r enilttnar ganglion ) lies in a depression known as the trigeminal cave (or Meckel's

car er. Thc trigeminal nervc cxits the trigeminal ganglion and cou$cs "backward" to entcr thc mid-lat-

eral aspect ofthe pons.

The mandibular division is the largcst ofthc 3 divisions ofthe trigeminal nerve. It has motor and sen-

so+ functions. It is created by a large sensory alld a small motor root that unitsjust after passing throughrhe foramen ovale to enter the iniiatemporal fossa. It immediately gives rise to a meningeal branch and

Ihen di!idcs into anterior and posterior divisions.

-\nterior Division: Smaller, mainly motor, with I sensory branch (huccal):

. \lasseteric: innenates thc masseter muscle and provides a small branch to the TMJ

. Anterior and posterior deep temporal: innervates the temporalis muscle

. )Iedial pter!goid: innervates the medialpterygoid muscle

. Lateral pterygoid: innervatcs the lateral pterygoid muscle

. Buccal: supplies the skin ovcr the buccinator muscle before passing through it to supply the mucous

membrane lining its inner surface and the gingiva along the mandibrlar molars

Posterior Division: Larger, mainly sensory with I motor branch frene to m!-lohroid)l. Auriculotemporali supplies the TMJ, auricle, and extemal auditory meatus. Lingual: supplies the mucous membrane ofthc anterior 2/3 ofthe tongue and gingiva on the lin-gual side ofthe mandibular teeth. lnferior alveolar: largest branch ofthc mandibular division; innervates all mandibular teeth and the

gingiva from the premolars anteriorly to the midline via the mental branch. Mylohyoid: supplics thc mylohyoid and the anterior belly ofthe digastric muscle

Remember: The trigeminal ncrve contains no parasympathetic component at its o.igin.

. Olfactory (CN I)

. Oculomotor (Clr'111)

. Abducens (Clr' @

. Trochlear (CN IV)

, Optic (CN II)

2A

Cop]rishr O 201l-2012 - Dental Decks

. All anterior teeth on the side of the injection

. Canine and first premolar on the side ofthe injection

. All teeth in that quadrant on the side ofthe injection

. Both premolars and first molar on the side ofthe injection

29Coptright @ 20ll-2012 - D€ntal Decks

Site of Exitfrom SkuU

olfactory(CN'

Speclrl semory

Optic(CN 1I)

Conveys lisual infomation from lbe rerina

(s en e N I s o Dn I i c elfe r e nt)

Generc t i s.en t elle tea t)

Supplics fourofthe six extlaocular muscles ofrhe eye andihe levaror palpebrae superioris muscle of lhe upper eyelid

Parasympathetic innen ation of rhe constrictor pupillae and

(CN II' kere rul s onatic ellerest)Inner!ates the superior oblique muscle

ICN TI' (se^e ru t ronatic elkrcnt)lnnenales rhe l.reEl rectus muscle

tC}; YII) bpeciat ,isce t etrercn,

ke nerat viscem t elleten t)

ke neft I s onatic allerc nt)

Special sensor.v

Supplies lhe muscles of facial expression: posleriorbelly ofdigastric nusclei stylohyoid. and sraped'us muscles

Parasldpathetic innch..ation of the lacrinal. submandibular,and sublingual glands. as wellas mucous mcnrbrancs ofthenasopharlnx and thc hard and softpalare

General sensalion from the skin ofthc concha oflhe auricleand from a small area behind the ear

Provides raste sensation from thc antcrior tworh irds oflhelonguer hard and so{i palates

Importanti Craniaf nerves llI (oculomolor), Vll (facial),lX (glossophary geal), and X {tagrslall har c parasympathetic activity.

\bu need !o qive a long buccal inj€ction in orderto extract the molars and second bicuspid. For operative pro-

ccdures, a long buccal iniection may not be needed for tbese teefi. The long buccal irjection anesthetizcs thcsoft tissuc and periosteum buccal to the mrndibular molar tecth. Thc nccdle is insened in thc mucous mem-

brane distal and buccal to the nost distal molar in lhe arch.'fo anesthetize the lingu!l nerve: When administering an infcrio. alveolar nene block slorvly withdraw thcslringc, and whcn approximately halfits length remains within tissues, r€aspirate. Ifnegativc, dcposit a por-

tion of the remaining solution /0.,1 ,r// to anesthetize the lingual nerve. Incisors may need local infilirationfor cxtractions-

Other Techniqucs of I\landibular 4nertheria:. Mental nen'e block: This nerve block is used whcn buccal sofFtissue anesthesia is n€cessary anterior tothe mcntal tbramen (around the second premolar) ro the midline and skin of the lower lip and chin. Theneedle is insened in mucobuccal fold tt orjust antcrior lo thc mental foramen. Ttrget area: mental ncneas it exits thc mcntal foftfien (usuall! located berween the apices (t the-lirst and second prcnblars).. Vazirani-Alkinosi closed-mouth mandibular block: although this tcchnique can be used *'henevermandibular anesthesia is desired, its primary indication remains those situations in which limited mandibu-far opeDing (i.e., patienls r\'ilh r/lrrrrsl precludes the use ofolher mandibular lechniques. Nerves anes-

thetized: inferior alveoiat incisive, mcntal. lingual, mylohyoid nen'es. Are! of needle insertion: soft tissue

overlying the medial /1lrgl/d/) border ofthe mandibular ramus dirccily adjacent to the maxillary tuberosity

at the height ofthe mucogingival junction ad.lacent to the maxillary third molar. Not€: The injeclion is per-

formed blindly becausc no bony endpoints exists, the needle is advanccd 25 mm into tissue (&r dn awrage-si:ed adult).'fhe distance is measured from the maxillary tuberosiry.. The Cow-Cates technique; this technique is a true mandibulirr nene block because it provides sensory

anesthcsia to virtually the entire distribution ofV3 ftnferior alrcolar, lingual, n\,lob'oid. nenlal, itcis[w,auriculotenporal, ancl buccal ner|es). hs primary use is when a conlentional inferior alveolar nervc blockis unsuccessful. Not€i Patient must cxtcnd his or hcr neck and open *ide for the duration ofihe technique

lthe nnaie hen assunes a more.frontal position and is closer to the andibular nerw trunv. Extraorallandmarksi comcr ofmouth, tragus ofear, and intcrtragic notch Area of needle insertion: lhe needle is

positioncd so that it is insened just distal 1o thc moxillary sccond molar at the height of its mesiolingual

cusp. The needle is slowly advance until bone lneck ofthe concl.rle) is conlacted. The avelagc deplh ofsofFtissue penetration to bone is 25 mm. The needle tip is withdrawr I mm, aspirate, and slowly deposit solu-

. Anterior superior alveolar and middle superior alveolar nerves

. Middle superior alveolar and posterior superior alveolar newes

. Posterior superior alveolar and inferior alveolar nerves

. Middle superior alveolar nerves and palatine nerves

30

Copright O 20l l-2012 - Dental Decks

. Increased vascular resistance

. Bradycardia

. Myocardial ischemia

. Mental status changes

. Adrenergic response

31

Cop).righr O 201 I -2012 - Dental Decks

. The posterior superior alveohr fP,Sl) nerve block, otherwise known as the tuberos-ity block or the zygomatic block, is used to achieve anesthesia for the pulps ofth€ max-illary third, second, and first molars (entire tooth = 7226; mesiobuccal root of themarillary first molar not anesthetized: 28%o). Target area: PSA nerve

-postedor,superior, and medial to the posterior border of the maxilla. Note: Potential forhematoma formation.. The middfe superior veolar (MSA) nerve block is useful for procedures where themaxillary premolar teeth or the mesiobuccal root ofthe first molar require anesthesia.

Target area: maxillary bone above the apex ofthe maxillary second premolar.

Note: The MSA nerve is present in only about 28% ofthe population.. The anterior superior alveolar (ASA) nerve block or infraorbital nerve block provides

profound pulpal and buccal soft-tissue anesthesia from the maxillary central incisorthrough the premolars in about 72 o/o of patients. Target area: infraorbital foramen(belov' the infraorbital notch).Remember: In order to extract the maxillary first molar, you must numb both the PSAand MSA nerves as well as the greater (anterior) palatine newe for palatal anesthesia

lsolt tissuel.

The term shock denotes a clinical slrldrome in which there is inadequate cellular perfusion and

inadequate oxygen delivery for the metabolic demands ofthe tissues.

Important: Reduced cardiac output is the main factor in all tlpes ofshock.

In eeneral. shock is characterized bv:."lncreased vascular resistance: co61 mottled skin, oliguria. Tachycardia. Adrenergic response: diaphoresis, anxiety, vomiting, diarrhea. \l]'ocardial ischemia. \lental status changes

The stages ofshock include: -l) Compensatory (early) stage: compensatory mechanisms (fu-

credsed heart rdte and peripheral resistazce) maintain perfusion to vital organs, 2) Progres-

sire stage: metabolic acidosis occurs (compensatoty mechanisms are no longer adequate),

3t lrrercrsible (refractot)) stqge). organ damage, survival is not possible.

\Iajor Categories of Shock:. Hlpovolemic shock is produced by a reduction in blood volume. Cardiac output will be

lou,due to inadequate left ventricular filling. Causes include severe hemonhage, dehydra-

tion. vomiting, diarrhea, and fluid loss fiorn bums.. Cardiogenic shock is circulatory collapse resulting from pump failure ofthe left ventri-

cle. most often caused by massive myocardial infarction.. Septic shock is due to severe infection. Causes include the endotoxin from gram-nega-

tive bacte a.. Neurogenic shock results from severe injury or trauma to the CNS.. Anaphylactic shock occurs with severe allergic reaction.

. 150 L at a pressure of2000 psi

. 300 L at a pressure of2000 psi

. 600 L at a pressure of2000 psi

. 750 L at a pressure of2000 psi

. Stage I

. Stage II

. Stage III

. Stage IV

32

Coplrighr @ 201 1,201 ? , Denial Decks

Cop'"ighr O 201 I -2012 - Dental lkcks

Nitrous oxide:. ls a colorless, nonirritating gas with a pleasant, mild odor and taste. Has a blood,/gas partition coe{Iicient of 0.47 and is thus poorly soluble in blood. ls excreted unchanged by the lungs. ls the oldest gaseous anesthetic in use today. ls the only inorganic substance used as an anesthetic. As a general anesthetic, the only disadvantage is its lack ofpotency

l. Nitrous oxide should be stored under pressure in steel cylinders painted blue.2. Oxygen is stored in green tanks.3. A full E cylinder ofoxygen contains approximately 600 L at a prcssure of2000 psi.4. At 2 L/min, a full E cylinder will deliver oxygen for approximately 300 min, or 5 hrs.

Advintigei tnd Dhrdvrnarge ofNit o|'s Oridc Anrlgelia

There isa"nisus€" etential witb both Dati€nts and denrish

The most common oatient cmDlaint is nuse!

It is rultable for dl.g6 and tha"Fudcfd may nEdiqlty oompmmised

It is not a compleie pain rcliever, a l@alanestheiic is sdllrequired todo mosl d€ntal prcc€dues

lr has vlrrudy !o !dEn. side efi@ts;n rhe abscnc€ oflypoxia

DifiNion hypo{r nay occur; ms}e sure you give I 00% oxygen atihe md ofdmlal prccedurc to prevent it.lmport nt: Tle inhalatim of 1 00% oxygen is contraiDdicared for a

It is ritat ble dd prodlrlr €uphoria

lmportant: Oxygen supplementation should be avoided or used with extreme caution in pa-

tients rvith severe COPD. These patients have an increased incidence ofpulmonary bullae orblebs (combined alveoft). Because ofnitrous oxide's low blood solubiliry, it can increase ther olume and pressure ofthese lung defects, which could create an increased risk ofbarotraumaand pneumothorax.

Geudel's Stages of Anesthesia:

St|ge | (amnesia and analgesia)': begins with the administration of anesthesia andcontinues to the loss of consciousness. Respiration is quiet, though sometimes irregu-lar. and reflexes are stillpresent.

Stage ll (delirium and excitement):begins with the loss ofconsciousness and includesthe onset oftotal anesthesia. During this stage the patient may move his limbs, chatterincoherently, hold his breath, or become violent. Vomiting with the attendart danger ofaspiration may occur. The patient is brought to Stage III as quickly and as smoothly as

possible.

Stage III (surgical anesthesia): begins with the establishment ofa regular pattern ofbreathing, total loss ofconsciousness and includes the period during which signs ofres-piratory or cardiovascular failure first appear. This stage has four planes.

Stage IV (premortem)i signals danger. This stage is characterized by pupils that are

maximally dilated and skin that is cold and ashen. Blood pressure is extremely low,often unmeasurable. Cardiac arrest is imminent. Rememtrer: The eyes appear geatlyenlarged in size and nonreactive to bright light when functional circulation to the brainhas stopped.

. Scopolamine

. Atropine

. Local anesthesia

. Benztropine

34Coplrighr 92011,2012 - Denlal Decks

Epinephrlne and levonordefrin ar€ added to localanesthetics becruse of theiri

. Ability to increase the potency ofthe local anesthetic

. Abilify to decrease the pain (buming) caused by the injection ofthe local anesthetic

. Vhsoconstrictive properties

. Ability to decrease the possibility ofan allergic reaction to the local anesthetic

Copyrighr O 201 1,2012 - D€ntal Decks

Local anesthesia acts by reducing sensitivity which therefore reduces anxiety and stress re-lated to treatment; salivation is also decreased.

Scopolamine, atropine and benztropine are anticholinergic drugs. Not only do they decrease

the flow ofsaliva, but also decrease the secretion fiom respirctory glands during general anes-

thesia.

l. The duration of action of local anesthetics is directly proportional to proteinbinding and lipid solubility. Increased protein binding

-increased lipid solu-

biliry - increased duration ofaclion.2. The lower the pKa (dissociation constant) of the local anesthetic, the fasterthe onset ofaction. Important point: a local anesthetic with a low pKa has a verylarge number oflipophilic free base molecules that are able to diffuse through tbenerve membrane.3. Increased blood flow

-shorter duration of action.

4. Metabisulfite is an antioxidant that protects the vasoconstrictor from oxidation.It has a low incidence of allergenicity.5. The local aresthetic prilocaine can produce methemoglobinemia in patients

with subclinical methemoglobinemia when administered in large doses. The top-ical anesthetic benzocaine also can induce methemoglobinemia, but only whenadministered in very large doses.

6. The administration of norepinephrine and levonordefrin should be avoid€d inpatients receiving tricyclic antidepressants. There is an increased sensitivity tovasoconstrictors. *** Epinephdne should be used cautiously.7. The administration ofvsoconstrictors in patients being ffeated with nonselectivebeta-blockers (i.e., Propranolol) increases the likelihood ofa serious elevationofthe blood pressure accompanied by a reflex bradycardia. Use vasoconstrictoncautiously.

Vasoconstrictors (i.e. , epinephrine and levonord.eJrin) are added to local anesthetics because oftheirvasoconstrictive propenics. Vasoconstriction at the site ofinjection is beneficial because it limits the up-take ofthe anesthetic by the vasculature, thereby incrersing the duration ofthe anesthetic and dimin-ishing systemic elTects (redueing systetuic toxicity). Notet The use of a vasopressor-containing local

aneslhetic also may actually be responsible for the sensation ofbuming on injection. The addition ofavasopressor and an antioxidant (sodium bisufite) Iowers the pH ofthe solution to between 3.3 and 4, sig-

nificantly more acidic than solutions not containing a vasopressor (pH about 5.5). Patients are more

likely to feel the buming sensation with these solutions. Note: Malamed's book states that "local anes-

thetics containing the vasoconstrictor levonordefrn Qleo-Cobefrir/ have become impossible to obtain

Uune 2004)".

Important: To minimize the likelihood ofintravascular injection, aspiration should be performed be-

forc the local anesthetic solution is injected. Ifblood is aspirated, the needle must be repositioned untilno retum ofblood can be elicited by aspiration.

Adverse reactions following the administration ofa local anesthetic are, in general, dose-related and may

r€sult from high plasma levels caused by excessive dosage, rapid absorption or unint€ntional in-travascular injection.Systemic toxicities of local .nesthetics: Initial clinical signs and symptoms of mild to moderate tox-icity include: talkativeness, apprehension, excitability, sluned speech, dizziness and disorientation. The

signs and symptoms ofsevere toxicity include: seizures, respiratory depression, coma, and death.

Important: The excitatory manifestations may be very briefor may not occur at all, in which case the

first manifestation oftoxicity may be drowsiness merging into unconsciousness and respiEtory arrest

Remember: Cardiovascular manifestations are usually depressant and are characterized by brady-

cardia, hypotension, and cardiovascular collapse, which may lead to cardiac arrest. Note: In local anes-

thesia, the depression ofrespiration is a manifestation ofth€ toxic effects ofthe solution.

L For a normrl heafthy (AM I) p^tient the maximum dose of epinephrine is 0-2 mg or 200

pg, this equates to roughly 11 cartridges of I :100,000 epinephrine.2. In a cardiac risk patient the maximum dose ofepinephrine is 0.04 mg or 40 pg, this equates

roughly to two cartridges of l:000,000 epinephrine.

After receiving rn injection of a local rnesthetic containing 29lo lidocalnewith 1:100,000 epinephrine, the patient loses consciousness.

Which of the following is the most probable cause?

. Acute toxicity

. Allergic response

. Syncope

. H)?erventilation syndrome

36Cop).righr C 201 1,2012 - Dental Decks

Which tooth has a root thrt is not consistentlyinnervated by the PSA nerve?

. The maxillary first molar

. The maxillary second molar

. The maxillary third molar

.AIl ofthe above

37Cop)righr C 201 l-:012 - Dental Decks

*** Caused by transient cerebral hypoxiaAnxiety-induced events are by far the most common adverse r€action associated with localanesthetics in dentistry. These may manifest in numerous ways, the most common ofwhichis syncope, In addition, they may present with a wide variety of symptoms, including hyper-ventilation, nausea, vomiting and altemtions in heart rate or blood pressure. Psychogenic re-

actions are often misdiagnosed as allergic reactions and may also mimic them, with signs such

as urticaria, edema and bronchospasm.

Proper management of syncope:. Place patient in supine position with feet slightly elevated @endelenburg position). Establish airway (head tilt/chin lift)

- Administer 1007o oxygen via face mask. 02 is indicated fbr the treahnent ofalltypes ofsyncope except for hlTrerventilation syndrome.

. Monitor vital signs and support patient- Pupils may dilate from brain not getting oxygen.

. Maintain your composure. Apply cool, wet towel to patient's foreh€ad.

. Follow-up treatment- Determine lactors crusing unconsciousness.

Remember: Hyperyentilation in an anxious dental patient leads to carpopedal spasm/a spasm ofthe hand, thumbs, foot, or toes).

\\'hen used to achieve pulpal anesthcsia, thc PSAnerve block is eflective for thc maxillary third, second,

and first molars in 77olo to 10070 ofpatients. Howevet the mesiobuccal root ofthe ma,\illary first molaris not consistenrly innervated by the PSA n€rve. In approximately 28% ofpatients the middle superiorah eolar nerve provides sensory ilnervation to the mesiobuccal root ofthe maxillary first molar. There_

fore. if anesthesia ofthis tooth for either restomtive dcntistry or extraction is requircd, an infiltration in-jection also should be performed over the second premolar tooth. Note: Patients experience fewsubjective signs ofanesthesia after receiving a poste or superior alveolar nerve block, as compared to

an inferior alveolar ner'-eblock (humb lip).

The risk ofa potential complication also must be considercd whencver the PSAblock is used. Insertion

ofthe needle too far distally may lead to a tempo..ary (10 to 14 days) unaesthetic hematoma. As a means

ofdecreasing the risk ofhematoma formation afler a PSA nerve block, the use of a "short" dcntal nee-

dle is recommended for all but the largest ofpatients. One must remember to aspirate seveial times be-

fore and during drug deposition during the PSAnerve block to avoid inadvertent intravascular injection

Important: Ifa patient's face becomes distended and swollen after a posterior superior alveolar nerve

block, the following treatment is recommended:

. Place cold packs and pressure on the affected side

. Explain to the patient that he/she may become black and blue on that sids

L Gauge ofa needle refers to the diameter ofthe lumen ofthe needle: the smaller the num-

ber, the greater the diameter ofthe lumen. A 30-gauge needle has a smaller intemal diame-ter than a 25-gauge needle. In the United States, ncedles are color-codedby gauge: 25-gauge,

red; 27-gauge, yellow; and 3O-gauge, blue.

2. Positive aspiration is directly correlated to needlc gauge.

3. Larger-gauge needles (i.e., 25-gauge) have distinct advantages over smaller ones:

. Less deflection as the needle passes through the tissues

. This leads to greater accuracy in needle insertion and, hopefully, to incrcascd success

lales. Largcr-gauge needles do not brcak as o{ien

Important: The 25-gauge needle is the preferred needle for all injections presenting a high risk ofpos-jtive aspiration.

z\' All ofthe following are rersons that vasoconstrictors are included in local. anesth etics EXCEPT one. Which one is th e EXCEPTIOM\l

. They prolong the duration ofaction ofthe local anesthetic

. They reduce the chance ofan allergic reaction to the local anesthetic

. They reduce the toxicity because less local anesthetic is necessary

. They reduce the rate ofvascular absorption by causing vasoconstriction

.They help to make the anesthesia more profound by increasing the concentrations ofthelocal anesthetic at the nerve membrane

38Cop)righr O 201 1,2012 - Dental Decks

' Lrrlngospasm is an uncontroll€d/involuntary muscular contraction (spasm)

ofthe laryngeal cords. It is a well known, infrequent but serious post-surglcalcomplication. In the operating room it is treated by ldministering:

. Nitrous oxide

. Oxygen

. Epinephrine

. Enflurane

39

Cop)rightO 20ll-2012 - Denral Decks

*** This is false.

Vasoconstrictors are invaluable to local anesthesia in dentistry. There are clear indications fortheir use, ofwhich improving the depth and duration ofanesth€sia are the most important.Without them, local anesthetics haye a very short duration ofaction intraorally. Vasoconstric-

tion is more important for infiltration techniques in vascular sites than it is for mandibularblocks. The presence of a vasoconstrictor may also reduce systemic toxic effects and canprovide hemostasis. The most common agent for this purpose is epinephrine, which is avail-able in fonnulations of l:50,000 (0.02 rng/ml), l:100,000 10.01 mg/ml) and l:200,000 (0.005

mg/mL).

There are three main adrenergic receptor subclass€s that vasoconstrictors interact with on car-

diovascular tissue in the human body. These are classified as alpha receptors fbot& alpha-l andalpha-2),beta-l receptors, and beta-2 receptors. Alpha receptors are densely located on arte-

fioles in the skin and mucous membrunes. Stimulation of these receptors leads to vasocon-

striction through activation ofG proteins and subsequent opening ofcalcium channels. Beta- Ireceptors are located on cardiac tissue, and stimulation olthem leads to an increase in heart

rate (posilive chronotropr) and aD increase in contraction force (positive i otropy), Beta-2 rc-

ceptors, Iike alpha receptors are located primarily in vascular beds. However, these receptors

are located primarily in vascular beds traversing skeletal muscle. when stimulated, beta-2 re-

cepto$ activate adenylate cyclase, leading to vasodilation.

Epinephrine is the more potent than levonordeliin. Its affrnity for alpha versus beta receptolsis roughly equivalent (50:50). Thus, although the primary event that occurs at the site ofin-jection beneath the oral mucosa is vasoconstriction, the relatively low systemic levels achieved

after dental local anesthetic injections can cause increases in heart rate and cardiac output, as

u,ell as peripheral vasodilation in skeletal muscle beds. Note: Levonordefiin is less potent

than epinephrine, its receptor affinity is 759/o alpha and2'%obeta. As noted earlier' local anes-

thetics containins levonordefrin have become impossible to obtain.

A patient under general anesthesia loses the laryngeal reflex. Ifblood and saliva collectnear the vocal cords, this stimulates the patient to go into spasrn (aryngospasm) and thevocal cords will close. When this happens, air cannot pass through and hence the prob-lem. The two most important steps in the initial management of a laryngospasm are ap-

pl-"-'ing oxygen under positive pressure and administering succinylcholine.

\ote: Succinylcholine is a skeletal muscle relaxant that is used when performing endo-

tracheal intubation and endoscopy procedures.

Laryngospasm is frequently cited as an adverse effect of ketamine, but it is rarely ob-

sened. Frequently, deep, heavy, loud respirations mistaken for laryngospasm are actu-

ally due to airway positioning. Such breathing is managed simply by repositioning the

patient's head. True laryngospasm during ketamine sedation is usually caused by stimu-lation ofthe vocal cords by instrumentation or secretions.

. Touch

. Warm

. Deep pressure

. Pain

. Cold

. Motor

40Coprigltr O'2011-?012 - Detrtal Decks

How will a larger than norm|l functional residualcapacity aff€ct nitrous oxide sedation?

. Nitrous oxide sedation will happen much quicker

. Nitrous oxide sedation will take longer

. Functional residual capacity does not affect nitrous oxide sedation

41

Cop"iShr O 2011,2012 - Dental Decks

Local ancsthesia causes loss of sensation by first blocking nerve conduction in thc smaller un-myelinated fibers that carry pain, and then progressing to the larger myelinated llbers for pressureand motor function. This phenomenon is called differential blockade. Differential blockade maybe due to the size ofthe nerve, the p.esence or absence ofmyelin, and firing frequency.

. Size of nerve: local anesthetics prefcrentially block small fibers bccausc the distancc ovcrwhich such fibers can passively propagate an electrical impulse is shorter During the onset oflocal anesthesia, when short sections ofnerve are blocked, the small diameter fibers are the firstto fail to conduct.. Preserce or absence of myelin: For myelinated nerves, three successive nodes of Ranviermust by blocked to halt impulse propagation. The thicker the nerve fiber, the farther apart thenodes tend to be, which explains, in part, the greate. resistance to block of lary€ fibers (e.g.,

nlotorfbers to skeletol muscle). Myelinated fibers tend to become blocked before unmyelinatedfibers of the same diameter n-ote: Sodium channels are very dense at the nodes of Ranvier innvelinated fibers which contributes to thern being blocked before unmyelinated libers of thesame drameter.. Firing frequency; sensory fibers, especially pain fibers, have a high firing rate and a rela-ti\ cly long action potential duration frp to 5 msec). Motor fibcrs fire at a slower rate and haveshoner action potential duration (< 0.5 msec).AdeltaandC fibers are small diameter fibers thatparticipate in high-frequency pain tnnsmission. Therefore, they are blocked sooner with lowerconcentmtions of local anesthetics than are A alpba (motot) frbers to skeletal muscle.

\otel Nerves regain function in reverse order.

The e\tent ofanesthesia depends on a variety offactors, including the amount ofmedication used,

bodl temperature, pH, the arnount of protein binding, and dilution by tissue fluids. Local ancs-rhctics work by blocking the flow ofsodium ions, thereby preventing depolarization ofthc nervetlber and conduction or transmission ofthe imDulse.

The functional residual capacity is the amount ofair remaining in the lungs at the end

of the normal expiration. Note: This air is used to provide air to the alveoli, which willaerate the blood evenly between breaths.

Note: Pulmonary volumes and capacity are about 20 to 25o% less in females than in males

and are greater in large and athletic persons. Nitrous oxide sedation will vary accord-

ingly.

R€spiratory air volumes during rest and exercise are of physical and clinical interest

and they can be measured using a spirometer. The main volumes ofinterest are:

. Tidal Volume (TV): amount of air breathed in and out during quiet breathing

. Expiratory Reserve Volume (ERV): amount ofair forced out ofthe lungs in a max-imal expiration, over and above that expired in normal breathing. Inspiratory Reserve Volume (IRV): amount ofair inlaled in a maximal inspiration,over and above that inhaled in normal breathing. \'ital Capacity (VC): TV + ERV + IRV. Residual Volume (RV): volume of air that remains in the lungs at all times (can't be

neosured by spir)metry). Total Lung Capacity (TLC): VC + RV

. not lipid soluble, mpid

. slightly lipid soluble, delayed

. moderately lipid soluble, delayed

. very lipid soluble, rapid

. Prilocaine

. Bupivacaine

. Lidocaine

. Procaine

. Mepivacaine

. Articaine

42Copright O 20ll-2012 - Detrtal Decks

43Coptriglr @ 201|,2012 - D€nral Decks

Barbiturates exhibit a dose-dependent CNS depression with hypnosis and amnesia. They are

very lipid soluble, which results in a rapid onset of action. They are used most often for in-duction ofanesthesia because they produce unconsciousness in less than 30 seconds.

Barbiturates:. Ultra-short acting: Methohexital (Brevital), thioper/''al (Pentothal), and thiamylal (Srir!tal). Short and intermediate acting: Amobarbrtal (Amytal), pentobarbital (Nembutql), seco-barbital (Seconal), and Butabarbital fI'ioticet, Fiorinal). Long acting: Phenobarbital (LtminaQ

Most commonly used barbiturates for induction of an€sth€sia:. Thiopental (Pentothal): Usually prepared as a 2.5To solution. An induction dose of 3-5mg&g produces a loss ofconsciousness within 30 seconds and recovery in 5-10 minutes.Because the elimination half-life is 6-12 hor.rrs, patients may experience a slow recovery.When injected intravenously, it can be initating. Usually prepared as 2.5olo solution. pH is

1 0.5.. llethohexital /Brcvitdr: is somewhat less lipid soluble and less ionized at physiologic pHthan thiopental. An induction dose of l-2 mg,&g produces loss ofconsciousness in less than20 seconds and recovery in 4-5 minutes. The elimination half-life ofmethohexital is 3 hours,rrhich ailows a clearance rate that is 3 to 4 times faster than that ofthiopental. pH is 10.5.

The side effect most often seen is hiccoughs. This is believed to be caused by rapid injec-tion of the Brevital.

. l. The most eff€ctive ag€nt in the initial treatment of respiratory d€pression due

\ot.! to the over dose ofbarbiturates is oxygen under positiv€ pressure.2. A primary advantage of IV sedation is the ability to titrat€ individualizeddosage.

Procaine (Novocaine) was, at one time, the most commonly used ester local anesthetic in dentistry Il isthc protolvpe for the ester group oflocal anesthetics but is no longer available in dental cartridgc fo.m.

An easy way to identify amide local anesthetics is to rcmember that the drug name contains an i plus -crine (lidocaihe, mepi|acaine, and bupivacaine). Estors such as procaine, benzocaine, and tetracaine

conlaln no 1.

Amide-t] pe local anestheticsi. Lidocairc (X),locainel: most commonly used. Pilocaine (Citanest). \t,rcaine (Septocaine/: has both amide and ester linkages. \Icpit acatne (Carbocaine). Bnpi ac arne I I[a rc a i ne). Eridocaine /Darznestlr removed from the U.S. market in 2002

Ester-tlpe local anestheticsi. Proc i're (Novocaine). P I opoxy caine (Raroc a i ne ). Bcnzocaine (Monocaine). Tetrac ine (Pontocaine)

TLrpical esters are still commonly used in the practice ofdentistry Most topical local ancsthctic oint-ments and gels contain benzocaine (an ester e.g., Httticaine, Celacaine). Benzocaine gels typicallycontain I 89 6 - 20% benzocaine. Lidocaine /a n amide) ls also avallable in two foms for topical applica-

ri(rn. EI1LA /ekrecric mixlure o.[ local anesthetic c],ea ), containsboth lidocaine and prilocaine.

-\mides are safe, versatilc, and effective local anesthetics. Ifhypersensitivity to a drug in this group pre-

chrdes its use, one of the ester-compound local anesthetics may provide analgesia without adverse effect

For patients allcrgic to both esters and amides, diphenhydramine (Benadryl) is ^

good choice

Esters are potent local anesthetics slightly different in chemical structure from the amide group. Tetra-

caine is most commonly used. Allergic rcactions are far more common with esters'

lmportant: The local anesthetics lidocaine and prilocaine are recommended for the pregnant (Class B)

patient. For the pregnant fcldsr C, patient, articaine, bupivacaine, mepivacaine, and epinephrine can bc

used.

Remember: The drug of choice in management ofan acute allcrgic reaction involving bronchospasm(an acule nat rowing oflhe rcspiralory ainray) and hypotension is epinephrine.

Notei Alleryic reactions to local anesthetic are usually caused by an antigen-antibody reaction

. Slowly injecting the anesthetic solution

. Watching the patient's color change during the injection

. Using a topical anesthetic prior to administration ofthe local anesthetic

. Injecting the anesthetic solution as quickly as possible

. Using a low concentration of vasoconstrictor

. Premedicating extremely anxious patients

. Sympathetic, but confident handling ofthe patient

Copfighr O 201l-2012, D€ntal Decks

. 0.10 mglml ofanesthetic

. I mg/ml of anesthetic

. 10 mg/ml of anesthetic

. 100 mg/ml ofanesthetic

45Cop! ghtO 20ll-2012 - Dmral Decks

The most common cause ofa transient loss ofconsciousness in the dental office is vasovagal syncope.This generally is due to a series ofcardiovascular events triggered by the emotional shess btought on bythe anticipation of or delivery ofdental care. Prevention ofvasovagal syncopal reactions involves properpalent preparalon.

Remember: Any signs ofan impending syncopal episode should be quickly treated by placing the pa-

tient in a supine position with the feet elevated (Trendelenbutg posiliol,/, monitoring vital signs, loos-

ening tight clothing and pJacing a cold compress on the forehead. Oxygen 3-4 L/minute should also be

given via nasal cannula. Important: The most common early sign ofsyncope is pallor.

Vasovagal Syncope:. Most common related to injections in younger individuals. Parasympathctic response often followed by sympathetic response secondary to anxiety. Warm feeling, pale, diaphoresis, "feeling faint or sick," nausea, bradycardia, and hypotension

Most Common Medical Emergenciesi. S).'ncope . Asthma attack.Hyperventilation'Acutemyocardialinfatction. Hypoglycemia . Seizure. Postural hypotension 'Allergic reactions. ,{ngina pcctons

Postural Hypotension: Management. Slo\\'to change position from laying to sifting to standing. \eed for change in medication'l (depends on severity). Rcccnt change in medication. Rule out precipitating causes

"Hl pervenlilation syndrome"- most commonly seen in dental office. Related to anxiety/ panic. Associated with lightheadedness. dizziness, chest pain, dysphagia, nausea. Rule out morc se ous potential conditions including pulmonary (aslhtna, PE), cardia. (CHF), en-

docnne ( d i a b et i c ke to ac ido s is)

To calculate the amount, in milligrams, ofany anesthetic and vasoconstrictor in a given solution:For local anesthetics, for every 1o% solution there is l0 mg/ml. Therefore:

Total milligrams = 7o ofthe solution x l0 x total millilitersFor vascoconstriction, for every I :100,000 there is 0.01 mg/ml-. Thereforc'

Total milligrams = ratio x total milliters

. Neuroleptic agent + narcotic analgesic

. Neuroleptic agent - nitrous oxide

. Neuroleptic agent + narcotic analgesic + nitrous oxide

. Narcotic analgesic + nitrous oxide

46Cop)righr e 201 l-2012, Dental Decks

Anestlrl

. Anaphylaxis

. Syncope

. Heart attack

. Seizure

17

Coplright O 201l-2012 - Dental Deck

Neurolept anesthesia is a state of neurolept analgesia and unconsciousness, produced by the

combined administration ofa narcotic analgesic and a neuroleptic agent, together with the inhala-tion ofnitrous oxide and oxygen.

Neurolept analgesia only produces an unconscious state ifnitrous oxide is also adrninistered f.reebelow).

Neuroleptic agent + narcotic analgesic = neurolept analgesia(Droperidol) (l'entanyl) (conscious)

Under the influence ofthis cornbination, the patient is sedated and demonstrates psychic indiffer-ence to the environment yet remains conscious and can respond to questions and commands.

Neurolcpt + nitrous oxide = neurolept anesthesiaanalgesia in oxygcn (wtconscious)

Induction of anesthesia is slow, but consciousness retums quickly after the inhalation ofnitrousoxide is stopped.

1. Neurolept analgesia is useful for minor surgical procedures, somc radiological pro-

Note3i. cedues, bum dressing, and endoscopy.

,.r.._,,.i 2. Neuroleptic agents such as droperidol (laapsine) causc areduction in all-{iety and

a state of indift'erence.3. Droperidol is an antiemetic and has adrenergic blocking (a/p ha block) activity.

4. Neurolept analgesia,/anesthesia may be especially useful in the elderly, debilitated

or seriously ill patient.5. The combination ofdroperidol and fentanyl (Sublimaze),is lnnovar.

6. Innovar produces slight circulatory effects, but can cause siSnificant respirutory de-

pression.

7. The low incidence of extmpyramidal side effects associated with droperidol use

may bc cffectively treated with the anti-cholinergic (anti-muscairlc, dmg, benztropine(Coge tin).

S.u-ncope is thc most common adverse reaction associated with administration of localanesthesia. Remember: It often occurs when upright, though can occur when sitting.It u'ill never occur when lying. The patient may complain offeeling generalized warmthrvith nausea and palpitations,

Thc initial event in a vasovagal syncope episode is the stress-induced release of in-creased amounts of catecholamines that causes the following: a decrease in peripheral\'ascular resistance, tachycardia, and sweating.

.{s blood pools in the periphcry a drop in blood prcssure appears, with a correspondingdecrease in cerebral blood flow. The patient will then complain offeeling dizry or weak.Compensatory mechanisms attempt to maintain adequate blood pressure, but they soon

fatigue, which lcads to vagally mediated bradycardia. Once the blood pressure drops

bclou lcrels necessary to sustain consciousness. syncopc occurs.

Place the patient in a supine position with the feet elevated (Trendelenburg posilion),monitor vital signs, tight clothing should be loosencd and a cold compress placed on

the forehead. Oxygen 3-4 L/minute should be given via nasal cannula.

Important: The single most important drug to use in any medical emergency, includ-ing chronic obstructive pulmonary disease, is oxygen.

Note: The primary ailway hazard for an unconscious dental patient in a supine positionis tonsue obstruction. Remember: Head titt/chin lift.

Tfeuma to muscles or blood vessels in the lsthe most common etiologicNl ftctor in trismus associated with

dental injections of local anesthetics,

. Pterygoid fossa

. Temporal fossa

. Submandibular fossa

. Infratemporal fossa

48Copltighr O 2011,2012 - Denral Decks

. The first stalement is true, the second is false

. The first statement is false, the second statement is true

. Both statements are true

. Both statements are false

49Cop)right O 201 I 201? - Denral Decks

Limited jaw opening, or trismus, is a relatively common complication following local anestheticadministration. In addition to tmuma to muscles or blood vessels in the infratemporal fossa, itmay be caused by hematoma formation, localized muscle necrosis secondary to the anestheticdrug or vasoconstrictor, infection in the fascial space, or introduction ofa foreign body.Note; In most instances of trismus the patient rcports pain and some difficulty opening his orher mouth on the day after treatment in which a posterior superior alveolar or inferior alveolarnerve block was administered.

The main symptom of trismus is the limitation of movement of thc mandible, which is oftenassociated with pain. Symptoms will arise from one to six days following an injcction. The du-ration of symptoms and their severity are both variable. Note: The medial pterygoid muscle is

most often af'fected.

Management of trismus:. Apply hot, moist towels to the site for approximately 20 minutcs every hour. Warm saline rinses. Use analgesics as required. Benzodiazepincs 1e.g., Diazepam) for muscle relaxation ifdeemed necessary. The patient should gradually open and close mouth as a means ofphysiotherapy

Follol ing an inferior alveolar nerve block injection or a mental block injection, a prickly ortingling sensation (paresthesiq), ever' complete numbness in the lower lip, may result and per-

sist tbr a considerable time. This is usually considered to be due to direct trauma or piercingof dre ncrve trunk by the needle. This happens more often in thc case of the mental block in-jection. The symptoms of paresthesia gradually diminish (uoy last from two i,eel6 to sixmonths). a\d recov ery is usually complete.

Remember: The most common cause of paresthesia of the lower lip is thc rcmoval of a

mandibular third molar (especially horizo lally impqcred ones).

\ausea and vomiting are the most conmon adverse effects ofnitrous oxide sedation, oc-

curring in l% to l0% of patients. Fasting is not required for patients undergoing nitrous

oride sedation. The practitioner, however, may recontmend that only a light meal be con-

sumed in the 2 hours prior to the administration of nitrous oxide. Diffusion hypoxia can

occur as a result ofrapid release ofnitrous oxide from the blood stream into the alveoli,

thereby diluting the concentration ofoxygen. This may lead to headache and disorienta-

tion and can be avoided by administering 1007o oxygen after nitrous oxide has been

discontinued.

Remember: The most common complication associated with nitrous oxide sedation is

a behavioral problen (laughing, giddy).

Note: Some literature states that nitrous oxide is acceptable for the pregnant patient,

however, from a risk management point it may be prudent not to use nitrous oxide on

any pregnant patlent.

Administration ofvolatile an€sthetics (desflurane, enflurane, halothQne, isoJlurane, and

sevo.flurane) is not a concern for COPD patients. All volatile anesthetics are bron-

chodilators and, therefore, are beneficial to patients with COPD (asthmatic bronchitis,

emphysema, sand chronic bronchitis).

Important: Sedation with nitrous oxide should be aYoided in patients with COPD.

. 15,000 - 45,000/mml

. 75,000 - 100,000/mm3

. 150,000 - 450,000/mm3

. 450,000 - 600,000/mmr

Cop}right O 20ll 2012, Denral Decks

How many milligrams ofepin€phrine are in cach certridge(1.8 cc) of 2oh lidocrine with 1:100,000 epinephrine?

. 0.018 mg

. lR mo

. 0.036 mg

51

Cop)'right C 201 l':012 - Dental D€cks

Thrombocytopenia is defined as a count of<150,000/mmr. Intraoperative bleeding can be severe withcounts of 40,000-70,000/mm3, and spontaneous bleeding usually occurs at counts <20,000/mmr. Theminimal recommended platelet count beforc surgery is 75,000/mmr.

Dctinttiod

While blood .ell coutrt 5,000 10,000/mmr 5.000-10,000/ndl

l4- l6 e/dl 12'14 z/dL

Per.etiagc of RBC l!|ass in 12yo-52ya 36%48%

150,000-450,00/Dml 150,000450,00/mr

RBC indices:

Me corpuscullr volume(]rcv)

AvmgE RBC volmes in lL 80 100 it 80-100 fL

h€moglobitr (MCH)Estinales weight ofHSb in

8vera8e RBC28'33 pg 28-31p8

Estindls !Ymg. corcmea-lion of Hgb ir almg€ RBC

3l-16 r/dl 32-36 e/dL

()rcHc)

L The minimal acceptable value for the hematocrit is 30D% for elective surgery.

2. Nomal values for coagulation:. Tcmplate bleeding time : I to 9 minutes. Prothrombin time (PT) = 1l to 16 s€conds (comparcd to nonnal control). Partial thromboplastin time (PTT) = activated, 32-46 seconds fcoupared to norual

lmportant: PT rvill be increased by warfarin, vitamin K deficiency, fat malabsorption,

livcr disease, DIC, and, artificially, increase toumiquet time. Warfarin blocks vitamin Kuse, whereas broad-spectrum antjbiotics elevate PT by killing normal bowel flora, whichdecreases vitamin K absorption. Heparin in high doses also will increase PT by alteringfactor X. FFP (fresh frozen plasma) 'rtill reverse warfa.in effects immediately.

Important:

. I cc oI2o/o lidocaine with epinephrine 1:100,000 contains the following:

- l0 mg of lidocaine: Blockade ofnerve conduction

- 0.01 mg ofcpineph ne: lncrease depth and duration ofanesthesia; decrease absorption oflocal ancsthetic and vasopressor

- 6 mg ofNaCL: Isotonicity ofthe solution- 0.5 mg of sodium (meta) bisulfatc: Antioxidant- I mg of methylparaben: Bacteriostatic agent

- Stenle Naler: A diluent to provide the volume ofsolution in a cartridge

. 1.8 cc of 2%o fidocaine (which is a calpule) with epinephrine 1:100,000 contains the following:

- 36 mg oflidocaine: 1 8 x 20 mg Note; Methylparabcn is no longer included

- 018 rng of epinephrine: l 8 x 0l mg ln ,ingt.-rr. o*ot cartridges oi local anes-

- 10'8 )ng of Nacl: 18x6mg thetic: however. it rs lbund inALL multidose

- .90 mg ofsodium {meta) bisulfate: 1 8 x 0 5 "i.i, "fIni".,.Uf.

a-*,- LI mg of methylparaben I .fi x I mg

- sterile watcr

Noaesl

Percent Solution = Milligrams (ng) x volume ofcrrtridge = Mitligrams per Crrtridg€

0.5=5X1.8=91.0=10x1.8=182.0 = 20 X 1.8 : 36

3.0 : 30 X 18 = 54

4.0=40x1.8=72Note: Some ofthe gencric anesth€tic cartridges are now containing 1.7 cc ofanesthelic'

. Plasma

. Kidney

. Liver

52

Coplrigh @ 20ll-2012, Denral Decks

The initial cllnical signs and symptoms of CNS toxicity for local anestheticsare usually excitrtory in nature. However, it is also possible that the €xcitatory

phase of the reaction may be extremely briefor may not occur at all.This is true especially with which two Iocal aneshetics?

. Lidocaine

. Tetracaine

. Etidocaine

. Procaine

. Bupivacaine

Copytighr O 201 l-2012 - Denral Decks

A significant difference between the two major groups of local anesthetics, the esters and theamides, is the means by which the body biologically transfoms the active drug into one that is phar-

macologically inactive. Metabolism (or biotransformationl of local anesthetics is important bc-cause the overall toxicity of a drug depends on a balance between its rate of absorption into thebloodstrcam at the sitc ofinjection and its mte ofremoval from the blood through the processes oftissue uptake and metabolism.

The primary site of biotansformation of amide drugs is the liver. Ester local anesthetics are hy-drolyzed in the pfasma to pala aminobenzoic acid (PABA) by the enzyne pseudocholinesterase. Pa-

tients with pseudocholinesterase inactivity are unable to detoxily ester tlpe agents at a normal rate.

Amide type anesthetics are recommended in these patients.

Allergic reactions to amide type local anesthetics are rare but may occur as a result ofhypersensi-tivity to thc local ancsthetic agent itselfor due to an allergy to methylparaben or other preserva-

tives used in many solutions. These reactions are characterized by cutancous lesions of delaycdonset or urticaria, edema, and other manifestations ofallergy. Important: For thosc patients aller-gic to both cstcr and amide type local anesthetics, Diphenhydramine is a safe and effective alter-nalive.

Est€rsEste'|s of bennic acid:

BulacaineCocaineElhyl aminobenzoate (b€nzocaire)Hexylcain€PiperocaineTetmcaine

Es lers of paraminobettzoic acid :ChloroprocaineProcainePropoxycaine

BupivacaineDibucaineEtidocaineLidocaineMepivacainePrilocaineRopivacaine

Quirolin€centbucridine

Local ancsthetics readily cross the blood-brain barrier Their phannacological action on the CNSis depression, At low (therapetic, nontoxic) bloodlevels, there are no CNS eflects ofany clini-cal significance. At higher (toxic, overdose) levels,thc primary clinical manifestation is a general-

ized tonic-clonic convulsion.

With a furthcr incrcase in the blood level ofthe local anesthetic above its "therapeutic" level, ad-

verse reactions may be observed. Because the CNS is nuch morc susceptible to the aclions oflocalanesthetics than other systems, it is not surprising that thc initial clinical signs and symptoms ofoverdose (toicity) are CNS in origin. Initial clinical signs and symptoms (slurred speech, tlizziness,

talkctiveness, apprehension, incrcased anxiety) ofCNS toxicity are usually excitatory in nature.

Lidocaine and procaine differ somcwhat from other local anesthetics in that lhe usual progression

of signs and syn'tptoms may not be seen. Lidocaine and procaine frequently produce an initialmifd sedation or drovsi\ess (here common with lidocaine).

Sedation may develop in place of the excitatory signs. Ifeither excitation or sedation is observed

in the initial 5 to l0 minutes alicr thc intraoral administration ofa local anesthetic, it should serve

as a wamirg to the clinician ofa rising local anesthetic blood level and the possibility (if the blood

level co li ues to risel ofa more serious reaction, possibly a gcncralized conl'ulsive episode.

Local anesthetics havc a direct action on the myocardium and peripheral vasculature ln general,

ho$ever, thc cardiovascular system appears to be nore resistant to the effects oflocal anesthetic

drugs than the CNS.. Direct action on the myocardium: Local anesthetics produce a myocardial dcpression that is

related to the local anesthetic blood level. Local anesthctics decrease electrical excitability ofthemyocardium, decrease the conduction rate, and decrease the lbrce ofcontraction. Direct action on the peripheral vasculature: All local aneslhetlcs (except cocaine and ropi-tacaine) produce a peripheral vasodilation, through relaxation of the smooth muscle in the

walls ofblood vessels.

.9.0;3to4

.7.4;5to6

.3.6;8to9

.8.0; 2 to 3

5,{

coplrishr O 201l-2012 - Dental DecIG

. Peripheral Nervous System (PNS)

. Central Nervous System fCNt

. Autonomic Nervous System (lNS)

Cop)righr @ 201l-2012 - D€nral Decks

It is well known that the pH of a local anesthetic solution fdrd lre pH ofthe tissue into which it is in-jected) greatly influences its nerve-blocking action. Acidification oftissue decreases local anesthetic ef-fectiveness. Inadequate anesthesia results when local anesthetics are injected into inflamed or infectedareas. Local anesthctics containing epinephrine or othcr vasopressors are acidifted by the manufacturerto inhibit the oxidation ofthe vasoprcssor. The pH ofsolutions without epinephrine is about 5.5; epi-nephrine-containing solutions have a pH of about 3.3. Note: Increasing pH (alkalinization) of a localanesthetic solution speeds the onset of its action, increases its clinical effectiveness, and makes its in-jection more comfortable.

The two factors involved in the action ofa local anesthetic are diffusion ofthe drug through the nerve

sheath and binding at the receptor site in the ion channel. Local anesthetics exist in ionized (cation) a dnon-ionized fbare) forms, the proportions ofwhich vary with the pH ofthe environment. The non-ion-ized (bd.re) portion js the form that is capable ofdiffusing across nerve membranes and blocking sodiumcha[nels.

n-itrous oxide is the only inorganic gas used by the anesthesiologist. Room air contains 2l%o

oxygen; you must mak€ sure that th€ pati€nt rec€ives at least this much oxygen. The max-imun nitrous oxide limitation is 60% nitrous oxide and 40olo oxvsen.

\itrous oxide is carried in the bloodstream in physical solution. There is no metabolism ordegradation ofnitrous oxide in the body. It is excreted solely via the lungs, unchanged. Highblood levels olnitrous oxide can be achieved quite quickly. It is non-toxic to body tissues.

Tle only toxicity with the use ofnitrous oxide is the lack ofoxygen that could result from the

operator's error. The gag reflex is only slightly obtunded with nitrous oxide analgesia. lt is be-

lie\ ed rhat nitrous oxide has its main effects on the reticular actiyating system and the lim-bic sl'stem.

\irrous oxide is a weak anesthetic. It is used to supplement inhalation agents. tt is the only in-halation anesthetic with sympathomimetic activity. It should not be used in dos€s higher than

60cb combined with 40% oxygen. It is known to diffuse into air containing spaces and to in-crease the pressure in such cavities. 100% oxygen should be administered during awakeningin order to avoid diffusion hypoxia.

Remember:. The first symptom ofnitrous oxide analgesia is tingling of the hands.. Nausea is the most common side effect ofnitrous oxide analgesia..The correct total liter flow ofnitrous oxide/oxygen is determined by the amount necessary

to keep the reservoir bag 1/3 to 2/3 full.. MAC (minimal alveolar concentrqtioz) ofnitrous oxide is 104. MAC is the concentration

of an inhaled anesthetic at I atm that prevents skeletal muscle movement's response to apainful stimulus (e.g., suryical skin incision) in 50%o of patients.

LosspK, =morc.apid onsetofaciion, more RN (ftebase fom) molecules pres€nr to dilluse through nedesheath; thus onset time is de$eased

Indeased lipid solubility = Increased pot€ncy

{example procaine = lr eiidGaine = 140)Etidocaine prcduces conduction blockadear eery lowconcentrations, wherea prccaine poorly sqpressesneNc conductiol. even at higher concenhations

lnreased protein bindiDg aUows anesrhetic cations(RNrD io be more nmly arrached to proteins locat.da(

sil6: lhus duration ofaciion is increased

lncreased diftusbrlrry = De(eased rime ofonset

Greater vasodilaror dciivity = lnreasedblood flow toregion = Rapid renoval ofanesrhetic moleculd liofrinjection siie; lhus dereased anesthelic poidcy and

. Calcium ions

. Chloride ions

. Potassium ions

. Sodium ions

. Induction

. Maintenance

. Recovery

56Coplr'ghr O 201t,2012 - D€ntal D€cks

Coplrighr O 20ll-2012 - Denral Decks

Which of the follo\Ding is that phrse of rnesthesia that begins withthe adminlstration of anesthetic and continuing until the desired level

Local anesthetics selectively inhibit the peak permeability of sodium, whose value is normallyabout five to six times greater than the minimum necessary for impulse conduction. Thefollowing sequence is a proposed mechanism of action of local anesthetics:

l. Displacement ofcalcium ions from the sodium channel receptor site, which permits...2. Binding oflocal anesthetic molecule to this receptor site, which thus produces...

3. Blockade ofthe sodium charmel, and a...

4. Decrease in sodium conductance, which leads to...5. Depression oflhe rate ofelectrical depolarization, and a...

6. Failure to achieve the threshold potential level, along with a...

7. Lack ofdevelopment ofpropagated action potentials, which is called...8. Conduction blockade

The mechanism whereby sodium ions gain entry to the axoplasm ofthe nerve, thereby initiating anaction potential, is altered by iocal anesthetics. The nerve membrane rcmains in a polarized state

because ionic rnovemcnts rosponsible for the action potential fail to develop. Nerve block produced

by local anesthetics is called a nondepolarizing nerve block.l. Local anesthetics reversibly block nerve impulse conduction and produce

reyersible loss of sensation at their administration site. The side of action of localanesthetics is at the lipoprotein sheath ofthe nerves.2. Local anestbetics are clinically effective on both axons and free nerve endings.

3. Important; Small, myeliDated nerv€ libers which conduct pain and tempenturesensations, are affected first, followed by touch, proprioception, and skeletalmuscle tone.4. Emergenc€ from a local anesthetie nerve block follows the same diffusionpattems as induction does; however, it does so in reverse order.5. Recovery is usually a slower process than induction beaause the anesthetic is

bound to the drug receptor site in tbe sodium channel and therefore is released moreslowly than it is absorbed.6. Potassium, calcium, and chloride conductance's remain unchangcd.

*** Stage I and Stage II of general anesth€sia together are referred to as induction.

The depth ofgeneral anesthesia fby irhalation) vnies with the partial pressure (tension) ofthe anesthetic agent in the brain, and lhe rates ofinduction arrd recovery depend upon the

rate ofchange oftension in this tissue (also blood supply to the lungs, pulmonary ventila-tion, and the concentration ofthe qnesthetic influence the rate of induction). ^Ihe signs and

stages of anesthesia are most likely to be seen with anesthetic that has a slow rate of in-duction.

L Maintenance is the process ofkeeping a patient in surgical anestlesta.2 . Recovery is the phase of anesthesia commencing when surgery is complete and

the delivery of the anesthetic is terminated and ending when the alesthetic has

been eliminated from the body.

3. The behavior of patients under general anesthesia suggests that the most re-

sistant part ofthe CNS is the medulla oblongata (cardiac, vasomotor, and res-

piratory centers of the brain).4. The most controllable route for administration of a general anesthetic is in-halation.5. Minimum alveolar concentration {MAC): alveolar concentration ofanestheticat which 50% ofthe palients are unresponsive to a standard surgical stimulus.

6. Meyer-Overton theory: anesthesia commences when a chemical substance

reaches a certain molar concentmtion in the hydrophobic phase.

7. Second gas effect: this occurs when one gas speeds the rate ofincrease ofthealveolarpartial pressure ofa second gas. Potent agents are administered with nitrous oxide so that the potent agent will be delivered in increased amounts to the

alveoli as gas rushes to replace the nitrous oxide absorbed by pulmonary blood.

. Enflurane

. Halothane

. Sevoflurane

. Desflurane

. Isoflurane

58

Coprighr C 201 l'2012 - Dental D€cks

. Vedian basilic vein

. \{edian cephalic vein

. Vedian antebrachial vein

. .drillary vein

59

CopFighr O 201 l-2012 - DeDtal Decks

lnhalation anesthetics are substances that are brought into the body via the lungs and are dis-tributed with the blood into the different tissues. The main target ofinhalation anesthetics (orso-cqlled yolatile anesthetics.) is the brain. Currently used inhalation anesthetics include fivevolatile liquids enflurane, halothane, isoflurane, sevoflurane, desflurane, and or'e gas (nitrousoxide). -fhe volattle liquids require a vaporizer for inhalational administration. The desfluranevaporizer has a heating component to allow delivery at room temperature.

Some inhalation agents have an unpleasant odor and may irritate the respiratory tract. This ir-ritation may cause coughing and muscle spasms in the voice box, or larynx (lary-ngospasm),

or in the bronchial tubes in the lungs (bronchospasm). Sevoflurane is less irritating to the air-way than the othen and is preferred for inducing anesthesia in children.

Important: All the potent inhalation agents are capable oftriggering malignant hyperthermiaLllH), a rare rnherrted disorder that is potentiallv fatal.

-{dministration ofan inhalation anesthetic is usually preceded by intravenous or intramus-cular administration ofa short acting sedative hypnotic drug, often abarbiturate (Thiopental).The procedure almost always requires endotracheal intubation.

l. Administration of volatile anesthetics is not a concem for COPD patients. All\ot€ volatile anesthetics are bronchodilators and therefore are beneficial to patients with

COPD.2. Volatile anesthetics depress the cardiovascular system, and this depression resultsin a reduced mean arterial pressue.3. Desflurane, isoflulane, and sevoflurane are potent vasodilators.

This Vein lies in the lateral aspect ofthe antecubital fossa (anterior to the elbow). Avordentering the brachial artery. If the artery is entered, the following symptoms will ap-pear: irnmediate buming at the site ofthe injection, the arm will appear blotchy, and thepulse in the arm v ill be weak compared to the other arm.

IV Sedation:. Usually done with a 21 gauge needle. Popular drug is Valium (Diazepam). The rate of injection of Valium is a I

nrr mrnure c€Phali' vein

- 1 ml of injectable Valium contains 5 mgof Valium. Injection is discontinued when the eyelidsdroop (ptosis)

Batili. vein

Three common signs indicating when the correctlevel of sedation has been reached when usins Vafium:

1. Blurring ofvision2. Slurring ofspeech3. 507o ptosis ofthe eyelids (this is called Ver-

rill's sign)

Remember: Valium is contraindicated for use ina patient with a history of narrow angle glaucoma.

cephali( vcin

Sarilic vein

Dlssociative anesthesia is a unique rnethod ofpain control that reduc€s anxi€tyand produces r trancelike st|te in which the person is not asleep, bul rather

feels s€parated from his or her t ody. The primary medication used is:

. Demerol

. Ketamine

. Pentobarbital

. Promethazine hydrochloride

60

Copright O 201 l-201: - Denlal Decks

Malignant hyperthermi^ (MH) is a pharmacogenetic disorder in which agenetic variant in the individual alters that person's response to certain

drugs. The major clinical characteristics of MII include all ofthe following EXCTPT one. Which one is the EXCEPTIOI'ft

. tugidity

. Fever

. Hlpermetabolism

' Myoglobinuria

. Alkalosis

6tCoprighl O 201 l-2012' Denhl Decks

ORAL SURGERY & PAIN CONTROL

Dissociative anesthesia is useful in emergency situations, such as an injury. It can also beused for short procedures that are painful, such as changing bandages. This method is safeand lasts only a short time. Because a person does not usually recall the procedure, thismethod is useful in children. The primary medication used is called ketamine. A sedativeis often given before ketamine to reduce anxiety.

Note: A person who has had dissociative anesthesia usually does not remember theprocedure, especially if a sedative has been given along with the pain medication. Mostpeople feel back to normal within a few hours. As the medication wears off, an individ-t;.aI (particularly adult patients) may have intense dreams and even hallucinations.

Ketamine, a phencyclidrLne (PCP) deivative, is l0 times more lipid soluble than thiopen-tal, enabling it to cross the blood-brain barrier quickly. It produces dissociative anesthe-

sia. which can be seen on EEG as dissociation between the thalamus and limbic system.

Rapid CNS depression with hypnosis, sedation, amlesia, and intense analgesia occurs in30-60 seconds after administration. The anesthetic induction doses are l-2 mg,&g IV, witheffects lasting 5-10 minutes or 10 mg/kg intramuscular, which acts in 2-4 minutes.

Ketamine:. Increases airway secretions, creating the need for anticholinergics such as glycopyrr-

olare in the preoperative period. lncreases BB heart rate, and cardiac output , but not respirations. Produces bronchial smooth muscle relaxation because of sympathetic stimulation. [s a potent cerebral vasodilator. Side effects include: hypertension, increased pulse and delirium

MH is a hypermetabolic state involving skeletal muscle that is precipitated by certainanesthetic agents in genetically susceptible individuals. The incidence ofMH is <0.5% ofall patients who are exposed to anesthetic agents. Inhalation anesthetic drugs that are

krown to trigger MH include halothane, enflurane, isoflurane, desflurane, and sevoflurane.Depolarizing neurornuscular blockade agents that can trigger MH include succinylcholine,decamethonium, and suKamethonium. Classic MH most often manifests in the operating

room, but it can also occur within the first few hours ofrecovery from anesthesia. Whenexposed to inlalational anesthetics, muscle metabolism increases, and a series ofsigns and

symptoms appear, which if left untreated can lead to death. The earliest findings are anincreased production olcarbon dioxide and signs of increased s),mpathetic nervous sys-tem activity.

Acute clinical manifestations of MH include tachycardia, tach)?nea, unstable blood pres-

sure, cyanosis, respiratory and metabolic acidosis, fever, muscle rigidity, and death. Mor-tality ranges from 6 3%o to 73o/o.Il vsually occurs in apparently healthy children and youngadults at an average age of 2l years.

When MH is diagnosed early and treated promptly, the mortality rate should be near zero.

Whenever anesthesia is administered, dantrolene should be readily available as well as a

protocol for managemeni of MH (100% oxygen, cooling procedures, and the correctionof acidosis and hyperkalemia). Dantrolene is, at the moment, the only known drug that

lreats MH. It impairs calcium-dependent muscle contraction and controls hypermetabo-

lism manifestations.

ST]RGERY& PAft CO:{TROL Anesth

The following signs: nausea, pallor, cold perspiration, widelydilated pupils, eyes rolled up, and brief convulsions are

indicative of a patient having a _ reaction.

. Somatogenic

. Psychogenic

. Either ofthe above

. None ofthe above

62Coplaighr O 201 l'2012 - D€nral Decks

. Transfusion reactions

. A fat embolism

. The anesthetic or analgesics on the myocardium

. Liver failure

63Coptrighr Cl 201 I 2012, Dental Decks

*** A psychogenic reaction is caused by psychological factors rather than physical factors(drugs).

Vasovagal s,'rlcope, a psychogenic r€action, is the most cornmonly experienced complicationassociated with the use oflocal anesthetic solutions. The clinical signs closely resemble thoseofshock. These psychogenic reactions readily respond to placing the patient in a supine posi-tion.

The following drugs, when administered one hour pdor to the dental appointment, are safe andeff€ctive ways to allay the fears ofan apprehensive adult dental patient and possibly avoid a

psychogenic reaction in the dental chair:. Diazepan\ (Vqlium): 5- l0 mg orally 1PO). Pentobarbital (Nembutal):50- 100 mg orally /POl. Secobarbital f^9econal): 50-100 mg orally (PO). Promethazine (P,lr energan): 25 mg orally (PO)

*** Note dosages and route of administration.

These drugs are not recomm€nded unless you have experience with them and can handleany complications that may happen from th€ir use.

\ote: For a dentist to use "ent€ral sedation" (the use of a pharnracological method thatproduces a minimally-depressed level o.f consciousness) some states require special trainingand registration with the stat€.

\ote: A somatogenic reaction is the development of a reaction from an organic pathophys-iologic cause.

*** Leading to myocardial depression.

Common causes of postoperative hypotension:. Intravascular hypovolemia. Rewarming vasodilation

'Hypothyroidism. Myocardial depression

*** Possible treatment options include:. Elevation ofthe lower extremities. Administration ofcarefully monitored fluid boluses. Administration of vasopressors (e.g., ephedrine)

The treatment is n rc n (a narcotic antagonist/ if hypotension is due to narcotics. Use

aftopine (qn anticholinergic) ifbradycardia is present.

Note: Postoperative [ypgltension is most often due to post-op pain. Treat withnarcotics and sedatives. Oth€r common causes include:

. Hypercapnia

. Anxlety

. Overdistention of the bladder

. HvDoxia

. Analgesia

. Excitement

. Surgical anesthesia

. Medullary paralysis

. 50olo oxygen; 50oZ nitrous oxide

. 60%o oxy gen;40olo nitrous oxide

. 40o% oxygen; 60% nitrous oxide

. 30% oxygen; 70olo nitrous oxide

. Varies according to the patient response

64Copltighr O 201 l-2012 - Dental Decks

Copyrighr O 201 1,2012 - Dental Decks

. Stage One (Anqlgesia) i The patient experiences analgesia or a loss ofpain sensation but remainsconscious and can carry on a conversation. Note: The best monitor ofthe level ofanalgesia is theverbal response.. Stage Two (Exciteuent): The patiefimay experience delirium or become violent. Blood pres-sure rises and becomes iregular, and brcathing rate increases. This stage is t)?ically bypassed byadministering a barbiturate, such as Methohexital or Thiopental, before the anesthesia.. Stage Three (^laryical Anesthesio): During this stage, the skeletal muscles relax, and the pa-tient's breathing becomes regular. Eye moyements slow, then stop, and sugery can begin.. Sttge Four (Medullary Paralysis): This stage occurs ifthe respirctory centers in the medullaoblongata ofthe brain that control breathing and other vital functions cease to function. Death canresult ifthe patient cannot be r€vived quickly. This stage should never be reached. Careful con-trol ofthe amounts ofanesthetics administered Drevent this occurrence.

l. The medulla is the last area ofthe brain to be depressed during general anesthesia.This area is the most vital part of the brain and contains lhe cardiac, the vasomotor,and respiratory centers ofthe bmin.2. The most reliable sign of "oxygen want" while monitoring a patient dudng gen-eral anesthesia is an increased pulse rate, Cyanosis may also be present.

3.The emeryency most frequently experienced during outpatient general anesthesia isrespiratory obstruction.4. The best anesthetic techlique used in oral suryery to avoid aspiration of blood orother debris when a patient is under general anesthesia is endotracheal intubationwith pharyngeal packs.

5. A patient with an acute respiratory inf€ction is contraindicated for general anes-thesia.6. The eyes are taped shut priorto draping a patientbefqre surgery to preyent cornealabrasion.

The dose ofthe gas combination for conscious sedation is variable and is based on the patient re-sponse. The maximum nitrous oxide limitation is 60010 nitrous oxide and 40olo oxygen.Nitrous oxide is a weak anesthetic and is used with other agents, such as thiopental, to produce

surgical anesthesia. It has the fastest induction and recovery and is the safest because it does notslou breathing or blood flow to the brain.Nitrous oxide has a low blood-to-gas partition coe{Ticient (0.46) and therefore low solubility. It can

leave the blood and enter air-filled cavities 34 times more quickly than nitrogen can leave the cav-ity to enter the blood. The use ofnitrous oxide can increase the expansion ofcompliant cavities,such as a pn€umothorax, bowel gas in a bowel obstruction, and an air embolism.Importantr The oral and maxillofacial surgeon needs to be cautious when keating the recent haumapatiett (e.g., motorvehicle accident victim). An asymptomatic, undiagnosed closed pneumothoraxcan double in size in l0 minutes after the administration of 70%o nitrous. Nitrous oxide sedation

should be postponed in patients with gashointestinal obstructions, middle ear disturbances, and,possibly, sinus infections.

Pr.ddol Co€ffcienb fo. hhrled Anesl]etics

ll3lothcrc Isoflrrane Nzo

Elood: g|g 0.42 2.4 0.46 0.68

Brrtn: blood l.l 29 1.6 r.l t.7

Mllak: blood 2.0 2.9 1.2 3.1

Frt blood 27 48

t8.7 90.8 1.4 47.2

MAC Agenl MAC

Nikols oride 104 D€sfluane 6.0

Ll5 S€vofiwane 1.7 |

Halo&aft 0.77

. Cellulitis

. A unilateral facial paralysis

. Phlebitis

. Syncope

Coplright O 20ll-201? Denial Decks

. Wtten a biopsy is being performed it ls important to:

.Incise perpendicular to the long axis ofany muscle fibers beneath the lesion

.Incise parallel to the long axis ofany muscle fibers beneath the lesion

.Incise as deep as possible into muscle fibers beneath the lesion

.Incise at a 45 degree angle to the long axis ofany muscle fibers beneath the lesion

CoDrightO 20ll-2012 - Denral Decls

Phlebitis is irritation or inflammation ofa vein. it is sometimes seen after IV administration ofval-ium. This is usually attributed to the presence ofpropylene glycol in the mixture.Phlebitis is more likely to occur if a vein in the hand or wrist is used and may be more commonfollowing repeated injections, especially in heary smokers, the elderly. and women taking oralcontraccptivcs.Common signs and symptoms ofphlebitis:

. Pain . Erythema

. Tendcmess . Streaking ofthe limb

. Edema

Treatment: Remove the IV catheter, elevate the affected linb, apply warm, n.roist packs to thc in-fected site, initiate IV ant:biot:Lcs (pre./brably celazolin [Ancefl, I gm IV bolus push etety I hours),for appropriate staphylococcus coveragc.Thrombosis is the formation of a blood clot that may partially or completely block a blood ves-

sel. A clot located in an inflamed, blood vessel is called thrombophlebitis.Virchow's triad is the name given to the thrce chicfcauscs ofdeep venous thrombosis fDlI):( l) damage to the endothelial lining ofthe vessel, (2) venous stasis, and (3) a change in blood con-

stituents attributable to postopcrativc increase in the number and adhesiveness of the patient'splatelets.The classical clinical featurcs ofDVT are:. Calfswelling . Sudden dyspnca. Feler . Tachypnea. Chcst pain

A patient who has developed DVT should be staied immediately on systemic anticoagulation withclevation of the affected Iimb.lmportant; The most frequent respiratory complications following oral and maxillofacial surgeryare: pulmonary atelectasis (mosl often in smokers), aspiration pneumonia fr?o.t, /ikely to mani-

.lest itlitially tu lhe patient's rigllt lwtg), and pulmonary embolus fmosl originate in lhe deep ve-

nous s,,'stems oftlrc lower extremities, especially in nonantbulatory'patients).

*** Whenever possible, the incisions should be oriented parallel to lines ofmuscle tension in orderto minimize scarring and wound dehiscence. Note: Biopsy incisions on the face should be orientedto follow Langer's lines.

Four major types ofbiopsy in and around the oral cavityl

. C)-tologyi should be used as an adjunct to, not a substitute for, biopsy. Indications include:$ hen large areas ofmucosal change must be monitored for dysplastic change, such as herpes orpemphigus. Technique: the lesion is scraped repeatedly and firmly with a moistened tongue de-

pressor or cement spatula. The cclls obtained are smeared evenly on a glass slide, and the sliders inrnediately immersed in a fixing solution and cxamincd under lhe microscope...\spiration biopsy or fine needle aspiration /FN,4): is the use ofa needle and syringe to pen-

errate a lesion lbr aspimtion ofits contents. Indications include: it should be carried out on all

lcsions thought to contain fluid (rith the possible exception ofa mucocele) or any intraosseous

lc,rion belbre surgical exploration. Technique: an l8-gauge needle is connected to a 5 or l0 mls1 ringe. The area is anesthetized and the I 8-gauge needle is inserted into the depth of the mass

during aspiration.. Incisional biopsy: rcmovcs only a representative portion or portions of a lesion along witha representation ofadjacent normal tissue. Indications: ifthe arca under investigation appears

diflicult to excise because ofits extensive size (larger than I cm itl diameter) or hazardous lo-cation, or whenever there is a great suspicion ofmalignancy.. Excisional biopsy: entails removal ofthe entire lesion along with at least 2 mm ofnormal mar-

ginal tissuc frorn the sides of the lesion. This technique should bc employed with smaller le-

sions i/1".rs tlrd, I cu in diameter) that on clinical examination appear to be benign.

lmportant: It can not bc ovcremphasized that all pertinent clinical information and the findings ofother diagnostic modalities must b€ provided to the pathologist at th€ time ofthe initial submission

ofthe specimen.

. 4 days

. 7 days

. 14 days

. 30 days

68

CoplriSh O 201 I -20 l2 - Denkl Decks

' An incislonal biopsy is indicated for which ofthe followlng lesions?

. A 0.5 cm papillary fibroma ofthe gingiva

. A 2.0 cm exostosis ofthe hard palate

. A 2.0 cm area ofFordyce's disease ofthe cheek

. A 3.0 cm hemangioma ofthe tongue

. A 3.0 cm area of leukoplakia ofthe soft palate

69Coplrighr @ 201 1,201 2 , Denial Decks

Almost all oral ulcers caused by trauma will heal within 14 days. Therefore, any ulcer thatis present for 2 weeks or more should b€ biopsied.

Biopsy is also indicated in the following instances:. Pigmented lesions (black/bown). When tissu€ is associated with paresthesia, this is often an ominous sign. lfa lesion suddenly enlarges, it should be biopsied

Note: Always aspirate a central bone lesion to rule out a vascular lesion. Ifa lesion seems

compressible, pulsatile, blue, or a bruit is heard, beware ofa vascular lesion and biopsy onlyunder a controlled hospital setting. *** A stethoscope is used to listen for a bruit.

,- - . ,. l. When the entire tumor is removed, it is called an excisional biopsy technique. lf.,'Notcsl-; only a psrtion ofthe tumor is removed, it is called an incisional biopsy technique.

;ri*t; 2. Brush biopsies are not recommended due to the number of false positives.3. After removal, the tissr.re should be immediately placed in l07o formalin solu-

tion (4okformaldehyde)that is at least 20 times the volume ofthe surgical specimen.The tissue must be totally immersed in the solution, and care should be taken to be

sure that the tissue has not become lodged on the wall of the container above the

level of formalin.4. A negative incisional biopsy report ofa highly suspicious oral lesion suggests

that another biopsy specimen is necessary in view ofthe clinical impressions. The

key is a highly suspicious oral lesion. Tissue samplings should be obtained frommultiple sites ofthe lesion.

Important: Unlike the more common ry?es oforal ulcers, malignant lesions are usually pain-1ess, growing and do not heal spontaneously. Consequentl% biopsy ofany ulcer that is pres-ent in the mouth for more than 2 weeks is mandatorv.

Leukoplakia is a premalignant lesion. This means that ifleft untreated, some ofthe lesions progress tocarcinoma. It is because of this chance of malignant transformation that all leukoplakias should be

biopsied.

Biops] Technique and Surgical Principles:. Anesthesia: Block local anesthetic techniques are employed when possible; ifnot, infiltration maybe used but the solution should bc injcctcd at lcast I cm away from the lesion. Tissue stabilization: Use fingers or clamps. Hemostasis: Cauze compresses (dvol righ speed suction) or gatze-wrappcd suction tip on a low-volume suction device. Idcision: Sharp scalpel. Extent oftissue: Obtain some normal tissue adjacent to lesion ifpossible. Handling of tissue: Use a traction suture through the specimen, not tissue forceps to avoid speci-

men trauma. Traction sutures can also mark a point on the specimen so that the lesion can be orientedshould thcrc bc a positive margin.. Specimen care: Alter removal, the tissue should be immediately placed in l07o formalin solutionthat is at least 20 timcs thc volume ofthe surgical specimen. Note: No othcr solution is acceptable.. wound management: Requires either a pimary closve (prefe,"d6l-r, or placement ofperiodontaldrcssings in cascs ofgingival or palatal biopsies where secondary hcaling will be necessary. Recordsi A Biopsy Data Sheet should be accurately filled out

The Method ofTissue Removal Varies Among the Type of Biopsies:

l.ln a needle (percutareo&t biopsy, the tissuc samplc is simply obtained by use ofa s)nnge. A nee-

dlc is passed into the tissue to be biopsied, and cells arc removcd through the needle.

2. In an open biopsy, an incision is made in the skin. the organ is exposed, and a tissue samplc is

taken.3. A closed biopsy involves a much smaller incision than open biopsy. The small incision is made toallow insertion ofa visualization device, which can guide the physician to the appropdate area to take

the sample.

. Pale or gray skin color

. Dry mouth

. Decreased skin turgor

. Modified state ofconsciousness

. High blood pressure

. Rapid pulse

. Reduced urine output

copyrtgtu o zor r10or: l"nt"r oe"r,s

. 50 mg/dl, 125 mg/dL

. 75 mg/dl, 150 mg/dl

. 100 mg/dl, 175 mgldL

. 126 nl dL, 200 mg/dl

71

Cop)'right O 201l-2012 - Denbl Decks

Dehydration is the loss ofwater and important blood salts like potassium (K-) and sodium(Na"). Vital organs like the kidneys, brain, and heart can't function without a certain min-imum amount of water and salt. Causes include decreased intake (ack ofwater) and. / orincreased output fvomititlg, diat"rhea, Ioss ofblood, drainageJi'om burns, diabetes melli-tus, diuretic use, or a lack ofADH owing to diabetes insipidus).

Initially, a patient suffering from dehydration will clinically demonstrate only dryness ofthe skin and mucous membranes.

However, as dehydration progresses, the turgor for fullness) ofthe skin is lost. Ifdehy-dration persists, oligruria (reduced urine output) occurs as a compensation for the fluidloss. More severe degrees of fluid loss are accompanied by a shift of water from the in-tracellular space to the extracellular space, a process that causes severe cell dysfunction,panicularly in the brain. Systemic blood pressure falls with continuous dehydration, anddeclining perfusion eventually leads to death.

Fluids in several forms should be continually urged on the patient. In severely dehy-drated individuals, they must get to the hospital right away. IV fluids will quickly reverse

dehydration, and is often life saving in young children and infants.

Diabetes Mellitus is an absolute or relative insulin insulficiency caused either by a low output ofinsulin from the pancreas or by unresponsiveness of peripheral tissues to insulin. Diabetes is the

leading cause of blindness, end-stagc renal disease, and non-traumatic limb amputation in the

Unired States. Diabctes increases risk for cardiovascular, cerebral, and peripheral vascular disease.

\lanl patients \rith diabetes mellitus have no symptoms, and the diagnosis is made because ofab-nomral blood glucose lcvels detected on a routine screening. Some patients may develop polydip-

sia. poll uria. polyphagia, and weight loss. In patients with severe insulin dcficiency, developmcnt

ofketoacidosis may cause nausea, vomiting, lethargy, confusion, and coma.

The major concem for the dentist treating a patient who has diabetes mellitus is hypoglycemia.S) mptoms of hypoglycernia: weakness, nervousness, excessive sweating, tremulousness, and pal-

pitations. The symptoms may progress from confusion and agitation to seizures and coma withoutrntervenhon.

,'- - -.-,. L The treatment ofchoice for hypoglycemia in a conscious diabetic is the administra-:Notcdl tion of an oral carbohydrate (packets of table sugdr, orunge iuice, cola beverages,:fu$ candy bars, etc.)

2. The treatment ofchoice for hypoglycernia in an unconscious diabctic patient: EMS

should bc contacted. Then I mg ofglucagon can be injected lM, or 50 ml of 50% glu-

cose solution can be given by rapid IV infusion. The glucagon injection should restore

the patient to a conscious state within 15 minutes; then some form oforal sugar can be

glvcn.3. People with well-controlled diabetes are no more susceptible to infections than peo-

ple without diabetes, but they have more di{Iiculty containing infections (this is caused

hy dltercd leukocyte function).4. Patients who take insulin daily and check their urine regularly for the sugar and ke-

toncs (controlletl diabel/., usually can be treated in the nomal manner without addi-tional drugs or diet alterations. lmportant: Ifany doubt exists as to the patient's medical

status, consultation with the patient's physician is indicated. Do not assume anything!

Your 60-year-old patient presents with cong€stive h€art failure. Theynote ctrdiac symptoms wlth mild activity trut are asymptomatlc at rest

lYhat is the functional classilication of heart failure in your patient?

. Class I

. Class II

. Class III

. Class IV

72Cop'.riglitO20ll'2012,Denral Decks

Match the term on the left with the correct meaning on the right.

. Apnea

. Hypercapnia

. Hypocapnia

. Dyspnea

. Hyperpnea

. Respiratory arrest

. Hyperventilation

. H)?oventilation

Below normal CO2 in arterial blood

Increase in depth ofrespiration

An increase in both rate and depth ofrespiration

Permanent cessation of breathing (arless corrected)

Transient cessation or absence of brealhino

Excess CO2 in arterial blood

A reduced rate and depth ofrespiration

The unpleasant sensation ofdifficulty in breathing

73Coprighr C 201 l-2012 - Dolal Decls

Class I congestive heart 1'ailure is defineu as no symproms , Class II is symp-toms with marked activity, Class Itl is symptoms with mild activity, and Class IV is symptoms atrest.Congestive heart failure (CHF) results ftom impaired pumping ability by the heart. A ventricularejection fraction bclou, 50% is indicative ofCHF. Valvular hcart discasc, coronary artery discasc,arrhythmias, hypothyroidism, high-cardiac output syndromes, and hypertension can lcad to heartfailurc. Note: Usually the left ventricle fails first, soon followed by right-sided failure. The pre-s€nting symptoms include dyspnea, orthopnea, paroxysmal noctumal dyspnea, fatigue, exerciseintolerancc, and odema. Note: The most comnron sign of lefFsided heart failure is pulmonaryedema, whcrcas righGsided heart failure causes pedal ed€ma or abdominal swelling.Pharmacologic therapy: goals are to contol fluid retention, control neurohormonal activation,and control sYmDtoms.

. Diuretic; fe.g., Lasix, Aldactone, Zaroxolyn), are uscd to control fluid retention

. ACE inhibitors fe.g., Captopril, Lisinopril), which interfere with the renin-angiotensin sys-ten, are required ofall paticnts with cardiac failure unlcss contraindicated. Vasodilators, including hydralazine and nitrates, are used when the use ofACE inhibitors isnot oossible. Beta blockers feg. , Car-vedilol, Bisoprolol, Metopt'olol, lten o/of, should be used in patientswith left ventricular dysfunction, unless contmindicated. Digitalis can improve symptoms and exercise tolerance by increasing cardiac contractility. Other medications include oxygen and morphine. Aspirin, NSAIDs, and calcium channel blockers should be avoided

Patient treatment and dental managemcnt considerations:. Prolonged rest, administration ofoxygen. Digitalis (patients are prone to nousea and vomiting). Diuretics/vasodilators (patients are prone to orlhostqtic hlpotension: a\oid excessive epi-nephrine/. Dicumarol (patients may have bleeding problem,/

Apnea Transient cessation or absence ofbreathins

Hypercapnia Excess CO: in arterial blood

Hypocapnia Below normal CO: in arterial blood

Dyspnea The unpleasant sensalion ofdifficulry in brcathing

Hlperpnea Increase in depth of respiration

Respiratory arrest Permanent cessation of breathing (unless corrected)

H}?erventilation An increase in both rate and depth ofrespiration

Hy'poventilation A reduced rate and deDth ofresDiration

1. Hyperventilation results in the loss of carbon dloxrde (CO) from the blood

:aotes 0+pocqpnia), thereby causing a decrease in blood pressure and sometimes fainting.2. Hypoventitation results in an increased level of carbon dioxide lCO/ in the

blood (hypercopnia).

J. The respiratory rate is l0-20 breaths/min in normal adults and 44 breaths/min in

infants. A respiratory rate of >20lmin is considered tachypnea, and a respiratoryrate < lO/min is bradypnea.,1. Kussmaul breathing is an increase in both rate and depth of respiration and is

synonymous with hyperventilation.5. Cheyne-Stokes breathing is altemating hyperpnea, shallow respiration, and

apnea. Children and the elderly normally show this pattern in sleep. In normaladults, causes of this pattem of breathing include heart failure, uremia, drug-in-duced respiratory depression, and brain damage.

6. Stridor is a high-pitched respiratory sound, such as the inspiratory sound heard

often in acute larvnseal obstruction.

. Bronchiectasis

. Atelectasis

. Pner.rmothorax

. Pneumonia

. Viral pneumonia

. Chronic bronchitis

. Emphysema

. Asthma

74Cop)'right () 20ll-2012 - D€nlal Dek

75Copltight C 201 l-2012 - Dental Decks

A Ss-year-old male presents to your ollice with a long history of a productlvecough. The patient states the cough has been present for 6 months each ofthe

last three years. The patient is afebrile and chest x-ray is unremsrkable.Which of the following is the most likely diagnosis?

Atelectasis occurs when mucus or a foreign object obstructs airflow in a mainstembronchus causing collapse ofthe affected lung tissue into an airless state. It typically oc-

curs 36 hours postoperatively and presents with mild dyspnea, low-grade fever, and hy-poxia. Note: Prolonged atelectasis can lead to pneumonia'

The treatment of postoperative atelectasis is aimed at expansion of the lung, and, formost patients, incentive spirometry @ncouraging the patient to take long, slow, deep

breaths) is adequate. However, in patients with severe atelectasis, endotracheal suction and

even bronchoscopy may be warranted.

Pneumothorax occurs when air leaks into the pleural space causing the lung to recoil

from the chest wall. In an awake patient, a pneumothorax typically presents with dyspnea,

chest pain, absence ofbreath sounds on the affected side, and evidence ofpneumothorax

on a chest x-ray. Tracheal deviation may be present.

The objective of treatment for a pneumothorax is to remove the air lrom the pleural

space, allowing the lung to re-expand. In an emergency, a small needle (such as a stan-

dard intravenous needle) may be placed into the chest cavity through the ribs to relieve

the excessive pressure. The definitive treatment is a chest tube, a large plastic tube that is

inserted through the chest wall between the ribs to remove the air completely.

. 1. Pneumonitis (inflammation of the lung) and atelectasis are two of the most

- roleg.' 66mmsn causes of fever in a patient who has had general anesthesia.

la;*;Jl 2. Th" -ost common post-op complication ofoutpatient general anesthesia is

nausea.

COPD is a disease due to persistent airway obstruction. Two diseases account for the bulk ofthe patients with COPD: €mphysema and chronic bronchitis. There is continuing debate as

to \rhether this term also includes acute asthma, however as a general ru1e, it is not incft'rded

as. even though it does have obstructive components to it, it is in part reversible, and is more

generally considered a restrictive lung disease. ln most cases, bronchitis and emphysema occur

togerher \ote: Secondary pulmonary hypertension is most often caused by COPD.

Emphysema Chronic Broncltitls

Description ''Pink puffei' "Blue bloater"

Vajor complaint Dyspnea Chronic cough

After age 50 years Late 30s and 40s

Body habitus Thin Overweight

Lune ex?Jn No advenlitious sounds Rhonchiare presmt

Peripherai edema Ntgative Positive

Hemoglobin Normal Elevated

Blood gases PO: normal or reducedPco, normal or reduced

Po: reducedPCO2 elevated

Chest X-ray IJyperinflated wiih flat diaphragms Increased interstitial markings and notmal diaph.agms

Important:l. Drugs with antiplatelet activity fasplnn) should be prescribed to COPD patients with cau-

tion. Hemoptysis has been reported after the use ofaspirin in patients with COPD.

2. COPD patients taking theophylline should not b€ prescribed erythromycin. Erythromycin

increases the metabolism oftheophylline and may cause toxiciry.

. Respiratory acidosis

. Respiratory alkalosis

. Metabolic acidosis

. Metabolic alkalosis

76

Copltighr O 201 l-2012 - Denral Deckr

. Was formally known as insulin-dependent diabetes

. Parients have little or no insulin spnrctinn nananirw

. Symptoms appear abruptly and include polyuria, polydipsia, polyphagia, and weightloss

. Accounts for 90olo ofall cases ofclinical diabetes

77Cop)right O 20ll-2012 - Denbl Decks

Acid-Base Disorders:. Normal range: pH = '7.35 - 7.45 Bicarbonate = 22-26 mtrol/L

Acidosis vs Alkalosis. IfpH is less than 7.35, the patient is acidemic. lfpH is greater than 7.45, the patient is alkalemic

Determine primary process. After evaluating pH, look at PCO2 and bicarbonate- IfpH is acidemic and PCO2 is greater than 45 mmHg, the primary procoss is respiratory; if

bicarbonate is less than 22, the primary process is metabolic- IfpH is alkalemic and the PCO2 is less than 35 mmHg, the primary process is respiratory;

ifbicarbonate is greater than 26, the primary process is metabolic.

Metabolic acidosis: Etiologies- diabetic or starvation ketoacidosis, lactic acidosis, uremia, severe

dehydration.Clinical manifestations: Dyspnea on exertion and nausea and vomiting are common

Metabolic alkalosis: Etiologies- vomiting, diuretic use, Cushing's syndrome, Conn sl,ndrome, and

exogenous steroids

Clinical manifestations: CNS symptoms such as confusion, delirium, and coma. Cardiac ar-

rhythmias and hypotension may be noted

Respiratory acidosis: Etiologies- COPD, asthma, severe pneumonia or pulmonary edema, CNSdepression fdrag.s, CNS event), acute airway obstmction, pneunothorax

Clinical manifestations: Related to degree and duration ofacidosis and presence ofhypoxia.In acute disease, CNS symptoms such as confusion, anxicty, psychosis, and seizures may be

noted: In chronic disease, there is lethargy, fatigue, and confusion

Respiratory alkalosis: Etiologies- anxiety, hypoxia, CNS discase, drug use (salicylates), preg-

nancy, sepsis

Clinical manifestations: May cause dizziness, perioral paresthesias, confusion, hypotcnsion,stezures. and coma

Diabet€s is the most common pancreatic endocrine disorder It is a metabolic diseaseinvolving mostly carbohydrat€s fglucosel and lipids. It is caused by absolute deficiencyof insulin (r,pe 1) or resistance of insulin's action in the peripheral tissues (Type 2). Theclassic triad of symptoms includes polydipsia, polyuria, and polyphagia.

be nornal or exc€€d nornal

Pcrcentage ofdiabclcs

Reduced sensitivity of insulin's rarget c€lls

Dietary conhol and weigha rcductiou

. Dyspnea or tachypnea

. Wheezing

. Hlpoxemia

. Occasionally hypercapnia

. Hemoptysis

78

Copright O 201l-2012 DenialDecks

.VI

. VII

. \'III

.IX

79Copyight O 20ll-2012, D€nral Decks

Asthma is a condition chamcterized by episodic reversible narrowing of the airways. The most

common symptoms include episodic wheezing, cough, chest tightness, and shortness of breath.

The disease can begin at any age, but about half ofpati€nts develop asthma before the age of 10.

There are three basic pathophysiologic changes: (1) Airway inflammation (2) Airway obstructionand (3) Airway hlperresponsiveness

lmportant: An acute asthmatic attack is best heated by administration ofsupplemental oxygenwith an inhalaled beta2-adrenergic agonist (albuterol, terbutaline). lf the patient is resistant to beta

agonists, theophylline should be considered. In a severe asthmatic attack that is unresponsive to the

above treatment, 0.3 mg of 1;1000 epinephrine should be administered subcutaneously.

Important: There are no contraindications for the use ofnitrous oxide sedation in asthmatic pa-

tients. Because anxiety is a stimulus for an asthmatic attack, nitrous oxide sedation is actually ben-

eficial for these patients. Ifpatient is taking steroids, consult physician for the possible need forcorticosteroid augmentation.

General guidelines for the management ofpatients with asthma:. Minimize stress: short appointments, use sedation techniques (nib'ous, diozepam or olher orala n t ianie t,v med icq t iotls ).. Avoid antihistamin€s. Minimize epinephrine \se (local anesthesid trp to 2 carpules of 226 lidocaine with 1:100,000

epinephrihe may be used). Avoid erythromycins and clarithromycin in patients on theophylline. Be arvare ofaspirin sensitivity; there is a clinical triad ofasthma, nasal polyps, and aspirin sen-

sitivity. h is inportant to be sure that the patient with asthma does not have this triad when as-

pirin-containing preparations are prescribed.

Status asthmaticus is the most severe clinical form ofasthma, usually requiring hospitalization,

that does not respond adequately to ordinary therapeutic measures. Ifnot managed properly, chronicpartial airway obstruction may lead to death from respiratory acidosis (which is produced by hy-p oxem i a a nd hypercapn ia).

Hemophilia A and B are inherited as a sexJitrked recessiYe trait by which males are allected and

females are carriers. The majority ofpeople af{licted with hemophilia have type A and it presents

under the age of 25. The signs, symptoms and clinical manifestations include excessive bleeding

from minor cuts, epistaxis, hematomas, and hemarthroses.

Classifi cations of Hemophilia:. Hemophilia A: considered the classical type, caused by a deficiency of coagulation factor\ lll (anti-hemophilic factor) .

. Hemophilia B (also called Christmas disease): due to a deficiency in fzctor lX (Christmas

factor). Hemophilia C (a/s o called Rosenthal's syndrome)', not sex-linked, less severe bleeding. Due

to a deficiency qf factor XL Rare disorder but more common in Ashkenazi Jews.

lmportant; A true hemophiliac is characterized by having the following:. Prolong€d partial thromboplastin time (PI!. Normal protbrombln time (PT). Normal platelet count. Normal bleeding time

Note: von Willebrand's disease is inherited as an autosomal dominant bleeding disorder, it oc-

curs with equal frequency in both seres. Due to the absence ol von Willebrand's factot (VWF),

which results in failurc to form a primary platelet plug. Labomtory features include a prolonged PTT

and prolonged bleeding time.Thrombocytopenia:

. Idiopathic thrombocytopenic pupnr^ (ITP)t autoimmune bleeding disorder in which pa-

tients develop antibodies against their own platelets. Signs and symptoms: no splenomegaly, su-

perficial bleeding ofthe skin, mucous membranes, and genitourinary tract.. Thrombotic thrombocytopenic purpura (TTP)| chaftcterized by severe thrornbocytopenia,

micrcangiopathic hemolytic anemia (ftave presence of schislocytes), andneu,rologic abnormal-

ities. Signs and symptoms: fever, neurologic abnormalities, including headache, aphasia, or stu-

por.

\..

. Diabetes mellitus

. AIDS

. Vahtlar disease

. End stage renal disease

80Cop)'right e 201 l-2012 - Dental Decks

A tall, thin patient presents to your olnce with shortness of breath.On examination you note the pati€nt is breathing through 6pursed' lips,

his expiratory phase is prolonged and lung sounds rre distant.Which of the following is the most likely diagnosis?

.Asthma

. Bronchiectasis

. Cystic fibrosis

. Emphysema

81

CopyriSht O 201 I '20 12 - Dmlal Decks

Mitralvalve prolapsedEndocarditisPapillary muscle dysfunction

Dyspn€a

Systolic ejection mulmu.Delaycd carotid upstr0ke

Diastolic rumbleOpening snap

Important: Patients with valwlar heart disease are also at risk for bacterial endocarditis.

R]leumatic fever is a sequela ofa previous Group A , beta hemolytic streptococcal infection,usually ofthe upper respimtory tract. The disease involves the heart,joints, centml newous sys-tem. skin, and subcutaneous tissues. lt is characterized by an exudative and proliferative in-flammatory lesion of the connective tissue, especially that ofthe heart, joints, blood vessels,

and subcutaneous tissue.

Hean inflammation (carditis) drsappears gradually, usually within five months. However, itma) permanently damage the heart valves, resulting in rheumatic heart disease. The valvebenr een the left atrium and ventdcle (mitral valve) is most commonly damaged.\ote: The pulmonary valve is rarely involved.

Remember: A heart murmur may have no pathological significance or may be an importantclue to the presence of valvular, congenital, or other structural abnormalities ofthe heart.

The emphysema. or "pink puffer" patient is typically thin and presents with dyspnea, pu$ed-lip breathing and pink skin color, Arterial blood gases reveal hypoxia and hlpercapnia. Em-physema is defined as destructive changes to the alveoli walls and enlargement ofair spaces.

Ir affects the lung parcnchyma distal to terminal bronchioles. Cigarette smoking is major riskfaclor (increases risk by 10 to 30 times otter nonsmokers). Note: Alpha- l -antitrypsin defi-ciency should be suspected in patients who develop emphysema in their late 30s.

Bronchiectasis: abnormal dilatation ofthe large conducting pathways, due to congenital struc-

tural abnormalities or acquired processes. Congenital causes include cystic fibrosis and alpha-

l-antitrypsin deficiency. Acquired processes include viral and bacterial infections, foreignbodies, and tumors. The major symptom is a cough, which is daily and productive with puru-lent sputum. Hemoptysis may accompany the cough. As disease progresses, exercise intoler-ance and dyspnea develop.

Cystic librosis: an autosomal recessive disease and most common lethal inherited disease inAmerican whites. Most patients are diagnosed in the preteen years. It is due to a defect in cys-tic fibrosis transmembrane conductance regulator. S).mptoms are due to development ofthicksecretions that block the airways and ductal system in other organs (usually pancreas and/1rc,.r. Common s),rnptoms include chronic cough with sputum production and dyspnea.

Remember: Patients with chronic bronchitis (or any COPD) can have difficulty during oralsurgery Many of these patients depend on maintaining an updght posture to breathe ade-

quately. They frequently experience difficulty breathing ifplaced in an almost supine positionor ifplaced on high-flow nasal oxygen.

Important: Patients with chronic bronchitis may be predisposed to lung cancer (bron-

chogenic carcinoma).

. The day before dialysis

. The day ofdialysis

. The day after dialysis

. Two days before dialysis

a2Cop)'right O 20ll-2012 - Dental Decks

. Is a natual constituent ofopium

. \4ay be given only by injection

. Has a calming effect on gastric mucosa

. Is stronger than morphine, more addictive, and more constipating

83

Coplaight O 20ll-2012 - Dental Dech

End-stage renal disease (ESRD) rs a condition in which there is a permanent and almostcomplete loss of kidney function. The kidney functions at less than I 0% of its normalcapacity. [n end-stage renal disease, toxins slowly build up in the body. Normal kidneys re-move these toxins /i.e., urea and creatinine) from the body through urine. In chronic renaldisease there is a slow, progressive decline in kidney functiot (low glomerular filtration lete

ICFRI andfall in uri e output).Creatinine clearance is a measure ofGFR:

. Normal range:Male: 120 +/- 25 ml/minFemale: 95 +/- 20 ml/min

*** End-stage renal disease: GFR < l0 ml/minPatients u,ith ESRD:

. Are often on steroid therapy

. Are more susceptible to post-op infections

. Have an increased tendency to bleed*** when oral surgical procedures are undertaken on these patients, meticulous attentionto good surgical technique is necessary to decrease the risks ofexcessive bleeding and infec-tion.

Some important points to remember when treating patients with renal insufltciency andrhose on hemodialysis:

. \er er measure the patient's blood pressure on the ann where the dialysis shunt has been

created. Avoid the use ofdmgs that are metabolized or excreted by the kidney. Ar oid the lollowing analgesics: aspirin, acetaminophen, NSAlDs, meperidine, and mor-phine. Perform oral surgery the day after dialysis. Consult physician for possible prophylatic antibiotics

\crr to morphinc, codcine is thc most important alkaloid of opium. Codeine has two primary thera-ft'rnic c'l1'ecIsr analgesic and antitussivc. Codcine is relatively less polent than morphine and does not have::e abuse potential ofmorphine. It is more likely than other opioids. othcr than morphine, to cause con-ii:F,r!ion and nausea- Codeine is usually combined with other drugs, for example, Empirin (Aspirin +arrr.rrr./. and Tt-lenol#2,3, and 4 (Acetattinophen + Codeine).\ote: Jlorphine is effectivc in providing reliefofmoderate to severe pain but is associated with the ad-r:rre etTects ofconstipation, nausea, and vomiting.Opr(.id analgesics are thought to inhibit painful stimuli in the substantia gelatinosa of the spinal cord,b::i:r tem. reticular actiYating system, thalamus, and limbic systcm. Opiate receptors in each ofthcse::eas lnreract \\'ith neuroffansmitters ofthe autonomic nervous system, producing alterations in reaction:.. p.rrnlul stimuli. Actions ofopioid analgesics can be defined by their activity al three specific recepior

i' p3i:. \lu receptors:

- \Iul: analgesia - Mu2: respiratory depression. bradycardia, physical dcpcndence, euphoria. Xappa receplors: analgesia, sedation, dysphoria, psychomimetic effects. Delta r€ceptors: analgcsia. moduiates activity at the mu recepto.

Drug

15'60 min 4-5 hi

10 30 Din 4i hr

I lydcodone (Vicodin. Ltrc.r. lorrab) l0-20 nin

Oxycodon€ {Percodan, Preel) l5-30 min 3-4 h.

Oxycodode, line-rclease lomula (O(r{4ntin) lhr I2 hr

Ily&oiorphme (Dilaudid) ,l-5lr

2-4 nt

FenLnyl (DuEgesi. haBdmal) t2-21h1

4-7 hr

Propox}?lenc (D.aon) +6 hr

. Midazolam

. Lorazepam

. Diazepam

uCoDrisht O 201 l-2012 - Denbl Decks

. Ibuprofen

. Acetaminophen

. Naproxen

85Copltighr O 201 I ,2012 - Dertal D€cks

Anterogmde amnesia, minimal depression of ventilation and the cardiovascular system, andsedative properties make benzodiazepines favorable preoperative medications. Clinical uses

for benzodiazepines include: preoperative medication, IV sedation, induction of anesthesia,maintenance ofanesthesia and suppression of seizure activity. Benzodiazepines act by poten-tiating the action of GABA, an amino acid and inhibitory neurotransmitter, which results inincreased neuronal inhibition and CNS depression. Benzodiazepines bind to specihc benzo-diazepine receptor sites, which are found on postsynaptic nerve endings in the CNS. Benzo-diazepines are the most effective oral sedative drugs used in dentistry.

The most common benzodiazepines used as amnestics in anesthesiology are: midazolam (mostco m mon). lorazepam. and diazepam.

. iN{.id^zolam (Uersedl: is the most lipid soluble ofthe three and, as a result, has a rapid onsetand a relatively short dumtion ol action. Is prepared as a water-soluble compound that istransformed into a lipid-soluble compound by exposure to the pH ofblood upon injection.This unique property ofmidazolam improves patient comfort when administered by the IVor lM route. This prevents the need for an organic solvent such as propylene glycol, whichis required for diazepam and lorazepam.. Diazeparn (Velium): is water-insoluble and requires the organic solvent propylene glycolto dissolved it. The onset time is slightly slower than that of midazolam.. Lorazepam (Ativan)r ls the least lipid soluble ofthe three main benzodiazepines, result-ing in a slow onset ofaction but long duration ofaction. It requires propylene glycol to dis-solYe it. which increases its venoirritation. Lorazepam is a more powerful amnestic agent

than midazolam, but its slow onset and long duration ofaction limit its usefulness for pre-operative anesthesia.

1. Chloral hydrate is a sedative and hlpnotic that is widely used for pediatric se-

dation.2. Emotional stress decreases the rate ofabsorption ofa drug when given orally.

Acetaminophen (Tylenol) is the only over-the-counter non-antiinflammatory analgesic

commonly available in the USA. It is a weak cyclooxygenase inhibitor in peripheral tis-sues. thus accounting for its lack of antiinflammatory effect. It may be a more effectiveinhibitor ofprostaglandin synthesis in the CNS, resulting in analgesic and antipyretic ac-

tion. Acetaminophen does not produce gastric ulceration like aspirin does. The combina-tion ofacetaminophen and propoxyphene (called Darvocet-N or Wygesic) is used to treat

moderate to severe pain due to dental procedures.

\ote: Propoxyphene (D&rvon) is an oral slmthetic opioid analgesic structurally similarto methadone. Darvon compound-65 is a combination of aspirin, caffeine, and

propoxyphene.

, --.. l. Acetaminophen does not affect clotting time as does aspirin -it does not

1Not5l1 h6vs significant antiplatelet effects. It is effective for the same indications as in-

@;if termediate-dose aspirin. It is therefore useful as an aspirin substitute, especially

in children with viral infections (who are at a riskfor Reye s syndrome iJ they

take aspirin).2. Aspirin is an anti-inflammatory antiplretic and analgesic that is used to re-

lieve headaches,toothaches, minor aches and pains, and to reduce fever The GItract rapidly absorbs it.3.Talwin compound combines the strong analgesic properties ofpentazocineand the analgesic, anti-inflammatory and fever-reducing properties ofaspirin.It is used for the relief of moderate pain. It does not produce euphoria.

4. The most appropriate time to administer the initial dose of an analgesic tocontrol postoperative pain is before the effect ofthe local anesthetic wears off.5. Remember: the following analgesics should be avoided in patients withrenal disease: aspirin, acetaminophen, NSAIDs, meperidine and morphine.

Which oftbese barbiturates can be classilied as

,n ultrr-short-acting compound?

. Amobarbital

. Thiopental

. Phenobarbital

. Pentobarbital

86Coprigh O 201 l'2012 - Dental Decks

-

should be used cautiously in the elderly. It should \

_ snoum De useo caunously ln rne erqerry. lr strour(lnever be given to patients on mono|mine oxidase inhibitors forpsychiatric disersc and is generally contraindicated in patients

receiving pbeny'toin @ilantin) for seizure disorders.

. Ibuprofen

. Acetaminophen

. Meperidine

. Codeine

a7Copyrighr O 201l'2012' Dental Dsks

Barbituates exhibit a dose-dependent central nervous system depression with hypnosis andamnesia. Barbiturates are very lipid soluble, which results in a rapid onset ofaction. They areused most often for induction ofanesthesia because thev oroduce unconsciousness in less than30 seconds.

Barbiturates inhibit depolarization ofneurons by binding to the GABA receptorc, which en-hances the transmission ofchloride ions. Note: Barbiturates are potent cerebral vasoconstric-tors resulting in decreases in cerebral blood flow, cerebral blood volume, and intracranialpressure (1CPl.

Ultrashort-acting barbiturates :

. Thiopental (Pentothal)

. Thiamylal (Surttal)

. Methohexrtal ( B rev i t a I )

Short-acting barbiturates :

. P entobarbital (Nembutal)

. Secobarbrtal ( S ec ona l)Interm€diate-acting barbiturales:

. Amobatbital (Amytql)

. Butabarbital (Fioricet, Fiorinql)Long-acting barbiturates:

. Phenobarbital (Luminal): generally not used in oral surgery

Important: Barbiturates are contraindicated in patients with respiratory disease or those\\ ho are pregnant.

\ote: Phl"sical dependence is likely to develop with barbiturates ifabused. The dependencehas a strong psychological as well as physical basis. Sudden withdrawal from high doses canbe fatal.

Meperidine (Demero, is a synthetic opioid analgesic with less potency than morphine. It isused for the reliefofmoderate to severe pain, for preoperative sedation, for posloperative anal-gesia, for obstetric anesthesia, and when given IV for supportive anesthesia. lt is probably the

most widely used narcotic in Americzm hospitals. It should be used with particular caution, ifat a)l, in the elderly. lt is the drug ofchoice among drug abusers and must be used with extreme

caution. Meperidine is the most abused drug by health professionals. The onset ofaction is

more rapid, but the duration ofaction is shorter, than that ofmorphine. Note: It produces slight

euphoria but no miosis.

\.leperidine is often prescribed as 50 mg every 4 hours as needed for pain. It is often simulta-neously presribed with the drug promethazine (Phenergan) in 25-50 mg doses every 4 hours.

The promethazine is a sedative and eniances the effect ofmeperidine. Therefore, less meperidine r-ields more analgesia when in combination with promethazine. In addition, promethazine

is an anti-emetic, which helps negate some ofthe side effects ofmeperidine, namely, nausea.

Important: Concomitant administration ofmeperidine and MAO inhibitors has resulted inlife-threatening hyperpyrexic reactions that may culminate in seizures or coma. Monoamine

oxidase (MAO) inhibitors are a class ofdrugs used for depression and Parkinson's Disease. Ex-amples of MAO inhibitors include isocarboxazid (brand name Marplan), phenelzine (Nardil),rranylcypromine /Parnate), ard selegiline (E ldepryl).

\lechanism of action: thought to act by increasing endogenous concentrations of norepi-

nephrine, dopamine, and serotonin through inhibition ofthe enzyme (monoamine oxidase) re'sponsible for the breakdown of these neurolmnsmillers.

r-ote: There is a decreased effectiveness ofmeperidine in the presence of phe\ytoir (Dilan'tin)

R€memb€r: Morphine is the standard drug to which all analgesic drugs are compared. ltcauses €uphoria, analgesia, and drowsiness along with miosis and respiratory depression.

. Reduction of salivation

. Prevention ofcardiac slowing during general anesthesia

. CNS depression

. Mydriasis

. Cycloplegia

88

Coplrighr O 201 I -20 l2 - Dental Lrects

. Respiratory depression

. Minor analgesia

. Decreased BMR

. All ofthe above effects

. None ofthe above effects

89

Coplright O20ll-2012 - Dental Decks

The cholinergic blocking (anticholinergic) drtgs competitively inhibit the action ofacetylcholine at parasympathetic postganglionic neuroeffector sites. The principal drugsin this category are atropine and scopolamine, which are useful in dentistry as agents tocontrol salivary secretion and as preanesthetic medication. The desirable clinical effectsofthe anticholinergics are mydriasis, antispasmodic actions, and reduction in gastric andsalivary secretions.

The pharmacologic actions ofatropine and scopolamine are similar in many respects. At-ropine in the usual dose employed in dentistry does not show a CNS response. Scopo-lamine, however, has a depressant effect on the CNS, which accounts for its usefulnessas a preanesthetic agent and perhaps its use in motion sickness in several over-the-counterpreparations. Both drugs will reduce salivary flow and in large doses block the cardiac-slowing effect ofthe vagus nerve.

Anticholinergic drugs should be used with considerable caution in patients with cardio-vascular disease and are contraindicated in patients with glaucoma, prostate hypertrophy,and intestinal obstruction.

Side effects are common with the anticholinergic drugs and include blurred vision, tachy-cardia. urinary retention, constipation, decreased salivation, sweating, and dry skin.

\ote: Atropine and scopolamine are also extremely useful in therapy and examination ofthe eye. These drugs produce dilation (nydriasis) and paralysis of accommodation fordistance vision and bght (cltcloplegia). Such effects are generally long lasting and can

also be manifested by larger systemic doses ofthe drugs.

Properties of barbiturates:. CNS depressants: CNS depression with barbiturates is additive with alcohol and opioids. Have no significant analgesic effect even at doses that produce general anesthesia. Ha\e anticonvulsant effects

\Iechanism of action of barbiturates:. Barbiturates inhibit depolarization ofneurons by binding to the GABA recepton, whichenhances the transmission ofchloride ions.

Barbiturates:. \\'ell absorbed orally, distributed widely throughout the body. \lerabolized in the liver to inactive metabolites that are excreted in the uflne

Therapeutic uses of barbiturates:. -{nesthesia: inlluenced by duration ofaction. Thiopental is an ultra-short acting barbitu-rute used IV to induce surgical anesthesia. Note: After IV administration, the last tissue tobecome saturated as a result of redistribution is fat (as conrpared to liver, brain, and mus-

. ,{nticonvulsant phenobarbital used in long-term management of tonic-clonic seizures,

status epilepticus and eclampsia. Anxiety: can be used as mild sedatives to relieve anxiety and insomnia

Drug interactions: CNS depressants, alcohol, and opioid analgesics enhance the CNS de-

pression of barbiturates.

Important: Barbiturates can lead to excessive sedation and cause anesthesia, coma and even

death. Barbiturate overdoses may occur because the effective dose of the drug is not too faraway ftom the lethal dose.

Note: The barbiturates can produce fetal damage when administered to a pregnant woman.

. The needle should be perpendicular when it enten the tissue

. Sutures should be placed at an equal distance from the rvoun d margin (2-3 mm) and at equaldepths

. Sutures should be placed from mobile tissue to thick tissue

. Suttrres should be placed from thin tissue to thick tissue

. Suhfes should not be over-tightened

. Tissues should be closed under tension

. Sutures should be 2-3 mm apart

. The suture knot should be on the side ofthe wound90

CopyrighrO 20ll-2012 - D€ntal D{ks

. Canine space

. Pterygomaxillary space

. Infratemporal space

. Pharyngeal space

. Maxillary sinus

91

Cop)'|ight O 201l-2012 - Dfrlal Decks

*** This is false; sutures should not be over-tightened or closed under tension.

The interrupted suture is the most common suture method. Because each suture is in-dependent, this procedure offers strength and flexibility in placement. Due to this advan-

tage, if one suture is lost or becomes loose, the integrity of the remaining sutures is notcompromised. The major disadvantage is the time required for placement ofthis pattem

of sutures. (See./igure #1 below)

Advantages ofa continuous pattern or method /See/igri re #2 below). Ease and speed ofplacement. Distribution oftension over the whole suture line. A more watertight closure than the interrupted pattem or method

Impacted maxillary third molars are occasionally displaced into two areas:. \Iariflary sinus (antrun): from which they are removed via a Caldwell-Luc ap-proach.Infratemporal space: during elevation ofthe tooth the elevator may force the toothposteriorly through the periosteur into the infratemporal fossa. If access and lightare good, the tooth may be retrieved with a hemostat. lfthe tooth is not retrieved aftera shon amount of time, the area should be closed. The patient should be infomed that

the tooth has been displaced and will be removed by an oral surg€on who will use a

special technique to remove it.

\ote: To minimize the chance of dislodging an impacted maxillary third molar into the

infratemporal fossa during its surgical removal, develop a full-thickness mucoperiosteal

t1ap. bringing the incision anterior to the second molar (add a releasing incision f nec-

€t\d]'r'l. to improve visualization ofthe impacted tooth and place a broad retractor distal

to the molar while elevating it.

Remember:L When performing a surgical removal ofa mandibular molar, do not section throughthe entire tooth. The lingual plate is often thin, and complete sectioning may perforate

the plate and injure the lingual nerve.

2. The inferior alveolar nerve most often lies truccal and slightly apical to the roots

ofa mandibular third molar.3. Buccal to lingual movement is not elficient when removing mandibular post€riorteeth because mandibular bone is too dense and does not expand in a similar fashion

to that ofthe maxillary bone.

Figure #l Figure #2

. Below the height ofthe operator's shoulder

. Above the height of the operator's shoulder

. At the same height ofthe operator's shoulder

.It makes no difference where the patient's upper jaw is in relation to the operator'sshoulder

92CopFighr O 20ll-2012 - Dental Decks

. Acute pericomitis

. Acute dentoalveolar abscess

. End-stage renal disease

. Acute infectious stomatitis

93Copyrigll O 20ll-2012 - D€nral Decks

The chair usually has to be repositioned to be satisfactory for exodontics. For mandibu-lar extractions, the patient should be positioned so that the occlusal plane ofthe mandibu-lar arch is parallel to the floor when the mouth is opened. The chair should be as low as

possible. For maxillary extractions, the upperjaw ofthe patient should be at the height ofthe operator's shoulder These positions allow the upper arm to hang loosely from theshoulder girdle and obviate the fatigue associated with holding the shoulders in an un-nanrrally high position during the course ofthe day. The low positions allow lhe operator

to bring the back and leg muscles into the operation to assist the arm. The chair can be

tipped backward slightly for maxillary extractions.

The fingers ofthe left hand (for a right-handed dentist) serye lo:. Retract the soft tissue. Provide the operator with sensory stimuli for the detection ofexpansion ofthe alveo-

lar plate and root movement under the plate. Help guide the forceps into place on the tooth. Protect teeth in the oppositejaw from accidental contact with the back ofthe forceps. Support the mandible while performing mandibular extractions

Remember: recommended sequence of extraction:. Maxillary teeth before mandibular teeth. Posterior teetlr before anterior teeth

An acute dentoalveolar abscess should not be a contmindication to extraction. It has been

shosn that these infections can rcsolve very quickly when the affected tooth is removed. How-ever. it may be difiicult to extract such a tooth, either because the patient is unable to open suf-ficiently wide enough or because adequate local anesthesia cannot be obtained.

There are fe\r,tlue contraindications to the extraction ofteeth. Note: In some instances, the pa-

rients' health may be so compromised that they cannot withstand the surgical procedue.

Examples of contraindications include:

. End-stage renal disease

. Ser ere uncontrolled metabolic diseases (i.e., uncontolletl diabetes mellitus)

. -A.d\ anced cardiac conditions (unstable angina)

. Patients \\'ith leukemia and lymphoma should be treated before extraction ofteeth

. Parients \r'ith hemophilia or platelet disorders should be treated before extruction ofteeth

. Parients with a history ofhead and neck cancer need to be treated with care because even

minor surgery can lead to osteoradionecrosis, Not€: These patients are often treated with hy-perbaric oxygen therapy pdor to dental sugery.. Pericomitis: infection ofthe soft tissues around a partially erupted mandibular third molar\ote: This infection should be treated p or to removal of the maxillary third molar. Acute infectious stomatitis and malignant disease are relative contraindications. Patients being treated with tV bisphosphonates increases the risk ofosteoradionecrosis ofthe Jaw

Note: Causes ofexcessive bleeding after dental extractions include; injury to the inferior alve-

olar artery during extraction ofa mandibular tooth (usually the third mola/), a muscular arte-

riolar bleed from a flap procedure, or bleeding related to the patient's history [.e., patients who

are on warfarix or drugs.for platelet ixhibition, pqtients vrho have hemophilia or von Wlle-brand's disease, or who have chronic liver insfficiency).

. Close the wound in layers to minimize the postoperative void

. Apply pressure dressings

. Use drains to remove any bleeding that accumulates

. Allow the void to fill with blood so that a blood clot will form

94Cop)righr O 20ll-2012 - Dertal Decks

. Buccal

. Palatal

. Mesial

. Distal

95Cop)righr O 201l'2012 - D€ntal Decks

Dead space in a wound is any area that remains devoid of tissue after closure of thewound. It is created by either removing tissues in the depths of a wound or by notreapproximating tissue planes during closure. Dead space in a wound usually fills in withblood which creates a hematoma with a high potential for infection. This is more likelyto happen in closed wound incisions or in an open wound that has closed over at the toptoo quickly, leaving "dead space" open underneath. Some of these may resolve them-selves, but most need to have the fluid drained and the "dead space" needs to be closed,either by deep suturing or by re-opening the top ofthe wound and packing until it healsfrom the bottom up.

Ways in which you can eliminate dead space:. Close the wound in layers to minimize the postoperative void. Apply pressure dressings. Use drains to remove any bleeding that accumulates. Place packing into the void until bleeding has stopped

Important: Infections are uncommon in healthy patients. However, whenever a mu-coperiosteal flap is elevated for a surgical extraction, there is a possibility for a subpe-

riosteal abscess. Thus, all surgical flaps should be irrigated liberally prior to closing$ ith sutures. Note: The treatment for a subperiosteal abscess is drainage of the abscess

and antibiotic treatment.

*** As opposed to the buccal direction in adults. This is because the deciduous molarsare more palatally positioned and the palatal root is strong and less prone to fracture.

In general. the removal of deciduous teeth is not difficult. It is facilitated by the elastic-it1. of young bone and the resorption of the root structure. Do not use the "cowhorn"forceps for extraction of lower primary molars because the sharp beaks ofthese forcepscould cause damage to the unerupted pennanent premolar teeth.

l. If the preoperative radiograph shorvs that the permanent premolar is

\ot€ wedged tightly between the bell-shaped roots ofthe primary tooth, the best treat-ment is to section the crown of the primary molar and remove the two portionsseparately. This will help in not disturbing the permanent tooth.2. After extraction ofmandibular teeth on a child in which mandibular blockwas given, always advise child not to bite on his/her lip while he or she is numb.lnform Darents as well to watch the child so this does not occur.

' During extrrction ofa madllary third molar, you realize the tub€rosi

. Remove the tuberosity fiom the tooth and reimplant the tuberosity

. Smooth the shar? edges ofthe remaining bone and suture the remaining soft tissue

. No special treatment is necessary

. None ofthe above

96Copyrighr O 201 1,2012 - D€ntal Decks

. A labial frenum

. A lingual frenum

. The mylohyoid ridge

. The genial tubercles

. An exostosis

97Copyrighl O 20ll-2012 - Dental Dec*s

A fracture ofthe maxillary tuberosity most commonly results from extraction ofan eruptedmaxillary third molar

-or a second molar if it happens to be the last tooth in the arch.

lf the tuberosity is fractured but intact, it should be manually repositioned and stabilizedwith sutues.

The complications most often seen after extraction of an freestanding, isolated maxillarymolar are:

. Fractwe ofthe tuberosity

. Alveolar process fiacture

Important: "Beware ofthe lone molar'r- it is often ankylosed to the bone.Remember: The ankylosed tooth emits an atypical, sharp sound on percussion.

Key point to remember: Tuberosity ftactures may occur and should be treated at the time ofsugery Ifthe operator is unable to do this he / she must arrange an immediate referral.

l. For denture construction, at the correct v€rtical dimension, the distance fromtho crest ofthe tuberosity to the retomolar pad should equal at least I cm.2. Ifthere is inadequate intermaxillary distance at the tuberosity a tuberosity re-

duction can be performed to remove excess tuberosity. An elliptic incision is made

over the tuberosity and carried down to bone. This wedge is resected, The buccal

and palatal tissues axe undermined subperiosteally. Submucous wedges are re-moved flom each flap and the wound is closed. This decreases the vertical and hor-

izontal dimensions of the tuberosity.

The genial tubercles are situated on the lingual surface of the mandible at a point about

mid*ay between the superior and inferior borders. There are four of them, two ofwhichare situated on each side and adjacent to the symphysis. Although usually relatively small,they may be fairly large and extend outwaxd from the surface as spinous processes. These

tubercles are the area of muscle attachment for the suprahyoid muscles.

Important: Ifthe genial tubercles were removed, the tongue would be flaccid.

l. When removing the mylohyoid ridge, be careful to protect the lingualnerve.2. When removing a mandibular exostosis (mandibular torus) it is recom-mended that an envelope flap design, which has no vertical components, be

used.

Bxo

. When the root is fully formed

. When the root is approximately two-thirds formed

. Makes no difference how much ofthe root is formed

. When the root is approximately one-third formed

98

Coprighr C 201 l-2012 - Dertal Decks

. Routinely

. Never

. Ifthe patient requests it

. \\hen there is severe bleeding from the gingiva or ifthe gingival cuffis torn or loose

99Copyrighl O 20ll-2012 - Dental Decks

. Patient would be around the age of 17-21.

. At this time, the bone is more flexible and the roots are not formed well enough to havc de-veloped curves and rarely fracture during extraction.

When the root is fully formed, the possibility increases for abnormal root morphology and forfracturc ofthe root tips during extraction.

Noteq

l. Patients who arc young tolerate surgery very well. Postoperative complications are

usually ninimal.2. Older individuals have the most postoperative difficulties, The bone is more

dense and usually the patient responds more slowly to the entirc process (anesthesia

and surgery).

\ormal post-€xtraction procedure:. -{li loose bone spicules and portions ofthe tooth, restoration, or calculus are removed

from the socket as well as from the buccal and lingual gutters and the tongue. The socket must be compressed by the fingers to reestablish the normal width pres-

ent before the buccal plate was surgically expanded. Note: The natural recontouringof the residual ridge occurs primarily by resorption ofthe labial-buccal cortical bone.. Sutures are usually not placed unless the papillae have been excised. The socket is covered with a gauze sponge that has been folded and moistened slightlyat its center with cold water. The patient is insfucted to bite down on the pressure dressing for 30-60 minutes. -{ printed instruction sheet is given to the patient. .A. prescription for pain is given ifthe need is anticipated

lf bleeding persists for some time following an extraction, it may be helpful to instructthe patient to bite on a tea bag. The tannic acid in the tea bag will help promote hemo-stasis.

Remember: The most common cause ofpost-extraction bleeding is the failure ofthe pa-

tient to follow post-extraction instructions.

Can be avoided by innially creating an adequately sized incisiot

caused by too much forc€; treated witlr pressure to stop bleeding and left

Manqed wilh a figure-eighl sulure over the socket, sinus pr€cautions,

artibiotics. and a nasal spny to preve.l inlection and keep the osliuft

Most common complication; r€moved with elevators /i.e., srfaiarr,cryer, sro!, and rool tip picks.

Fracture of teelh or reslorations

For exampl€, maxillary molar rool into the maxillary sinus

From too much force used to r€move teelhAlveolr p1ocffs and maxillary

newe trav€ls very close to the lingual cortex of lhe mandible in this area-May occur in the area of lh€ .oots of lhe mandibular third molars. Lingual

Can occur in 3% ofnandibular third molar extractions. Willh€al wilhirrigalion and localtreahent forpain control

Th€ most commonly impacted teeth are the mandibularthird molars, maxillary third molars, and the:

. Maxillary canines

. Maxillary lateral incisors

. Mandibular first molars

. Mandibular premolars

100

Coplrigh! O 20l l-2012 - Dental D€cks

. Throbbing pain (often radiating)

. Bilateral lymphadenopathy

. Fetid odor

. Bad taste

. Poorly healed extraction site

101

Copl.right O 20ll-2012, Denral Decks

Classifications of impacted teethAngulation: Mesioangular lecsl diJlicult to rcmove for mandibular impaclionsl, distoangular(most dillicult to remove fol mandibulu impactions),v ertical and horizontal

Pell and Gregory Classification: rclationship to anterior border ofthe ramus. Class 1: normal position anterior to the ramus. Class 2: one-halfofthe crown is within th€ ramus. Class 3: entire crown is embedded within the ramus

Relationship to occlusal plane:. Class A: tooth at the same plane as othgr molant. Class B: occlusal pane ofthird nolar is between the occlusal plane and the cervical line ofthe second molar. Class C; entire crown is embedded within the mmus

Contraindications to extractionofimpacted teeth:

. Compromised medical status

. Likely damage to adjacent

structures. Extremes ofages (preteen oran asymptomatic .full bony im-paction i a patient> 35 ),ea/sof age

The etiology ofdry socket is not absolutely clear but is thought to develop because of in-creased fibrinolytic activity causing accelerated lysis ofthe blood clot. It is most commonlbllon ing extraction ofthe mandibular molars. Smoking, premature mouth rinsing, hotliquids. surgical trauma, and oral contraceptives all have been implicated in the develop-ment ofa dry socket. Note: Careful technique and minimal traula reduce the frequencyof patients developing dry socket.

Treatment for dry socket:. Flush out debris with slightly warmed saline solution

-gently !!l

. Place a sedative dressing in socket (eugenol). The dressing should be removed within48 hours and replaced until the patient becomes as)lnptomatic. Note: (l) The gauze

provides an aftachment for the obtundent paste so it stays in the socket (2) Eugenol is

the active component in most sedative dressings.. Nonsteroidal anti-inflammatory analgesics should be prescribed ifnecessary.*** Antibiotics are senerallv not indicated.

LDry socket is the most common complication seen after the surgical removalof a mandibular molar.2. Curetting a dry socket can cause the condition to worsen because healingwill be further delayed, any natural healing already taking place will be de-

stroyed, and there is a risk ofcausing the localized inflammatory process to be

spread to the adjacent sound bone.

* Present in young patients

Roots one tlid to two thirds fom€dr

* Present in young patients

. An inlraoral picture should be taken

. A mandibulax torus ifpresent, should be removed

. A stent should be fabricated

. A biopsy should be taken

102Coplaight O 201 l-2012 - Dental Decls

. Venical

. Horizontal

. Distoangular

. Mesioangular

103

Coplright @ 201 1,201 2 , Dmial Decks

Maxillary tori present few problems when the maxillary dentition is present and onlyoccasionally interfere with speech or become ulcerated from frequent trauma to the palate.

Indications for the removal include a large, lobulated torus with a thin mucoperiostealcover extending posteriorly to the vibrating line ofthe palate that prevents seating of adenture and also prevents a posterior seal at the fovea palatini. Other indications for theremoval ofmaxillary tori are, chronic initation, interference with speech, rapid growth andin patients that have a cancer-phobia.

Technique for removal:. A stent should be fabricated prior to removal of a palatal torus. This is done on a

study model that has had the exostosis removed.. A double-Y incision should be made over the midline ofthe torus. After careful elevation ofthe flaps, the torus should be scored multiple times in theanterior, posterior, and transverse dimensions. An osteotome can be used to remove each ofthese small portions. A large bur or bone file is used to smooth the area. After thorough irrigation, the wound is closed loosely with horizontal mattress su-

tlrles. The stent is placed to prevent hematoma formation and to support the flap

Important: The maxillary torus should not be excised en masse to prevent entry into the

nose (the palatine bone will come out with torus).

lmportant: This is the exact opposite ofimpacted maxillary third molars' where the mesioan-

gular impactions (122o/ are the most di{ncult and the vertical f63lo) and distoangular impactions

/2i / are the essiest to remove.

Surgical principles for removing impacted teeth:

L Adequat€ exposure (adequate-sized-flap): an envelope flap is most often used, but releasing

incisions are common. Note; The base portion ofthe flap should always be wider thar the apex

portion ofthe llap to maintain adequate blood supply to the released soft tissues.

2. Bone removal: a trough ofbone on the buccal aspect of the tooth down to the cervical line

should be removed initially, more bone removal may be required depending on the particular

tooth. Important; Bone is rarely, ifever, removed on the lingual aspect ofthe mandiblc because

ofthe likelihood ofdamaging the lingual nerve.

3. Tooth sectioning: sectioning ofthe tooth may also be needed. This is most often perfomred

with a straight bur, such as a No. 8 round bur, or with a fissure bur, such as a No. 557 or 703.

4. Copious irrigation of the wound is very important and replacement ofthe soft tissue flaps

comDletes the Drocedure.

. Rotation

. h ing

. Pushing

. Luxation

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. Palatal root ofthe maxillary first premolar

. Palatal root ofthe maxillary first molar

. Palatal root ofthe maxillary second molar

. Palatal root of the maxillary third molar

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Luxation is the loosening ofthe tooth in the socket by progressive severing ofthe periodon-tal ligament fibe6. Patience and controlled force are needed, not brute strength. The forceshould be applied as low down the root as possible when extraciing teeth. You should supportthe jaw with your other hand and have a thumb and frnger on either side ofthe tooth being ex-tracted. Note: Rotation forces can be used on single rooted teeth. Teeth are extracted by lux-ation forces perpendicular to the long axis ofthe tooth, not by pulling along the long axis. Thefulcrum is as close to the apex ofthe tooth as possible.

Remember: The beak of the extraction forcep is designed so that most of the pressure ex-erted during an extraction is transmitted to the root ofthe tooth.

Important: When using dental elevators, one should always have respect for the forces gen-

efated. Due to the large amount of leverage, dental elevators can genente tremendous forcesduring normal use, and have potential to cause iatrogenic damage.

\ote: A Class [I fever is used during tooth extractions (see picttu?s below)

Class l Lever Class Il Lever Class III Lever

f,n,A .t ,A ."t"r"l!","r

- - p*"ii'"int

Important: If an entire tooth or a large fragment of one is displaced into the sinus, itshould be removed. If the tooth fragment is irretrievable through the socket, it should be

rerieved through a Caldwell-Luc approach ASAP. However, only perform this ifyoukno\ what you are doing. Ifnot, refer patient to an oral surgeon.

\ote: If a small communication is made with the maxillary sinus during extraction of arooth. the best treatment is leave it alone and allow the blood clot to form.

Post-operative instructions to patient:. -\'oid nose blowing for 7 days. Open mouth when sneezing. -{\.oid vigorous rinsing. Soft diet for 3 days

Ifa sinus communication should occur the following medications may be prescribed forone u eek:

L Afrin: local (nasal) decorgestant2. Antibiotics (Amoxicillin)i. Actifed: systemic decongestant

I . If the opening is of moderate size (2-6 mm), a figure-eight suture should be

place over the tooth socket.2. Ifthe opening is large (7 mm or latger),lhe opening should be closed with aflan orocedure.

Remember: The integrity of the floor of the maxillary sinus is at greatest risk with sur-gery involving the removal ofa single remaining maxillary molar. The fear here is pos-

sible ankylosis.

.\*oie* l

The Caldwell-Luc procedure eliminates blind procedures and facilitates therecovery oflarge root tips or entire teeth that have been displaced into thel,l.LUu rU.U .[t

maxillary sinus. When performing this procedure an openingis msde into the faciil wall of the antrum aboye the:

. Maxillary tuberosity

. Maxillary lateral incisor

. Maxillary premolar roots

. Maxillary third molar

. 2/0

.3/0

. 4i0

.50

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Ila large root fragment or the entire tooth is displaced into the maxillary sinus (antrum),it should be removed. The usual method is a Caldwell-Luc approach. This is a surgicalprocedure in which an opening is made into the maxillary sinus by way ofan incisioninto the canine fossa above the level ofthe premolar roots. The tooth or root is then re-moved. Post-operative management includes a figure-eight suture over the socket, sinusprecautions, antibiotics, a nasal spray and a systemic decongestant to keep the sinus os-tium open and infection free. Important: An oral surgeon to whom the patient shouldbe referred should perform this procedure.

If the root tip is small (2 or 3 mn), noninfected, and cannot be removed through thesmall opening in the socket apex, no additional surgical procedure should be performedthrough the socket, and the root tip should be left in the sinus. Ifthe root tip is left in the

sinus, measures should be taken similar to those taken when leaving any root tip in place.The patient must be informed ofthe decision and given proper follow-up instructions.

Remember: The palatal root ofthe maxillary first molar is most often dislodged intothe maxillary sinus during an extraction procedure.

\ote: If a root tip of a mandibular third molar disappears from site while trying to re-trieve it, the most likely location for it to be in is the submandibular space. Other pos-

sible locations would be the inferior alveolar canal or the cancellous bone space.

Suture size is based on strength and diameter. The gauge or thickness ofthe suture ma-terial is denoted by O gradings. As the thickness ofthe material decreases, the O gradingrises. Hence 2/0 is thicker than 3/0, which is thicker than 4/0 and so on.

Because suture material is foreign to the human body, the smallest-diameter suturesufficient to keep the wound closed properly should be used. Most oral and maxillofacialsurgical procedure s (intraoral suturing) require the use of3/0 or 4/0 gauge material buton extraoral skin surfaces, finer gauge is preferred such as 6/0 or even finer This helps

reduce scar visibility.

Note: The primary function of sutures is to help to stabilize the flap during the healingphases without imposing needless traction on the soft tissue.

. Inflammatory phase

. Proliferative phase

. Remodeling phase

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. l-2 days postoperatively

. 5-7 days postoperatively

. 9-l I days postoperatively

. l3- l5 days postoperatively

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Wound healing is a process that can be divided into three phases:

1. Inflammatory Phase (initial lag phase)

. Immediate to 2-5 days

. Hemostasis- Vasoconstnction- Platelet aggregation- Thromboplastin makes clot

. Inflammation- Vasodilation- Phagocytosis

2. Proliferative phase (fibroblastic phase)

. 2 days to 3 weeks

. Granulation- Fibroblasts lay bed ofcollagen- Fills defect and produces new capillaries

. Contraction- Wound edges pull together to reduce defect

. Epithelialization

3. Remodeling Phase (maturation phase)

. 3 weeks to 2 years

. Nerv collagen fonns which increases tensile shength to wounds

. Scar tissue is only 80 percent as strong as original tissue

Factors that impair wound healing: diabetic patients, patients with protein deficiencics, oldcr pa-

tients. infections, foreign material, necrotic tissue, ischemia, and tension on the wound.

Remember: 370 hydrogen peroxide is the agent ofchoice for thc debridement ofintraoral wounds.

Tlre two basic categorics ofsuturcs are (l) rcsorbable and (2) nonresorbable:. Resorbable: These sufures are resorbed after a certain time, which usually coincides with heal-ing of the *'ound. These sutures are made of gut or vital tissue (catgut, collagen, lascia, etc.) and.

are plain or chromic, or ofsynthetic material, e.g., polyglycolic acid (Dexon). Plain catgut sutures

are resorbed postsurgically over 8 days, chromic sutures in 12- 15 days, and q.nthetic (Dercn) su-

rures in approximately 30 days. These types of sutures are used for flaps with little tension, chil-drcn. mentally handicapped patients, and gcnerally for patients who cannot retum to the oIfice toha\-e the sufues removed.. \onresorbable: These suturcs rcmain in the tissues and are not resorbed. but have to be cut and

removed about 5-7 days aftcr thcir placement. They are fabricated ofvarious materials, mainly sur-gical silk (nonoflamenlous or mukiflame tous), in many diameters ancl lengths) ar'd srrrgical

conon surure. Silk sutures are the easiest to use and the most economical, and have a satisfactory

abili\" to hold a knot.

\ote: Resorbable sutues evoke an intense inflammatory reaction. Thjs is the main reason neitherplain gut or chromic gut are used for suturing the surface ofa skin wound. When suturing an exffac-don site in the anticoagulated paticnt, a non-resorbable suture is recommended. Resorbable sutures

are accompanied by an inflammatory response, increasing fibrinolytic activity, potentially resulting

in clot brcakdown.

T\\ o basic methods ofwound healing fsof tissrel:

l. Primar) intention (also called primary c/osrre); involves minimal re-epithelialization and col-lagen formation, allowing the wound to be "sealed" within 24 hrs. Healing occurs more npidlyrvith a lower risk ofinfection, with less scar formation and less tissue loss than wounds allowedto heal by sccondary intention. Examples include: well repaired and well-reduccd bone fractures.

2. Secondary intention (also called secondary closure). involves re-epithelialization via migla-rion from the wouod edges, collagen deposition in the connective tissue, contracture. and remod-eling. The site fills in with granulation tissue. Healing is slower and results in scarring and wounddepression. Examples include: extraction sockets, poorly reduced iiactures, and large ulcers.

. Mid-buccal ofthe tooth

. At the line angle ofthe tooth

. Midlingual of the tooth

. Beyond the depth ofthe rnuco-buccal fold

t't0Coplright O 201 1,2012 - Dmtal Decls

. Use a larger forcep and luxate remaining portion oftooth to the lingual

. qenqrafp rhe r^^t<

. Irrigate the area and proceed to remove the rest ofthe tooth

. Place a sedative filling and reschedule patient

11'lCopFighl O 20ll-2012 - D€nral Deks

Regardless of the flap design used, certain principles should be followed while incising andreflecting the gingiva. These include:

. Incision should be made with a firm. continuous stroke

. lncision should not cross underlying bony defect that existed prior to surgery, or would be pro-duced by the surgery. Vertical incisions are madc in the concavities between bony eminences. Terminatiqn ofvertical incision at the gingival crest must be at the line angle ofthe tooth. Vertical incision should not extend beyond the depth ofthe muco-buccal fold. Base ofthe flap must be as wide as the width ofthe free edge (supraperiosteal vessels runningverticalU shoxld not be transected). Periosteum must be reflected as an integral part ofthe flap

lmportant: The correct position for ending a vertical releasing incision is at a tooth line angle notover the buccal surface of a tooth. lf it ends over a buccal surface, the edges are difficult to ap-proximate and this may lead to pe odontal problems. Incision should never cross bony promi-nences as this increases the chance for wound dehiscence.

Three types ofincisions used in oral surgery:

1 LiI|ear: straight line incision used for apicoectomies.2. Releasing: used when adding a vertical leg lo a horizontal creation incision. For extractions,augmentations, etc.3. Semi-lunar: curved incision mostly used for apicoectomies.

Tle basic principles oforal surgical flap design:. Flap design should ensure adequate blood supply; the base ofthe flap should be largcr thanthe apex. Reflection ofthe flap should adequately expose the operative field. Flap design should permit atraumatic closure ofthe wounds. Flap should be closed over bone ifpossible

*** This can be done with a chisel, elevator, or most easily with a bur.

Teeth with two or more roots often need to be sectioned into single entities prior to successful re-moval. A popular method ofsectioning is to make a bur cut between the roots, fbllowed by insert-ing an elcvator in the slot and tuming it 90o to causc a break.

Roots can be removed by closed technique. The surgeon should begin a surgical removal if the

closed technique is not immediately successful.

Indications for surgical extractions:. After initial attempts at forceps extraction have failed . Hypercementosis or widely divergent. Patients with dense bone. In older patients, due to less elastic bone . Extensive decay which has destroyed. Short clinical crowns with severe attrition (bruxers) most ofthe crown

T€eth are resistant to crush but are not resistant to shear Therefore:. Place the beaks ofthe forceps opposite to each other at the same level on the tooth.. The beaks should be applied in a line parallel with the long axis ofthe tooth.

Remember: When luxating a tooth with forceps, the movements should be firm and delibcrate, pri-marily to the facial with secondary movements to the lingual. The maxillary first bicuspid is leastIikelv to be remoyed by rotation forces due to its root structure (obviously molars.tre nol re-

moved b!* totation).

. -. 1. It is recornmended to use a bite block when removing mandibular teeth to diminish

l;otes,, pressure on the contralateral TMJ.2. Distilled water is not used for irrigation because it is a hypotonic solution and willcnter cells down the osmotic gndient, causing cell lysis and rapid death ofbone cclls.3. Buccal to lingual movement is not efficient when rcmoving mandibular posterior

teeth because mandibular bone is too dense and does not expand in a fashion similarto that ofmaxillary bonc.4. The root ofth€ zygoma can interfere with efficicnt removal ofa ma,rillary first molar

. In the infratemporal fossa

. In the submandibular space

. In the mandibular canal

. In the pterygopalatine fossa

112Cop)riglt O 201l-2012 - Dental Decks

. Replacement ofthe connective tissue by fibrillar bone

. Hemorrhage and clot formation

. Replacement of granulation tissue by connective tissue and epithelialization of thesrte

. Recontouring ofthe alveolar bone and bone maturation

. Organization ofthe clot by granulation tissue

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Important: To prevent this, avoid all apical pressures when removing the roots or roottips ofall mandibular molars. Ifa mandibular molar root tip is displaced inferiorly, it mayeither be in the mandibular canal or through the lingual cortical plate. The mandibularcanal is generally found buccal to the roots ofthe mandibular third molar.

The submandibular space is a potential space ofthe neck bounded by the oral mucosaand tongue anteriorly and medially; the superficial layer ofd€ep cervical fascia laterally,and the hyoid bone inferiorly. The mylohyoid muscle, stretching across the floor of the

mouth, divides the submandibular space into a portion above this muscle: sublingual arrd

a portion below: submaxillary spaces.

Note: The submaxillary submental and sublingual spaces are collectively referred to as

the submandibular space. This space usually drains infections from the mandibularbicuspids and molars because their apices lie below the mylohyoid muscle attachment.

The submental space is the medial part of the submaxillary space. It contains the

submental lymph nodes that drain the median parts ofthe lower lip, tip of the tongue'and the floor ofthe mouth. Usually drains infections from the mandibular incisors and

canines because their apices lie above the mylohyoid muscle attachment.

The sublingual space is the superior part ofthe submandibular space, containing the sub-

lingual gland and loose connective tissue surrounding the tongue.

Remember: Ludwig's angina is the most commonly encountered neck space infection(involves the sublingual, submandibular, and submental spaces).

\ote: Glucocorticoids have been shown to have the greatest effect on granulation tissue --

the! retard h€aling. This is believed to be due to the fact that:. Glucocorticoids interfere with the migration ofneutrophils and mononuclear phagocytes

into a site of inflammation; the phagoq'tic and digestive ability ofmacrophages is also re-

duced.. Glucocorticoids inhibit formation ofgranulation tissue by retarding capillary and fibrob-last proliferation and collagen synthesis.

The same stages that occur in normal wound healing of soft tissue injuries also occur in the

repair ofinjured bone. However, osteoblasts and osteoclasts are also involved to repair dam-

aged bone tissue.

Bone heals by primary and secondary intention as does soft tissue.. Primary intention bone repair involves both endosteal and periosteal proliferation. Thistype of bone repair occurs when either the bone is incompletely fractured or a surgeon

closely reapproximates the fractued ends ofa bone. Littl€ librous tissue is produced withminimal callus for

. Digastric muscle

. Temporalis muscle

. Lateral pterygoid muscle

. Medial pterygoid muscle

. LeFort I

. Le Fort II

. LeFort III

. Zygomatic fractures

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115Copyright O 20ll-2012 - Dental Decks

Muscles involved in displacing mandibular fractures include the medial and lateral ptery-goid, temporalis, masseter, digastric, geniohyoid, genioglossus, and mylohyoid. The lat-eral pterygoid displaces the condyle ant€riorly and medially because of its insertion onthe pterygoid fovea. Muscles attached to the ramus (i.e., temporalis, n,asseter,.tnd me-dial pterygoid) result in superior and medial displacement ofthe proximal segment. Asfractures progress anteriorly toward the canine region, the digastric, geniohyoid, ge-nioglossus, and mylohyoid exert a posterior-inferior force on the distal segment.

The lateral pterygoid muscle is the only muscle that inserts directly on the neck ofthemandibular condyle. In subcondylar fractures, the forces of this muscle frequently re-sult in anterior and medial displacement ol the condyle. In higher condylar fracturesand in intracapsular fractures above the insertion olthe lateral pterygoid, the small frag-ment can occasionally be seen displaced in a pure hodzontal or vertical direction.

)tlote: Displacement of the proximal segment of the condyle usually occurs in an an-teromedial direction because ofthe pull ofthe lateral pterygoid muscle. The patient willdeviate to th€ side ofth€ fracture upon opening because ofthe unopposed action ofthecontralateral lateral pterygoid muscle.

Z,vgomaticomaxillary complex (ZMC1 fractures involve four major processes: the zygomati-cotiontal rcgion. inliaorbital rim, zygomatico buttress, and zygomatic arch. Zygomatic fracturcs arc

commonl)' encountered in lbcial trauma because oftheir prominent position on the facial skeleton.

The rnost conlmon mechanism producing facial fractures is auto accidents. About 70 7o ofauto ac-

cidents produce somc type of lacial injury, although most are limitcd to soft tissue. The face seerns

to be a favo.ite target in fights or assaults, which arc the ncxt most common mechanisrn. As withmandible fractures, midface fractures are described by the bone involved, as simple /closed),com-pound /operr, or comminuted.

Fracture type prevalence:

. Zygomaticomaxillary complex: 40 %

. LeFort I: 15 70

II: l0 %III: 10 %

. Zygomatic arch: l0 o%

. Alveolar process ofnaxilla: 5 %

. Smash fractures: 5 70

. Other: 5 %

1. The maxilla and mandible are in a critical relationship to the upper airway; therefore

displacemcnt of ftactures can cause obstruction ofthe airway resulting in respiratoryarrest. Control ofthc airway is vital to any trcatment ofa patient with facial ftactures.

2. Maxillary fractures have a greater tendency towafds the production of facial defor-mity than do mandibular fractures.

3- Maxillary Lefort fractures, orbital fractures and zygomatic fractures usually requireintemal rigid fixation.3. Thc highest incidence of fmctures occLlrs in young males between the ages of l5 and24. These fractures are usually the result oftrauma.

,. Nofeg-

Abnoinal mobilily ofthe boie

. Hematoma

. Wound dehiscence

. Facial or trigeminal nerve injury

. Infection

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. Attachment of the muscle

r Trrna nff.rnt""-

. Direction of muscle fibers

. Line of fracture

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Of these, infection is one ofthe most problematic; it is the most frequent complication and is animportant cause of non-union.The most common cause ofpostoperative infection is movement at the fracture site due to loose,mobile hardware, such as a loose screw in an otherwise stable plate.

Four reasons that a fracture does not heal:l. Ischemia: the navicular bone ofthe wrist. the femoml neck. and the lower third ofthe tibiaare all poorly vascularized and therefore are subject to ischemic necrosis after a fracture.2. Excessive mobility: healing is prevented and pseudoarthrosis or a pseudo-joint may occur3. Interposition of soft tissue occuls between the fractured ends.

4. Infection: compound fractures have a tendency to become infected.*** Important: a fat embolism is most often a sequela of fracfures.

f nappropriate healing (three rypes) :

l. Delayed-union: satisfactory healing which requires greater than the normal six week period.May be caused by infection, interposition ofsoft tissue or muscle between the fracture segments.

2. Non-union: failure ofthe ftactwe segnents to unite properly. May be caused by infection, im-proper immobilization, or interposition ofsoft tissue.3. Mal-unionr can be either delayed or complete union in an improper position. May be causedby improper immobilization or imperfect reduction.

The line of fracture will determine whether muscles will be able to displace the fracturedsegments from their original position. Favorability is determined by the forces exerted by themasticatory muscles on the lracture segments. A favorable lracture is one that is not dis-placed by masticatory muscle pull, and an unfavorable &acture occws when the line offrac-ture permits the fragments to s€parate.

The four muscles of mastication are the temporalis, masseter, medial pterygoid, and lateralpterygoid. After discontinuity ofthe mandible due to fracture, these muscles exert their actions

on the lragments. leading to malocclusion.

Signs and symptoms that may be associated with mandibular fractwes:. Pain and tendemess at tbe fracture site. Changes in occlusion. Ecchymosis ofthe floor ofthe mouth or skin. Crepitation on manual palpation. Changes in mandibular range of motion. Soft tissue bleeding. Sensory disnrrbances (numbness ofthe lower lip). Der iarion ofthe mandible on opening. Soft tissue swelling. Trismus. Step-in occlusion. Palpable fracture line intraorally or at the inl'erior border ofthe mandible

Approximately 43% ofall patients with mandibular fractures have associated other systemic

injuries. Cewical spine fractures were found in I l% ofthis group ofpatients. It is imp€rativeto rule out cervical neck fractur€s, especially in patients who are intoxicated or unconscious

and in patients who are involved in vehicular accidents. Posteroantedor, lateral films, and CTofthe neck should be reviewed with the radiologist before trcatment is initiated in these pa-

tlents.

z\fn general, mandibular fractures are less common in children than in adults.When mandibular fractures occur in children. fractures ofthe

. r . . matrdible, particularly in the condylar region]lii&iitely common. )

. Simple

. Greenstick

. Compound

. Comminuted

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. Mandibular fractures at the angle

. Fractures ofthe mandibular condyle

. Le Fort I fractures

. Zygomatic fractures

. All ofthe above

1r9Copyrighr @ 2011,2012 - Dental Decks

The ossification capability ofchildren allows faster healing and distinguishes it from the adultmandible. As a result, many mandibular fractures in children can be treated with immobiliza-tion for a shorter period or observation and soft diet only than in an adult. Note: Open reduc-tion and intemal fixation in children is reserved for severely displaced fractures.

In an adult, the location oflacial fractures is influenced by both the resistance ofthe bone tofracture and how prominent its position on the facial skeleton is. Adult facial fractures are

most commonly seen in the nasal bones followed by the zygoma, mandible, and maxilla. Inchildren, early growth in the cranium and orbits predisposes young children to fiontal boneand orbital fractures.

The following categories classil! mandibular fractures by describing the condition ofthe bone

fragments at the fiacture site and possible communication with the extemal environment:. Simple: divides a single bone into two distinct parts with no extemal communication.These are closed fractures with no lacerations ofthe oral mucosa or facial tissues.. Compound: fracture communicates with the outside environment (open fracture). Thismay occlu by laceration of the oral tissues exposing the bone fragments, fracture of the

maxilla into the sinuses, or by way ofskin lacerations that would expose the fracture seg-

ments. Infection is common.. Comminuted: are multiple fractures of a single bone. They may be simpl€ or comp-ound.. Gre€nstick: fracture that extends only through the cortical portion of th€ bone without-complete fracture ofthe bone. Greenstick fractures are closed fractures involving incom-plete ftactures with flexible bone. Most often seen in children.

Remember: (l) The most common complication ofan open fracture is inf€ction.(2) Any jaw fracture extending through tooth beaxing bone is considered an open

fracture due to potential tears in the PDL and exposure ofthe fiacture to the oralflora.

Note; For a long time in the past, a posteroanterior oblique wate6 view or a reverse Waters viewtogether with a posteroanterior and submgntal vertex view ofthe skull were used for evaluating zy-gomaticomaxillary c omplex (ZMC) fractures. However, the CT sc^n Ooth axial qnd cotonal ori-entations) is c\tfier'tly the diagnostic imaging ofchoice forevaluating these fractures as well as theother fraciures listed. This imaging modality shows the location of the fractures, degree of dis-placement ofthe bones, and status ofsunounding soft tissues.

lmportant: Dysfunction ofthe infraorbital nerve is common in a patient with a ZMC fracture. Anophthalmologic examination is ofparamount importance. Also, fractures ofthe facial bones, par-

ticularly the zygomatic complex may on rare occasions be complicated by damage to the contents

ofthe superior orbital fissure.

Other possible complications ofthe zygomatic complex fracture include:. Par€sthesia fmoJl con,aon): usually subsides. The antrum /s,rrs) may be filled with a hematoma, which usually evacuates itself. Ocular muscle balance rnay be impaired because offracture ofthe orbital process

Note: Fracture ofthe infraorbital rim presents with the following symptoms:. Numbness ofthe followi.g areas on the affected side; upper lip, cheek, and nose

Note: The most feared, but fortunately rare, complication ofZMC fractures is blindness.

Remember: By definition, the four articulating sutures (ZE ZT ZM, ard ZSJ are disrupted in this

fracture. Therefore the commonly applied term "tripod fracture" is a misnomer and does not cor-

rectly describe this fracture.

Most practitioners consider CT scanning to be the gold standard imaging rnodality for evaluation

of mandible fractures. A CT scan allows the entire face to be evaluatcd in one study. Despite the

popularity ofCT imaging, in many facilities the initial imaging studies may consist ofpanoramicradiography or a plain-view series ofthe mandible ((i.e., posteroanterioti Waters, reverse-Towne,

or subtnentovertex projections) Many nrral hospitals still use a plain-vicw series ofthe mandible.

Therefore familiarity with plain radiographs is important.

. Favorable, non-displaced fractures

. Displaced and unstable fractures, with associated mjdface fractures, and when MMF iscontraindicated

. Either ofthe above

. None ofthe above

120CopriSht O 201l-2012 - Dental Dects

. One way: by direct or primary bone healing which occurs without callus formation

.One way: by indirect or secondary bone healing which occurs with a callus precursorstage

. Trvo ways: by direct or primary bone healing which occurs without callus formationand indirect or secondary bone healing which occurs with a callus precursor stage

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Treatment options ofmandible fractures can be divided into rigid fixation, semirigid fixation. andnon-rigid or closed reduction. Methods considered rigid fixation are the lag screw technique,compression plating, reconstruction plates, and extemal pin fixation. Miniplate fixation and wircfixation are types of semirigid fixation. Maxillomandibular fixation ([MMFJ \\'ith i'vy loops, archbars, or lransalveolar screw), gunning splints, and lingual splints are considered non-rigid fixation.Rigid fixation allows for primary bone healing without callous formation. Non-rigid fixation al-lows for secondary bone formation with inflammatory infiltration and callous lormation. Semi-rigid fixation allows for areas of primary and secondary bone formation.. Closed reduction is best used in the treatment of favorabl€, non-displaced fractures. It is also used

in situations in which Open Reduction lntemal Fixation (OR1F) is contraindicated. Maxillo-narulibrllar fixation (MMF) is obtained by applying wires or elastic bands between the upper andlower jaws, to which suitable anchoring devices can be attached, such as arch bars or skeletalscrews. The standard length ofmaxillomandibular lrxatlon (MMF) is 4-6 weeks.. Open reduction involves direct exposure ofthe fracturc site and placement of intemal fixationto prcvent movement ofthe fracture site. Open reduction is used in displaced and unstable fractures,

*ith associated midface fractures, and when MMF is contraindicated. In addition, some surgeons

advocate ORIF for patient comfort and for expedited retum to activity and work. Arch bars are al-$ays placed first to establish occlusion, then ORIF is performed. The plates can be placed inhao-rally, extraorally via a cervical incision, or percutaneously. Dynamic compression plates (DCPJ

can be used for most body, angle, symphyseal or parasymphyseal fractules.

Note: Initial management of mandibular ftactures starts after the patient has been stabilized. Allfractures oftooth bcaring arcas ofthe mandible are considered open and should be treated with an-

tibiotics that cover mouth flora, specifically gram positive and anaerobic organisms. Mouth rinses

with peridex solution or half strength hydrogen peroxide in water are useful to keep the mouthclean. Timing ofrepair is controversial. Several studies have shown a decreased incidence of in-fection ifcompound fractures arg repaired within 48 hours. Other studies have shown no change iffractures are repaired in less than a week. Regardless ofinfection rates, patient comfort dictates that

the earliest date lbr repair is the best as displaced fractures are painful.

Primary bone healing involves a direct attempt by the cortex to re-establish itselfafter interrup-tion. Bone on one side ofthe cortex must unite with bone on the other side ofthe cortex to re-es-tablish mechanical continuity. Under these conditions, bone-resorbing cells on one side of the

f.acture sho.,\,a tunneling resorptive response, whereby they re-establish new haversian systems byproriding pathways for the penetration ofblood vessels.

Secondar! bone healing involves the classical stages offracture healing.

Stages of fracture healing:. Stage l: lnflammation - bleeding from the fractured bone and sunounding tissue causes theliactured area to swell. This stage begins the day you fracture the bone and lasts about 2 to 3\\'ecks,. Stage 2; Soft callus- between 2 and 3 weeks after the injury the pain and swelling will decreasc.

-\t rhis point, the site ofthe fracture stiffens and new bone begins to form. The new bone cannot

be seen on x-rays. This stage usually lasts until 4 to 8 weeks after the injury.. Stage 3: Hard callus- between 4 and 8 weeks, the new bonc b€gins to bridge the fracture. Thisbony bridge can be scen on x-rays. By 8 to l2 weeks afterthe injury new bone has filled the frac-IUre.. Stage 4: Bone remodeling- beginning about 8 to I 2 weeks after the injury the fracture site re-models itself, correcting any deformities that may remain as a result of the injury. This finalstage offracture hcaling can last up to several years.

The rate ofhealing and the ability to remodel a fractured bone vary tremendously for each person

and depend on the patient's age, health, the kind of fracture, and the bone involved. For example,children are able to heal and remodel their fractures much faster than adults.

Compartment syndrome: Severe swelling after a fracture can put so much pressure on the bloodvessels that not enough blood can get to the muscles around the fracture. The decreased blood sup-ply can cause the muscles around the fracture to die, which can lead to long-term disability.

. Nasal bleeding

. Exophthalmos

. Malocclusion

. Numbness in the infraorbital nerve distribution

122Coplrighr O 201 1,2012 - D€ntal Decks

\

.,1

. LeFort I

. Le Fort II

. LeFort III

123CopF,ghtO 201l-2012 - De alD4ks

Other signs and symptoms of a mandibular body or angle fracture include:. Lower lip numbness. Mobility, pain, or bleeding at the fracture site

The important points in treating mandibular fractures are immobilization ofthe fractures, the ap-

propriate use ofantibiotics, and restoration of form and function. The usual treahnent for mandibu-

lar fractures that are displaced and mobile is with open reduction and intemal fixation using titaniumbone plates and screws. tfthe patient has teeth, the occlusion is used as a guide for the surgeon to

repair the fracture. Other methods ofrepair include splinting (/or pedistric patients) and maxillo-nandibdar fixation (see below) .

. Establishing a proper occlusal relationship by wiring the tceth together is termed maxillo-mandibular lixation (MMF) or intermaxillary fixation (IMF). The nost common techniqueincludes the use ofa prefabricated arch bar that is adapted and wired to teeth in each arch; the

maxillary arch bar is wired to the mandibular arch bar, thereby placing the teeth in their proper

relationship. Other wiring techniques such as Ivy loop or continuous loop wiring have also been

used for the same purpose.

More recentl% techniques for rigid internal fixation (NF) have ga;Lned popularity for treatment

offractures. These use bone plates, bone scrcws, or both to fix the fractwe more rigidly and stabi-

lize the bony segments during healing. Even with rigid fixation, a proper occlusal relationship must

be established before reduction stabilization and fixation ofthe bony segments. Advantages ofRlFfor treatment of mandibular fractures include decreased discomfort and inconvenience to the pa-

tient because [MF is eliminated or reduced, improved postoperative nutdtion, improved postoper-

ative hygiene, and frequently better postoperative management ofpatients with multiple injuries.

Notei Mandibular angle fractures are generally more prone to the development of complications

compared with the body or symphyseal areas. Multiple complications may arise but most com-

monly include loose hardware necessitating rcmoval, infection, malocclusion, delayed union, and

fibrous union. Damage to the inferior alveolar and lingual nerve can be a complication ofthe ini-tial injury or a consequence oftreatnent.

Types of Le Fort's fractures:. Le Fort l: the fracture line traverses the maxilla through the piriform aperture above the alve-olar ridge, above the floor of the maxillary sinus, and extends poste orly to involve the ptery-goid plates. This fracture allows the maxillae and hard palate to move separately fiom the upperface as a single detached block. Le Fort I fracture is often referred to as a transmaxillary frac-ture.. Le Fort II: superiorly, this fracture traverses the nasal bones at the frontonasal sutures. It ex-tends laterally through the lacrimal bones, crossing the floor ofthe orbit, fracturing the medialand inferior orbital rirns, and fracturing the pterygoid plates posteriorly. ln this fracture, the aF

tachment of the zygomatic bones to the skull at the lateral orbital rims and at the zygomaticarches is preserved. As a result ofthis fracture, the maxillary and nasal regions are movable rel-atiye to the rest ofthe midface and skull. Because ofits triangular pattem, this fracture is oftcnrefened to as a pyramidal fracture.. Le Fort tll: this fracture line involves fracture ofall the buttress bones linking the maxilla tothe skull. This fracture allows the entire upper face (nasal, maxillary and zygomatic regions) tomove relative to the skull. [n this fracture, there is a craniofacial disjunction with a separation at

the liontozygomatic suture, nasofrontal junction, orbital floot and zygomatic arch latcrally.

Clinical manifestations of midface fractur€s:. Clinical diagnosis ofmidface fractures is reasonably easy to make when therc is a displacement

ofthe fracture, which is often manifested by the presence ofmalocclusion, mainly antedor open

bite. Pain and swelling are the other signs ofmidface fractures. Mobility of the midface. Nasal bleeding, subconjunctival ecchymosis, maxillary hypoesthcsia, and tendemess of the

bony buttresses ofthe midface are other signs and symptoms ofmidfacial and maxillary fractwes.

lmportant The first step in the treatment ofthese fractues which affect the occlusal relationshipis similar to the treahnent ofmandibular fractures

- to re-establish a proper occlusal relationship

by placing the maxilla into proper occlusion with the mandible.

. Body

. Angle

. Symphysis

. Coronoid process

. Hyperparathyroidism and cancer

. Diabetes and hypothlroidism

. Renal failure and hypoalbuminemia

. Grave's disease and hypopituitarism

124CopriShr e 201 l-2012 - Dertal Decks

125Cop'right O 20ll-2012 - D€nral Decks

Patients with hypocalcemia have an lonized calcium levelb€low 2.0 or serum calcium concentntion lower than 9 mg/dl.

Some ofthe most common causes are:

The location and extent of mandibular ftactures axe determined largely by the direction andintensity ofthe blow and the specific points ofweakness in the mandiblc.

The condylar neck (29.1o.4 offractures) is a safety featue which allows the blow to the jawto be dispersed at this point rather than driving the condyle into the middle cranial fossa. Bi-lateral dislocated fiactures ofthe condylar necks will cause an anterior open bite and the in-ability to protrude the mandible. A unilateral fracture through the neck may cause forwarddisplacement ofthe head ofthe condyle due to pull ofthe lateral pterygoid muscle.

The symphysis (22'% offractures) is usually where blows are sustained. These blows oftenresult in fractures of the subcondylar region.

Remember: The patient's mandible will deviate to the side of injury upon opening.

Note: Mandibular fiactures can almost always be identified on a panoramic radiograph. Ifafracture is suspected, at least two different radiographs should be taken for comparison(i.e., panoramic, posteroanterior, Waters, reverse-Tbwne, or submentovertex projections).

Calcium levels are regulated by parathlroid hormone and to some extent by the kidney tubules

and GI mucosa. Other causes ofhypocalcemia are vitamin D deficiency, hlpoparathyroidism,pancreatitis, rhabdomyolysis, severe hypomagnesemia, multiple citrated blood transfusions,

and d gs (antineoplastic agents, antimicrobials, agents used to treat hryercalcemia). Cfuonichypocalcemia can be asymptomatic. Clinical manifestations are paresthesias of the lips and

extr-emities due to increased excitability ofnerv€s, tetany, cramps, and abdominal pain due tospasm ofskeletal muscle, and convulsions.

\ote: Chvostek's and Trousseau's signs are seen in hlrpocalcemia. Chvostek's is twitching ofthe facial muscles as a result of tapping over the facial nerve in the preauricular area, and

Trousseau's sign is carpopedal spasm due to occlusion of the brachial artery when a bloodpressure cuff is applied above systolic prcssure for 3 minutes.

Hlpercalcemia is an abnormally high level ofcalcium in the blood, usually more than 10.5

mg,dL. The most common causes ofhypercalcemia are hlperparathyroidism and cancer.

Ilnemonic for symptoms of hypercalcemia:. Stones: renal calculi. Bon€s: bone destruction. Moans: confusion, lethargy, fatigue, weakness. Abdominal groans: abdominal pain, constipation, polyuria, and polydipsia

1. Renal failure with oliguria is the most common cause oftrue hyperkalemia (roo

much potassium in the blood). Sorne signs and symptoms include nausea, vomiting,diarrhea, and ventricular fibrillation leading to cardiac arrest.

2. Usually the fi$t sign ofhypokalemia is skeletal muscle weakness or cramping.3. The major extracellular cation is sodium.4. The major intracellular cation is potassium.

\

. Duration

. Origin

. Color

. Size and location to vital structures

126Coplrighr O 20ll-2012 - Dental Decl!

. After one minute ofCPR

. After two minutes of CPR

. After three minutes of CPR

. Immediately when an adult is found to be unresponsive

127

Coplright O 201 l-2012 - Dental Decks

Treatment ofchoice; should be used whenit crn be safely be done without sacrilicing

Creating a surgical window in thewall ofthe cyst, evacuating lhecontents ofthe cyst; and main-taining continuity between thecyst and the oral cavity

When etrucleatior would damage adjacentsttuctules

Ifcyst is not totally obliteBted afiermarsupialization heals

Marsupialization is done first.Aftcr initial healing secondaryenucleation may be undertakenwithout injury to adjacentstrucfures

After enucleation a curette or buris used to rcmove I to 2 cm ofbone around the entire peripheryof the cystic cavity

. When remo\ring an odontogenickeratoc'st

. Any cyst that recws after what wasdeemed thorough Emoval

. Notesl:l. Marsupialization, decompiession, and the Partsch operation all refer to creating a surgi-cal window in thc wall ofthe cyst. The cyst is uncovered or "deroofed" and the cystic lin-ing made continuous with the oral cavity or sunounding structures. The cyst sac is opened

and emptied.2. Cysts and cysFlike lesions can be classificd as fissural or odo[togenic. Odontogenic ker-atocysts have a higher rate ofrecurrence than do fissural and cysts ofodontogenic inflam-matorv onsln.

*** For an infant or child victim the EMS should be activated after I minute or 5 cvcles ofCPRCardiopulmonary R€suscitation:

-{ = Airway. Place victim flat on his/her back on a hard surface.. Shake victim at the shoulde$ and shout "are you okay?". If no respons€, call emergency medical system - 911 then,. Head-tilt/chin-lift: open victim's airway by tilting their head back with one hand whileliliing up their chin with your other hand.

B = Breathing. Position your cheek close to victim's nose and mouth, look toward victim's chest, and. Look, listen, and feel for breathing (5-10 seconds). Ifnot breathing, pinch victim's nose closed and give 2 full breaths into victim's mouth. Ifbreaths won't go in, reposition head and try again to give breaths. Ifstill blocked, per-

forrn abdominal thrusls (Heimlich maneuver)

C = Circulation. Check for carotid pulse by feeling for 5- 10 seconds at side of victim's neck.. lfthere is a pulse but victim is not breathing, give rescu€ breathing at rate ofl breathevery 5-6 seconds or l0-12 breaths p€r minute.If there is no pulse, begin chest compressions as follows:

- Place heel ofone hand on mid-position of victim's stemum. With your other hand di-rectly on top offirst hand, depress stemum L5 to 2 inches.

- Perform 30 compressions to every 2 bre ths (rute ofcompressions: 100/min).

- Check lor a pulse after the fiISt minute and every few minutes thereafter.*** Continue uninterrupted until advanced life support is available.

. Vascular

. Leukocytic

. Platelet

. Coagulation

129Coplright O 20l l-2012 - Dqtal Declr

. Once every 3 seconds

. Once every 5 seconds

. Once every 8 seconds

. Once every 10 seconds

'| 30

Coplrighr O 201 I ,2012 - Dental D€cks

When a chlld or infant has a putse but is breathtess,what is the recommended rate ofr€scue breathlng?

.\

There are three phases ofhemostasis:l Vascular phase

. Vasoconstriction

. Begins immediately after injury2. Platelet phase

. Platelets and vessel walls become sticky

. Mechanical plug ofplatelets seals offopenings ofcut vessels

. Begins seconds after injury3. Coagulation phas€

. Blood lost into surrounding area coagulates through extrinsic and common pathways

. Blood in vessels in area ofinjury coagulates through intrinsic and common pathways

. Slower than other phases

Important: If a patient is taking aspirin, anticoagulants, broad-spectrum antibiotics, alcoholor anticancer medications you should be prepared to take special measures in order to con-trol the bleeding. Note: Patients with specific systemic diseases will also have a prolongedbleeding time. These include nonalcoholic liver disease, hepatitis, cinhosis, and hypertension.

Five means ofobtaining wound hemostasis:

L By assisting natural hemostatic mechanisms -usually

accomplished by placing a

cotton sponge with pressure on bleeding vessels or the use ofa hemostat directly on thelessel.2. By the use of heat on the cut vessels (called thermal coagulation).i. By suture ligation ofthe vessel.1. By the placement ofa pressure dressing over the wound most bleeding fiom oral sur-gery can be controlled this way.5. By using vasoconstrictive substances (epinephrine) in local anesthetics

* When an adult has a pulse but is breathless, the recommended rate ol rescue breathing is

once every 5-6 seconds (l0-I2 breqths/minute).* A victim rvhose heart and breathing have stopped has the best chance for survival if emer-gency medical services are activated and CPR is begun within four minutes.* 5-10 seconds is used to assess the pulse. The brachial pulse is assessed in infants, whereas

rhe carotid pulse should be assessed in children and adults.

" The best indicator ofeffective ventilation is seeing the chest rise when delivering breaths.* lfchest compressions are interrupted, the blood flow and blood pressure will drop to zero.* -{r least I sec,breath is the length of time recommended to deliver each breath to an adultr lctlm.* Time is not as critical with the new guidelines conceming the length of time recommended

to deliver each breath to an infant or child. Now it is imoortant to deliver breaths that make

the r.ictim's chest rise.

Rescue breathin& victim has ap1lse, give breath €v€ry:

In lhe cenrcrofthebreast bone, betweenthe nipples

In the cantcr of theb.east bone, hetweenthe nipples

One finger width belowthe nipple line

Compressions arc preformedwi&:

Heal of I hand, secondhand on top

About l/3 to l/2 the d@th ofthe chest

. Class I

. Class 2

. Class 3

. Class 4

. Class 5

13.t

Cop)righr O 2011-2012 - Dental Deks

. Chewing gum

. Cigarette

. Tongue

. Hard candy

132Coplright C20ll-2012 - Dental D€cks

What is the most frequent cause of airw|yobstruction in an unconscious person?

The ASA classification was first established in 1940 for the purpose of statistical studiesand hospital records. It is useful for both outcome comparisons and as a convenient means

of communicating the physical status of a patient among anesthesiologists. The fiveclasses. as last modified in 1961. are:

Class I - Healthy patient, no medical problems

Class 2 - Mild systemic disease

Class 3 - Severe systemic disease, but not incapacitating

Class 4 - Severe systemic disease that is a constant threat to life

Class 5 - Moribund, not expected to live 24 hours regardless ofoperation

*** An organ donor is usually designated as a class 6

The first step when initiating CPR is to establish unresponsiveness (shake and shout - "Are you

OK'). Then:

CALL BLOW

catt 9l Itt ]lt,

utr G]t,GlltttlltII||l

am r:al|t|nl

ta]I|ar ulrlrr rtl G:mt Itrtt !!r3r

;Lllrtllt lt:lrtt|lllltat Il:rftrrtal|ftt

Slt rtrrr tll llll[tltt ta rrr'l lllll rtltllllltl

Important points to remember in CPR:. The first maneuver the rescuer should use to open the airway in an otherwise uninjured patient

is the head tilt with chin lift. If eforts are effective, the pupils will constrict. Iftoo much pressurc is incorrectly applied directly over the xyphoid process, the liver maybe injured

Remember, you should stop CPR only under the following conditions:.lfanother trained person takes over CPR lbr you. lf EMS personnel arrive and take over care of the victim. lfyou are exhausted and unable to continue. [f the scene becomes unsafe

PUMP

.IMR

.IGR

.ITR

.INR

133

Copyright O 20ll-2012 - Denral Decks

. Applying the blood pressure cufftoo tightly

. Applying the blood pressure cuff too loosely

. Overinflating the blood pressure cuff

. Underinflating the blood pressure cuff

. The use oftoo large or too small cuffs

t34Cop),righr O 20ll-2012 - Dental Decks

The accuracy ofthe Prothrombin Time (PT) is known to be very system-dependent. TheWorld Health Organization has addressed this system variability problem by (l) the es-tablishment of primary and secondary intemational reference preparations of thrombo-plastin and (2) the development ofa statistical model for the calibration olthromboplastinsto dedve the International Sensitivity Index (ISI) and the lNR.

INR (International normalized ratio):. Developed to improve consistency oforal anticoagulant therapy. Converts the PT ratio to a value that would have been obtained usins a standard PTmethod. INR is calculated as (PTou1i"rr1 / PTrror-u1)rsl

*** (lSI is the intemational sensitivity index assigned to the test system). The recommended therapeutic ranges for standard oral anticoagulant therapy andhigh-dose therapy, respectively, are INR values of2.0-3.0 and 2.5-3.5.

Other tests used to measure a patient's clotting mechanisms:. Prothrombin time (PT): the nonnal range is I I to 13.5 seconds. To be a good can-didate for surgery the PT time should be within 5-7 seconds ofthe control sample. Partiaf Thromboplastin Time (PTT)t detects coagulation defects of the intrinsicsystem. Basic test for hemophilia. Normal value is 25-36 seconds.. Bf eeding time (Iry method): nomal value is less than 9 minutes. Platelet counts: normal value is 150,000 - 450,000 per I cu mm ofblood. The min-imal platelet count for oral surgery is 50,000

Important: Perhaps the single most important consideration in ruling out hemorrhagicdisorder is historv.

Important: Use ofthe wrong cuffsize can result in enoneous readings. A normal adult bloodpressure cuff placed on an obese patient's arm will produce falsely elevated readings. Thissame cuffapplied to the very thin arm ofa child will produce falsely low readings.

. Before performing a blood pressure reading, the patient should be comfortably seated withthe back and arm supported, the legs uncrossed, and the upper arm at the level ofthe dghtatrium.. Proper cuff size selection is critical to accurate measurement. The bladder length andwidth of the cuff should be 80% and 40%, respectively, of the arm circumf'erence. Bloodpressure measurement erors are generally worse in cuffs that are too small vs those thatare too big.. Blood pressure measurement in sitting and recumbent positions is acceptable. The dias-

tolic blood pressure can be expected to be about 5 mm Hg higher in the sitting position.. A difference in blood pressure between the two arms can be expected in about 20% ofpatients. The higher value should be the one used in treatment decisions.. When measuring blood pressure, the cuffshould be inflated to 30 mm Hg above the pointat which the radial pulse disappears. The sphygmomanometer pressure should then be re-

duced at 2 to 3 mn/second. Two readings should be performed at least one minute apart.

140-159

. Xenogenic bone

. Allogenic bone

. Autogenous bone

. Alloplastic bone

135

Cop)right @ 20ll-201? Denral Decks

The most commonly used allogeneic bone is:

. Freeze-dried

. Demineralized freeze-dried bone

. Fresh frozen

136

Coplright O2011,2012 - Denlal Decks

An autogenous bone graft is the transplantation ofbone from one site to another site withinthe same person. These grafts may be ofcancellous, cortical or a combination ofcortical andcancellous bone. Autogenous bone is the only gaft that possesses all ofthe lollowing prop-erties, osteoinduction, osteoconduction, and osteogenesis. Additionally, tbere are no in-munogenic complications. The dom sides to autogmft are the finite quantity available anddonor site morbidiryTypes of autog€nous bone grafts:

. Cortical grafts: advantages are due to its structural capabilities, Also has a higher con-centration of BMP (bone morphogenic protein). The dtsadvantages are due to the lamellararchitecture. Common donor sites: iliac crest, ribs, anterior cortex ofthe chin, lateral cor-tex ofthe rumus/extemal oblique ridge.. Cancellous grafts: advantages are mostly based on its rich cellular capability. The mostabundant supply can be harvested from the anterior or posterior iliac crest. The only disad-vantage arises from th€ fact that they do not possess any macroscopic structuml integrity.Thus the graft cannot be rigidly fixed and will deform, migrate, or resorb ilplaced undertension or compressive functional forces.

1. The bone manow for grafting defects in the mandible and ma"rilla is generally ob-

^\ot€*, tained from the iliac cr€st (anterior and posterloy'. Also used for ridge augmen-... ..-.. li tation.

of the cytokine family of growth factors, which occurs in the organic portion ofbone called the bone malrix.3. A costochondral rib graft may be employed with the cartilaginous portion sim-ulating the TMJ and condyle. When used for ridge augmentation there is a great

deal ofshrinkage.4. Bone plates, biphasic pins, titanium m€sh, and intraosseous wires are used inthe fixation ofbone grafts. Sutues are not generally used.

Allogeneic bone is nonvital, osseous tissue harvested from one individual and transfened toanother of the same species. Three forms of allogeneic bone include: fresh frozen, freeze-dried, and demineralized freeze-dried bone. Fresh frozen bone, howevel is rarely used dueto the concem related to transmission ofdisease.

. Freeze-dried bon€ is osteoconductive, howevel it has no osteogenic or osteoinductive ca-pabilities. Freeze-dried allogeneic grafts are usually placed in conjunction with autogenousgrafts.. Demineralized freeze-dried allogeneic bone lacks mechanical shength, but has osteo-conductive and osteoinductive capabilities. Demineralizing the freeze-dried bone exposes

the bone morphogenetic proteins which has been shown to induce bone formation.

The three processes by which bone can be repaired or regenerat€d are:. Ost€ogenesis (osteogenic potentia, is the formation of new bone from osteoprogenitorcells. Spontaneous osteogenesis is the formation ofnew bone from osteoprogenitor cellsin a wound. Transplanted osteogenesis is formation of new bone from osteoprogenitorcells placed into the wound from a distant site. Osteogenic grafts include the advantages ofosteoinductive and osteoconductive grafts, in addition to the advantages of transplantingfully differentiated osteocompetent cells that will immediately produce new bone.. Osteoconduction is the formation ofnew bone from host-derived or fansplanted osteo-progenitor cells along a biologic or alloplastic framework, such as along the fibrin clot intooth extraction or along a hydroxyapatite block. Osteoconductive grafts provide only a

passive framework or scaffolding. The grafted material therefore does not have the abilityto actually produce bone. This type of graft simply conducts bone-forming cells from the

host bed into and around the scaffolding.. Ost€oinduction refers to new bone formation fiom the differentiation of osteoprogenitorcells, derived liom primitive mesench],rnal cells, into s€cretory osteoblasts. Such grafts helpnroduce the cells that are necessary to Droduce new bone.

Which of the following refers to a horizontalosteotomy of the anterlor mandible?

. Blepharoplasty

. Genioplasty

. Cervicofacial rhytidectomy

. Rhinoplasty

137

Coptrighr e 201i '2012 , DentalDecks

. Autogaft

. Allograft

. Xenograft

. Isograft

Tissue removed from an animal donor and surgically trans-planted to a human

Tissue surgically removed fiom one area of a person's body,such as the iliac crest, and transplanted in another site on thesame person

Tissue surgically transplanted from an individual of the same

species who is genetically related to the recipient

Tissue surgically transplanted from one individual to a geneti-cally non-identical individual ofthe same species

t38Coplri8hr O 2011,2012, Dfrral Declr

Cenioplasty refers to a horizontal osteotomy of the anterior mandible. Chin implant refers toeither an alloplastic implant or an autogenous implant. Alloplastic implants and sliding ge-nioplasty represent the two currently accepted methods ofchin augmentation,

A sliding genioplasty involves removing a horseshoe shaped piece ofthe chin bone and slid-ing it either backwards or forwards, finally fixing it in place using titanium scr€ws. The mostcommon complication after genioplasty surgery is a neurosensory disturbance, followed byhematoma and infection.

Alloplastic augmentation can also be considered for the treatment ofa genial deficiency. Thematerials most commonly used include high-density polyethylene, hard tissue replacamentpolymer, polyamide mesh, solid medical-grade silicone rubber, hydroxyapatite, and Gore-Tex.

Problems that are frequently encountered when using alloplastic materials for the treatmentofa genial deficiency:

l. Migration from the position in which they were placed at the time of sugery2. Erosion ofthe chin prominence contiguous with the implant3. Unpleasant sensation in the implant region when exposed to cold temperatwes

Remember: Alloplastic grafts are inert, man-made synthetic materials. The modem artificialjoint replacement procedures use metal alloplastic grafts. For bone replacement a man-made

material that mimics natural bone is used. Most often this is a form of calcium ohosohate(i.e., ticalcium phosphate, calcium cqrbo qte, ot hydroxyLpatite).

Classification ofgralts (or impla ts):. Autogenous grafts (also called autografts) are composed of tissues taken from the same in-dividual. Most frequeltly used in oral surgery.. Allogetreic grafts fa ko called allografts) are composed oftissues taken from an individual ofthe same species who is not genetically related to thc patient fi/ sually cadaver bone).. lsogeneic grafts (also called isografts) are composed oftissues taken from an individual ofthesame species who is getretically related to the recipient.. xenogeneic implants (also called xenografls or heterografls) are composed oftissues taken

from a donor ofanother species, for example, animal bone grafted to man. Rarely used in oralsurgery.

Note: Rejection ofthe graft is most common when allografts or xenografts ofbone and cartilageare used in oral surgery Autogenous grafts, although frequently presenting surgical and technicalproblems, do not as a rule involve rejection (or immunological complications).

The ideal graft should:. Be replaced by the host bone. Withstand mechanical forces. Produce no immunologlc rcsponse (or lejection). Actively assist osteogenic (bone-forming) processes of the host. The greatest osteogenic po-

tential occurs with an autogenous cancellous graft and hemopoietic marrow.

. Original

. Natural

. Synthetic

. Genuine

. Fibro-osseous integration

. Osseointegation

. Biointegmtion

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Coplriglu O 2011,2012 - Dental Dects

14D

CopFight O 20l l-2012 - Detrtal D€cks

The term alloplastic is synonymous with synthetic, This indicates that the material is pro-duced from inorganic sources and contains no animal or human components. Alloplasticmaterials offer a prepackaged solution to common reconstructive surgical problems with-out the need for autogenous grafting and donor site morbidity.

For bone replacement a man-made material that mimics natural bone is used. Most oftenhydroxyapatite (HA) is used for augmentation of the mandible. Hydroxyapatite is adense, biocompatible material that can be produced synthetically or obtained from biologicsources such as coral. The granular or particle form is most commonly used for alveo-lar ridge augmentation. Note: When placed in a subperiosteal environment, HA bondsboth physically and chemically to the bone.

Some advantages and disadvantages of restructuring an atrophic ridge with hydroxya-patite granules:

. Advantages:- It is a simple surgical technique suitable as an office procedure- No donor site is required to obtain autogenous bone graft material- Hydroxyapatite is totally biocompatible and nonresorbable

. Disadvantages:- Migration ofthe hydroxyapatite granules

- Poor ridge form /inadequate height)- Abnormal color under the mucosa- Mental nerve neuropathy - usually occurs from excessive augmentation- Cannot participate in phase I osteogenesis since no viable osteogenic cells are

Dresent

The bone-implant interfac€:Fibro-osseous integration

. Connective tissue-encapsulated implant within bone

. \ot seen often with newer materials

Osseointegration. .A direct structural and functional connection between living bone and the surfaces of

a load-carrying implant without soft-tissue. Yields most predictable long{erm stability. Several important factors involved: materials, surface characteristics, bone, timing

Biointegration. lmplant interface that is achieved with bioactive materials such as hydroxyapatite (I1,4)

or bioglass that bond directly to bone.. HA coated implants appear to develop bone faster than do non-coated implants but, after

a yeal there is little difference between coated and non-coated.

lmportant principles for success of dental implants: primary stability, amount of bone,

anatomic structures (i.e., adjqce t nqtural teeth, maxillary sinus, nasql cqvit),, inferior alveo-

lur canal).

- . , - 1. To ensure the development ofkeratinized tissue around a dental implant the best

,,Note*'i time to augment the soft tissue is Stage ll surgery...6-: - 2. Guided tissue regeneration is a surgical procedure used to eliminate a bony de-

fect around a dental implant. This process decreases the connective tissue growth

while increasing the groMh of bone in the defect.3. A gentle surgical technique requires that you do not heat bon€ above 47oC.

Above this temperature, bone tissue damage occws,

Which of the following is found between th€ bone rndimplant of an endosseous dental imphnt?

. Periodontal ligament

. Peri-implant ligarnent

. Epithelial ligament

. A bone-implant interface

141

coptrighr O 201 l'2012 - Dental Decks

. Hlpertension

. Patient over 70 years ofage

. Smoking

. Alcohol

. Post by-pass surgical patient

112Coplright O 20l l-2012 - Dental Decls

Which of the following faclors would have the grertestnegative influence on a dental implantrs success?

The histologic definition of osseointegration is best described by the following: The directconnection between living bone and a load-bearing endosseous implant at the light micro-scopic level. Only endosseous and transosseous implants are considered true osseointegratedimplants.

Criteria for success ofa dental implant:. Clinical immobility under load-bearing conditions. Symptom free. Minimal loss of crestal bone. No peri-implant radiolucency. Success rate of 857o after 5 years and 80o/o after l0 years

... - 1.In order for an implant to be successful you need adequate transfer offorce and

Noteal biocompatibility..-;:;;.1,,' 2.Handpieces for preparation of dental implant receptor sites are lowspeed/high

torque.3. In the event an endosseous dental implant is mobile, the proper procedure is toremove the failed implant, debride the socket, and consider placing a bone graftwith a resorbable membrane.4. You need a minimum of10 mm ofbone height to place an endosseous (rootJbrm)

dental implant.5. The minimum required distance lrom the apex ofa mandibular posterior implantto the superior asp€ct ofthe inferior alveolar canal is 2 mm.6. Titanium and titanium alloy are the most common materials used today for two-stage endosseous imPlants.

*** Because smoking affects the healing of bone and overlying tissue, it should be con-sidered a relative contraindication to implant placcment.

Any toothless arca can be considered for dental implants. Determining whether implarrts are

an option and the type of implants to use include: the patient's rcquirements and expecta-tions. the amount ofadditional work needed (i.e., bone groftlng), the dentist's skill level, and

the long-term prognosis.

Some indications for implant placement:. Fixed restoration of single or multiple teeth in a partially edentulous jaw. Retention of a removable prosthesis in a partially edentulous jaw. Retention of a prosthesis in a completely edentulous jaw. Rctcntion ofa fixed prosthesis in a completely edentulous maxilla or mandible

Important: In patients with uncontrollcd systemic diseases such as diabetes, immuno-compromised patients, and patients with blceding disordcrs, implant placemcnt should be

considered with extreme caution.

Remember:l. Thc highest failure rate is seen in the posterior maxilla where the bone is thc soft-est (D4) quality.2. Mobility of the implant is regarded as the most common sign of implant failure.3. A dental implant supported prosthesis should fit passively on thc dental implant.4. The minimum space required for a 4.0 mm diameter implant is 7.0 mm - 1.5 mmon each side ofthe implant plus the diameter olthe implant5. The maximum amount of taper to allow for proper draw on an overdenture attach-ment such as an "O" dng is l5 degrees.

. Blade form implants

. Subperiosteal implants

. Transosseous implants

. Root form implants

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. Cephalexin

. Amoxicillin

. Clarithromycin

. Erythromycin

. Azitfuomycin

. Clindamycin

144CoDright O 20l l-2012 - Denul Deck

Dental implants are divided into three categories based on their relationship to the oral tis-sues:

1. Endosseous implants are implants that are surgically inserted into the jawbone. Thcy arc

thc most frequently used implants today. They are further subdivided into root form and blade(plate) form.2. Subperiosteal implants are framcworks specifically fabricated to fit on top of supporting

areas in the mandible or maxilla under the mucoperiosteum. This type of implant "rides on"bone.3.Transosseous implants are implants that are similar to endosseous implants in that they are

inserted into thejawbone. However, these implants actually penetrate the entirejaw so that they

actually emerge opposite the cntry site, usually at the bottom ofthe chin. Note: Their primaryindication is in the very atrophic mandible where root form implants may further compromise

the strength ofthe jaw.

Remember: Osseointegrated implants are anchorcd directly to living bone. This detemlination

is rnadc by radiographic and light microscopic analysis. Only endosseous and transosseous im-plants are considered true osseointegrated implants.

. Root form implants: cylindrical in shape, can be smooth, thrcaded, perforated, and solid or hol-

lo$, vented, coated, or tcxtured. They are available in various widths (3.2 mm to 7 nm) and

lenglhs (8 mm to 18rufi/. Typically made of titanium. Treatment with root form implants is di-vided into three phases; surgical, healing and prosthetic. Note: These implants are the most pop-

ular,. Blade implants folso known as plate form implants): arc fTatter in appearance and are utilizedrvhen there is insufficient width ofbone but adequate depth is present. They are available in sin-gle and two stage forms. Typically made oftitanium as well.

Two basic types ofimplant placement:

l. Submerged: requires a second surgical prccedlre (two'stage) to uncover the fixturc2. Nonsubmerged: does not require a sccond surgical proccdurc (one-slage)

In adults, the new antibiotic regime recommended for the prevention of infective endo-carditis is:

. Amoxicillin: 2.0 grams, 30-60 minutes hour prior to the procedwe (bur 500mg tqblets)

For those patients allergic to penicillin,. Clindamycin: 600 mg, 30-60 minutes to the procedure (bur 150 mg tablets)

The guidelines for children are:. Amoxicillin: 50 mg,&g, 30-60 minutes prior to the procedure

For those patients allergic to penrcillin,. Clindamycin: 20 mglkg, 30-60 minutes prior to the procedure

These new guidelines involve a number of changes from the previous set ofguidelines:. Only one antibiotic dosage is required. The recommended antibiotic for penicillin-allergic patients is clindamycin not eryth-romycin. Prophylaxis is no longer required for many dental procedures

Alternatives for patients who are allergic to penicillin and who cannot take clin-damycin include cephalexin, clarithromycin, and azithromycin.

. Buccal space

. Canine space

. Infratemporal space

. Submaxillary space

l,lsCoplright O 201 I -20 l2 - Dental Decks

ORALSI'RGERY&PAINCONTROL ., MiS

. Surgically extract the unerupted second molar

. Uncover the crown and keep it exposed

. Prescribe an anti-inflammatory medication and schedule a follow-up appointment insix months

. No treatment is necessary at this time

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Remember: The mylohyoid muscle, stretching across the floor ofthe mouth. divides the submandibularspace into a portion above this muscle /srblingual space) and aportion below fru6lr4rillary space).

Spme Usual Source of lnfection

Marillary Sp.ces

Canines space Canines

Buccal Spacc Maxillary molars, premolars

lnfratemporal space Maxillary tbird mola$

Maldibular SDaces

Buccal spac€ Mandibular molars, premolam

Subm€ntal spsce Mandibular incisors

Submandibular space Mandibular molars, premolars

Sublingual space Mandibular molars, premolats

Submaxillary space Mandibular molars

Ptqygomandibnlar space Mandibular molars, premolars

Masseteric space Mandibular third molars

Temporal space Other spaces (i fratemporal. masseteric andpterygomandibular)

Masticator space Other sp ces (pterygomandibular and temponl

,\..oter Peniciilin V is often the preferred drug to heat odontogenic infections. It is effective against Shep-

tococci and oral anaerobcs. For penicillin-allergic patients, clindamycin or clarithromycin can be used

Narrow specmlm antibiotics are preferred over broad-spectrum antibiotics and bacteriocidal ag€nts are

preferred over bactcriostatic agents.

Dentigerous cysts are those associated with the crowns ofunerupted teeth. Some litera-ture refers to these cysts as "follicular" or "primordial" cysts. Note: They are proba-

bly the result ofdegenerative changes in the reduced enamel epithelium.

Remember: Ifcysts form when a tooth is erupting, they are called eruption cysts. These

cysts interfere with normal eruption ofthe teeth. Eruption cysts are more commonly foundin the child and young adult, and may be associated with any tooth. If treatment is indi-cated, simDle incision or "deroofing" is all that is needed.

Dentigerous cyst

Eruption cyst

. Buccal

. Canine

. Submandibular

. Masticator

. Vestibular

. Orally

. Axillary

. Rectally

. Aurally

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14CopriShi O 201 1,2012 - Dental D€cls

Fascial spaces: layers offascia "create" potential fascial spaccs (they are called potential because inhealth there is no space/; all are filled by loose areolar connective tissue. The hyoid bone is the mostimportant anatomic structure in the neck that limits thc spread of infection. Infections or other inflam-matory conditions spread by the path ofleast resistance to rcach the fascial spaces. The most commonspace involved is the vestibular space.

The spaces directly adjacent to the origin ofthe odontogenic infections are the primary fascial spaces.

Infections spread from the origin into thcsc spaces, which are: buccal, canine, sublingual, submandibu-

lar. submental and vestibular.Note: Canine space infections and deep temporal spacc infcctions can result in cavemous sinus thtom-bosis via the ophthalmic veins.

Fascial spaces that become involved following sproad of infection to the primary spaces are the sec-

ondary fascial spaces: The secondary spaces are: pterygomandibular, infratl-mporal, masseteric, lateralpharyngcal, Superflcial and deep temporal, retropharlngeal, masticator and prevertebral.

Note: Lateral pharyngeal infections can traverse the rehopharyngeal and prcvertebral spaces and spread

into the mediastinum.

Factors that influencc the spread ofodontogenic infectioni (l) Thickncss ofbone adjacent to the of-fending tooth (2) Position ofmuscle attachment in relation to root tip (3) Virulcnce ofthe organism and

(,1) Status ofpatient's immune system

. l. The masticator space contains the contents ofthe pterygomandibular space and is con-

\otes, tinuous with the lempoml space-

. : 2.Thc most delinite clinical sign indicating extension ofan odontogenic infection into the

'' -'r'- masticator space is trismus. Trismus is difficulty in opening the mouth due to a tonic spasm

of thc muscles ofmastication.3. Trismus may also result from passing the needlc through the medial pterygoid muscle

during an inferior alveolar nerve block.4. other s),rnptoms offascial space infection include pain, dysphagia, and dysphonia.5. The submandibular space is continuous with the latcral pharyngeal space. The mylohy-oid muscle divides this space into a portion above this muscle (suhlingual space ) and a

ponron below (s u bmaxillary sp ace).

General considerations when ch€cking vital signs:. The patient should not have had alcohol, tobacco, caffeine, or pedormed vigorous exer-

cise u ithin 30 minutes of the exam. tdeally the patient should be sitting with feet on the floor and their back supported The

eramination room should be quiet and the patient comfortable. History of hypertension, slow or rapid pulse, and current medications should always be

obrained

Routine Vital Signs:. Blood pressure: normal 120/80. Pulse rate: normal 72. Respiralion mte: normal 15

. Temperature can be measured in several different ways:

- Oral with a glass, paper, or electronic thermometer ft?ozral 98.C F / 3TC)- Arilfary with a glass or elechonic thermometer (normal 97.f F / 36.3'C)- Rectaf or "core" with a glass or electronic thermometer (rornal 99.6"F / j7.7"C)

- Aurzl (the eqr) Nith an electronic thermometer (normal99.6"F / 37.7C)*** For every l"C rise in body temperature, there is a corresponding 9-10 beats/min in-

crease in the patient's heart rate.

\ote: Abnormalities ofvital signs are often clu€s to diseases, the alterations in vital signs are

used to evaluate a patient's progress.

Five najor arcas to be discussed when taking a patient history: l. Chief complaint 2. His-

tory of present illness 3. Speciflrc drug allergies 4. Review of systems (heart, Iivet kidnev,

brain, etc.) 5. Nature of systems.

Important: In complicated cases, don't be hesitant to call patient's physician, previous den-

tists. or other health Drofessionals.

. Periosteum

. Soft tissues

. Cortical bone

. Cancellous bone

l,l9Coplright O 20ll 2012 - DentalDecks

. Prosthetic heart valve

. Complex cyanotic congenital heart disease

. Prior coronary anery blpass grafi

. Surgically constructed systemic pulmonary shunts or conduits

. Mitral valve prolapse with regurgitations and./or thickened leaflets

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Osteomyelitis is a relatively rare inflammatory process within the medullary 6rareculor) porliorrof bone that involves the marow spaces. Osteomyelitis is generally classified into two majorgroups; suppurative and non-suppurative. Suppurative osteomyelitis is classified into acute,chronic, or infantilc osteomyelitis. Non-suppurative osteomyclitis is classified into chronic scle-rosing (Jbcal and dillitse), Garre's osteomyelitis, and actinomycotic osteomyelitis.

Infection, inflammation, and ischemia are the mechanisms by which osteomyelitis spreads. Themost common initiating causes are odontogenic infection and trauma. The infection usually beginsin thc medullary space involving the cancellous bone. Evcntually thc cortical bone, periosteum,

and soft tissues become involved.

Note: Garrc's ostcomyelitis is characterized by localized, hard, nontender, bony swclling of thelateral and inferior aspects ofthe mandible. lt is primarily present in children and young adults and

is usually associated with carious molar and low-grade infection.

Importanti Acute osteomyelitis occurs more frequently in the mandible as opposed to thc max-illa. The primary reason for this is that the blood supply to the maxilla is mucb richer and is de-

rived from a number of different arteries, while the mandible tends to draw its primary supplyfrom the inferior alveolar artcry Thc dcnsc ovcrlying cortical bonc ofthe mandible prevents pen-

etration ofperiosteal blood vessels, thus the mandibular cancellous bone is more likely to become

ischemic and therelbrc infected. lmportant point: a reduced blood supply will predispose boneto osteomyelitis,

The most frequently found bacteria in patients with osteomyelitis ofthejaws include: Gram-posi-rire cocci /1.e., Streptococci, Staphylococcus aurers), anaerobic cocci and gram-negative rods.

The treatment ofostcornyelitis ofthejaws usually includes both surgical intervention and medicalmanagemcnt ofthe patient, as well, as sensitivity tcsting. Medical management involvcs adminis-rralion ofempirical antibiotics, performing Gran stain, and the administration ofculture-guided an-

tibiotics. Surgical treatment includes removal of loose tceth and foreign bodies; sequestrectomy:

debridement; decortication: rcsection; and reconstruction, if necessary.

Endocarditis Prophylaxis Not Recornmended

Isolated secundum atrial septal defect

Surgical repair ofatrial septal defect, ventricular septal

defect. or Datent ductus art€riosusSurgicall) construcled systemic pulmonaryshun6 or conduits

Prior coronary artery blTass graftComplex cyanotic congenital hean disease

Physiologic, functional, or innocent hean murmurs

\tost other coneenital caadiac malformations Previous Kawasaki disease without valwlar dysfunction

Previous rheumatic fever without vah'ular dysfunction

Cardiac oacemakers and imDlanted defibrillators

Mitral valve prolapsed with regugitationandor thickened leafl ets

Why is a conventioarl handplece thrt expels forced air.i. . . controindicated when performing dentoalveolar surgery?

. Too much bone will be removed

. These handpieces can cause tissue emphysema or al air embolus which can be fatal

. These handpieces are not high-powered enough to remove bone

. All ofthe above

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. E.K.G

.MRI

. Panorex

r Biopsy

't52Coplright O 20ll-2012 - Dental Dects

Very important: Most high-speed tubine drills used in routine restorative dentistry are to-tally unacc€ptable for oral surgery. The air exhausted ftom these drills goes into the woundand may be forced deeper into tissue planes and produce tissue emphysema, a potentiallydangerous situation.

Rongeur forceps are the most commonly used instrum€nts for removing bone. However,the technique that most oral surgeons use when removing bone is the bur and handpiece.

lrrigation of the surgical wound during and after the cutting of bone cannot be emphasizedenough. Copious amounts ofcoolant spray are crucial in minimizing osseous necrosis caused

by heat generated from the bur. Irrigation serves also to cleanse the crypt and areas beneaththe flap ofbony debris, tooth fragments, and blood. Distilled water is not used for irrigationbecause it is a hypotonic solution and will enter cells down the osmotic gradient causing celllysis and rapid death ofbone cells.

Note: An acute infected tissue emphysema is usually caused by the indiscreet use of:I . Air-pressure syringes: In drying out a root canal with a compressed air syringe, septicmaterial may be forced through the apical foramen into the cancellous portion ofthe alve-olar process and ultimat€ly out through the nutrient foramina into adjacent soft tissues, re-

sulting in formation ofa septic cellulitis and tissue emphysema.2. Atomizing spray bottles activated by compressed air: A similar condition can be in-duced by the use ofa compressed-air spray bottle for irrigation ofwounds, particularly inthe retromolar region. It is safer to use a hand-activated sytinge when irrigating wounds ordrying root canals since it is unlikely that a tissue emphysema would be produced underthese circumstances.

Routine Admission Tests

. A complete blood count that includes an evaluation ofthe hemoglobin and hemat-ocrit indices

. A total white blood cell count with a differential count

. A gross and microscopic urinalysis

*** Anyone scheduled for general anesthesia should have a chest x-ray and patients over40 years old should also have an E.K.G.

Factors to be considered in the decision to hospitalize a patient for an elective proce-dure:

. Medical problems compromising treatment (diabetes, hemophilia, etc.)

. Difficulty and extent of surgery

. Consideration ofthe individual patient (emotionally disturbed, handicopped, etc.)

. Cost of hospitalization (time and money)

. A culture for artibiotic sensitivity has been performed

. Localization ofthe infection

. A sinus tract is formed

. The patients fever has cleared up

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. Diamond excision

. V-Y advarcement

. Z-plasty

t54CoplriSht O2011,2012 - Dental Decks

Physiologically, it is at this time that nature has constructed a barrier around the abscess, walling it off fromthe circulation and making it possible to palpate th€ presence ofpurulent material within the abscess cavity(known a.t lluctuanc e ).

The important components in treatment ofodontogenic infection are:

. Determirling rhe severity ofinfection

. Dctermining whether the infection is at the cellulitis or abscess stage

. Evaluating the state ofthe patient's host defense mechanisms. Compromised host defenses include: severediabetes, alcoholism, malnutrition, uremia, leukemia, malignant tumors, lymphoma, o. someone on cancer

chemotheftpeutic or immunosuppressive agents.. Determine whether paticnt should bc treated by a general dentist or an oral surgcon. Criteria for referralto an oral surgeon include: rapidly progressive infection, difficulty i breathing or swallowing, fascial spaceinvolvement, elevated temperature P ,/r1'O, severe jaw trismrrs (< I0 mm), toxic appeannce, or compro-mised host defenses.. Treating the infection surgically. Removal ofthe source ofinf€ction and drainage ofpurulence.

- Methods ofdrainage ofodontogenic infcctions: endodontic ffeatment, €xtraction ofthe ollendingtooth or incision and drainage ofthe soft tissue.

. Support the patient m€dically: airway maintenanc€, rehydration, analgesia, nutrition, etc.

. Prescribe appropriate arltibiotics. Indications for the use ofantibiotics include: rapidly progressive swelling,difirse swclling, compromis€d host defenses, involvement of fascial spaces, severe pcricoronitis and os-

teomyelitis. Penicillin V is often thc prefencd drug. Ifthe patient is pcnicillin-allergic, use clindamycin.

Surgical principles ofincision and drainage:. Before incision. obtain fluid for culture. Incise the abscess in healthy skin or mucosa and in a cosmetically or functionally acceptable place, usingblunr disscction and thorough exploration ofthe involved space. Use one-way drains in intraoral abscesses; use through-and-through dminage in extraoral cases. Remove the dmin gradually from deep sites

.. L For odonfogenic infections, the most common organisms are aerobic gram-positive cocci,rNota*': anaerobic gram-positive cocci, and anaerobic gmm-negative rods.

2. Streptococcus species lwhich arc highly virulent a d aerobic) initiate lhe infectious proccss,

a cellullhs then occurs, followed by proliferation ofanacrobic organisms.

When a frenum is positioned in such a way as to interfere with the normal alignment ofteeth or results in pulling away ofthe gingiva from the tooth surface causing recession itis often removed using a surgical process known as a frenectomy.

Three surgical techniques used for a frenectomy:

. Diamond excision \ are effective when the mucosal and fibrous tissue band is rela-

. Zpfasty / tively narrow. These techniques relax the pull of the frenum.

. V-Y advancement is often preferred when the frenal attachment has a wide base.

This technique is good for Iengthening tissue and usually results in less scarring.

Note: Local anesthetic infilhation is usually sulficient for surgical treatment offrenal at-tachments. Care must be taken to avoid exc€ssive infiltration directly in the frenum area

since it may obscure the anatomy that must be visualized at the time ofexcision.

. transverse facial vein; pterygoid plexus ofveins, angular; inferior ophthalmic veins

. inferior alveolar, anterior superior alveolar arteries, descending palatine; greater palatinearteries

. supratrochlear; supraorbital veins, superficial temporal; lingual veins

. angular; inferior ophthalmic veins, transverse facial vein; pterygoid plexus ofveins

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Coplrighr O 2011,20!2 - Dental Decks

. Closed reduction

. Operculectomy

. AlveoloplasW

. GingivoplasV

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Cavemous sinus thrombosis is an uncommon but potentially lethal extension ofodontogenic infection.Valveless veins in the head and neck allow retrogmde flow ofinfection liom the face to the sinus. Theptcrygoid plexus ofveins and angular and ophthalmic veins may contributc to retrograde flowNote: Canine space infections and deep temporal space infections can result in cavemous sinus thrcm-bosis via the ophthalmic veins.

The first clinical signs ofcavemous thrombosis include vascular congestion in periorbital, scleral, andretinal veins. Other clinical signs include periorbital ed€ma, Woptosis (exophthalmos), thrombosis ofthe rctinal vein, ptosis, dilated pupils, absent comeal reflex, and supraorbital sensory deficits.

Important: The infection is life-threatening and requires prompt and agglessive treatment, consistingofeljmination ofthe source ofinfection, drainage, parenteral antibiotic therapy, and neurosurgical con-sultation.

Rem€mberi Cranial nerues lII,lY,Y (ophthalnic divisio of f), and VI pass through the cavemoussinus.

-{n alveoloplasty is the surgical preparation ofthe alveolar ridges (i.e., removing under-tuts d d sharp edges from areas such as the mylohyoid ridge) for the reception ofden-tures or shaping and smoothing the socket margins after extractions of teeth withsubsequent suturing to insure optimal healing.

The objectives of this recontouring should be to provide the best possible tissuecontour for prosthesis support, while maintaining as much bone and soft tissue as possi-ble.

Remember:I . In some cases, the bone is well-contoured for denture or partial denture constructionbut the soft tissues may interfere with the fit or function of the prosthesis. These softtissues areas include: the mandibular retromolar pad, the maxillary tuberosity, exces-sive alveolar ridge tissue, labial and lingual freni, or a condition called inflammatoryfibrous hyperplasia.2. A closed reduction is the closing of the space between fractured bone withoutcutting though the soft tissue or surrounding bone.3. A gingivoplasty is a surgical procedure to reshape the gingivae to create a normal,functional form.4. An operculectomy is the removal ofthe operculum, which is the flap oftissue overan unerupted or partially erupted tooth.

ORAL SURGERY & PAIN CONTROL Misc.

While there are many reasons for autotransplanting teeth, tooth loss as ares[lt ofdental caries is the most comrnon indication, especially when:

. Maxillary central incisors are involved

. Mandibular first molars are involved

. Mandibular canines are involved

. Maxillary third molars are involved

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ORAL SURGERY & PAIN CONTROL Misc.

All ofthe following are systemic contraindications to elective surgeryEXCEPT one. which one is the EXCEPZOM

. Blood dyscrasias (i.e., hemophilia, Ieukemia)

. Controlled diabetes mellitus

. Addison's disease or any steroid deficiency

. Fever ofunexplained origin

. Nephritis

. Any debilitating disease

. Cardiac disease

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Cop)righl Ol 201 l-?012 Dental Decks

Fimt molars erupt early and are often heavily restored. AutotransplNntation in this situation in-volves the removal ofathird molar which may then be transf€rred to the site ofan uucstorable firstmolar Other conditions in which tansplantation can be considered include tooth agenesis (especially

ofpremolors and lateral lrcrsols), traumatic tooth loss, atopic eruption ofcanines, root r€sorption,large endodontic lesions, cervical root fractures, localized juvenile periodontitis as well as otherpathologies.

Patient sel€ction is very important for the success of autotransplantation. Candidates must be ingood health, able to follow post-operative instructions, and available for follow-up visits. Theyshould also demonstrate an acceptable level oforal hygiene and be amenable to regular dental care.

Most importantly, the patients must have a suitable recipient site and donor tooth. Note: If surgeryis done on a diabetic patient antibiotic coverage should be considered particularly ifthe diabetes isnot well controlled or uncontrolled.

The most important criteria for success involving the recipient site is adequacy ofbone support.There must be sufficient alveolar bone support in all dimensions with adequate attached keratinizedtissue to allow for stabilization ofthe transplanted tooth.

The donor tooth should be positioned such that extraction will be as atraumatic as possible. Ab-normal root morphology, which makes tooth rcmoval exceedingly difficult and may involve toothsectioning, is conhaindicaled for this surgery. Teeth with either open or closed apices may be donors;

ho$'ever, the most predictable results are obtained with teeth having between ore-halfto two-thirds compl€ted root development. Note: The most likely cause offailure will be a chlonic, pro-gressive external root resorption.

Important: An allogeneic tooth tansplant rcfers to a situation in which a tooth from one individ-ual is placed in another individual. The almost universal sequelae ofan allogeneic tooth hansplantis ankylosis and progressive root resorption, Remember: The change in continuity ofthe oc-clusal plane observed rfter allkylosis ofa tooth is caused by the continued eruption ofthe other non-

ankylosed teeth and glowth ofthe alveolar process.

*** Uncontrolled diabetes mellitus is a systemic contraindication to elective surgery

Important: Patients with these systemic conditions can be tleated, but you need to consult with the pa-

tienfs physician before treatment. In most cases, these patients are best treated in the hospital by an oralsurgeon.

Examples of contrrindications include:. End-stage renal disease. Severe uncontrofled metabolic diseases /1. e., uncontrolled diabetes mellitus). Advanced cardiac conditions (uhstable a gina). Patients with leukemia and lymphoma should be treated before extraction ofteeth. Patients with hemophilia or platelet disorders should be tleated before extraction ofteeth. Patients with a history ofhead and neck cancer need to be treated with care because even minor sur-

gery can lead to osteoradionecrosis. Notei These patients are often treated with hyperbaric oxygen

therapy prior to dental surgery. Pericomitis: infection ofthe soft tissues around a partially erupted mandibular third molarNote: This infection should be treated pdor to rcmoval of the maxillary third molar.. Acute infectious stomatitis and malignant disease are relative contraindications. Patients being treated with IV bisphosphonates increases the risk ofosteoradionecrcsis ofthe jaw

\ote: Cardiac disease, such as coronary artery disease, uncontrolled h)?€rtension, and cardiac de-

compensation can complicate exodontia. Usually r postinfrrctioo patient is not subjected to oral sur-gery within six months ofhis infarction. However, emergency procedures can be perform€d, provided

the patient's physician has been consulted.

Important:l. Infected maxillarymolars and mandibular molars willusually drain into the buccal space which lies

between the buccinator muscle and overlying skin and superficial fascia.

2. The submandibulrr space which lies between the mylohyoid muscle and skin and superficial fas-

cia is primarily infected by mandibular first, second and third molars.

. Buccal mucosa

. Tongue and floor ofthe mouth

. Palate

. Attached gingiva

. Mydriasis

. Stidot (crowing sounds)

. Sweating

. Tachycardia

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The most common sites of the oral cancer are the tongue and the floor of the mouth. The othercommon sites are the buccal vestibule, buccal mucosa, gingiva and rarely the hard and soft palate.

This cancer is extremely malignant and even ifthere is slight delay it spreads to lymph nodes ofthe neck.

Squamous cell carcinoma (epidermoid carcinoma) is the most commolr form oforal cancer OralSCC usually presents as an indunted ulcer with poorly defined borders. The lesion is characteris-

tically painless, unless inflammation from superinfection or ch.onic mechanical irritation is pres-

ent. An indolent clinical presentation in the form ofa small superficial ulceration, leukoplakia, orerythroplakia is also likely, especially in the early stages ofdevelopment.

Remember: SCC usually affects the lower lip and rarely the upper lip. This occurrence has beenattributed to greater exposure ofthe lower lip to sunlight. Lip carcinoma commonly presents as an

ulcer. In many cases, a keratin crust covers the ulcer. The rest ofthe lip vermilion may show ac-

tinic changes.

Important: Carcinoma in situ is an epithelial dysplasia that includes all the layers ofthe epithe-lium but does not extend beyond the basal layer. Once the malignant cells have penetrated the basal

layer into the lamina propria, early invasive squamous cell carcinoma has been established. If tumorinvasiveness extends deeper into the tissues, involving fat, muscle, or other struchrres, then true in-vasive squamous cell carcinoma has evolved.

The degree ofhistologic dilferentiation best describes the degree ofmalignancy ofa tumor. Ma-lignant neoplasms are histologically classified as (l) well differentiated (2) moderately differenti-ated. or (3) poorly differentiated (anaplostic) tumors. From a histologic point of view, poorlydifferentiated tumors have the highest de$ee ofmalignancy.

' . -- l. The salivary glands, blood vessels, lymphatics, muscle, bone, and other comective tis-

r'J\-otedt sue can also give rise to primary malignancies of the head and neck.'$6$ 2. Cancer ofthe breast, prostate, lung, kidney, thyroid, hematopoietic system, and colon

can metastasize to the head and neck region.

***stridor is a high-pitched, noisy respiration, like the blowing ofthe wind. It demands im-mediate attention. It is caused by partial obstruction ofthe airway at the level ofthe larymx ortrachea.

Because total airway obshuction usually occurs during inspiration, there is usually adequate

oxygen left in the cerebml blood to permit up to 2 minutes of consciousness. Ifthe obstruc-

tion is not recognized and managed and oxygen delivered to the victim's lungs, blood, and

brain, permanent neurologic damage occurs within 3 to 5 minutes.

Non-invasive Procedures for Obstructed Airwayr. Back blows, manual thrusts, Heimlich maneuver, chest thrust, and finger sweep

lnvasive Procedures for Obstructed Airways:*** These procedures should only be performed by persons trained in these techniques and

ifproper equipment is available..Tracheotomy: ls used more for long-term airway maintenance and not for emergency

arrways. Cricothyrotomy: ls a procedure for establishing an emergency airway where othermethods are unsuitable or impossible. The access site is the cricothyroid membrane ofthe trachea, located on the anterior neck, between the cricoid and thyroid cartilages.

Important: A c cothyrotomy may be lifesaving in an anaphylactic r€action in which a pa-

tient shows signs oflaryngeal obstruction. Ifa patient shows signs of laryngeal obstruction,that is, stridor (crowing sounds), epinephrine should be given and oxygen administered. Ifapatient loses consciousness and appears to be unable to breath€, an emergency cricothyro-tomy may be required to bypass the laryngeal obstruction.

. Maxillary third molar

. Maxillary second molar

. Mandibular third molar

. Mandibular second molar

t6tCoplrighr O 20ll-2012, Denial Decks

. Purpura, petechiae, ecchymosis

. Petechiae, ecchymosis, purpura

. Ecchymosis, purpura, petechiae

. Petechiae, purpura, ecchymosis

162Copyriglr O 201 1,2012 - D€ntal Decks

The clinical picture is that ofa markedly red, swollen, suppurutive lesion. The involved tissueis very tender and often accompanied by pain radiating to the ear, throat, and floor of themouth. Excruciating pain is produced when the opposing tooth impinges upon the inflamedtissue during mastication. There may be trismus ofthe masticator muscles on the affected side.

Involvement of the cervical nodes, fever, and malaise are common. If this occurs, antibiotictheraov is indicated.

The principal etiologic factors in pericoronitis are debris and bacterial waste Droductswhich have accumulated under the soft tissue flap, overlying a partially erupted tooth. This tis-sue is often traumatized during mastication which further exacerbates the situation.Satisfactory emergency treatment is as follows:

L Carefully cleanse beneath the tissue flap using a dental scaler if available. Then flushthoroughly with an irrigating syringe, warm saline and/or Chlorhexidine Gluconate.2. Instruct the patient to dnse with warm saline hourly.3. Prescribe a soft diet and instruct tbe patient to refiain fiom chewing on the affected side

ofthe mouth.4. Repeat treatment daily until the inflammatory reaction subsides.

Important: The maxillary third molar is the most frequent conbibuting factor to pericoro-nal infections found around mandibular third molars. Always examine the maxillary thirdmolar, it may be supererupted or malaligned.

Postoperative ecchymosis is a result of trauma to the underlying blood vessels. Blood es-

capes from the vascular tree and accumulates in the tissues. It is common after extrac-tions in elderly patients due to the fragility of the vessel walls. All patients should be

$arned that it may occur following extraclions. Note: Sometimes the patient will com-plain ofa diffilse, non-painful, yellowish discoloration ofthe skin. Moist heat often speeds

the resolution olpostoperative ecchymosis.

\'{ost common adverse eff€cts of radiation therapy on the oral and paraoral tissues:

. Rampant caries . Difficulty in swallowing

. Radiation mucositis . Varying degree of trismus

. Xerostomia . Radiation dermatitis

Important: Osteoradionecrosis does not develop unless the patient's oral condition isnot optimized before radiation therapy, and postirradiation dental procedures are per-formed without proper precautions.

l,,lote: Hlperbaric oxygen therapy must be considered if surgery is to be performed on

an irradiated mandible.

Thrombocytopeniz (ow pbtela courr, thrt is less than _an absolute contraindication to elective surgical procedures

because of the possibility of signilicant bleeding.

. 50,000 / mm3

. 75,000 / mm3

. 100,000 / mm3

. 125,000 / mm3

,63CopI i8hr O 201l'2012 - Dental Decks

] ORAL SURGERY & PAIN CONTROL JCe

. Erlthroplasia

. Ulceration

. Duration

. Slow growth

. Bleeding

. Induration

. Fixation

464Copltighr e 201l-2012 ' D{tal Decl6

EXCEPT one.Which one is the EXCEPTION?

\ote3'

Patients with less than 10,000 - 20,000 platelets have been known to bleed spontaneously.Platelet counts between 50,000 and 100,000 have not been associated with significantbleeding, provided platelet function is normal.

Possible etiologies for low platelet counts are:. Idiopathic thrombocytopenic purpura (1ZP). Disseminated intravascular coaeulation (DIC ). Marrow invasion or aplasia. Hypersplenism. Drugs. Cirrhosis. Transfusions. Viral infections (infectious mononuc leosis)

l. Normal platelet count is 150,000 - 450,0002. Emergency procedures may be done with a few as 30,000 platelets if the

dentist is working closely with the patient's hematologist and uses excellenttechniques of tissue management

3.Bleeding time is a screening test that assesses platelet number and function.4. Aspirin irreversibly blocks cyclooxygenase function, inlibiting platelet ag-

gregation for their 7 to l0 day life span. Because approximately l0olo ofplateletsare replaced each day, it takes an average of2-3 days for bleeding time to nor-malize, but most experts reconmend allowing 7 days without aspirin before sur-

gery. Other NSAIDs will alter platelet function only temporarily.

Characteristics of lesions that raise the suspicion of malignancy:. Er!'throplasi& lesion is totally red or speckled red and white. L'lceration: lesion is ulcerated or is an ulcer. Duration: more than two weeks. Rapid grolvth. Bleeding: Bleeds on gentle manipulation. Induration; lesion and sunounding tissue is firm to the touch. Firation: feels attached to adjacent structures

-\ red but not ulcerated area on mucous membrane is called erythroplasia. The texture may

be normai or roughened. Size is variable, some being so small as to vinually escape detection* hereas large areas are conspicuous to casual inspection. There are usually no symptoms.Being neither elevated nor depressed, they present as quiet, unpretentior.N lesions. The bordermal be sharp or blend imperceptibly into surrounding normal mucosa. It must constantly be

kepr in nind that early carcinoma frequently appears as an area oferythroplasia. There are cer-tain areas ofthe oral mucosa which seem more prone to develop nalignancy. Additionally, oralcancer is more often seen in those over age 40. Because ofthis, an area ofery4hroplasia in acancer prone area in a patient past 40 is highly suspicious for malignancy and should be biop-sied on rhe day it is seen. This is especially true for those lesions whose duration exceeds 2

ueeks.

Note: Local spread of oral carcinoma is achieved by direct invasion and infiltration of adja-

cent structures. Perineural invasion and spread is particularly important because it can ad-

versely influence the actual extent of the tumor Regional spread to the neck lymph nodes

occurs by the lymphatic route.

. The step osteotomy

. Mandibular ramus sagittal split osteotomy

. The vertical ramus osteotomy

. The vertical body osteotomies

165

Coplaight O20ll-2012 - Dental Decks

. Postherpetic neuralgia

. Buming mouth syndrome

. Trigeminal neuralgia

. Temporal arteritis

r66Coplr;ghr O 201 1-201 2 , Dental Decks

The mandibularramus sagittal split osteotomy has be-come one ofthe most commonly performed mandibularorthognathic procedures. The mandible is split sagittallyand can either be used to advance the mandlble ftn thecase of rettogn^thi^) or to set back the mandible fl,treating progn^thi^) . lt is the standard procedure usedtoday. Note: The position ofthe condyle is unchangedduring conection ofmandibular prognathism or retrog-natnlsm.

Vertical ramus osteotomy: can be used to setthe mandible f'osteriorly. Used for the correcrionofprognathism.

Vertical body osteotomies: procedures that involveexnacting mandibular teeth bilaterally frsrd I ly bicuspidr.A picce ofbone is also rcmoved liom the mandible and youslide everything back. Used for prognathism.

The step osteotomy: may be indicated in cases ofmandibular prognathism, retrognathism, asymmetry andapenognathia. By performing bilateral step-shaped cuts

in rhe body ofthc mandible, the lowerjaw is divided intolhree separate. Independenrly moveable pieces.

Note: Maxillary surgeries are rcfered to as LeFort I osteotomies. The maxilla can be moved forwardand down more easily than it can be moved up or back. Distraction osteogenesis fDOJ involvcs cuttingan ostcotomy to separate segments ofbone and the application ofan appliance that will facilitatc thc grad-

ual and incremental separation ofbone segments. Used for patients with cleft lip and palate as well as

other deformities ofthe facial skeleton.

Neuropathic painr. Trigeminal neuralgia: prototypic neuropathic fascial pain; Typically there is a triggcr point and

the pain presents as electrical, sharp, shooting, and episodic (seconds to minutes in dwation). Mostcommonly seen in patients over 50 years of age. Carbamazepine (Tegretol) is still the mainstay oftreatment,. Odontalgia secondary to deafferent^tion (atypical odontalgia): occ.urs as a result of trauma or!$gery hoot canal or eil/4cliox). Results from damage to the afferent pain transmission system.. Postherpetic neuralgia: is a potential sequela ofa herpes zoster infection. Pain is described as bum-ing, aching, or electric shock-like. Treated with antidepressants, anticonwlsants, or sympatheticblocks. Ramsey Hunt syndrome is a herpes zoster infection of the sensory and motor branches ofCNVII and CN VIll.. \euromas: may occur after nerve injury This atea (neuroma) can become very sensitive to stimuliand cause chronic neuropathic pain.. Burning mouth syndrome: is most commonly seen in postmenopausal females. Chiefcomplaintsare pain, dryness, and buming ofthe mouth and tongue. Some complain ofaltered taste sensation. Halfofpatients get befter without treatment over a 2 year pcriod.. Chronic headache: categorized as being either migraine, tension type, or cluster. Temporal arteritis fgra nt cell at'teritis): is the most common folm ofvasculitis that occurs in adults.

Almost all patients are over the age of50. Commonly causes headaches,joint pain, facialpain, fever,

and difficulties with vision, and sometimcs permanent visual loss in one or both eyos. Often difficultto diagnose.

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. Intraorally

. Externally over the posterior surfac€ ofthe condyle with the mouth open

. Through the external auditory meatus

. Any ofthe above

167

Coplright O 201 I,20 12 - Dmtal Decls

. Laterally

. Medially

. Posteriorly

. Anteromedially

168

Coplright @ 2011"2012, Dmial Decks

The temporomatrdibular joiDt should be evaluated for tendemess and noise. When checking for jointnoises (clicki g and clepitus), the joint is p lpated laterully (in front of the external auditory neatus)while the patient opens and closes the mandible.

Tenderness can be assessed by palpating the lateral aspects ofthejoints when the mouth is closed andduring opening ofth€ mouth. The joint should also be palpated for tendemess while the patient opensmaximally, and the ftngertip should be positioned slightly posterior to the condyle to apply force todetemine if therc is inflammation of the retrodiscal tissue.

Note: By placing fingertips in the patient's extemal auditory meatus, this technique can produce falsejoint sounds during mandibular function because ofpressure against the thin ear canal cartilage.

Remember: (l) The posterior aspect of the condyle is rounded and convex, whercas theanteroinferior aspect is concave. (2) The condyles are not symmetrical nor identical

Temporomandibuhr disorders:

. Myofascial pain disorder fMPD): most common cause of masticatory pain and compromised func-tion. The symptoms are diffuse, poorly localized in the preauricular region, often involving the mus-cles of mastication. The pain and tendemess develop as a result of abnormal muscle function andh'?eractivity. It can be the rcsult ofdisc displacement disorders or d€generative arthritis.. Disc displacement disorders: are seen with and without reduction (the return ofthe nonbal disc-to-condyle rclationship). See card 170.. Systemic rrthritic conditions: include rheumatoid axdritis, systemic lupus, and pseudogout. Pa-

tients with these conditions usually have other clinical systemic signs and s,'nptoms.. Chronic recurreot dislocation: occurs when the mandibular condyle translat€s anterior to the ar-

ticular eminence and requires mechanical manipulation to achieve reduction. It is associated withpain and muscle spasm.. Ankylosis: can occur intracapsularly or extracapsularly, and can b€ fihous or bony. Bony anrylo-sis results in morc limitation ofmotion. Trauma is the most common cause of ankylosis. These pa-

tielts have a severely restricted mnge ofmotion that may be accompanied by pain.

In a healthy temporcmandibularjoint ffM"/), the articulardisc is seated on th€ condyle and is held in place bythe coffater{l ligaments (also called "discal ligaments") that are attached to the medial and lateral poles ofrhe condyle. Attached to the anterior portion ofthe articular disc are muscle fibers from the lateral pterygoid

muscle.

$:llen rhe collateral ligaments become elongated or torn, they become loose which allows the lateral ptery-goid muscle to pull the articulardisc out ofplace. Wlen this occurs, it is called a disc disphcement. Because

of rhe anteromedial direction ofthe lateral pterygoid muscle, the articular disc is usually displaced antero-

medieUl.\ote: \\:hen the articulat disc is displaced anteromedially to the condyle, a click souDd is usually d€mon-

stmred when the mouth is opened and the condyle moves past the thick posterior band ofthe afticular disc-

There can also be a clicking sound when the mandible moves to the opposite side as the condyle again movespasr the thick posterior band ofthe aiticular disc. Often anothff click will be demonshated vhen the mouth is

subsequently closed and the condylemoves liom the thin centalareaofthe disc and then past the thickerpos-rerior band as the arhcular disc once again becomes displaced. A Crepitation sound faho lnown as "Crepi-

tus - muhiple scraping or grating sounfu) is usually associated with a degenemtive process (osteoarthritis)

ofthe condyle, the dull thud is usually associated with a self-reducing subluxation ofthe condyle, and tinni-tus is described as ear ringing.

\oDsurgical therapy for TMJ dysfunction. Prtient education: parafunctional habi6 fe.g., nail and pencil bitittg) and stress can be associated withmyofascial pain disordet (MPD). These habits or sttess should be d€alt \ /ith by a trained professional..lvledic.tions: for TMJ disorden include NSAIDs, steroids, narcotic and non-narcotic analgesics, antide_

oressants. and muscle relaxants.. Physical therrpy: treannent may include biofeedback, ultrasoun4 transcutaneous electrical stimulation

/IENS.,/, massage, thermo-ffeatment, €xercise, and iontophoresis.. Occfusaf splints: can be classified as either iutorepositioning a/or m*tcle or joint pain when no speciJic

anatomically based pathologic entity can be identifed) ot ,ftefior repositioning. The anterior reposition-

ing splint protrudes the mandible into a forward position, h)?othetically recapturing the normal disc-to-

condyle relationship. occlusal modification may be accomplished via equilibration, full mouth

reconstruction, orthodontics and orthognathic sugery. Arthrocentesis: for patients with intemal dera[gement. A few milliliters ofsalin€ or lactated ringers are

injected into the superior j oint space.

. Preauricular

. Submandibular

. Both are the same

169

Cop).right O 201 I -2012 - Dental Decks

. Ringing in the ears

. Reciprocal clicking

. Muscle inflammation

. Headaches

170Cop)right O 201 1'201 2 - Denial De.ks

Surgical approaches to the TMJ!. Preauricular: the best incision to expose the TMJ. A perpendicular incision is made just ante.ior tothe extemal ear parallel to the superficial tempoml afiery. The incision extends from one inch abovethe zygomatic arch to the lower extremity ofthe ear The condyle is approached ftom behind. Note:With this approach, care must be taken not to damag€ either the facial nerve or the vessels that richlysupply this area.

. Subma[dibular approach (Risdon approacr): this is one standard surgical approach to the ramusofthe mandible rnd neck ofthe condyle. [t is not th€ b€st apprcach for prccedures with-in the jointspace itself

Patients with pain and dysfunction whose signs and symptoms do not respond satisfactorily to nonsur-gical therapy with a period of3 months may be candidates for surgery particularly ifthey are diagnosedwith advance intemal derangement caused by ankylosis, rheumatoid arthritis, or severe degenerative os-teoarthritis. Patients with no improvement in range and ofmotion and mouth opening despite conserva-tive treatment arc also candidates for surgical therapy.

Surgical trertments:.Arthroscopy allows direct visualization ofthe anatomic structure ofthe TMJ, biopsy ofpathologictissue, and .emoval of osteoarthritic fibrillation tissue, as well as direct injection of steroid into in-fl amed synovial tissues.. Disc repositioning swgery bpen arthroplasly): is used in patients with painful, persistent clicking-popping and closed lock, The disc is mobilized and a postfiior wedge may be removed, with sutur-ing used to reposition the disc in a better anatomic position.. Dfuc repair or remov^l (discectomy): is irldicated when the disc is severely damaged. Results varywidely as to whether it is a viable option for patients. R€placement materials have been prcblematic,so there is a tendency to favor autogenous mateials (i.e., temporalis muscle andfascia).. Condylotomy:is accomplished by performing an inhaoral vertical mmus osteotomy. Has been used

for the treatment of intemal demngement with and without reduction and chronic dislocation.. Total joint replacement: is indicated in the severely pathologic joint, as seen in rheumatoid arthri-tis, severe degenerativ€joint disease, ankylosis, and neoplasia. Costochondral bone graft reconstmc-tion is the most common autogenous material used.

The most common form ofpain and discomfort associated with TMJ disorders is masticatorymyalgia or myofascial pain. This is a disorder characterized by pain and masticatory mus-cle spasm and limitedjaw opening. The condition is characterized by a unilateral dull, achingpain which increases with muscular use.

Internal derangement ofthe articular disc:. First stage: reciprocal clicking is considered pathognomonic. In the first stage of intemalderangement, clicking begins suddenly and spontaneously or aftet an injury. The noise isoften loud and may be audible to others, but is rarely associated with severe pain.. Second stage: the second stage of disc derangement is recipmcal clicking with inter-mittent locking. The typical patient complains that the jaw becomes locked and there isusually, but not always, severe pain over the affected joint.. Third stage: is associated with limited opening and has been termed closed lock. a lim-ited opening of< 27 mm and severe pain over the affected joint are characteristic findings.Not€: ln contrast to the second stage, few patients are able to unlock or relocate their closed

lock and restore normal function.. Fourth stag€: the final stage is characterized by an increase in opening and crepitus oc-

curring within the joint dudng movement due to degenerative changes in the disc and artic-ular surfaces. Note: This stage appears to be less painful than previous stages, because theneurovascular tissue is no longer impinged between the condyle and the glenoid fossa.

The occunence ofTMJ pain caused by rheumatoid arthritis depends on the severity ofthesystemic disease. Most studies show that about one third ofthe patients with rheumatoid arthri-tis will experience pain in the joint at some time, with nearly 60olo ofpatients suffering frombilateraljoint dysfunction. Note: Th€ target tissue ofrheumatoid arthritis is the synovial mem-brane. Progression in the TMJ follows a general scheme with exudation, cellular infiltration,and pannus formation. The articular surfaces of the temporal and condylar components are

destroyed, the disc becomes grossly perforated, and the subchondral bone is resorbed.