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What is considered insensible loss?Sweating, Evaporation from lungs due to anesthesia dry vapors, wound evaporation
How much insensible loss occurs in OMFS procedures?-2-4cc/kg/hr?
How do you calculate volume status of an immediate postop patient?1. Calculate Maintenance fluids utilizing 4:2:1 Rule (4cc/kg/hr for the first
10kg, then 2cc/kg/hr for the 2nd 10kg, then 1cc/kg/hr thereafter): e.g., 70kg pt =110cc/hour
2. Calculate total “outs”:a. NPO from midnight until surgery (unless in-house and getting
maintenance fluids) represents missed maintenance fluids: e.g., NPO at midnight to 8am= -880cc
b. Maintenance fluid during surgery: e.g., 4hr surgery=-440ccc. Estimated blood loss x 3 (b/c blood is colloid): e.g., 550cc = -
1650ccd. Insensible loss (3cc/kg/hr for OMFS): e.g., 70kg pt in 4hr surgery=
-840cce. Urine output during case: e.g., -300cc
3. Calculate total “ins”:a. Crystalloid given during surgery: e.g., 4000cc LR=+4000ccb. Colloid given during surgery (blood/albumin) x 3: e.g., 1 unit packed
red blood cells (~250cc)=+750cc4. Add numbers to find status: e.g., pt is POSITIVE 200cc
What is ideal urine output for an adult? for a child?1cc/hr/kg for child 40kg pt = 40cc/hr0.5cc/hr/kg adult 70kg pt = 35cc/hr
If patient had Negative body balance of 1 liter how much do you have to change maintenance fluid if you want to do it slowly over 5hours?70kg pt maintainence is 110cc/hour (1000cc/5hours = 200cc/hr) The patient would have to have fluid rate of 310 per hour for 5 hrs.
What ways can you check bloods loss?Skin Turgor, Specfic gravity of urine, Orthostatic vital signs, skin temp (if hands are cold to the elbow there is a 10% blood loss)
1unit EBL represents what change in HCT?-3% is correct but LBK might state 5%
What is considered orthostatic changes?After waiting 2 min at new position HR increased >10 bpm or BP dropped >20mmHg
What are the causes of vertical maxillary excess?Upper airway occlusion, i.e. enlarged tonsilsMouth breathers their tongue is not against the palate shaping it.
LeFort I with impaction patient is complaining to excessive tearing. What is this called and what likely happened?EpiphoraBlockage of the nasolacrimal duct with bone or edema or from over impaction
How far is the nasolacrimal duct from nasal floor?10-15mm.
What are the causes of post op 3rd molar infections with unerupted teeth?1. Fracture of the mandible during extraction2. Retained foreign body ie sponge3. Hematoma under the flap that secondarily gets infected4. Metastatic lesion in the jaw that secondarily infects5. Immunocompromised host HIV, cancer, steroid dependent pt
When you harvest ribs for TMJ surgery you get called that the patient is having difficult breathing what likely happened?Pneumothorax
On PE how can you diagnose pneumothorax?Ausculation = decreased breath sounds on the affected side.
If you suspect pneumothorax what do you do next?Place pt on 02, place pulse ox on patientCheck post op chest xrayOrder STAT new chest xray
Name the sutures involved in ZMC fracture?ZygomaticomaxillaryZygomaticotemporalZygomaticofrontalZygomaticosphenoidal
What are the Knight and North classifications for ZMC fractures? Group I: nondisplaced fractures Group II: Arch fractures only with classic three fracture lines producing V-
shaped deformity Group III: Unrotated body fx. - direct blow to zygomatic prominence. The
zygoma is driven posterior and medially. The infraorbital rim is displaced inferior and medially at the buttress
Group IV: Medially rotated body fractures Group V: Laterally rotated body fractures - superior displacement of inferior
orbital rim with lateral displacement at the frontozygomatic suture Group VI: Complex/comminuted fractures
In 1961, Knight and North proposed a new anatomically based classification system of zygoma fractures (based on Water’s view radiograph), which they hoped would help better determine the prognosis and treatment of such injuries.
Group I encompassed fractures with no significant displacement as evidenced clinically and radiographically. While fracture lines may be seen, their recommendation was that this group requires no surgical intervention. A soft diet and careful avoidance of any further injury is prudent.
Group II fractures include only those of the arch caused by a direct blow that buckles the malar eminence inward. This fracture is often associated with trismus. Often, this type of fracture can be treated satisfactorily by a Gillies approach or other standard techniques.
Unrotated body fractures, medially rotated body fractures, laterally rotated body fractures, and complex fractures (defined as the presence of additional fracture lines across the main fragment) belong to groups III, IV, V, and VI, respectively. Knight and North defined these groups by their stability after reduction. They found that 100% of group II and group V fractures were stable after a Gillies reduction, and no fixation was required. However, 100% of group IV, 40% of group III, and 70% of group VI were unstable after reduction and required some form of fixation.
Name the bones of the orbit? (Name clockwise or counterclockwise) Roof: Frontal bone, Lesser wing of sphenoid Medial: Maxilla, lacrimal, ethmoid, Body of sphenoid Floor: Maxillary, palatine, Zygoma Lateral Zygoma, Greater wing of the sphenoid
What two dissection approaches can be taken in lingual nerve explorations/repairs?ProximaldistalDistalproximal
Where do you expect to find the proximal segment of the lingual nerve?Between the medial pterygoid and the temporalis tendon
What is the OMENS classification? What does it stand for? ffforor?for?
forfor?
What cancers are likely to metastasize to the jaws? Breast, Lung, Kidney, Prostate, Thyroid (LBK answer)Women: breast followed by the adrenal, colo-rectum, female genital organs and thyroidMen: lung, followed by the prostate, kidney, bone and adrenal. The most common location of the metastatic tumors was the mandible, with the molar area the most frequent site involved.Hirshberg A, et al. Metastatic tumors to the jawbones: analysis of 390 cases.J Oral Pathol Med. 1994 Sep;23(8):337-41
When consenting for extraction of 3rd molars what is the risk for lingual or inferior alveolar nerve paresthesia vs anesthesia?Lingual 1/1500 chance of paresthesia of these 10% will have permanent anesthesiaIAN: 1/750 chance of paresthesia of these 3% will have permanent anesthesiaNumbers vary by study this is what LBK states
Why is IAN more likely to regain function after injury during extraction?Bony IAN canal acts as a conduit for regeneration
What is a Tinels Sign?Steadman’s Med Dictionary: Tinel's sign is elicited by percussing the skin over the median nerve just proximal to the carpal tunnel; when it is positive, the patient will complain of an electric sensation radiating into the thumb, index, middle, or ring fingers.
What is a “Tinel-like Sign”?It can used to describe lingual nerve patients when one percusses over the site of lingual nerve injury and the patient gets a shock like sensation traveling down the tongue. This suggests that that nerve is regenerating. If compared over time the sensation will travel more distal on the tongue. This is to be distinguished from dysesthesia which is pain on percussion at the site of injury. It is best to banish this “Sign” from your vocabulary if you’re in LBK’s presence…
What are the most stable to least stable skeletal movements during orthognathic surgery? Maxilla up, Mandible forward, Chin any direction, Maxilla forward, Maxilla asymmetry, Maxilla up and mandible forward, Maxilla forward and mandible back, Mandible asymmetry, Mandible back, Maxilla down, Maxilla wider
What are the least stable skeletal movements during orthognathic surgery? Maxilla widening or maxillary disimpaction
Why does one leave a 2-3mm posterior open bite when performing bilateral costochrondral rib grafts to the mandible ramus condyle unit?It allows for settling of the graft helping to avoid a relapse open bite.
What are the stages of fracture healing with closed reduction?
Secondary Healing (Stages are Initial stage hematoma, Cartilaginous callus, Bony callus, remodeling)
What are the stages of fracture healing with open reduction with internal fixation?Primary healing (requires excellent anatomic reduction, minimal mobility, good vascular supply)
Describe the process in which a non vascularized bone graft is integrated into the donor site?
What are the ways in which a mandible fracture can be reduced? Closed, Open wires (semi rigid fixation), plates and screws (rigid fixation), external fixation
What constitutes rigid fixation for mandible fractures?
What are the LeFort I anatomic landmarks during surgery?
How many millimeters can you safely place an external fixation marker in the nasal bone for Le Fort I osteotomies?13mm
What is the incidence of IAN anesthesia/paresthesia after BSSO?
What radiographic signs are associated with inferior alveolar nerve injury during third molar removal?Diversion of the inferior alveolar canalDarkening of the third molar rootInterruption of the cortical white line of the canal
How do you calculate respiratory distress index?[Apenas + Hypopneas + RERAs/ Total sleep time]
How do you calculate apnea hypopnea index?[Apenas + Hypopneas/ Total sleep time]
What is an apneic vs an hypopneic event?Apnena = no breathing. Actually 20% basal airflow for 10 seconds.Hypopnea = 80% or lower basal airflow with a 4 % drop in O2 sat Respiratory effort related arousal (RERA) = no change in O2 sat due to increased respiratory effort (often noticed as a big snort or gasp).
What respiratory distress index is clinically significant?RDI > 5 is abnormal, RDI>20 is clinically significant for OSA
What are normal cephalometric measurements for OSA workups:Mandibular Plane – Hyoid distance Normal is 15.4 +/- 3mmSoft Palate length PNS – Tip of soft palate Nl is 37+/- 3mmPosterior Airway space Point B through Gonion Nl is 11+/-mm
What is the maximum dose of local anesthetic that can be used?
What % of Class III bites are due to maxillary hypoplasia?~70%
What % of vascular malformations will have deformities of the underlying bone? (Whether directly involved or not…)~35% (As a corollary to this question, it does not appear to make a difference what type of vascular malformation it is (ie: its not a “pressure” or “flow” thing) since high flow malformations don’t necessarily have more change in the underlying bone and in fact, lymphatic malformations often have the most profound effects on the mandible, leading to hemihypertrophy of the involved side. This is hypothesized to be due to some sort of upregulating signal from the vascular malformation.)
What is the advantage of the endoscopic approach to submandibular gland stone removal?The duct is dilated and navigated through multiple subdivisions and irrigated. Also one can find additional stones. 50% of patients have 2-4 additional stones
missed on traditional imaging (CT, Sialogram, Technician salivary flow studies). Strictures can also be identified to be dialated or marsupulized if extremely narrow.
How long is the stent left in place after sialodochoplasty?2-4 weeks
What are the post op instructions for a salivary stone retrieval patient?Drinks extra fluids, gland massage, use sialogogues (ie lemon drops)
How much does the chin move forward with mandibular closure of an open bite?The bony chin point moves forward 2mm with every 1mm of open bite closed.
What defines the following anatomic spaces?Canine- Between levator anguli oris and levator labii superiorisBuccal Between buccinator and overlying skin between zygomatic arch and
border of mandibleInfratemporal- Posterior to the maxilla; medially by the lateral pterygoid plate,
superiorly by base of skull, inferiorly by lateral pterygoid, laterally by temporalis muscle and continues with deep temporalis space
Submental- Between 2 anterior bellies of the digastric and mylohyoid and skinSublingual- Between oral mucosa and mylohyoidSubmandibular- Between mylohyoid and overlying skin, anterior digastric
anteriorly, Posterior Digastric posteriorlyMassenteric- Between medial aspect of medial pterygoid and lateral aspect of
masseterPterygomandibular- Medial to mandible and lateral to medial pterygoidTemporal- Temporal line superiorly, arch inferiorly, medially the muscle; deep
temporal is deep to the muscle and continuous with the infratemporal space
Lateral Pterygoid- Between medial pterygoid laterally, superior constrictor medially, from skull base to hyoid bone; anterior is the raphe, posteriorly is the retropharyngeal space; slyoid process and associated muscles divide it into anterior and posterior compartments
Retropharygeal- Between superior constrictor and alar portion of prevertebral fascia; from skull base to C7-T1 where alar and buccopharyngeal fascia fuse can extend into posterosuperior mediastinum
Prevertebral- Between alar fascia and prevertebral fascia; from pharyngeal tubercle of skull base to diaphragm; can extend into entire mediastinum
When completing LeFort I cut of lateral nasal wall which structure must you be aware of? Descending palatine artery
What is bone strength at different times of healing? 6wks =30%3mo=70%6mo=90%1yr=95%
How much does the lingual nerve regenerate each day1mm
How many patients after lingual nerve repair have functional sensory return after 1 year? 88.5%
What is the success rate for return of taste after lingual nerve injury?35%
What constitutes functional sensory return? 2pt sensation <20mm, no pain, brush stroke and light touch intact
What pt is likely to get 100% return of function after lingual nerve injury?Sharp knife injury in a child with immediate repair
What contributes to failure of lingual nerve repair:?Waiting more than 3 months to repair the nerve in pt’s with anesthesia or if there is a large size discrepancy between the proximal and distal nerves
What defines neuropraxia? Loss of nerve function for 3-6 weeks
When patient is under general anesthesia what can the anesthiologist follow to ensure adequate cardiac output? Urine output
When pt is undergoing hypotensive anesthesia why do they receive so much fluid?To ensure adequate end organ perfusion
What if the RN calls statingBP is elevated HR is elevated = pain = Hypoxia
What is a sequence to death in patient in MMF?Overmedication, upper airway obstruction, hypoxia, fatigue, respiratory arrest, cardiac arrest
Vital sign indicators:BP low, HR High Hypovolemia check urine color, check fluid balance, check skin turgor,
BP elevated and HR decreased Concern for increased intracranial pressure
BP and HR low Overmedication
Iliac crest harvest: Anterior iliac spine is landmark for lateral femoral cutaneous nerve (nerve usually sits
10mm anterior/inferior to AIS) Expected blood loss of approximately 1 unit per harvest 3 possible approaches:
o lateral to crest Preferred Kaban method Tissue drifts laterally away from crest (hidden in bikini line for good
esthetics) Farthest from nerve
o medial to crest – good estheticso on crest – highest incidence of wound breakdown
Use of drains:o Advantages:
Reduce rate of infection Speed up recovery Decrease chance of wound breakdown due to minimized hematoma Allow staff to keep track of blood loss
o Disadvantages: Collapse dead space and decrease amount of subsequent bone fill –
therefore less bone is available for re-harvest if necessary
The clinical sign differentiating superior orbital fissure syndrome from orbital apex syndrome is:
A. absence of superior palpebral fold
B. proptosis
C. dilated and fixed pupil
D. decreased visual acuity
ANSWER: D
RATIONALE:
Symptoms of superior orbital fissure syndrome include:
1. Pupillary dilation via alteration in cranial nerve III function in it's innervation of the pupillary constrictors.
2. Paresis of cranial nerves III, IV, and IV causing ophthalmoplegia.
3. Cranial nerve III involvement causes paresis of the levator palpebrae superiorus muscle, leading to ptosis and loss of the superior palpebral fold.
4. Neurosensory disturbance to the first division of cranial nerve V with hypesthesia of the supraorbital and supratrochlear nerves and loss of the corneal reflex.
5. Proptosis from engorgement of the ophthalmic vein and lymphatics.
The orbital apex syndrome includes all of the above plus optic nerve involvement, leading to changes in visual acuity.
When closing oronasal fistulae where should the suture knots be buried?
The knots should be placed so that they are on the nasal surface.
What are the goals of alveolar cleft closure?
The rationale for its closure includes 1) stabilizing the maxillary arch, 2) permitting support for tooth eruption, 3) eliminating oronasal fistulae, and 4) providing improved esthetic results.
What is Osteoconductive Stimulation?"Osteo" means "bone". Osteoconduction refers to the ability of some materials to serve as a scaffold on which bone cells can attach, migrate (meaning move or "crawl"), and grow and divide. In this way, the bone healing response is "conducted" through the graft site, just as we say that electricity is conducted through a wire. Osteogenic cells generally work much better when they have a matrix or scaffold to attach to.
What is Osteoinductive Stimulation?Induction of bone formation refers to the capacity of many cytokines or peptides in the body to stimulate primitive "stem cells" or immature bone cells to grow and mature, forming healthy bone tissue.
How many films are needed to adequately image the mandible?ABOMS Board answer is that you need 2 views at right angles to each other
What films are in a mandible series and what can they image?B Mandiblular obliques = angles to premolar regionTownes view (AP skull film)= Posterior zygomatic archs, Condyles (since closer to the film)PA skull film, Lateral skull film, Submentovertex
When harvesting iliac crest what nerves can be damaged?Lateral femoral cutaneous = Paresthesia to the lateral thighSciatic Nerve from the bump roll placed under the gluteus musclePeroneal from the patients safety strap being placed lower on the leg resulting in foot drop
How many degrees does the maxilla have to cant to be clinically obvious?Four degrees or more
What reference point is used to correct a maxillary cant?The amount to of tooth show at the canines, the degrees of cant are equal to mm of needed movement to correct. ie 4 degrees equal bringing down the canine 4mm to level the plain plus and additional 2mm if you want to show the canines.
When performing a BSSO what unfavorable fractures can result?Horizontal fracture of the ramus, Buccal plate fracture, Lingual plate fracture, Subcondylar, Sigmoid notch fracture
Pt sustained blow to face and can’t open their mouth, what likely happened?Trismus is likely from a depressed zygomatic arch fracture or ZMC that is impinging on the coronoid.
What mandibular fractures should one worry about with a blow to chin?Parasymphsis and/or subcondylar,
What are the injuries that can be sustained with a blow to the chin?Skin laceration, subcondylar fracture(s), cervical spine injury
What % of patients undergoing orthognathic surgery require removal of hardware postoperatively? What are the most common reasons?~2.5% of patients usually have hardware removed due to:
1. Palpable hardware2. Temperature sensitivity
What are the normal TMJ ranges of motion?MIO is ~35-55 with a mean of 43mm. Normal excursive movements are 6-12mm.
What percentage of a child’s body weight is from blood volume?7-8%
What are the steps in the TMJ ankylosis release?1. Aggressive resection of the ankylotic segment2. Ipsilateral coronoidectomy3. Contralateral coronoidectomy4. Lining the joint space with temporalis fascia or cartilage5. Reconstruction of the ramus with a costochrondral graft6. Rigid fixation of the graft7. Early mobilization and aggressive PT8. If patient loses MIO then should have manipulation under anesthesia
What artery supplies the temporalis muscle flap used in TMJ surgery?Deep temporal artery
What are the causes of TMJ ankylosis?Trauma 32-98% cases Possibly from intra-articular hematoma with scarring Local or systemic infection 10-49% cases Otitis media or mastoiditis hemotogenous spread
Why does the cornoid have to be ressected in TMJ ankylosis surgery?Ankylosis prevents movement of the mandible at the TMJ. The suprahyoid muscles pull on the mandible and the temporalis muscle pull which resists movement causes bony hyperplasia of the coronoid
How do you decide if the contralateral coronoid has to be removed in TMJ ankylosis release?Once the affected side is released and the ipsilateral coronoid is resected you enter the mouth and see if the mandible can easily be dislocated on the contraleral side with minimal force. IF it can’t then you must also ressect the contralateral coronoid.
Diagram the modifications to the sagittal split osteomtomiesObwegeser & Trauner technique (1957) Original description of sagittal split osteotomy
Hunsuck modification (1968)-Allow the horizontal osteotomy to propagate posteriorly without completing a complete corticotomy
DalPont modification (1961)-Bringing vertical corticotomy anteriorly on buccal surface of the mandible to area of first molar (allowing increased length of movement).
What is the position of the premaxilla in patients with bilateral cleft palates?The premaxilla starts off being protrusive and long in the vertical plane. It frequently returns to a “normal” position by the time patients are teenagers.
What are the 4 modification for genioplasty?Tessier – Osteotomy proximal to the mental foramina to ensure smooth transition
between mandible and new chin positionKaban – Dissection the mental nerves freeing them so that they are mobile and not
sacrificedPerrot – Adapting “x” plate so that the screw holes are oriented vertical instead of
perpendicular to the buccal surface of the advanced chin this prevents the patient from being able to feel the plate
Troulis – She recommended a microplate at the lateral wings instead of wire stablization
What is the MGH abx protocol for post orthognathic surgery?1 dose preop, 1 dose intraop, 1 dose in recovery room; unless: Pt has bonegraft, medpore implant, then should have full course of Abx. If a drain is placed, pt should be on Abx for 48 hrs post removal of drain.
What is Beckwith-Wiedemann syndrome? It is generally accepted that the diagnosis can be established if at least three diagnostic findings are present. macrosomia (pre-natal and/or post-natal gigantism), macroglossia and abdominal wall defect (omphalocele, umbilical hernia, diastasis recti)
hemihyperplasia, embryonal tumors, adrenocortical cytomegaly, ear anomalies (anterior linear earlobe creases, posterior helical pits), visceromegaly, renal abnormalities, neonatal hypoglycemia, cleft palate, and a positive family history.
What must a patient with Beckwith-Wiedemann syndrome be monitored for? Children with BWS have an increased risk for embryonal tumor development, primarily within the first 5-8 years of age. The most common tumors include Wilms' tumor and hepatoblastoma, but others including rhabdomyosarcoma, adrenocortical carcinoma, and neuroblastoma have been reported.
What keeps a zygomatic arch reduced following a Gilles approach?The arch is held in place by the deep temporal fascia from above and the origin of the masseter from below.
What are the most common causative organism leading to sialadenitis?Alpha-hemolytic Strep and anaerobes.
What is the most common causative organism leading to acute, supporative parotitis? What age group(s) is this most commonly seen in?Staph. The very young and the elderly. Recent illness and dehydration are both risk factors.
Bone graft facts:1. Bone morphogenic proteins (BMPs) are found in greater concentrations in cortical
vs cancellous grafts.2. BMPs are released as the bone graft is resorbed3. Cortical bone graft strength decreases steadily following grafting, reaching its
nadir at 3 months.4. Cancellous bone graft strength increases steadily following grafting.
Cancellous graft Cortical graft
Better survival of osteogenic cells because the structure allows diffusion and early microvascular
anastomosesDense bone is a barrier to diffusion
Large endosteal surface supplies osteoprogenitor cells Small endosteal surface
Abundant red marrow supplies many osteoprogenitor cells Fewer osteopregenitor cells
Healing by creeping substitution; new bone is deposited on dead trabeculae followed by
removal of necrotic matrix
Removal of necrotic matrix from around the central canals of osteons occurs first followed by
new bone formation
Relatively weakRelatively strong
How is osteomyelitis diagnosed?History is most important, followed by radiographic imaging.
What is a three phase bone scan?Tc labeled phosphorus shows increased uptake in area of high osteoblast activityThe images obtained are immediate (flow), 15 minute (blood pooling), and four hour (bone imaging). The scan findings are different in cellulitis and osteomyelitis. Cellulitis results in increased activity in the first two phases and normal or diffusely increased activity in the third phase. In comparison, osteomyelitis results in intense uptake in all three phases. False positive findings can occur with posttraumatic injury, following surgery, diabetic feet, septic arthritis, noninfectious inflammatory bone disease, cancer, healed osteomyelitis, and Paget's disease.
What is an indium bone scan? How does it work?Indium labeled leukocyte scanning uses white blood cells labeled with radioactive indium as the tracer. It accumulates at sites of inflammation or infection and in the bone marrow. It is not specific for bone. Since it accumulates in marrow, it is less sensitive for imaging those areas with red marrow (eg, the axial skeleton)The indium scan can also be used for the diagnosis of osteomyelitis at sites of fracture nonunion. Two prospective studies found a sensitivity and specificity of 91 and 97 percent, respectively, in this setting
What diagnostic imaging is utilized in diagnosing osteomyelitis?Plain film-panorexCTMRI-earliest indicator is inflamed marrow Bone Scan-Technetium-non-specific
-Indium tagged WBCs (most specific in acute osteomyelitis)
What are the most common events leading to mandibular osteomyelitis?Tooth extraction (usually third molar)Under-treated or untreated fractureHematogenous spread (Third World)
Is there a critical timeframe within which a mandibular fracture must be treated?Prior to the advent of rigid fixation, untreated fractures older than 24-48hrs were considered infected and were at increased risk for osteomyelitis.
What is the Ellis protocol for treatment of an infected fracture?Given recent evidence, the best treatment is to start IV abx until any purulence discharge ceases, then take to the OR, débride and complete rigid fixation.
What if the infection is chronic, or there is a defect?If debridement of the (chronic) infection leads to a defect, then a bone plate is necessary. A young patient will often bridge the defect whereas an older patient will require a bone graft once the site is healed.
What are 3 causes of posterior vertical maxillary excess (VME) leading to anterior open bite?
1. Purely skeletal-demonstrated on lateral ceph with longer than normal Sella-PNS2. Purely dentoalveolar-demonstrated on lateral ceph with normal Sella-PNS but
increased distance from PNS to occlusal surface of molar3. Combined dentoalveolar/skeletal-combination of the above
What are the two main types of vascular malformations?Tumors and malformations?
Infantile hemangioma is a true tumor (neoplasm), is not present at birth, undergoes a proliferative phase and then involutes, sometimes leaving a fibro-fatty residual. Hemangiomas are Glut 1+.
Vascular malformations can be categorized as high flow or slow flow malformations. High flow malformations are usually AVMs. Slow flow can be capillary, venous, lymphatic or combination of the above malformations.
Venous malformations are present at birth, do not involute, and can increase in size later on in life and may increase in size during puberty.35 % of AVMs involve the bone.
What is the infection rate with primary bone graft reconstruction at the time of tumor resection?
10-50% that is why some advocate that you do not reconstruct at the same time
What reason would you want a free vascularized graft at the time of reconstruction?If you were concerned that you might need radiation treatment. This prevents the delay in needing to go back to the OR for the free flap.
What is the maximal distance one can graft with a nonvascularized graft?5cm.
When treating TMJ ankylosis patients what is considered a functionally acceptable result?
20-25mm at one year
How much mouth opening do you need to be able to do the following activities speaking, chewing, posterior dental work?Speaking 5-10mmChewing 20-25mmPosterior Dental Work 30mm
If treatment planning for a LeFort II or III instead of Lefort I, what must you take into consideration?The position of the globes relative to the orbit.
If there appears to be a smaller advancement on your model surgery what happened? How could you pick this up prior to going to the OR?The models were not mounted correctly in CR
Check the lateral ceph and ensure that the movement on the models agrees with the lateral ceph.
What is Goldenhar Syndrome? (Mulliken states old term as it is hemifacial microsomia with extracranial manifestations, and term should not be used) Per LBK extended spectrum hemifacial microsomia with epibulbar dermoid cysts
What extracranial abnormalities can accompany hemifacial microsomia?Skeletal ( bifid ribs, Vertebral axoatlantal instability, Scolosis, pectum excavatum, CNS Hydrocephalus, Cardiovacular: VSD, Tetrology of Fallot, MVP, Anomalous pulomary return, Renal: Agenesis, Vescorueteric reflux, GI: Diaphragmatic hernia, GERD, Intestinal malrotation, Annular pancreas, Pulmonary: Tracheoesophageal fistula.
What OMENS score is associated with extracranial findings?See for answer
Title: OMENS-Plus: analysis of craniofacial and extracraniofacial anomalies in hemifacial microsomia.
Source:
The Cleft palate-craniofacial journal [1055-6656] Horgan yr:1995 vol:32 iss:5 pg:405 -12
What is the difference between Treacher Collins and B Hemifacial microsomia?
Rarely bilateral hemifacial microsomia is symmetric treacher collinsCheck genetics on pt Tcof1/Treacle gene present in many cases of Treacher CollinsTreacher Collins is Autosomal DominantHemifacial MicrosomiaTreacher Collins will also have lower-eyelid colobomas and medial third eyelash deficiency, palpebral fissure anomaly with antimongoloid slant
How many anterior open bites are due to posterior vertical maxillary excess?~60%
What are the theoretical limits of amount of posterior impaction during LeFort?Anatomic Posterior Choane- Iatrogenic posterior nasal obstruction
Inferior Turbinate Nasolacrimal ductEsthetics
Occusal plane steepening up 12 degrees once exceeded pt appears retrognathic as the mandible is not completely closed.
What muscles control EOM? Primary and secondary?
What are the inervations to the extraocular muscles?
What are the issues in describing subcondylar fractures?a. Intracapsular vs Extracapsular (High vs Low)b. Displacment (In Fossa vs out of Fosssa)c. Override and Overlap (How much on medial or lateral)
What muscle pull contributes to deviation of the chin with a subcondylar fracture?Unopposed contralateral lateral pterygoid muscle pull
How much blood loss is expected with a bicortical anterior iliac crest bone graft?250-350cc intraoperative then additional 250cc in the first 24hours post op especially if there is a drain in place (A patient can lose up to one unit of blood)
How much marrow can you harvest from each of the follow sites?1. Anterior iliac = 20-30cc uncompressed marrow2. Posterior iliac = 20-40cc uncompressed marrow3. Anterior tibial plateau = 20 cc uncompressed (depends on how you approach tibia)
What movements are most stable if you treating a patient with idiopathic condylar resorption use conventional orthognathic surgery without a rib graft?Less than 5mm of sagittal movement, treating the deformity in one jaw alone, if the posterior ramus height is greater than 35mm
When placing a CC rib graft what prevents overgrowth in the growing patient?Harvesting only 1mm of cartilage on the rib
What leads to overgrowth of the CC rib graft in the growing patient?Micromotion at the osteochrondral junction if the there is a large piece of cartilage this leads to tumor like overgrowth of the cartilage very much like a osteochrondroma This is from stimulation of the chrondrocytesLinear growth also in the young patient if too much cartilage is present at the growth center . This leads to prognthism and class III malocclusion.
After a fracture or osteotomy what is the bone strength? When is it at full strength?6 weeks 30% strength3months 70% strength
1 year normal strength
Who is Gilles? Sir Harold Gilles Plastic surgeon from New Zealand who developed many region flaps for facial reconstruction. Also described at the approach to Zygmomatic fractures and ZMC’s. Also he described the use of the submentovetex film.
What are the anatomic Barriers for a Gilles approach to the Zygomatic arch?Laterally the masseter muscle, medially the temporalis fascia
What can you use instead of Gilles forcep to reduce a Zygomatic arch?Foley inflated under the arch, packing packed extraorally and removed 5 days later intraorally.
What are the indication to open a mandible fracture?1. Pt cannot tolerate MMF ie not reliable (drunk, homeless, seizure disorder
handicapped)2. Fracture is proximal to the tooth bearing segment ie a displaced angle fracture.
If there is a parasymphyseal fracture what can you use to stabilize the fracture?A lingual splint much like a retainer with an arch bar also on the teeth.
What are the 3 most common clinical signs of TMJ prosthesis failure requiring surgical intervention?-Malocclusion-Decreased ROM-Pain
What are the films included in a Mandibular Series?-PA Skull-Lateral Skull-Right Lateral Oblique-Left Lateral Oblique-Towne’s View
How long should you leave Prolene sutures on the face? -5 days
Why 5 days, not more, not less?-The skin seals in 48h, but the tracts will epithelialize if more than 6 days, leaving “railroad tracks”
Why should you do dermal layer?
-To prevent the spread of the wound. The dermal layer has collagen and is the strength layer. To prevent dead space and hematoma formation.
How long does vicryl last?- 3 weeks (21 days)
Why especially that time?-It takes 21 days (3 weeks) to have enough collagen to bridge the edges of the dermal layer in a sufficient quantity to reach 60% of the tensile strength of the wound.
How can you avoid unfavorable fractures in Le Fort I osteotomy? - Pterygoid osteotome should be placed “downhill” along occlusal plane and not “uphill.” Improper uphill positioning can cause unfavorable fracture. This can result in retrobulbar hematoma and cause damage to the optic nerve.
If you have bilateral parotid swelling and imaging shows (CT) cystic lesions in parotid, what malignancy is in your differential?Warthin’s tumor
What’s a treatment protocol for a subcondylar fracture (neither high nor low)? Tight MMF for 3 weeks, elastics for 3 weeks, elastics only at night for 3 more weeks. The condyle will not heal in the right place, therefore the occlusion will depend on muscle memory. There will always be a CR/CO discrepancy on the affected site after fracture heals.
What is the sensory innervation of the TM joint? Greater auricular, auriculotemporal and deep temporal nerves all contribute.
