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- Dr. Dona Bhattacharya
Surgical anatomy of maxillary sinus – note on OAF
Contents1. Introduction 2. Embryology of maxillary sinus3. Anatomy of maxillary sinus4. Vascularization & innervation5. Microscopic anatomy 6. Physiologic nature of mucus layer7. Drainage of sinus8. Functions of sinus9. Maxillary sinusitis10. Oroantral fistula11. Conclusion12. References
IntroductionParanasal sinuses
Air containing bony spaces present around the nasal cavity
Usually lined by respiratory mucus membrane
Four paired
Maxillary sinusPneumatic space lodged in
the body of maxilla that communicates with the external environment by way of middle meatus and nasal vestibule - by Orban’s
Also known as antrum of Highmore (1651)
EmbryologyFirst sinus to develop
Initial development of sinus follows number of morphogenic events in differentiation of nasal cavity
EmbryologyHorizontal shift of palatal shelves
and fusion with one another
Nasal septum separates 20 Oral cavity from nasal chambers
Influence expansion of lateral nasal wall and 3 walls begin to fold
3 conchae & meatus
Superior & inferior- Shallow depression
for half of IU Life
Middle- Expansion in lateral wall and in inferior
direction
EmbryologyDevelopment of sinus
begins as evagination of mucus membrane in lateral wall of middle meatus when nasal epithelium invades maxillary mesenchyme ( Kitamura, 1989)
Growth of sinus takes place by pneumatization Primary (10th weeks) Secondary (5th month)
EmbryologyMaxillary sinus has biphasic growth 0-3 years
and 7-12 yearsPost natally grows @ 2 mm vertically and 3
mm AP Radiographically; triangular area medial to
IOF (5th month)3 growth spurts
a) 0-2.5 yearsb) 7.5-10 yearsc) 12-14 years
Embryology
0-3 years• Ovoid
appearance
• 7 mm x 4mm x 4mm volume 6-8 ml
• 5th month - pneumatization
• 20th month – posterior development
• 3rd year – ½ adult size
3-4 years• ↑ in width with
facial growth
• Position; 2nd deciduous molars and crypts of 1st permanent molars
• Prone to infections
7-9 years• Dimensions 27
mm x 18 mm x 17 mm
• Growth corresponding to permanent teeth eruption
• Canine present as ridge in anterior surface of sinus
Embryology
9-12 years• Antral floor
same level with nasal floor
• Portions of alveolar process vacated become pneumatized
• Assumes pyramidal shape
12-15 years• Floor of sinus
5–12.5 mm below nasal floor
• Dimensions 32-34 mm x 28-33 mm x 23-25 mm
• Volume 15-20 ml
• Floor i.r.t 1st and 2nd molars and 2nd premolar
Old age• Resorption of
ridge – thinning of sinus wall
• Extension of sinus till crest
• Anterior & infratemporal surface reverts to infantile condition
Embryology
Embryology
Developmental anomalies1. Agenesis 2. Aplasia3. Hypoplasia4. Supernumary maxillary sinus
AnatomyLargest of
PNS,communicate with other sinuses through lateral nasal wall.
Horizontal Pyramidal shaped
BaseApex4 walls
Wall thickness varies with individual
superior
inferior
lateralanterior
AnatomyVarious shapes
Hyperbolic-47% Paraboloid-30% Semi-ellipsoid-15% Cone shaped-8%
Dimensions (Therner, 1902) H: 3.5cm W: 2.5cm L: 3.25cm
Vol:15-30 ml
AnatomyReceses-
Alveolar Zygomatic Palatal Frontal
Teeth in proximity 2nd, 1st , molar>3rd molar>2nd pm>1st pm>canine
Medial wallFormed by lat nasal wall
Below-inf nasal conchaeBehind-palatine boneAbove-uncinate process of ethmoid,lacrimal
bone
Contains double layer of mucous membrane(pars membranacea)
Medial wall
Imp structures Sinus ostium Hiatus semilunaris Ethmoidal bulla Uncinate process Infundibulum
Applied aspect
Natural ostiumLocated in posterior ½
of infundibulum or behind lower1/3 of uncinate process.
Tunnel shaped, length: 1-22mm;3-6mm diameter
Not detected endoscopically
Unfavorable position for gravity dependent drainage
Post edge-continuous with lamina papyracea(imp for surgical dissection)
Accessory ostium
2-3 in no.(30-40%)Bony dehiscences covered by
mucosa(ant/post frontanelles)
Superior wall
Forms roof of sinus and floor of orbitImp structures
Infraorbital canal Infraorbital foramen ASA nerve
Applied aspect Vulnerable to trauma Erosion of this wall by tumor
Posterolateral wallMade of zygomatic and greater wing of sphenoid
bone(maxillary tuberosity)Thick laterally,thin mediallyImp structures
PSA nerve Maxillary artery Maxillary nerve Pterygopalatine ganglion Nerve of pterygoid canal
Applied aspect Involvement of PSA-pain in post teeth Surgical access by careful removal of segment of wall
Anterior wallExtends from pyriform aperture anteriorly to ZM
suture & IO rim superiorly to alveolar process inferiorly.Convexity towards sinusThinnest in canine fossaImp structures
Infraorbital foramenASA, MSA nervesLevator labii, obicularis oculi muscles
Applied aspect
Floor of sinusFormed by junction of anterior
sinus wall and lateral nasal wall
1-1.2 cm below nasal floor Close relationship between
sinus and teeth facilitate spread of pathology
Inner surface is rough by bony septaRetrieval of root fragment Interferes with sinus
drainage
Vascularization & innervation
Arterial Supply
a) Nasal Mucosal Vasculature
SP, Ethmoid
b) Osseous Vasculature
IO, PSA, ASA, GP, Facial
Venous Drainagea) Medial wall - SP
b) Other walls – Pterygomaxillary Plexus
Lymphatic Drainage Collecting vessels in middle meatus
Nerve Innervation ION, GP, PSA, MSA, ASA
Clinical significancePO2 of sinus = 116 mm Hg
Vascularization & innervation
Microscopic anatomy3 layers
EpitheliumBasal laminaSub epithelium
EpitheliumPseudostratified columnar ciliated epithelium Cells
Columnar ciliated Goblet BasalNon – ciliated
Ciliated epithelium100 motile and no. of immotile microvilli
present along apical surfaceFunction: mucus clearance along with
entrapped debris from nose and PNSCiliary motility dependent on ATP driven
molecular motors cause outer doublets of axoneme to slide over each other
All cilia beat together to form metachronous wave
Each cilia has power stroke followed by recovery stroke
Ciliated epithelium
Microvilli
Hair like projection of actin filament Length 1-2 mm Function:
Increase surface area of cellPrevent drying of surface
Physiologic nature of mucus layer
Sino nasal epithelium covered by mucus blanket
Traps particles>0.5-1 umComposition
Water (95%)Others (5 %)
Peptides Salts Debris
Ph = 5.5-6.5
Physiologic nature of mucus layer
2 layers
Inner sol- Continuous
- Low viscosity- Surrounds shafts of
cilia
Outer gel-Discontinuous- High viscosity
-Along ciliary tips
Drainage of sinus
Mucus transported from nose and PNS to nasopharynx, ingested and presented to GIT (Messerklinger)
Forms basis of fess
Drainage of sinus
Mucociliary flow from anterior sinuses converge at OMC, carried to posterior nasopharynx & inferiorly to eustachian
tube orifice
Mucus coursing along lateral wall, carried medially along roof to reach ostrium
Drainage into ethmoidal infumdibulum
Upward course along walls of entire cavity and then towards natural ostium in superomedial wall
Flow of mucus superiorly against gravity
By Donald et al & Antunes et al
Drainage of sinus
Drainage of sinusMucociliary flow Smooth:0.85 cm/minute
Jerky: 0.3 cm/minute
Mucostasis: <0.3 cm/minute
Basal lamina & subepithelium
Contains serous glands and blood vesselsSubepithelium – 10 serousMucosa removal – 73% decrease in serous
glands and 30% in goblet cells
Functions of sinus1. Decrease skull weight2. Impart resonance to voice3. Mucus production and storage4. Humidify and warm inhaled air5. Define facial contour6. Immunodefensive action7. Conserve heat from nasal fossae8. Moisturize air9. Filters debris10. Dampen pressure differential during inspiration11. Limit extent of facial injury from trauma12. Serves as accessory olfactory organ
Maxillary sinusitis
Group of diseases mainly inflammation & infection which affect the nasal mucosa and PNS
Maxillary sinusitis
Classification
According to duration
a) Acute: 7 days - 4 weekb) Subacute: 4-12 weekc) Chronic : > 12 weekd) Recurrent acute: 4 episodes per year
Presence/absence of
polyps/etiology
a) Bacterial b) Fungalc) Virald) Mycobacteriae) Parasite
Based on histological
markers
a) EO chronic hyperplasticb) EO chronicc) Non EO chronic hyperplasticd) Non EO chronic
Maxillary sinusitisAnatomical variations
influencing the development of sinusitis
a) Variations of uncinate process
b) Variations in bulla ethmoidalis
c) Variations of middle turbinate
d) Accessory ostium e) Deviated nasal septumf) Nasal masses g) Haller cell
Maxillary sinusitis
1. Infectious causesa) Bacterial b) Viral c) Fungald) Parasitic
2. Non infectious causesa) Allergicb) Non allergicc) Pharmocologic d) Irritants
3. Disruption of mucociliary drainagea) Surgeryb) Infectionc) Trauma
Extrinsic causes 1. Genetic
a) Structuralb) Immunodeficiencyc) Mucociliary abnormality(cystic fibrosis, dismotility)
2. Acquireda) Aspirin hypersensitivityb) Autonomic dysregulationc) Hormonal d) Structural (Tumors, cysts)e)Idiopathic/ autoimmunef) Immunodeficiency
Intrinsic causes
Maxillary sinusitisDiagnosis
1. History 2. Physical examination
Inspection Palpation Percussion Diagnostic techniques
a. Rhinoscopyb. Endoscopyc. Nasal valve
examinationd. Culture and sensitivity
Maxillary sinusitisMajor & Minor Factor Associated with the
Diagnosis of Chronic Rhinosinusitis
Major Factors Minor Factors
Facial pain/pressure Headache
Facial congestion/fullness
Fever (non-acute cases)
Nasal obstruction/blockage
Halitosis
Nasal discharge/purgulence/discolored postnasal discharge
Fatigue
Hyposmia/anosmia Dental pain
Purulence in nasal cavity on examination
Cough
Fever (in acute rhinosinusitis only)
Ear pain/pressure/fullness
Maxillary sinusitis3. Radiological examination
a) OM viewb) Caldwell viewc) Lateral viewd) CT scane) MRI
4. Tests for mucociliary functionsa) Nasomucociliary clearanceb) Ciliary beat frequencyc) NO measurementd) Rhinomanometry
5. Test for olfaction
Maxillary sinusitisManagement
Medical
1. Antibiotics2. Steroids3. Decongestants4. Analgesics5. Antihistamines6. Nasal spray & saline irrigation7. Hydration8. Mucolytics(guaifenesin,KI)
Surgical
1. sinus aspiration and lavage2. Maxillary needle sinusotomy3. Caldwell luc4. FESS
AntibioticsAntibiotic Micro factors Pediatric dosage
First line therapy
Amoxicillin45 mg/kg/day or 90 mg/kg/day divided
500 g BID
Second line therapy
Amoxicillin/potassium calvulanate
22.5-45 mg/kg/day divided (dose based on amoxicillin component)
500-875 mg BID
Azithromycin10 mg/kg/day on day 1, then 5 mg/kg/day on days 2-5
500 mg QID on day 1, then 250 mg QID on days 2-5
Cefdinir 14 mg/kg/day 300 mg BID
Cefpodoxime 10 mg/kg/QID 200 mg BID
Cefprozil 15 mg/kg/QID 250-500 mg BID
Cefuroxime 15 mg/kg/QID 250 mg BID
Ciprofloxacin 500 mg BID
Clarithromycin 7.5 mg/kg/day 500 mg BID
Cindamycin 8-20 mg/kg/day divided QID 150-450 mg BID
Doxycycline 100-200 mg QID
Garifloxacin 400 mg QID
Levofloxacin 500 mg QID
Sulfamethoxazole/trimethoprim
6-12 mg/kg/day divided (based on trimethoprim)
800-160 mg BID
Steroids
1st line of therapy: topical intranasal (betamethasone, dexamethasone, triamcinolone)
Systemic steroids: Prednisolone:0.5-1mg/kg x3-4 days
Decongestants
Systemic (phenylpropanolamine, pseudoephidrine):
Contraindications: hypertension, hyperthyroidism, asthma
Topical: phenylepinephrine HCl, oxymetazoline HCl
Adv. Effects- rhinitis medicamentosa
Analgesics & antihistamines
Analgesics: Opoid: acetaminophen, codeine NSAIDS:
Antihistamines: Mequitazine, terfenad Contraindicated in bacterial sinusitis Adv effect: sedation
Nasal lavage & sprays
m/a: Removes debris & dead tissue Washes inflammatory secretions Eliminates nutrient source
Methods: Lavage pot Syringe Irrigating bulb
Nasal lavage & sprays
Techniques of nasal sprays1. Moffet position2. Mygind technique
Surgical management
Indications
• Bilateral chronic sinusitis with polyps
• Fungal sinusitis• Presence of
complications• Tumor of PNS• Csf rhinorrhea
Contraindications
• Presence of extensive polyps
• Pt withc/c of headache and midfacial pain
• Medically compromised
• Hypoplastic sinuses
Sinus aspiration & lavageDirect removal of bacteria laden secretionsIndication: no response to medical therapyD/A
Maxillary needle sinusotomyd/a
Requires force to enter anterior wall
Alternatives: Mallet Steinmann pin
Complications: Bleeding Infection Dental injury Sensory nerve disturbance Instrument breakage
Infiltration of LA
Preparation of site
Transcutaneous puncture ant & post to canine eminence
Caldwell luc sinusotomyBy George Caldwell (1893) & Henry Luc (1897)Indications
Fungal sinusitis Multiple antral lesions Antrochoanal polyp Excision of tumor Closure of OAF Removal of antral foreign body Antral revision procedures surgical approach for transantral
sphenoethmoidectomy, orbital decompression
Caldwell luc sinusotomy
Caldwell luc sinusotomy
ModificationsComplications
Bleeding Dental sensitivity Infraorbital neuralgia Osseous defect in anterolateral wall Entrapment of inferior rectus muscle
FESSCoined by Kennedy
Intranasal endoscopic technique that allows establishment of adequate sinus drainage without negative impact on sinus mucosa physiology and function.
Principle: stop the cycle that begins with ostium blockage that leads to chronic sinusitis via stagnated secretions, tissue inflammation and bacterial infections.
FESSArmamentarium
FESS
FESS
Minor hemorrhageHyposmiaAdhesionsPeriorbital emphysema
Intracranial hemorrhageBrain injuryCSF leakDiplopiaBlindnessAnosmiaEpistaxisNL duct injuryMeningitis
Complications
SinusitisComplications:
Facial cellulitisOrbital
extensionIntracranial
extension
Oroantral fistulaFistular canal between oral cavity and
sinal mucous membrane covered with epithelium which may or may not be filled with granulation tissue or polyposis.
Duration and width of lumen contributes to infection of sinus.
OAC OAF(incidence: 0.3-3.8 %)
Oroantral fistula
OAC OAF Defect > 5mm diameter No approximation of gingival tissues Post op regime not followed Loss of clot or wound dehiscence Cyst enucleation Smoking, drinking
Oroantral fistulaEtiology
• Iatrogenic (50%)• Presence of periapical lesions• Injudicious use of instruments• During attempted extraction• Trauma(7.5%)• Chronic infections(11%)• Malignant diseases(18.5%)• Infected maxillary dentures(3.7%)• h/o sinus surgery(7.5%)
Oroantral fistulaPredisposing factors
• Proximity of sinus floor / tuberosity• Thickened tooth cement / tooth fused to jaw bone• Infected teeth / long-standing decay• Marked periodontitis / gum disease• Lone-standing• Previous history of OAC’s.
Oroantral fistula
Acute Chronic
1. Escape of air and fluids through nose & mouth
1.Pain, tenderness over cheeks
2. Epistaxis 2. Purulent discharge
3. Excruciating pain 3. Post nasal drip
4. Altered voice 4. Presence of polyps
5. h/o surgery in vicinity of sinus 5. Generalized constitutional symptoms
Common in males,2nd-3rd decade Immediate sign:
Displaced root /tooth Tuberosity #
Oroantral fistulaDiagnosis
h/o previous extractionValsavin testMouth mirror testCotton wisp testInspectionRadiological
IOPAOPGOM
Oroantral fistulaManagement
• 3mm-5mm heals spontaneously(HANAZANE)• Ideal treatment :immediate surgery followed by
Ab prophylaxis• Acute OAF: closure by simple reduction of
buccal and palatal socket walls, followed by acrylic splint.
• Treatment for small opening
Oroantral fistula
1) antibiotics : Pn & derivatives2) nasal decongestants:
Ephedrine dropsInhalations(steam,benzoin ,menthol)
3) Analgesics:Aspirin 500mgParacetamol 500mgIbuprofen 400 mg
4) Antral lavage
Oroantral fistulaAntral lavage
Oroantral fistulaWhitehead’s varnish
Oroantral fistula• Acrylic plates
Surgical closure
Closure of Oroantral Communications:A Review of the Literature, Susan H. Visscher et al, J Oral Maxillofac Surg68:1384-1391, 2010
•Temporalis flap•Forehead flap
Overview of the treatment modalities of Oro-Antral Communications
Surgical closure
Factors determining flap selection Size of communication Timeline of diagnosing Presence of infection
Buccal flap• Advantages• Disadvantages• Modifications
• Moczaic• Laskin & Robinson
Palatal flap
Palatal pedicle flapA) Ito & Hara
modificationB) Island flap
Gullane & Arene modification
Combined flap
Distant flaps
BUCCAL FAT PAD
Tongue flap
Introduced by lexer,1909TechniqueAdvantagesDisadvantages
Grafts
GraftsGRAFTS
AUTOGENOUSIliac crestChinRetromolar areaZygoma
ALLOGENOUSCollagen sheetFibrin glueGold foilTantalumPMMAHydroxyapatite
XENOGRAFTSPorcine dermisBio guide & Bio oss
Sandwich Technique
Other techniques
Third molar transplantation(kitagawa et al)Interseptal alveolotomy(hori et al)GTR(Waldrop & Semba)Prolamine gel(Gotzfried & Kaduk)Laser light(Janas)Splints for immunocompromised pts(llogan and
coates)
Conclusion
Due to close proximity of maxillary sinus to orbit, alveolar ridge, maxillary teeth, diseases involving these structures may produce confusing symptoms. Hence a precise information about the surgical anatomy is essential to surgeons.
The oroantral fistula is a problem that requires detailed attention to the management of a flap in the mouth. For the sake of obtaining the best results and to give the patient the benefit , proper knowledge about the different types of modalities and their limitations is necessary.
References
• ECAB: Clinical update-otorhinolaryngology-Paranasal sinuses and rhinosinusitis-V.P Sood
• OMFSClinics of North America-Diagnosis & treatment of disorders of maxillary sinus-Laskin
• Principles of oral and maxillofacial surgery-Peterson
• Textbook of oral and maxillofacial surgery-Killey and kay
• Maxillary sinus and its dental implications:dental practice handbook-Killey and Kay
• Review of oral and maxillofacial surgery-Ghosh
References
• Open access atlas of otolaryngology, head & neck operative surgery -johan fagan
• Treatment of Oroantral Fistula-Klara Sokler et al, Acta Stomatol Croat, Vol. 36, br. 1, 2002
• Oronasal fistula closure by tongue flap-Manimaran K et al, JIADS,Jan-mar 2011
• A New Surgical Management for Oro-antral Communication,The Resorbable Guided Tissue Regeneration Membrane – Bone Substitute Sandwich Technique-C Ogunsalu, West Indian Med J 2005; 54 (4): 261
Thank You
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