2. Contents
1. Introduction
2. Embryology of maxillary sinus
3. Anatomy of maxillary sinus
4. Vascularization & innervation
5. Microscopic anatomy
6. Physiologic nature of mucus layer
7. Drainage of sinus
8. Functions of sinus
9. Maxillary sinusitis
10. Oroantral fistula
11. Conclusion
12. References
3. Introduction
Paranasal sinuses
Air containing bony spaces present
around the nasal cavity
Usually lined by respiratory
mucus membrane
Four paired
4. Maxillary sinus
Pneumatic 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)
5. Embryology
First sinus to develop
Initial development of sinus follows number of morphogenic
events in differentiation of nasal cavity
6. Embryology
Horizontal 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
Superior & inferior
- Shallow depression for
half of IU Life
3 conchae & meatus
Middle
- Expansion in lateral wall
and in inferior direction
7. Embryology
Development 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)
8. Embryology
Maxillary sinus has biphasic growth 0-3 years and 7-12
years
Post natally grows @ 2 mm vertically and 3 mm AP
Radiographically; triangular area medial to IOF (5th
month)
3 growth spurts
a) 0-2.5 years
b) 7.5-10 years
c) 12-14 years
13. Anatomy
Largest of PNS,communicate
with other sinuses through
lateral nasal wall.
Horizontal Pyramidal shaped
Base
Apex
4 walls
superior
inferior
lateral
anterior
Wall thickness varies with
individual
16. Medial wall
Formed by lat nasal wall
Below-inf nasal conchae
Behind-palatine bone
Above-uncinate process
of ethmoid,lacrimal bone
Contains double layer of
mucous membrane(pars
membranacea)
18. Natural ostium
Located 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)
19. Accessory ostium
2-3 in no.(30-40%)
Bony dehiscences covered by mucosa(ant/post
frontanelles)
20. Superior wall
Forms roof of sinus and floor of orbit
Imp structures
Infraorbital canal
Infraorbital foramen
ASA nerve
Applied aspect
Vulnerable to trauma
Erosion of this wall by tumor
21. Posterolateral wall
Made of zygomatic and greater wing of sphenoid
bone(maxillary tuberosity)
Thick laterally,thin medially
Imp 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
22. Anterior wall
Extends from pyriform aperture anteriorly to ZM suture
& IO rim superiorly to alveolar process inferiorly.
Convexity towards sinus
Thinnest in canine fossa
Imp structures
Infraorbital foramen
ASA, MSA nerves
Levator labii, obicularis oculi muscles
Applied aspect
23. Floor of sinus
Formed 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
septa
Retrieval of root fragment
Interferes with sinus drainage
24. Vascularization & innervation
a) Nasal Mucosal Vasculature
SP, Ethmoid
Arterial Supply
b) Osseous Vasculature
IO, PSA, ASA, GP, Facial
a) Medial wall - SP
Venous Drainage
b) Other walls – Pterygomaxillary Plexus
Lymphatic Drainage Collecting vessels in middle meatus
Nerve Innervation ION, GP, PSA, MSA, ASA
Clinical significance
PO2 of sinus = 116 mm Hg
28. Ciliated epithelium
100 motile and no. of immotile microvilli present
along apical surface
Function: mucus clearance along with entrapped
debris from nose and PNS
Ciliary 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
30. Microvilli
Hair like projection of actin filament
Length 1-2 mm
Function:
Increase surface area of cell
Prevent drying of surface
31. Physiologic nature of mucus layer
Sino nasal epithelium covered by mucus blanket
Traps particles>0.5-1 um
Composition
Water (95%)
Others (5 %)
Peptides
Salts
Debris
Ph = 5.5-6.5
32. Physiologic nature of mucus layer
2 layers
Inner sol Outer gel
- Continuous -Discontinuous
- Low viscosity - High viscosity
- Surrounds shafts of cilia -Along ciliary tips
33. Drainage of sinus
Mucus transported from nose and PNS to
nasopharynx, ingested and presented to GIT
(Messerklinger)
Forms basis of fess
34. Drainage of sinus
Flow of mucus superiorly against gravity
Upward course along walls of entire cavity and then towards natural
ostium in superomedial wall
Drainage into ethmoidal infumdibulum
Mucus coursing along lateral wall, carried medially along roof to reach
ostrium
Mucociliary flow from anterior sinuses converge at OMC, carried to
posterior nasopharynx & inferiorly to eustachian tube orifice
By Donald et al & Antunes et al
37. Basal lamina & subepithelium
Contains serous glands and blood vessels
Subepithelium – 10 serous
Mucosa removal – 73% decrease in serous glands and
30% in goblet cells
38. Functions of sinus
1. Decrease skull weight
2. Impart resonance to voice
3. Mucus production and storage
4. Humidify and warm inhaled air
5. Define facial contour
6. Immunodefensive action
7. Conserve heat from nasal fossae
8. Moisturize air
9. Filters debris
10. Dampen pressure differential during inspiration
11. Limit extent of facial injury from trauma
12. Serves as accessory olfactory organ
39. Maxillary sinusitis
Group of diseases
mainly inflammation &
infection which affect
the nasal mucosa and
PNS
41. Maxillary sinusitis
Anatomical 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 septum
f) Nasal masses
g) Haller cell
42. Maxillary sinusitis
Extrinsic Intrinsic
causes 1. Infectious causes causes 1. Genetic
a) Bacterial a) Structural
b) Viral b) Immunodeficiency
c) Fungal c) Mucociliary
d) Parasitic abnormality
2. Non infectious (cystic
causes fibrosis, dismotility)
a) Allergic 2. Acquired
b) Non allergic a) Aspirin
hypersensitivity
c) Pharmocologic
b) Autonomic
d) Irritants dysregulation
c) Hormonal
3. Disruption of
mucociliary drainage d) Structural
(Tumors, cysts)
a) Surgery
e)Idiopathic/
b) Infection autoimmune
c) Trauma f) Immunodeficiency
43. Maxillary sinusitis
Diagnosis
1. History
2. Physical examination
Inspection
Palpation
Percussion
Diagnostic techniques
a. Rhinoscopy
b. Endoscopy
c. Nasal valve examination
d. Culture and sensitivity
44. Maxillary sinusitis
Major & 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 Fatigue
discharge/purgulence/discol
ored postnasal discharge
Hyposmia/anosmia Dental pain
Purulence in nasal cavity on Cough
examination
Fever (in acute rhinosinusitis Ear pain/pressure/fullness
only)
45. Maxillary sinusitis
3. Radiological examination
a) OM view
b) Caldwell view
c) Lateral view
d) CT scan
e) MRI
4. Tests for mucociliary functions
a) Nasomucociliary clearance
b) Ciliary beat frequency
c) NO measurement
d) Rhinomanometry
5. Test for olfaction
52. Nasal lavage & sprays
Techniques of nasal sprays
1. Moffet position
2. Mygind technique
53. Surgical management
Indications Contraindications
• Bilateral chronic • Presence of
sinusitis with polyps extensive polyps
• Fungal sinusitis • Pt withc/c of
• Presence of headache and
complications midfacial pain
• Tumor of PNS • Medically
• Csf rhinorrhea compromised
• Hypoplastic sinuses
54. Sinus aspiration & lavage
Direct removal of bacteria laden secretions
Indication: no response to medical therapy
D/A
55. Maxillary needle sinusotomy
d/a
Requires force to enter anterior wall
Preparation of site
Alternatives:
Mallet
Infiltration of LA
Steinmann pin
Complications:
Transcutaneous
Bleeding
puncture ant & post to
canine eminence Infection
Dental injury
Sensory nerve disturbance
Instrument breakage
56. Caldwell luc sinusotomy
By 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
59. FESS
Coined 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
64. Oroantral fistula
Fistular 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 %)
65. 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
66. Oroantral fistula
Etiology
• 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%)
67. Oroantral fistula
Predisposing 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.
68. Oroantral fistula
Acute Chronic
1. Escape of air and fluids through nose & 1.Pain, tenderness over cheeks
mouth
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 #
69. Oroantral fistula
Diagnosis
h/o previous extraction
Valsavin test
Mouth mirror test
Cotton wisp test
Inspection
Radiological
IOPA
OPG
OM
70. Oroantral fistula
Management
• 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
75. Surgical closure
•Temporalis
flap
•Forehead
flap
Overview of the treatment modalities of Oro-Antral Communications
Closure of Oroantral Communications:A Review of the Literature, Susan H. Visscher et al, J Oral Maxillofac
Surg68:1384-1391, 2010
76. Surgical closure
Factors determining flap selection
Size of communication
Timeline of diagnosing
Presence of infection
86. 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)
87. 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.
88. 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
89. 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