Dr. Ahmed M. Adawy, Professor Emeritus, Dep. Oral & Maxillofacial Surgery. Former Dean, Faculty of Dental Medicine Al-Azhar University. There are four pairs of air sinuses making the boundaries of the nasal cavity. Maxillary sinus is the largest air cell. Anatomy and physiology of the maxillary sinus are given. Maxillary sinusitis is an inflammation of the sinus. Odontogenic causes represent nearly 30% of the etiology. Clinical and radiographic examinations are discussed together with treatment plan. Oro-antral fistula is a rare complication of surgery at the posterior maxillary region. Several techniques for closure are presented. Additionally, information about sinus lift procedure is given.

2. Dr. Ahmed M. Adawy
Professor Emeritus, Dep. Oral & Maxillofacial Surg.
Former Dean, Faculty of Dental Medicine
Al-Azhar University

3. There are a total of four paired sinuses, namely; frontal,
ethmoidal, maxillary and sphenoid sinuses. They form
the various boundaries of the nasal cavity. These sinuses
are essentially mucosa-lined airspaces within the bones
of the skull

4. Maxillary sinus, also known as antrum of Highmore. is a
hallow cavity lies chiefly within the body of the maxilla.
The maxillary sinus is pyramidal in shape with its base at
the naso-antral wall and its apex in the root of the zygoma.
In the adult, the upper wall or roof is thin and situated
under the orbit. The floor of the sinus is the alveolar
process of the maxilla. Medially, the nasal wall separates
the sinus from the nasal cavity. The nasal cavity contains
the outlet from the sinus through the ostium which is
situated beneath the roof of the antrum. This situation
precludes the possibility of good drainage
(1)

5. The nerve supply is from the maxillary branch of the 5th
cranial nerve. The posterior superior alveolar branch
supplies the lining mucosa of the sinus. Its blood supply is
derived from the infraorbital artery, a branch of the maxillary
artery. The adult maxillary sinus averages 34 mm in antero-
posterior direction, 33 mm in height, and 23 mm in width.
Its volume is approximately 15 cc. The sinuses are lined by
respiratory epithelium, a mucous secreting, pseudo-stratified,
ciliated columnar epithelium and periosteum. The cilia and
mucus are necessary for drainage of the sinus. Proper ciliary
function is especially important because the direction of
drainage is against the pull of gravity

6. Pneumatization of maxillary sinus, though generally
complete in adolescence, may still increases during
adulthood with further development into the alveolar
process especially when posterior maxillary teeth are lost
prematurely. In such instance, the antral cavity may be
near to the crest of the ridge. The roots of the maxillary
second bicuspid, first molar, and second molar are the
most frequently involved

7. The function of paranasal sinuses is:
 Give resonance to the voice
 Act as reserve chambers to warm the inspired air.
 Reduce the weight of the skull.
Several anatomic and physiologic features obstruct the flow of
drainage from the sinuses thus precipitating infection. These are:
Inadequate anatomic openings
Obstructive polyps
Septal deviation
Hyperplasia of the turbinate

8. The intimate anatomical relation of the upper teeth to the
maxillary sinus promotes the development of odontogenic
infection into the maxillary sinus. Recently, up to 30-40% of
chronic maxillary sinusitis cases have been attributed to
odontogenic cause . Sinusitis can be broadly defined as
inflammation of one or more of the paranasal sinuses.
Maxillary sinusitis occurs when the Schneiderian sinus
membrane is violated by conditions such as infections of the
maxillary posterior teeth, pathologic lesions of the jaws and
teeth, maxillary trauma, or by iatrogenic causes such as
dental and implant surgery complications and maxillofacial
surgery procedures in the posterior maxillary region
(2)

9. Classic symptoms suggestive of an odontogenic source can
include sinonasal symptoms such as unilateral nasal
obstruction, rhinorrhea, and/or foul odor and taste .
Headaches, unilateral anterior maxillary tenderness and
postnasal drip, may be additional symptoms . Tooth ache
is present in only 29% of the patients
Generally, sinusitis is classified as:
Acute when symptoms last less than 4 weeks
Subacute when symptoms last 4 to 8 weeks
Chronic when symptoms last longer than 8 weeks
Recurrent when three or more acute episodes a year
(3)
(4)
(5)

10. Clinical Examination
Palpation for tenderness over the lateral wall of the
sinus. Transillumination of the sinuses is an additional
diagnostic test. The light source is placed over the
infraorbital rim, in a darkened room and light
transmission is observed through the hard palate.
Compared with the sinus of the opposite side, the
involved sinus shows decreased transmission of light
due to accumulation of fluids, debris, pus and thickening
of the sinus mucosa.

11. Radiographic Examinations
Radiographic examination is an essential aid for the study
of pathologic conditions of the maxillary sinus.
Interpretation of radiographs is not difficult. The findings
in the normal antrum are those to be expected of a rather
large air filled cavity surrounded by bone and dental
structures. The body of the sinus should appear
radiolucent and should be outlined in all peripheral areas
by a well demarcated layer of cortical bone.

12. It is helpful to compare one side to the other when
examining the radiograph. There should be no evidence of
thickened mucosa on the bony walls (usually indicative of
chronic sinus disease), nor air filled levels caused by
accumulation of mucus, pus or blood, or foreign bodies.
Complete opacification of the maxillary sinus may be
caused by the mucosal hypertrophy and fluid
accumulation of sinusitis, filling with blood secondary to
trauma, or by neoplasia.
Dental pathologic conditions such as cysts or granulomas
may produce radiolucent lesions that extend into the sinus
cavity

13. Panoramic radiograph is particularly useful for evaluation
of the degree of pneumatization of maxillary sinus and its
relationship to the roots of maxillary teeth

14. Mucous retention cyst, Lt maxillary sinus

15. Water’s (occipito-mental) projection. Rt. side
maxillary sinusitis. Please note the “fluid level”

16. Water’s projection, showing complete opacification
of the Rt. maxillary sinus

17. CT scan - coronal section, carious maxillary first molars
with periapical lesions are associated with localized
thickening of mucosa in both maxillary sinuses

18. Axial CT scan demonstrates a trimalar fracture involving the
anterior and posterolateral walls of the left maxillary sinus and
the zygomatic arch (arrows) Note partial opacification of the
sinus

19. Although CT remains the gold standard in the diagnosis of
maxillary sinus diseases due to its high resolution and ability to
visualize detailed anatomy, MRI is best used to evaluate soft
tissue structures, and can distinguish between inflammatory
and malignant disease (6)
MRI: T2 axial and coronal sections showing a large
hypointense tumor mass in the left maxillary sinus

20. Although rare, complications of acute sinusitis
can occur through direct, local extension. Clinical
presentation may include facial edema, cellulitis,
orbital, visual, and meningeal involvement

21. 1. Elimination of the source of the infection
2. Amoxicillin is the first line of antibiotic choice. Purulent
material is submitted for culture and sensitivity testing
3.The result of the culture and sensitivity tests should be
evaluated and changes of the prescribed antibiotics should
be made if indicated
4. Local and systemic decongestants are used to decrease
mucosal edema and inflammation and to promote drainage
5. Contrary to acute form, chronic sinusitis do not respond
will to long term antibiotics. Instead, corticosteroids are
more efficacious
6. Surgical management may be indicated in cases refractory
to medical treatment

22. Indications for the Caldwell-Luc operation:
1. Retrieval of a root or tooth from the sinus
2. Enucleation of odontogenic cysts or mucoceles from the
sinus
3. Removal of odontogenic tumor from the sinus
4. Treatment of acute maxillary sinusitis resistant to
medical therapy or showing evidence of extending beyond
the sinus
5. Treatment of chronic sinusitis
6. Management of oroantral fistula
7. Repair of fractures of the antrum or zygoma

23. Caldwell-Luc operation comprises osteotomy of the
anterior sinus wall and creation of artificial opening of
the sinus into the inferior nasal meatus. The procedure
is criticized as aggressive surgery with relatively high
incidence of complications. Most important, the
efficacy of inferior meatal antrostomy, is doubtful, as
the mucociliary clearance remains directed toward the
natural sinus ostium in the middle meatus. Further,
opening of the sinus on its anterior wall has to be
performed, which results in permanent defect of
anterior maxilla, sclerosis of the antral walls and
collapse of the sinus cavity(7)

25. Because of less traumatic approach, lower rate of
complications and better preservation of antral lining,
functional endoscope sinus surgery has gained popularity
for last decades against Caldwell-Luc procedure in
treatment of chronic sinusitis of dental origin (8)

26. Oroantral communications are rare complications of oral
surgery. Extraction of maxillary posterior teeth is the
most common cause. Maxillary cysts, benign or
malignant tumors and trauma can be other causes. It
must be emphasized that unlike the oro-antral
communication, oro-antral fistula is characterized by the
presence of epithelium arising from the oral mucosa
and/or from the antral sinus mucosa that, if not removed,
could inhibit spontaneous healing. Closing this
communication is important to avoid food and saliva
contamination that could lead to bacterial infection,
impaired healing and chronic sinusitis.

27. The size of the fistula depends on the depth and range
of the surgical stress. Defects less than 3 mm and
without epithelialization might heal spontaneously in
the absence of infections. In the latter case, infection
must be cured before surgery to avoid impaired
drainage. Communications wider than 5mm require
surgical treatment.

28. Buccal sliding flap , is usually employed for
immediate closure of oro-antral communications. After
cutting the communication edges, two vertical release
incisions are made to provide a flap with dimensions
suitable for closure of the antral communication.
Mobilization of the flap is facilitated by horizontal
releasing incision of the periosteum and by reduction of
the alveolar bone height. The flap is then positioned
over the defect by means of mattress sutures from the
buccal flap to the palatal mucosa
(9)

30. In most instances, patients who present with a chronic
oroantral fistula not only require closure of the fistula but
also require management of the inflammatory sinus
disease that co-exists with the fistula. The most common
cause of failure is insufficient control of maxillary
sinusitis. For this reason, foreign bodies, infected and
degenerated polypoid mucosa and infected bone should be
removed. Functional endoscopic sinus surgery and
Caldwell-Luc procedure are the most important surgical
techniques used. Whatever, the used technique, excision of
the epithelialized fistulas tract should be performed first

32. The most common surgical technique for the closure
of an oroantral fistula is the buccal sliding flap. The
advantage of the buccal flap procedure is that it
allows the Caldwell-Luc operation and the closure of
the oroantral fistula to be performed simultaneously if
sinus disease is present. The disadvantage is that
nearly 50% of patients experience permanent
reduction of vestibular depth, and therefore needs for
a vestibuloplasty

33. Rotated palatal pedicle full thickness flap based on greater
palatine artery has been frequently used for closure of oro-
antral fistula . In contrast to the buccal flap, palatal flap
is more resilient, less prone to infection and does not lead
to lowering of the vestibule. The blood supply of palatal
flap is better than buccal flap and it is preferred in large
and recurrent oroantral fistulas. The drawbacks of this
technique include mild palatal surface denudation and the
kink that occurs along the arch of rotation which may
jeopardize the vascularity causing flap necrosis.
(10)

34. Rotated palatal pedicle flap

35. Various modifications of palatal flaps have been described
for closure of oroantral fistulas. One modification is the
Tunnel technique . The technique is characterized by
leaving a band of tissue between the pedicle flap and the
fistula on the palatal side. The pedicle flap is then tunneled
under the bridge of tissue before closing the fistula. This
reduce tension on the flap and help protect and stabilize it.
In addition, because flotation and upsurge are minimized
in the region of the mucoperiosteal flap, postoperative
discomfort can be relieved.
(11)

36. Tunnel Technique for the Closure of Oroantral Fistula

37. The palatal island flap is another modification
that is used to correct large palatal defect
involving soft palate. Sub mucosal connective
tissue pedicle flap is an additional modification
by which the epithelial layer is used to cover the
bone surface at the donor site

38. Buccal fat pad is another alternative that can be used to
close medium to large sized defect, particularly when the
fistula is located at the posterior region of the maxilla. The
tongue flap, whether anterior, lateral or posterior based,
can also be used to correct ore-antral fistulae with large
bony defect. Various materials like gold foil, gold plate,
tantalum plate, soft polymethylmethacrylate and bone
graft have been used to repair oro-antral fistula with
varying degrees of success

39. Sinus lift, sometimes called a sinus augmentation is
indicated when there is no enough bone in the upper jaw
(atrophic), or when the sinus is too close to the jaw, and
there is a need for dental implant to be placed. Elevation
of the maxillary sinus floor is an option in solving this
problem. Various surgical techniques have been presented
to enter the sinus cavity elevating the sinus membrane and
placing bone grafts. The use of autogenous bone grafts are
considered the gold standard due to their maintenance of
cellular viability and osteogenic capacity
(12)

40. To date, two main techniques of sinus floor elevation
are in use: a two-stage technique with a lateral window
approach, followed by implant placement after a
healing period, and a one-stage technique using either
a lateral or transalveolar approach. The decision to
apply the one or the two-stage techniques is based on
the amount of residual bone available and the
possibility of achieving primary stability for the
inserted implants

41. Dental implants after sinus lifting procedure,
two years follow-up radiograph

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