Anatomical facts and location:
√ The largest
para-nasal sinuses.
√ Situated in
the maxilla.
√ Has pyramidal
shape.
√ Lateral nasal
bone forms its base.
√ Apex headed
towards the zygomatic bone.
√ Canine fossa, orbital floor and hard palate form the pyramidal walls.
√ Communicates with nasal cavity through maxillary ostium, in the posterior end of hitus simlunaris of middle meatus.
√ Canine fossa, orbital floor and hard palate form the pyramidal walls.
√ Communicates with nasal cavity through maxillary ostium, in the posterior end of hitus simlunaris of middle meatus.
Anatomical morphology:
√ Size varies from one person to another.
√ Asymmetry existed in the same individual.
√ Small in children and grows up with aging.
√ Average height is about 3.5 cm, depth 3.2 cm
and width 2.5 cm.
√ Capacity of about 15 cc.
√ Divided into several
compartments by bony septa (underwood’s septa).
√ Lined with pseduo-stratified
columnar ciliary epithelium (schneiderian membrane).
Relation with other structures:
√ Alveolar bone
and dentition.
√ Nasal cavity
and nasopharynex.
√ Orbital
cavity and its contents.
√ Hard palate
and oral cavity proper.
√
Pterygomaxillary fissure and its contents.
√ Neurovascular
structures including infraorbital and superior alveolar nerve.
Development:
√ Develops from invagination of the mucous
membrane of middle meatus of the nasal cavity at about the 3rd month of intrauterine life.
√ Fully development reaches with the age of 16
years.
√ Loss of permanent teeth and alveolar bone may
make the sinus to appear huge in size.
Blood supply:
Blood supply
from facial, maxillary, infraorbital, greater and lesser palatine arteries and
lateral and posterior nasal branches of sphenopalatine artery.
Venous drainage
to the anterior facial vein, sphenopalatine vein and pterygopaltine plexus.
Nerve supply:
√ Infraorbital nerve.
√ Posterior, middle and anterior superior
alveolar nerves.
√ Greater and lesser palatine nerves.
Lymphatic drain:
The lymphatic
drain of the sinus is through the nose or the submandibular lymph nodes.
Physiology:
Unknown but the
following functions have been proposed:
√ Speech and voice resonance.
√ Reduce weight of skull.
√ Warmth inspired air.
√ Filtration of inspired air.
√ Immunologic barrier ( body defense).
Pathology:
- Congenital anomalies.
- Inflammatory diseases.
- Cysts and odontogenic infection.
- Bone metaplasia and benign tumors.
- Neoplasia.
- Trauma.
Congenital anomalies:
√ Cleft palate.
√ Facial fistula and cleft.
√ Cystic formation.
√ Atresia.
Inflammatory diseases:
√ Bacterial infection.
√ Bacterial infection secondary to viral
infection.
√ Fungal infection.
Sinusitis
Acute sinusitis:
Suppurative or
non suppurative inflammation of the mucosal lining of the sinus. It involves
one or both sinuses.
Causes:
√ Secondary to hay fever and allergic rhinitis.
√ Secondary to acute rhinitis (common cold) and
URT infection.
√ Bacterial infection due to: dental sepsis,
swimming and diving, trauma and foreign body dislodgment.
Sings and symptoms:
√ Headache.
√ Pain and tenderness.
√ Nasal obstruction.
√ Nasal discharge.
√ Toxic manifestations.
√ Heavy filling with bending.
√ Nasal congestion.
√ X-ray and transillumination findings.
Treatment:
√ Rest and fluid and mouth hygiene.
√ Antibiotics (C&S); pneumococci and
streptococci are the most causative organisms.
√ Analgesics and antihistamines.
√ Local treatment (decongestant and steam
inhalation).
Chronic sinusitis:
It is a chronic
type of infection affected the mucosal lining of one or both sinuses, resulted in mucopus or pus
collection. A polypoidal type of inflammation can lead to formation of multiple
or single mucosal polyps.
Causes:
√ As a consequence of non resolved acute
sinusitis.
√ Dental abscesses.
√ Virulent organism with low resistance.
√ Foreign body dislodgement or trauma
Signs and symptoms:
√ Headache.
√ Nasal obstruction
√ Nasal discharge.
√ Fatigue.
√ Hyposmia/ cacosmia.
√ Transllumination findings.
√ Proof puncture.
Treatment:
√ Antibiotics.
√ Systemic decongestants.
√ Sinus wash-out.
Mycotic infection:
Aspergillosis:
Opportunistic
infection caused by maxillary sinus flora fungi environment in susceptible
individual, leads to obliteration of the sinus space and erosion of its bony
components.
Complications of sinusitis:
- Orbital abscess and orbital cellulites.
- Intracranial abscesses.
- Meningitis.
- Cavernous sinus thrombosis.
- Spread of infection to neighboring sinuses, structures and organs.
- Osteomyelitis.
- Gastrointestinal disturbances.
Cysts and odontogenic tumors:
Odontogenic
cysts:
√ radicular
cysts.
√ residual
cysts.
√ dentigerous
cysts.
√ premordial
cysts.
Non-odontogenic cysts.
Mucocele and
retention cysts.
Odontogenic tumors:
√
ameloblastoma.
√ Myxoma.
Bone metaplasia and benign tumors:
√ Fibrous dysplasia.
√ Ossifying fibroma.
√ Transitional papilloma.
√ Osteoma.
√ Giant cell lesions.
Neoplasia:
√ Squamous cell carcinoma.
√ Adenocarcinoma.
√ Sarcoma (osteosarcoma).
√ Ewing’s sarcoma.
Trauma:
√ Tuberosity fracture.
√ Dentoalveolar fracture.
√ LeFort’s fractures.
√ Zygomatic complex fracture.
√ Pure and impure orbital floor fractures.
√ Establishment of oro-antral fistula.
Clinical examination:
Inspection
√ Assess
asymmetry.
√ Color of
overlaying skin.
Palpation
√ Tenderness.
√ Swelling and expansion.
√ Depression.
Examination of nasal passage
√ Nasal
patency.
√ Pus
discharge.
√ Nasal polyps.
√ Erythema,
redness, change in the color of nasal mucosa.
Transillumination
Diagnostic sinus lavage
√ sinus rinsing
through the canine fosaa.
√ Nasal
antrostomy.
Radiographical examination:
Routine radiographical examination
√
Orthopantomogram (OPG)
√
Occipitomental (water’s view), with lateral tilt.
Special investigation and radiographical examination
- Sinuscopy
- Sinogram
- CT scan
- MRI
- Microbiology and histological examination:
- Culture and sensitivity and biopsy.
