King Saud University Dental College Oral and Maxillofacial Surgery Maxillary Sinus in Health and Disease

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 √ 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.

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.

Anatomical morphology: √ 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.

√ Fully development reaches with the age of 16 years. √ 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.

Unknown but the following functions have been proposed: 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.

√ Secondary to hay fever and allergic rhinitis. 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.

√ Toxic manifestations. √ Heavy filling with bending. Sings and symptoms: √ Headache. √ Pain and tenderness. √ Nasal obstruction. √ Nasal discharge. √ Toxic manifestations. √ Heavy filling with bending. √ Nasal congestion. √ X-ray and transillumination findings.

√ Rest and fluid and mouth hygiene. 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).

Sinusitis 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.

√ As a consequence of non resolved acute sinusitis. Causes: √ As a consequence of non resolved acute sinusitis. √ Dental abscesses. √ Virulent organism with low resistance. √ Foreign body dislodgement or trauma.

√ Transllumination findings. √ Proof puncture. 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.

Clinical examination: Palpation √ Tenderness. √ Swelling and expansion. √ Depression.

Clinical examination: Examination of nasal passage √ Nasal patency. √ Pus discharge. √ Nasal polyps. √ Erythema, redness, change in the color of nasal mucosa.

Clinical examination: Transillumination

Clinical examination: 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.

Sinuscopy Sinogram CT scan MRI Radiographical examination: Special investigation and radiographical examination Sinuscopy Sinogram CT scan MRI

Microbiology and histological examination: Culture and sensitivity and biopsy.