The nose & Paranasal sinuses

1. The nose & Paranasal sinuses • Bones around the nasal cavity are hollowed out • These cavities are the paranasal sinuses and communicate by small aperture with the cavity • Lighten the face • Resonance of voice • Insulator for incoming cold air • Determine the position of the orbital cavities • Lined by respiratory epithelium, columnar ciliated with mucous glands

2. The nose & Paranasal sinuses • The maxillary sinus: • It is pyramidal in shape with • The base at the lateral wall of the nose • The apex the zygomatic process of the maxilla. • The roof is the floor of the orbit • The floor is the alveolar process of the maxilla

3. The nose & Paranasal sinuses • Begins developing about the 4th month of intra-uterine life and continue to grow till the 3rd decade • It varies in size and is the largest of all the paranasal sinuses

4. The nose & Paranasal sinuses • It lies at a lower level than the floor of the nose. • The ostium is high up on its nasal wall, 2 – 4 mm in diameter at the posterior end of hiatus semilunaris in the middle meatus.

5. The nose & Paranasal sinuses • The infra-orbital nerve lie in the roof, its branches to the teeth descend along the anterolateral wall, leadind to facial and dental pain when the sinus is diseased • The upper teeth are in close relation to the floor, 1st and 2nd molar teeth • Disease of the sinus as a result of infected teeth

6. The nose & Paranasal sinuses maxillary sinus: • Blood supply: • Branches from the facial, maxillary, infraorbital and greater palatine arteries • Nerve supply: • supplied by branches from the superior alveolar nerves and the greater palatine nerve. • Lymph drainage: • drain into the submandibular lymph nodes

7. The nose & Paranasal sinuses • Ethmoidal sinus: • lies between the orbit and the nose in the ethmoidal labyrinth. • It is not a single cavity (8-10 thin-walled intercommunicating cavities) • It is divided by bony septa into three ethmoidal air cells, anterior, middle and posterior, each with it is own ostium, draining into the middle and superior meatus.

8. The nose & Paranasal sinuses • The lateral wall is the medial surface of the orbit • The medial wall is the lateral surface of the nasal cavity with the superior and middle conchae projecting from it

9. The nose & Paranasal sinuses • Above is the anterior cranial fossa and the frontal lobe • Anteriorly, is the frontal sinus • Posteriorly, the sphenoid bone • Inferiorly, the nose • Separated from these surrounding structures by thin wall • Infection (ethmoiditis) spread rapidly • is the commonest cause of orbital cellulitis • Meningitis, subdural and cerebral abscesses and cavernous sinus thrombosis

10. The nose & Paranasal sinuses Ethmoidal sinus: • Blood supply: • from both internal and external carotid arteries via the supraorbital, anterior and posterior ethmoidal and sphenopalatine. • Nerve supply: • from both maxillary and ophthalmic nerves, supra-orbital, anterior & posterior ethmoidal, orbital and lateral posterior nasal. Referred pain ??? • Lymph drainage: • submandibular and retropharyngeal nodes.

11. The nose & Paranasal sinuses • Sphenoidal sinus: • A large cavity situated in the body of the sphenoid bone • Divided by a septum that bend to one side leading to right and left halves, that vary greatly in size. • It lies beneath the pituitary fossa, extend into the basiocciput, greater wing of sphenoid and the pterygoid process. • Begins to develop at the 5th month of I-U life as a recess in the nasal bone and extend into the sphenoid bone at the age of 7

12. The nose & Paranasal sinuses • The roof is related to the pituitary fossa and the optic nerve – sudden loss of vision in case of sinus infection • Anteriorly, the ethmoid air cells • Lateral, the cavernous sinus containing the internal carotid artery and Abducent nerve – Stabismus and Diplopia • The floor is the nose

13. The nose & Paranasal sinuses • The ostium is in the anterior wall of the sinus and open into the sphenoethmoidal recess, above superior concha. • Blood supply: • posterior ethmoidal & sphenopalatine from maxillary • Nerve supply: • posterior ethmoidal • orbital branch of pterygopalatine ganglion • ophthalmic and maxillary nerve

14. The nose & Paranasal sinuses • Frontal sinus: • the only sinuses not present at birth, appear after the second year. • The two sinuses are unequal in extent. They are related to the anterior cranial fossa and the orbit • It present a posterosuperior wall, anterior wall and floor • Posterosuperior wall is thin and separate the sinus from the meninges and the frontal lobe of the brain • The anterior wall form the forehead • The floor separate the sinus fron the orbit, nose and anterior ethmoid sinus

15. The nose & Paranasal sinuses • The ostium open into the semilunar hiatus, with the other openings: • Infection travel from one sinus to the other • Deviation of the nasal septum might aggravate the infection • Infection give serious complications • The posterosuperior wall, infecting the brain • The floor, eye infection • Blood supply: • supratrochlear, supraorbital and anterior ethmoidal • Nerve supply: • supraorbital and supratrochlear nerves.

16. The nose & Paranasal sinuses • Clinically: • Maxillary sinus • might get infected from the nasal cavity or upper molar teeth • Ca maxillary sinus might spread medially, superiorly, inferiorly, laterally or posteriorly. • Ethmoidal and frontal Sinuses: • Frontal lobe abscess • Fracture with C.S.F. leak