The nose & Paranasal sinuses Bones around the nasal cavity are hollowed outBones around the nasal cavity are hollowed out These cavities are the paranasal

The nose & Paranasal sinusesThe nose & Paranasal sinuses

• Bones around the nasal cavity are Bones around the nasal cavity are hollowed out hollowed out

• These cavities are the paranasal These cavities are the paranasal sinuses and communicate by sinuses and communicate by small aperture with the cavitysmall aperture with the cavity

• Lighten the faceLighten the face• Resonance of voiceResonance of voice• Insulator for incoming Insulator for incoming

cold aircold air• Determine the position Determine the position

of the orbital cavitiesof the orbital cavities• Lined by respiratory epithelium, Lined by respiratory epithelium,

columnar ciliated with mucous columnar ciliated with mucous glandsglands


• The maxillary sinus:The maxillary sinus:• It is pyramidal in shape It is pyramidal in shape

with with • The base at the lateral The base at the lateral

wall of the nose wall of the nose

• The apex the zygomatic The apex the zygomatic process of the maxilla.process of the maxilla.

• The roof is the floor of The roof is the floor of the orbit the orbit

• The floor is the alveolar The floor is the alveolar process of the maxillaprocess of the maxilla


• Begins developing Begins developing about the 4about the 4thth month of month of intra-uterine life and intra-uterine life and continue to grow till continue to grow till the 3the 3rdrd decade decade

• It varies in size and is It varies in size and is the largest of all the the largest of all the paranasal sinusesparanasal sinuses


• It lies at a lower level than It lies at a lower level than the floor of the nose.the floor of the nose.

• The ostium is high up on its The ostium is high up on its nasal wall, 2 – 4 mm in nasal wall, 2 – 4 mm in diameter at the posterior diameter at the posterior end of hiatus semilunaris in end of hiatus semilunaris in the middle meatus. the middle meatus.


• The infra-orbital nerve lie The infra-orbital nerve lie in the roof, its branches to in the roof, its branches to the teeth descend along the teeth descend along the anterolateral wall, the anterolateral wall, leadind to facial and leadind to facial and dental pain when the sinus dental pain when the sinus is diseasedis diseased

• The upper teeth are in The upper teeth are in close relation to the floor, close relation to the floor, 11stst and 2 and 2ndnd molar teeth molar teeth• Disease of the sinus as a Disease of the sinus as a

result of infected teethresult of infected teeth

The nose & Paranasal sinuses The nose & Paranasal sinuses maxillary sinus:maxillary sinus:

• Blood supply:Blood supply:• Branches from the facial, maxillary, infraorbital Branches from the facial, maxillary, infraorbital

and greater palatine arteriesand greater palatine arteries

• Nerve supply:Nerve supply:• supplied by branches from the superior alveolar supplied by branches from the superior alveolar

nerves and the greater palatine nerve.nerves and the greater palatine nerve.

• Lymph drainage:Lymph drainage:• drain into the submandibular lymph nodesdrain into the submandibular lymph nodes


• Ethmoidal sinus:Ethmoidal sinus:• lies between the orbit and the lies between the orbit and the

nose in the ethmoidal labyrinth.nose in the ethmoidal labyrinth.

• It is not a single cavity (8-10 It is not a single cavity (8-10 thin-walled thin-walled intercommunicating cavities)intercommunicating cavities)

• It is divided by bony septa into It is divided by bony septa into three ethmoidal air cells, three ethmoidal air cells, anterior, middle and posterior, anterior, middle and posterior, each with it is own ostium, each with it is own ostium, draining into the middle and draining into the middle and superior meatus.superior meatus.


• The lateral wall is the The lateral wall is the medial surface of the orbit medial surface of the orbit

• The medial wall is the The medial wall is the lateral surface of the nasal lateral surface of the nasal cavity with the superior cavity with the superior and middle conchae and middle conchae projecting from it projecting from it


• Above is the anterior cranial Above is the anterior cranial fossa and the frontal lobefossa and the frontal lobe

• Anteriorly, is the frontal sinusAnteriorly, is the frontal sinus• Posteriorly, the sphenoid bonePosteriorly, the sphenoid bone• Inferiorly, the noseInferiorly, the nose• Separated from these Separated from these

surrounding structures by thin surrounding structures by thin wallwall• Infection (ethmoiditis) spread Infection (ethmoiditis) spread

rapidlyrapidly• is the commonest cause of is the commonest cause of

orbital cellulitis orbital cellulitis • Meningitis, subdural and Meningitis, subdural and

cerebral abscesses and cerebral abscesses and cavernous sinus thrombosiscavernous sinus thrombosis

The nose & Paranasal sinuses The nose & Paranasal sinuses Ethmoidal sinus:Ethmoidal sinus:

• Blood supply:Blood supply:• from both internal and external carotid arteries via from both internal and external carotid arteries via

the supraorbital, anterior and posterior ethmoidal the supraorbital, anterior and posterior ethmoidal and sphenopalatine.and sphenopalatine.

• Nerve supply:Nerve supply:• from both maxillary and ophthalmic nerves, supra-from both maxillary and ophthalmic nerves, supra-

orbital, anterior & posterior ethmoidal, orbital and orbital, anterior & posterior ethmoidal, orbital and lateral posterior nasal. lateral posterior nasal. Referred pain ???Referred pain ???

• Lymph drainage:Lymph drainage:• submandibular and retropharyngeal nodes. submandibular and retropharyngeal nodes.


• Sphenoidal sinus:Sphenoidal sinus:• A large cavity situated in the A large cavity situated in the

body of the sphenoid bonebody of the sphenoid bone• Divided by a septum that bend to Divided by a septum that bend to

one side leading to right and left one side leading to right and left halves, that vary greatly in size.halves, that vary greatly in size.

• It lies beneath the pituitary fossa, It lies beneath the pituitary fossa, extend into the basiocciput, extend into the basiocciput, greater wing of sphenoid and the greater wing of sphenoid and the pterygoid process.pterygoid process.

• Begins to develop at the 5Begins to develop at the 5thth month of I-U life as a recess in month of I-U life as a recess in the nasal bone and extend into the nasal bone and extend into the sphenoid bone at the age of 7 the sphenoid bone at the age of 7


• The roof is related to the The roof is related to the pituitary fossa and the optic pituitary fossa and the optic nerve – nerve – sudden loss of vision in sudden loss of vision in case of sinus infectioncase of sinus infection

• Anteriorly, the ethmoid air cellsAnteriorly, the ethmoid air cells• Lateral, the cavernous sinus Lateral, the cavernous sinus

containing the internal carotid containing the internal carotid artery and Abducent nerve – artery and Abducent nerve – Stabismus and DiplopiaStabismus and Diplopia

• The floor is the noseThe floor is the nose


• The ostium is in the anterior wall The ostium is in the anterior wall of the sinus and open into the of the sinus and open into the sphenoethmoidal recess, above sphenoethmoidal recess, above superior concha.superior concha.

• Blood supply:Blood supply:• posterior ethmoidal & posterior ethmoidal &

sphenopalatine from maxillarysphenopalatine from maxillary• Nerve supply:Nerve supply:

• posterior ethmoidalposterior ethmoidal• orbital branch of pterygopalatine orbital branch of pterygopalatine

ganglionganglion• ophthalmic and maxillary nerveophthalmic and maxillary nerve


• Frontal sinus:Frontal sinus:• the only sinuses not present at birth, appear after the second the only sinuses not present at birth, appear after the second

year.year.

• The two sinuses are unequal in extent. They are related to the The two sinuses are unequal in extent. They are related to the anterior cranial fossa and the orbitanterior cranial fossa and the orbit

• It present a posterosuperior wall, anterior wall and floorIt present a posterosuperior wall, anterior wall and floor• Posterosuperior wall is thin and separate the sinus from the Posterosuperior wall is thin and separate the sinus from the

meninges and the frontal lobe of the brainmeninges and the frontal lobe of the brain

• The anterior wall form the forehead The anterior wall form the forehead

• The floor separate the sinus fron the orbit, nose and anterior The floor separate the sinus fron the orbit, nose and anterior ethmoid sinusethmoid sinus


• The ostium open into the semilunar hiatus, with the other The ostium open into the semilunar hiatus, with the other openings:openings:

• Infection travel from one sinus to the otherInfection travel from one sinus to the other

• Deviation of the nasal septum might aggravate the infectionDeviation of the nasal septum might aggravate the infection

• Infection give serious complicationsInfection give serious complications

• The posterosuperior wall, infecting the brainThe posterosuperior wall, infecting the brain

• The floor, eye infectionThe floor, eye infection

• Blood supply:Blood supply:• supratrochlear, supraorbital and anterior ethmoidalsupratrochlear, supraorbital and anterior ethmoidal

• Nerve supply:Nerve supply:• supraorbital and supratrochlear nerves.supraorbital and supratrochlear nerves.


• Clinically:Clinically:• Maxillary sinusMaxillary sinus

• might get infected from the nasal cavity or might get infected from the nasal cavity or upper molar teethupper molar teeth

• Ca maxillary sinus might spread medially, Ca maxillary sinus might spread medially, superiorly, inferiorly, laterally or posteriorly.superiorly, inferiorly, laterally or posteriorly.

• Ethmoidal and frontal Sinuses:Ethmoidal and frontal Sinuses:• Frontal lobe abscessFrontal lobe abscess

• Fracture with C.S.F. leak Fracture with C.S.F. leak

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The nose & Paranasal sinuses Bones around the nasal cavity are hollowed outBones around the nasal cavity are hollowed out These cavities are the paranasal