Download The nose & Paranasal sinuses

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
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
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
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.
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
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
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.
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
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
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, supraorbital, anterior & posterior ethmoidal, orbital and
lateral posterior nasal. Referred pain ???
• Lymph drainage:
• submandibular and retropharyngeal nodes.
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
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
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
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
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.
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