Mandible, TMJ's, Sinuses and Temporal bone Flashcards
what does the temporal bone have
petrous pyramid
what do the petrous pyramids house
the organs of hearing and balance
thin upper portion of the temporal bone
squamous portion
how many pairs of sinuses
4
thickest densest bone in the cranium
petrous pyramid
what bone forms a large part of the middle cranial fossa and a small part of the posterior cranial fossa
temporal bones
the temporal bone consists of
squamous portion, tympanic portion, styloid process, zygomatic process, petromastoid portion
zygomatic process
prominent arched process that projects anteriorly to articulate with zygoma and complete the zygomatic arch
mandibular fossa
receives condyle of mandible to form TMJ
atricular tubercle
forms anterior boundary of mandibular fossa
tympanic portion location
below squama and in front of petromastoid portion
styloid process
slender, pointed bone projecting inferiorly, anteriorly, and slightly medially from inferior surface of tympanic portion
mastoid process
conical process projecting from mastoid portion
first of the mastoid air cells to develop
mastoid antrum
the mastoid antrum is
quite large and communicates with the tympanic cavity
the internal carotid artery courses in the ___ ___ and enters the inferior aspect of the ____ ____ and passes superior to the ____ and medially to exit the ___ ___
carotid canal
petrous portion
cochlea
petrous apex
where does the top of the ridge lay
TEA
the carotid canal opens into the
foramen lacerum
the organ of hearing
ear
the organs of hearing and equilibrium consist of three main divisions
external ear, middle ear and internal ear
two parts of the external ear
auricle and EAM
sound conducting canal
EAM
superior attachment of the auricle
TEA
how long is the EAM
1 inch
deep central depression of the auricle
concha
outer third of the canal wall is _______ and the inner two thirds Is _______
cartilaginous, osseous
middle ear consists of
tympanic membrane, tympanic cavity and three auditory ossicles
three auditory ossicles
malleus, incus, and stapes
what functions in hearing
cochlea
what functions in equilibrium and balance
vestibule and semicircular canals
the inner ear consists of
cochlea, vestibule and three semicircular canals
stapes articulates with the
oval window of the inner ear
inner ear lies immediately below
arcuate eminence
the cochlea communicates with the
middle ear through the round window
largest and densest bone of the face
mandible
slowest healing facial fracture
mandible
the mandible consists of
curved horizontal portion called body
two verticle portions called rami
most anterior and central part of the mandible
symphysis
which is more superior the coronoid process and condylar process
coronoid process
small opening on each side of the mandible for transmission of nerves and blood vessels
mental foramina
how does the TJM slant
15 degrees posteriorly and 15 degrees inferiorly and medially
functions of the sinuses
serve as a resonating chamber for the voice
decrease the weight of the skull
aid in warming and moisturizing inhaled air
act as shock absorber in trauma
possibly control the immune system
which sinuses do not develop until puberty
ethmoid air cells
which sinuses are usually the only ones developed enough to be demonstrated radiographically at birth
maxillary
at what age is the frontal and sphenoid sinus distinguishable from ethmoids
6-7 years of age
largest sinuses
maxillary
second largest sinuses
frontal
frontal sinuses drain into the
middle nasal meatus
Reids baseline
line drawn from the inferior margin of the orbit to the auricular point and extending backward to the center of the occipital bone
air-fluid levels for sphenoid sinuses which position would you do
cross-table lateral
what projection do you do when there is a suspected rami fracture
PA projection- perp central ray- CR exiting the Acanthion
what projection do you do when there is a suspected body of mandible fracture
PA projection- AML nearly perp- CR exiting level of the lips
precise technical factors for paranasal sinuses
small focal spot, IR free of artifact, kVp and mAs must be right for that patient, no movement of the head and no breathing
exudate
sinus fluid- thicker
which projections best shows sphenoid sinuses
lateral sinus
most important EC for lateral sinus
sella turcia in profile
superimposed orbital roofs
superimposed mandibular rami
when the lateral projection for sinuses is used for preoperative measurements what should the SID be
72
what projection is best for frontal sinuses and anterior ethmoidal air cells
PA Axial projection, Caldwell method
is angled grid or vertical grid caldwell method perferred
angled grid
why is the angled grid preferred over vertical
because the vertical increases the OID and can cause distortion
which projection shows the maxillary sinuses best
parietocacanthial projection waters method
waters method for sinuses will also show
foramen rotundum
what does the parietoacanthial waters open mouth demonstrate
sphenoid sinuses
SMV for sinuses are good for looking at
sphenoid and ethmoid sinuses
which sinuses are best seen on a Caldwell sinus projection
frontal
largest and densest facial bone
mandible
superior border of the body of the mandible consists of spongy bone called
alveolar portion
joints of the teeth are
gomorphus
upper portions of the petrous ridge lies at the level of
TEA
how long is the auditory tube
1 1/2 inch
hoe long is the EAM
1 inch
where do the semicircular canals lie
under the arcuate eminence
organ of hearing
cochlea
organs of equilibrium and balance
cochlear and vestibular nerves
