Test 9 Workbook/Text Notes Flashcards
largest immovable face bone?
maxilla
4 processes of maxilla?
frontal
zygomatic
alveolar
palatine
which process of maxilla is most superior?
frontal
which facial bones form the post. aspect of the hard palate?
horizontal portion of palatine bones
2 cranial bones that articulate w the maxilla
frontal, ethmoid
facial bone assoc. w tear ducts
lacrimal
purpose of conchae/turbinates?
to divide nasal cavity into compartments and circulate incoming air (to warm and clean it before entering lungs)
which 2 facial bones are located interiorly and not visible on the exterior skull?
vomer and palatine
(from ant. to post.) the cone-shaped orbits project upward at an angle of?
30º
the cone-shaped orbits are projected toward the MSP at an angle of?
37º
which facial bone opening is formed by a cleft btw the greater and lesser wings of sphenoid?
sup. orbital fissure
bilat horizontal fractures of the maxillae are called
LeFort fracture
what evidence on an AP axial Towne (skull) XR indicates whether the correct CR angle and head flexion were used?
dorsum sellae and post. clinics should be projected into foramen magnum
TRAUMA PT, what must be determined BEFORE performing SMV?
rule out any possible C-spine fractures/subluxation
AP Axial Towne reveals R petrous ridge is wider than L side; what pos error occurred?
rotation to L
15º PA Axial Caldwell shows that the distance btw the R midlat orbital borders and lat margin of cranial cortex is greater than the L side. what error occurred?
rotation to L
SMV reveals that mandib. condyles are w/in petrous bone. what error occurred?
insufficient skull extension/CR not perp to IOML
lat skull shows that the orbital plates are not superimposed. (1 plate is slightly sup. to the other). what occurred?
tilt
lat skull shows that one mandib. ramus is about 0.5 cm more ant. than the other. what occurred?
rotation
facial XRs are best performed?
erect
basic PA axial Caldwell for facial bones requires a ___º caudad angle to project what?
15º, petrous ridges in lower 1/3rd of orbits
what modality is ideal for facial bones?
CT
what is helpful in diagnosing occult facial bone fractures?
nuclear med
name of fracture from a direct blow to the orbit leading to a disruption of the IOM?
blow-out fracture
“free-floating” zygomatic bone is the frequent result of a
tripod fracture
major disadvantage performing a straight PA XR for facial bones, w no CR angle/neck extension by comparison w the Caldwell?
petrous ridges superimpose the orbits, obscuring facial bone structures
what facial bone structures are best seen w a parietoacanthial XR?
orbits, including infraorbital rims, bony nasal septum, maxillae, zygomatic bones and ARCHES
what CR angle is needed to project the petrous ridges just below the orbital floor w a PA axial Caldwell
30º caudad (nasion)
which specific structures are visualized better w the modified waters XR?
orbital rims/floors
2 reasons why facial bones are performed PA whenever possible
less OID, less exposure to thyroid
2 pos. difference’s btw lat facial and lat skull?
- IR LW for facial
2. CR center to zygoma for facial
T/F: both obl. inferosuperior (tangential) XRs for zygomatic arches are generally taken for comparison
true
where is CR centered for an AP axial projection for zygomatic arches?
1” sup. to glabella (to pass through mid arches)
XR that best shows floor of orbits (blowout fracture)
modified waters
XR that best shows optic foramen
parieto-orbital obl XR (Rhese)
XR that best shows view of single zygomatic arch
obl inferosuperior (tangential) XR
XR that best shows bilat zygomatic arches
SMV
XR that best shows IOM, maxillae, nasal septum, nasal spine, zygomatic bone and arches
parietoacanthial XR (waters)
what XR produces an elongated view of the condyloid processes?
PA Axial mandible
which XR projects the opp. 1/2 of the mandible away from the side of interest
axiolat obl
how much skull rotation is needed on the axiolat obl XR to demonstrate the ramus region?
0º
how much skull rotation is needed on the axiolat obl XR to demonstrate the body of the mandible?
30º
how much skull rotation is needed on the axiolat obl XR to demonstrate the mentum region?
45º
how much skull rotation is needed on the axiolat obl XR to demonstrate a general survey of the mandible
10-15º
maximum CR angle necessary for all axiolat obl XRs of mandible?
25º
where should CR exit for a PA axial mandible?
acanthion
what should be perp to IR for a true PA XR of mandibular body (if it’s the area of interest)?
AML
which aspect of mandible is best seen w an AP axial XR?
condyloid processes (CONDYLES!!!)
where is CR centered for AP axial of mandible?
glabella
which XR of mandible will demonstrate the entire mandible, including the coronoid and condyloid processes?
SMV
T/F: modified law method provides a bilat and f(x)al study of TMJ
true
T/F: mandibular condyle moves post. as the mouth is open.
false. (ant.)
which TMJ XR requires skull to remain in true lat pos?
Schuller
axiolat (schuller) for TMJ requires a CR angle of?
25-30º caudad (to 1/2” ant. & 2” sup. to EAM)
lat facial reveals that rami are not superimposed. what occurred?
skull rotation
30º PA axial facial reveals petrous ridges are projected at the level of the IOMs. Is this acceptable? how do you correct?
yes; you don’t - XR ok
lat facial reveals that mandibular bodies are not superimposed (one is about 1 cm sup. to the other). what happened? how do you correct?
skull tilt; make sure MSP is II to IR, and IPL is perp to IR, and IOML is perp to front edge of IR
Rhese XR reveals that the optic foramen is located in the upper outer quadrant of orbit. is this acceptable? how do you correct?
No. + neck extension. AML should be perp to IR to ensure optic foramen is open & projected into lower outer quadrant of orbit
an axiolat obl mandible reveals that the body of the mandible is severely foreshortened. body of mandible is area of interest. what pos error led to this outcome?
insufficient skull rotation (should be rotated 30º toward IR from lat)
pt w possible blowout fracture of R orbit comes into ER. in addition to basic facial routine, what single XR best demonstrates this type of injury?
modified waters
pt w possible fracture of L zygomatic arch enters ER. neither the AP axial, nor SMV showed the L side well. what other XR can be done to show this area?
obl inferosuperior (tangential); bilat XRs generally done for comparison
which XR is ideal in showing a depressed fracture of the zygomatic arch (usually from trauma)
obl inferosuperior (tangential) of zygomatic arch
tech attempts SMV XR. bc of size of pt’s shoulders, he is unable to flex his neck adequately to place IOML II to IR. what can tech do to produce acceptable SMV XR?
angle CR so it’s perp to pt’s IOML
Waters XR reveals that the distance btw the MSP and the outer orbital margin is not equal. what occurred?
skull rotation
SMV reveals that the distance btw the mandibular condyles and lat border of the skull is not equal. what occurred?
skull tilt
waters method reveals that the petrous ridges are projected just below the maxillary sinuses. what pos error occurred?
none.
majority of hard palate is formed by?
palatine bones
which facial bone contains 4 processes?
maxilla
which facial bone forms lower, outer aspect of orbit?
zygoma
which facial bone lies just ant. and med. to the frontal process of maxilla?
nasal bones
which facial bone is the unpaired bone in the adult?
mandible
which facial bone is located ant. in the med. aspect of the orbit?
lacrimal bones
which facial bone helps to mix air drawn into nasal cavity?
inf. nasal conchae
which facial bone posses a vertical and horizontal portion
palatine bones
what prevents the superimposition of the ramus on the C-spine for the axiolat obl mandible XR?
chin extension
what structures are better defined when the CR angle is increased from 35º to 40º caudad for the AP axial Towne mandible?
TM fossae (center 40º caudad to OML to reduce superimposition from temporal bone)
during an orthopantomographic procedure, it is important to keep the _____ pos. line II to the floor.
IOML
Waters method projects all but one facial bone superior to petrous ridges to free them from superimposition. which facial bone remains obscured?
mandible
(trauma) CR for the AP axial should not exceed __° or excessive distortion will hinder the visualization of essential anatomy
45º
Zygoma aka
Malar bone
