Chpt 11 facial bones and sinuses self test Flashcards
The majority of the hard palate is formed by:
maxilla
which of the following is not an aspect of the maxilla?
frontal process
body
zygomatic process
ramus
ramus
what facial bone is considered the “unpaired bone in the adult”?
mandible
what facial bone is considered located anteriorly in medial aspect of orbit?
lacrimal bones
what facial bone possesses a vertical and horizontal portion?
palatine bones
what facial bone helps to mix air drawn into nasal cavity?
inferior nasal conchae
what facial bone lies just anterior and medial to the frontal process of maxilla?
nasal bones
what facial bone contains four processes?
maxilla
what facial bone forms the lower outer aspect of orbit?
zygomatic bone
on avg, how many separate cavities make up the frontal sinus?
1-2 sinuses
all of the paranasal sinuses are contained within cranial bones, except the maxillary sinuses.
true
the frontal sinuses are usually larger in men than in women.
true
which aspect of the ethmoid bone contains the ethmoid air cells?
lateral masses/labrinth
the sphenoid sinus lies directly inferior to the:
sella turcica
facial bone studies should be performed erect whenever possible
true
which frontal projection of the facial bones best visualizes the region of the maxilla and orbits?
parietoacanthial (Waters)
which single projection of the facial bones best demonstrates any possible air-fluid levels in the paranasal sinuses if the pt cannot stand or sit erect?
horiz. beam lat. (x-table)
which plane is placed parallel to the IR with a true lat projection of the facial bones?
MSP
what is the angle between the OML and plane of IR with a parietoacanthial (Waters) projection?
this places the _________ positioning perpendicular to the IR.
37°
MML
The CR is centered to exit at the level of the ____________ for a well-positioned 15° PA axial proj. of the facial bones
nasion
The CR is centered to exit at the level of the _________ for a well positioned parietoacanthial proj.
acanthion
which positioning line is placed perpendicular to the IR for a modified parietoacanthial proj.
LML
Where is the CR centered for a lateral projection of the nasal bones?
.5” to nasion
which positioning line, if placed, parallel to IR, ensures adequate extension of the head for the SMV proj. for zygomatic arches?
IOML
how much skull tilt and rotation are required for the oblique inferosuperior (tangential) proj. for zygomatic arches?
15° rotation and tilt toward affected side
how much CR angle is required for the AP axial projection of the zygomatic arches if the IOML is placed perp. to the IR?
37° caudad
Where should the optic foramen be located with a well-positioned three point landing projection?
lower outer quandrant of orbit
How much skull rotation (from lateral position) toward the IR is required for the axiolateral oblique projeciton specifically for the mentum?
45°
What type of Cr angulation should be used for a PA axial projection of the mandible?
20-25° cephalad
Were is the CR centered for an SMV projection of the mandible?
1.5” inf. to mandibular symphysis
A grid is not required for the lateral projection of the nasal bones.
true
Where is the CR centered for a lateral projection of the paranasal sinuses?
midway between outer canthus and EAM
Why should a pt remain in an erect position for at least 5 mins before sinus radiography?
to allow any fluid in sinuses to settle
Which routine projection is best for demonstrating the maxillary sinuses?
parietoacanthial (Waters)
A radiograph of a 15° PA projection of the facial bones shows the petrous ridges are projected at the level of the midorbital rims. What specific positioning or CR angling error led to this radiographic outcome?
excessive flexion of head or CR angle
A radiograph of lateral position for paranasal sinuses shows the greater wings of the sphenoid bone are not superimposed. What positioning error is present?
rotation
A patient with severe facial bone injuries comes into the ER. The patient is wearing a cervical collar and cannot be moved. What type of positioning routine should be performed for this situation?
reverse Waters with use of cephalic CR angle and horizontal beam lateral projection
A superoinferior tangential projection for the nasal bones was taken with the following exposure factors: 8 x 10” IR portrait, 90 kVp, 13 mAs, 40 inch SID. The resultant radiograph was unsatisfactory because of poor visibility of the nasal bones. Which technical factor should be changed for the repeat exposure?
reduce kVp to 50 to 60 and increase mass accordingly
patient with possible facial fractures, including a possible blowout fracture to the right orbit was brought from the ER to the radiology department. What special facial bone projection should be included with a basic facial bone routine of a lateral parietoacanthial (waters), and PA axial (Caldwell)?
modified waters or PA axial with 30° caudad angle
A patient with a clinical history of secondary osteomyelitis, comes to the radiology department. Which imaging modalities or procedures can be performed to demonstrate the extent of damage to the paranasal sinuses?
routine sinus series or CT of sinuses
