20 terms

Radiology for DH chapter 13

cabrillo college DH, radiology 163A
Left lateral oblique
The best extraoral projection for viewing an impacted left mandibluar third molar is...
Reduce object scatter
Grids are used to...
In extraoral radiography, an increased FFD is necesary to...
a- decrease patients exposure
b- increase the beam divergence
c- decrease the beam divergence
d- increase film quality
e- decrease image magnification
The best way to visualize maxillary sinus pathology using a dental xray machine is a
a- lateral oblique projection
b- maxillary occlusal projection
c- posterior anterior projection
d- transcranial projection
e- Waters projection
In taking a Waters projection the patient's...
a- head is inclined 15 degrees
b- nose and chin touch the cassette, open mouth
c- nose and chin touch the cassette, mouth closed
d- forehead and nose touch the cassette, mouth open
e- forehead and chin touch the cassette
All the above
Extraoral cassettes...
a- may be rigid or flexible
b- contain intensifying screens
c- are light-tight
d- are available in varying sizes
The safelight is too intense
If all of your extraoral films appear dense and fogged after processing while all your intraoral films are satisfactory, the probable cause is...
Extraoral films are processed
a- only with automatic processors
b- by the time-tempurature method
c- by sight developement
d- with special solutions
e- none of the above
B, C
Holding devices have the advantage of...
a- preventing fogged film
b- standardized techniques
c- preventing patient and film movement
Posteroanterior projection
A fractured zygomatic arch can be seen on a(n)...
Decreased definition
The major disadvantage of using extraoral projections with screens in dentistry is...
The screen film used in extraoral radiography is
a- more sensitive to light
b- more sensitive to radiation
c- eequally sensitive to both light and radiation
d- not changed by light or radiation
e- none of the above are significant statements
Posteroanterior projection
A pathologic condition in the midline of mandible can best be diagnosed using what kind of projection?
Anterior curve of the mandible
The lateral oblique projection of the mandible is not diagnostic anterior to the canine because of the superimposition caused by...
All of the above
Exposure, mA, and kVp settings vary with extraoral radiographs depending on the
a- film speed
b- intensifying screens
c- size of the patient
d- none of the above
e- all of the above
Some states have statutes that prohibit or limit the dental professional from performing certain extraoral techniques
Extraoral screen films are less sensitive to light that are intraoral films
The lateral oblique projection of the mandible is used for viewing mandibular third molar impactions and pathology
Waters view of the maxillary sinuses is used for maxillary sinus pathologic conditions and facial fractures of the upper third of the face
For the submentovertex projection, the central ray is directed from beneath the chin at 45 degrees to the cassette