Deck 22: Panoramic Imaging

Question 1

The tubehead of the panoramic unit always rotates ____ the patient's head as the film rotates ____ the patient.

A) behind; behind
B) in front of; in front of
C) behind; in front of
D) in front of; behind

Answer 1

behind; in front of

Question 2

In panoramic radiography, which of the following exposure factors cannot be changed?

A) Milliamperage
B) Kilovoltage
C) Exposure time
D) Both a and c

Answer 2

Exposure time

Question 3

In panoramic radiography, the x-ray tube rotates around the patient's head in one direction while the film rotates ____ direction.

A) Horizontally in the same
B) Horizontally in the opposite
C) Vertically in the same
D) Vertically in the opposite

Answer 3

Horizontally in the opposite

Question 4

The collimator used in the panoramic x-ray machine is a(n) ____ plate.

A) Aluminum
B) Silver
C) Lead
D) Copper

Question 5

Green-sensitive film must be paired with intensifying screens that produce ____ light.

A) Yellow
B) Blue
C) Red
D) Green

Question 6

Which component in the panoramic x-ray machine tubehead is most different from that found in an intraoral x-ray machine tubehead?

A) Filament
B) Target
C) Heat sink
D) Collimator

Question 7

In panoramic radiography, the pivotal point, or axis, around which the cassette carrier and x-ray tubehead rotate is termed a:

A) Terminal hinge axis.
B) Rotation center.
C) Tipping point.
D) Germinal center.

Question 8

The vertical angulation in the tubehead of the panoramic unit:

A) Is fixed in position so that the x-ray beam is directed slightly upward.
B) Is fixed in position so that the x-ray beam is directed slightly downward.
C) Can be adjusted according to the size of the patient.
D) Can be adjusted for maxillary or mandibular films.

Question 9

The collimator used in panoramic radiography has an opening in the shape of a ____ slit.

A) Narrow horizontal
B) Narrow vertical
C) Wide horizontal
D) Wide vertical

Question 10

Advantages of panoramic films over intraoral periapical films include visualization of:
1) Impacted third molar teeth.
2) Jaw fractures.
3) Large lesions in the posterior mandible.

A)1, 2, 3
B)1, 2
C)1, 3
D)2, 3

Question 11

Panoramic screen film is exposed by:

A) Photons.
B) Electrons.
C) Intensifying screens in a cassette holder.
D) A shutter in the cassette with visible light.

Question 12

The panoramic film is typically used to evaluate and diagnose:

A) Caries.
B) Periodontal disease.
C) Impacted teeth.
D) Periapical lesions.

Question 13

Structures are clearly demonstrated on a panoramic radiograph in a ____ zone.

A) Two-dimensional straight
B) Two-dimensional curved
C) Three-dimensional straight
D) Three-dimensional curved

Question 14

Panoramic units may differ in the:
1) Number of the rotation centers.
2) Size and shape of the focal trough.
3) Type of film transport mechanism used.

A)1, 2, 3
B)1, 2
C)1, 3
D)2, 3

Question 15

In panoramic radiography, the movement of the film and the tubehead produces an image through the process known as:

A) Scanography
B) Digitizing
C) Scintillation
D) Tomography

Question 16

In panoramic radiography, the ____ is a theoretical concept used to determine where the dental arches must be positioned to achieve the clearest image.

A) Waypoint
B) Focal trough
C) Neutral zone
D) Home zone

Question 17

The rotational change in a panoramic machine allows the image layer to conform to the ____ shape of the dental arches.

A) Square
B) Tapering
C) Ovoid
D) Elliptical

Question 18

A panoramic film is ____ film(s) taken using an ____ technique.

A) A series of; intraoral
B) A series of; extraoral
C) A single; intraoral
D) A single; extraoral

Question 19

In panoramic radiography, the ____ rotate(s) around the patient.

A) Film
B) Tubehead
C) Tubehead and film
D) Dental chair

Question 20

The closer the rotation center is to the teeth, the wider the focal trough. In most panoramic machines, the focal trough is wide in the anterior region and narrow in the posterior region.

A) Both statements are true.
B) Both statements are false.
C) The first statement is true; the second statement is false.
D) The first statement is false; the second statement is true.

Question 21

The anterior teeth will appear "skinny" if the:

A) Chin is tipped down.
B) Chin is tipped up.
C) Teeth are positioned too far back on the bite-block.
D) Teeth are positioned too far forward on the bite-block.

Question 22

A ghost image appears ____ than its actual counterpart.

A) Smaller
B) Lower
C) More indistinct
D) More distinct

Question 23

A lead apron ____ a thyroid collar should be used when exposing a panoramic film, and the patient should be told to raise the tongue up to the ____.

A) Without; palate
B) Without; occlusal plane
C) With; palate
D) With; occlusal plane

Question 24

Rare earth screens emit ____ light and are considered faster than calcium tungstate screens, which emit ____ light.

A) Blue; green
B) Blue; blue
C) Green; green
D) Green; blue

Question 25

If the patient's lips are not closed on the bite-block during the exposure of a panoramic film, a ____ shadow results that obscures the anterior teeth.

A) Light radiopaque
B) Dark radiopaque
C) Light radiolucent
D) Dark radiolucent

Question 26

A disadvantage of panoramic dental radiography when contrasted with intraoral dental radiography is:

A) Panoramic radiography results in higher exposure to the patient than intraoral radiography.
B) Fewer anatomic structures can be viewed on a panoramic film than on a complete intraoral radiographic series.
C) The images seen on a panoramic radiograph are not as sharp as those on intraoral radiographs because of the intensifying screens.
D) The exposure of a panoramic radiograph is readily accepted by the patient because there is no discomfort involved.

Question 27

An "exaggerated smile line" is seen on the radiograph if the patient's:

A) Chin is tipped down.
B) Chin is tipped up.
C) Teeth are positioned too far back on the bite-block.
D) Teeth are positioned too far forward on the bite-block.

Question 28

A cassette has ____ intensifying screen(s).

A) One
B) Two
C) Three
D) Four

Question 29

A "reverse smile line" is seen on the radiograph if the patient's:

A) Chin is tipped down.
B) Chin is tipped up.
C) Teeth are positioned too far back on the bite-block.
D) Teeth are positioned too far forward on the bite-block.

Question 30

The anterior teeth will appear "fat" if the:

A) Chin is tipped down.
B) Chin is tipped up.
C) Teeth are positioned too far back on the bite-block.
D) Teeth are positioned too far forward on the bite-block.

Question 31

A ghost image occurs when:

A) The patient moves while the film is being exposed.
B) The film is reversed after being removed from the film carrier.
C) All metallic or radiodense objects are not removed before the exposure of a panoramic film.
D) The patient raises his or her hand while an exposure is being made.