Deck 23: Extraoral Imaging

Question 1

Which of the following choices is a lateral jaw projection?

A) Lateral cephalometric projection
B) Reverse Towne projection
C) Waters projection
D) Body of the mandible projection

Answer 1

Body of the mandible projection

Question 2

An occlusal film (size ____) may be used for some extraoral radiographs.

A) 0
B) 1
C) 2
D) 4

Answer 2

4

Question 3

Extraoral films are primarily used in which of the following specialty areas?

A) Endodontics
B) Periodontics
C) Oral surgery
D) Pediatric dentistry

Answer 3

Oral surgery

Question 4

The front side of the cassette is typically constructed of ____ and permits the passage of the x-ray beam, whereas the back side is made of ____ to reduce scatter radiation.

A) Metal; metal
B) Plastic; plastic
C) Plastic; metal
D) Metal; plastic

Question 5

An extraoral radiograph is placed ____ the mouth during x-ray exposure. Extraoral radiography is used to image ____ areas of the skull or jaws.

A) Outside; small
B) Outside; large
C) Inside; small
D) Inside; large

Question 6

The extraoral film is typically used to evaluate:

A) Gutta percha root canal fillings
B) The integrity of the crest of alveolar bone
C) The temporomandibular joint area
D) Interproximal decay

Question 7

The grid is placed between the ____ and the ____.

A) Aluminum filter; PID
B) PID; patient's head
C) Patient's head; film
D) Film; cassette

Question 8

A(n) ____ is a device used to reduce the amount of scatter radiation that reaches an extraoral film during exposure.

A) Collimator
B) Grid
C) Cassette
D) Intensifying screen

Question 9

A grid can be used to ____ film fog and ____ the contrast of the radiographic image.

A) Decrease; decrease
B) Increase; increase
C) Decrease; increase
D) Increase; decrease

Question 10

A grid is composed of a series of:

A) Wire mesh that is similar to the screen in a window or door.
B) Copper wires around an armature.
C) Thin lead strips.
D) Thick lead strips.

Question 11

The most common extraoral film is the ____ projection.

A) Lateral cephalometric
B) Posteroanterior
C) Waters
D) Panoramic radiograph

Question 12

Which of the following projections would be best for evaluating impacted third molars?

A) Body of the mandible projection
B) Ramus of the mandible projection
C) Reverse Towne projection
D) Waters projection

Question 13

To compensate for the strips found in the grid, ____ must be used to expose a film.

A) Increased kilovoltage
B) Increased milliamperage
C) Increased exposure time
D) Decreased exposure time

Question 14

An occlusal film ____ be used for some extraoral radiographs. When used extraorally, it covers a ____ area than a screen film.

A) May; smaller
B) May not; smaller
C) May; larger
D) May not; larger

Question 15

Extraoral radiographs may be used in conjunction with intraoral films. The images seen on extraoral film are not as defined or sharp as the images seen on an intraoral radiograph.

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 16

Scatter radiation:

A) Increases film fog.
B) Increases film contrast.
C) Reduces film contrast.
D) Both a and c.

Question 17

For the ____ projection, the patient's head is tipped toward the side being imaged.

A) Body of the mandible
B) Lateral cephalometric
C) Reverse Towne
D) Waters

Question 18

Lateral jaw radiography:

A) Requires the use of a special x-ray unit.
B) Provides for more diagnostic information than a panoramic radiograph.
C) Is used to examine the anterior portion of the mandible.
D) Is valuable for patients with limited jaw opening because of a fracture or swelling.

Question 19

Which of the following is the fastest recommended screen and screen film combination?

A) Calcium tungstate screen with blue light
B) Calcium tungstate screen with green light
C) Rare earth screen with blue light
D) Rare earth screen with green light

Question 20

Which of the following is the most commonly used extraoral film size?

A) 3 × 5
B) 4 × 6
C) 5 × 7
D) 10 × 12

Question 21

For the ____ projection, the patient faces the cassette with the head tipped down and the mouth open as wide as possible.

A) Waters
B) Posteroanterior
C) Reverse Towne
D) Submentovertex

Question 22

Which of the following projections is used to evaluate fractures of the zygomatic arch?

A) Lateral cephalometric
B) Posteroanterior
C) Waters
D) Submentovertex

Question 23

The purpose of the ____ projection is to identify fractures of the condylar neck and ramus areA.

A) Reverse Towne
B) Posteroanterior
C) Waters
D) Submentovertex

Question 24

The left side of the patient's head is positioned adjacent to the cassette for the ____ projection.

A) Lateral cephalometric
B) Posteroanterior
C) Waters
D) Submentovertex

Question 25

The beam should be directed ____ degrees for the ramus of the mandible projection.

A) Downward at 15 to 20
B) Upward at 15 to 20
C) Downward at 45
D) Upward at 45

Question 26

The purpose of the transcranial projection is to evaluate the articular eminence and ____ surface of the condyle.

A) Anterior
B) Posterior
C) Superior
D) Inferior

Question 27

The patient's head and neck are tipped back as far as possible for the ____ projection.

A) Lateral cephalometric
B) Posteroanterior
C) Waters
D) Submentovertex

Question 28

For the transcranial projection, the central ray is directed toward a point ____ inches above and 0.5 inches behind the opening of the ear canal.

A) 0.5
B) 1.0
C) 2.0
D) 4.0