DENT 1050 Chapter 23

Question 1

1. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Lateral jaw projection-body of mandible

Answer 1

Head position: tipped approximately 15 degrees toward the side being imaged and chin extended and elevated slightly;
Receptor placement: flat against patient’s cheek, centered over the body of the mandible, parallel with the body of the mandible and held in place with patients thumb placed under edge of cassette and palm against outer surface of cassette;
Beam alignment: central ray directed to a point just below the inferior border of mandible on the side OPPOSITE of cassette, directed upward (-15 to -20 degrees), centered on body of the mandible and perpendicular to the horizontal plane of the receptor

Question 2

2. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Lateral jaw projection - ramus of mandible

Answer 2

Head position: tipped approximately 15 degrees toward the side being imaged and chin extended and elevated slightly;
Receptor placement: flat against patient’s cheek, centered over the ramus of the mandible, parallel with the ramus of the mandible and held in place with patients thumb placed under edge of cassette and palm against outer surface of cassette;
Beam alignment: central ray directed to a point posterior to the third molar region on the side OPPOSITE of cassette, directed upward (-15 to -20 degrees), centered on the ramus of the mandible and perpendicular to the horizontal plane of the receptor

Question 3

3. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Lateral cephalometric projection

Answer 3

Head position: left side of patient’s head positioned adjacent to the cassette, midsagittal plane aligned perpendicular to floor and parallel to cassette, Frankfort plane aligned parallel to floor and head centered over the cassette;
Receptor placement: perpendicular to the floor in a cassette-holding device with long axis of cassette positioned horizontally;
Beam alignment: central ray directed through center of cassette and perpendicular to cassette

Question 4

4. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Posteroanterior projection

Answer 4

Head position:
Receptor placement: perpendicular to the floor in a cassette-holding device with long axis of the cassette positioned vertically;
Beam alignment:

Question 5

5. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Waters projection

Answer 5

Head position:
Receptor placement:
Beam alignment:

Question 6

6. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Submentovertex projection

Answer 6

Head position:
Receptor placement:
Beam alignment:

Question 7

7. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Reverse Towne projection

Answer 7

Head position:
Receptor placement:
Beam alignment:

Question 8

8. Describe the head position, receptor placement, and beam alignment for each of the following extraoral images:
   Transcranial projection

Answer 8

Head position:
Receptor placement:
Beam alignment:

Question 9

9. Which of the following projections is best for the examination of the maxillary sinus?
   a. lateral jaw projection
   b. reverse Towne projection
   c. Waters projection
   d. submentovertex projection

Answer 9

c. Waters projection

Question 10

10. Which of the following projections is best for the examination of fractures of the zygomatic arch?
    a. submentovertex projection
    b. reverse Towne projection
    c. Waters projection
    d. lateral cephalometric projection

Answer 10

a. submentovertex projection

Question 11

11. Which of the following projections is best for examination of fractures of the condylar neck?
    a. submentovertex projection
    b. Waters projection
    c. lateral cephalometric projection
    d. reverse Towne projection

Answer 11

d. reverse Towne projection

Question 12

12. Which of the following projections is best for the examination of the soft tissue profile of the face?
    a. transcranial projection
    b. lateral cephalometric projection
    c. reverse Towne projection
    d. posteroanterior projection

Answer 12

b. lateral cephalometric projection

Question 13

13. Which of the following projections is best for the examination of the condyle and articular eminence?
    a. transcranial projection
    b. posteroanterior projection
    c. Waters projection
    d. submentovertex projection

Answer 13

a. transcranial projection

Question 14

14. Which one of the following projections is best for the examination of fractures of the mandibular body?
    a. lateral cephalometric projection
    b. submentovertex projection
    c. lateral jaw projection
    d. transcranial projection

Answer 14

c. lateral jaw projection

Question 15

15. Which of the following projections is best for the examination of a large lesion in the ramus?
    a. posteroanterior projection
    b. Waters projection
    c. lateral cephalometric projection
    d. lateral jaw projection

Answer 15

d. lateral jaw projection