LP2 Chapter 18

Question 1

Where is the receptor placed for the bisecting technique?

Answer 1

Close to the tooth on the lingual surface; forming an angle.

Question 2

How is the imaginary bisector created for the radiographer?

Answer 2

By dividing the angle formed by the receptor and long axis of the tooth in half to give a plane to direct the central rays perpendicular to.

Question 3

What does the imaginary bisector bisect?

Answer 3

The angle formed by the receptor and the long axis of the tooth.

Question 4

How is the central ray directed to the imaginary bisector?

Answer 4

Perpendicular

Question 5

What does the imaginary bisector create?

Answer 5

Two right, congruent triangles.

Question 6

What are two advantages to using the bisecting technique?

Answer 6

1. More comfortable for the patient.

2. No anatomical restrictions

Question 7

What are 4 anatomical situations that may require the use of the bisecting angle technique.

Answer 7

1. A shallow palate
2. A large palatal torus
3. Shallow or tender floor of the mouth
4. A short lingual frenum (tongue-tied)

Question 8

What are two disadvantages to the bisecting angle technique?

Answer 8

1. More distortion; not parallel (apecies mesh with other structures)
2. X-Ray beam position; difficult to visualize

Question 9

What are the five steps to the bisecting technique?

Answer 9

1. Receptor placement (make sure you have the teeth you need)
2. Receptor placement (close to tooth/teeth)
3. Vertical angulation (perpendicular to the imaginary bisector)
4. Horizontal angulation
5. PID (make sure it covers the receptor)

Question 10

What occurs if the vertical angulation is off?

Answer 10

Foreshortened images = too steep

Elongation images = too shallow

Question 11

What happens if horizontal angulation is off?

Answer 11

overlapping in contact areas or cone cuts.

Question 12

What happens to the dental image hen a short(8-in) PID is used?

Answer 12

Magnification results

Question 13

Which size receptor is used with the bisecting technique?

Answer 13

Size 2

Question 14

Which beam alignment deice is recommended for use with the bisecting technique because it aids in the alignment of the PID and reduces patient exposure?

Answer 14

Rinn BAI instruments (we use snap a ray)

Question 15

How is the patient’s head positioned before exposing mandibular periapicals with the bisecting technique?

Answer 15

Mandibular arch parallel to the floor; midsagittal plane perpendicular to the floor.