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Flashcards in Radiology Exam 4 Deck (68)
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1

Why is the bisecting technique less likely to produce superior diagnostic quality radiographs?

Because it satisfies fewer shadow cast principles

2

When is the bisecting technique used?

When something in oral prevents us from being able to use the paralleling technique

3

How is the angle formed when using the bisecting technique?

Formed by the long axis of the tooth and the plane of the image receptor must be bisected

4

After visualizing the two planes in the bisecting technique, a third line is imagined and that is called the______

bisector

5

The central x-ray beam is directed ______to the imaginary bisector.

perpendicular

6

The long axis of the tooth and the plane of the image receptor are NOT______

parallel

7

When using the bisecting technique, you need a shorter_____-image receptor distance.

target

8

What size PID is preferred for using the bisecting technique?

8 inch

9

Although the central beam is normally directed perpendicular to the imaginary bisector, in mandibular regions, it is more of a ______technique due to the position of the teeth.

parallel

10

What type of receptor holders are appropriate when using the bisecting technique?

short biteblock
snap a ray
wing a ray

11

Can L shaped receptor holders be used when doing the bisecting technique?

no

12

Where should patients bite on the receptor when using the bisecting technique?

Patients should bite on the bite block as close to the teeth as possible

13

How is correct vertical angulation determined?

By imagining the bisector

14

How is correct horizontal angulation determined when using the bisecting technique?

Using teeth contact points and image receptor. Aim the central ray directly through the contacts of the teeth you are imaging.

15

What is the recommended angulation for the bisecting technique on canines?

+45 to +55 maxillary
-20 to -30 mandibular

16

What is the recommended angulation for the bisecting technique on incisors?

+40 to +50 maxillary
-15 to -25 mandibular

17

What is the recommended angulation for the bisecting technique on premolars?

+30 to +40 maxillary
-10 to -15 mandibular

18

What is the recommended angulation for the bisecting technique on molars?

+20 to +30 maxillary
-5 to 0 mandibular

19

How is proper horizontal angulation achieved when using the bisecting technique?

Image receptor must be parallel to the interproximal space or embrasure space of 2 determined teeth, same as paralleling technique.

20

What happens when an image is foreshortened and what do we need to do to fix this?

there is too much vertical angulation so we need to decrease angulation.

21

What happens when an image is elongated?

there is not enough vertical angulation so angulation needs to be increased.

22

What must be done to prevent a cone cut when using the bisecting technique?

receptor must be centered within the x-ray beam to avoid cone cut error. BEAM MUST BE CENTERED OVER THE RECEPTOR

23

How must the patient be seated when using the bisecting technique?

Occlusal plane must be parallel to the floor.

24

Because the images are never that pretty when using the bisecting techniuqe, why would you do it?

This technique is used when you can't achieve the parallel relationship

25

What type of bite block is needed for the bisecting technique?

short bite block NOT L SHAPED

26

What is the purpose of a Lateral Cephalometric Projection?

To evaluate facial growth and development, trauma, disease and developmental abnormalities

27

What is the purpose for a posteroanterior projection?

to evaluate facial growth and development, trauma, and disease and developmental abnormalities.

28

What is the purpose of the waters projection?

to evaluate the maxillary sinus area

29

What is the proper receptor placement and head position when taking a waters projection?

The receptor is perpendicular to the floor and the chin touches the receptor, the tip of the nose is .5 to 1 inch from receptor.

30

What is the submentovertex projection?

it is an image used to identify the position of the condyles, the base of the skull and evaluate the fractures of the zygomatic arch