Chapter 14: The periapical Examination- Bisecting Technique

d

Which of the following statements regarding image receptor holders is false?

A) Short biteblocks should be used for the bisecting technique.

B) Biteblocks with a 105-degree angle backing plate should be used with the bisecting technique.

C) External aiming devices eliminate the need to position the patient's head precisely.

D) Biteblocks with an L-shaped backing plate should be used with the bisecting technique.

c

Which of the following statements regarding patient preparation for dental radiography is not correct?

A) The patient should be protected with a lead/lead-equivalent apron and thyroid collar.

B) The patient's occipital protuberance should be against the headrest during exposure.

C) The patient's eyeglasses may be left in place to protect the eyes.

D) Objects in the mouth such as dentures, partials, and retainers should be removed prior to exposure.

a

The presence of each of the following conditions may indicate using the bisecting technique instead of the paralleling technique except one. Which one is the exception?

A) A class II malocclusion

B) An edentulous region

C) A large palatal or mandibular tori

D) A very low or shallow palatal vault

c

To determine the vertical angulation when using the bisecting technique, the central rays of the x-ray beam should be directed

A) perpendicular to the image receptor.

B) parallel to the image receptor.

C) perpendicular to the imaginary bisector.

D) parallel to the imaginary bisector.

b

Which of the following is true of the bisecting technique?

A) It is easy to standardize subsequent films.

B) There is increased patient comfort during image receptor placement.

C) There is decreased radiation exposure for the patient.

D) It is less likely to cause image distortion.

a

Which of the following will correct an elongated image?

A) Increasing the vertical angulation

B) Decreasing the vertical angulation

C) Directing the central ray perpendicular to the plane of the image receptor

D) Directing the central ray perpendicular to the long axis of the tooth

b

Which of the following will correct a foreshortened image?

A) Increasing the vertical angulation

B) Decreasing the vertical angulation

C) Directing the central ray perpendicular to the plane of the image receptor

D) Directing the central ray perpendicular to the long axis of the tooth

c

Which of the following will correct an overlapping error?

A) Increasing the vertical angulation

B) Decreasing the vertical angulation

C) Directing the central ray perpendicular to the plane of the image receptor

D) Directing the central ray perpendicular to the long axis of the tooth

d

Which of the following best describes the correct vertical direction of the central ray when using the bisecting technique?

A) 90 degrees to the long axes of the teeth

B) 90 degrees to the plane of the image receptor

C) 90 degrees to the long axes of the teeth and the plane of the image receptor

D) 90 degrees to the imaginary bisector

a

The bisecting technique is useful in patients who cannot tolerate parallel placement of the image receptor. The bisecting technique produces images with reduced image distortion.

A) The first statement is true. The second statement is false.

B) The first statement is false. The second statement is true.

C) Both statements are true.

D) Both statements are false.

b

Which of these is not a disadvantage of the bisecting technique?

A) It produces images with dimension distortion.

B) Image receptor positioning is difficult for patients with small mouths.

C) Adjacent structures are often superimposed.

D) Estimating the location of the imaginary bisecting may be difficult.

a

Which of these image receptor holders is designed for use with the bisecting technique?

A) 105-degree angled backing plate and short biteblock

B) 105-degree angled backing plate and long biteblock

C) 90-degree angled backing plate and long biteblock

D) 90-degree angled backing plate and short biteblock

True

True or False? The bisecting technique is applied when the image receptor cannot be placed parallel to the long axes of the teeth

False

True or False? The bisecting technique is applied when the image receptor cannot be placed parallel to the long axes of the teeth

True

True or False? Specific vertical angulations required when using the bisecting technique differ from those used with the paralleling technique

True

True or False? Changes in vertical angulation are indicated when the patient's palatal vault is high or low

False

True or False? Excessive vertical angulation when using the bisecting technique will elongate the image

True

True or False? Because it satisfies fewer shadow-casting principles, the bisecting technique is less likely to produce superior diagnostic-quality radiographs

True

True or False? Careful attention to the steps of the bisecting technique can produce acceptable radiographs

True

True or False? The two planes that can be visualized by the radiographer are the estimated long axis of the tooth and the plane of the image receptor

False

True or False? An isometric angle has sides that are inversely related to the base

False

True or False? A longer (12 or 16 inch) PID is better suited to the bisecting technique

False

True or False? When using the bisecting technique, because the long axis of the tooth and the plane of the image receptor are not parallel, a shorter target-image receptor distance will increase magnification and distortion

True

True or False? It is possible to place the image receptor close to the mandibular molars and still achieve a parallel relationship between the image receptor and the long axis of the teeth

False

True or False? It is possible to place the image receptor close to the maxillary anterior teeth and still achieve a parallel relationship between the image receptor and the long axes of the teeth

True

True or False? Even when the positioning and angulation steps are accurate and precise, the bisecting technique will produce some dimension distortion

True

True or False? When using the bisecting technique, the patient should bite down on the image receptor biteblock as close to the teeth as necessary

True

True or False? The patient must be seated correctly to use predetermined vertical angulations when emplying the bisecting technique

True

True or False? The horizontal angulation is determined in the same manner for both the bisecting and paralleling technique

False

True or False? The seating position of the patient is not important is using predetermined anatomical landmarks to direct the central ray of the x-ray beam toward the point of entry

False

True or False? The goal of accurate bisecting technique is to direct the central ray of the x-ray beam perpendicular to both the long axes of the teeth and the plane of the image receptor simultaneously

False

True or False? To avoid conecut error when using the bisecting technique, the point of entry should be the occlusal plane of the teeth