Chapter 14 Flashcards
What is the bisecting technique useful for?
The bisecting technique is useful in patients who cannot tolerate parallel placement of the image receptor.
What is a major advantage of the bisecting technique?
Its ease of use with patients who cannot tolerate parallel placement of the image receptor.
What is a major disadvantage of the bisecting technique?
The inherent dimensional distortion.
Which statement is true regarding the bisecting technique?
A) The first statement is true. The second statement is false.
Which of these is not a disadvantage of the bisecting technique?
B) Image receptor positioning is difficult for patients with small mouths.
Which image receptor holder is designed for use with the bisecting technique?
A) 105-degree angled backing plate and short biteblock.
Is the bisecting technique applied when the image receptor cannot be placed parallel to the long axes of the teeth?
TRUE
Is the image receptor placed parallel to the long axes of the teeth when using the bisecting technique?
FALSE
Do specific vertical angulations required when using the bisecting technique differ from those used with the paralleling technique?
TRUE
Are changes in vertical angulation indicated when the patient’s palatal vault is high or low?
TRUE
Does excessive vertical angulation when using the bisecting technique elongate the image?
FALSE
Is the bisecting technique less likely to produce superior diagnostic-quality radiographs?
TRUE
Can careful attention to the steps of the bisecting technique produce acceptable radiographs?
TRUE
What two planes can be visualized by the radiographer?
The estimated long axis of the tooth and the plane of the image receptor.
Does an isometric triangle have sides that are inversely related to the base?
FALSE
Is a longer PID better suited to the bisecting technique?
FALSE
Will a shorter target-image receptor distance increase magnification and distortion when using the bisecting technique?
FALSE
Can the image receptor be placed close to the mandibular molars and still achieve a parallel relationship?
TRUE
Can the image receptor be placed close to the maxillary anterior teeth and still achieve a parallel relationship?
FALSE
Will the bisecting technique produce some dimension distortion even when positioning and angulation steps are accurate?
TRUE
Should the patient bite down on the image receptor biteblock as close to the teeth as necessary when using the bisecting technique?
TRUE
Must the patient be seated correctly to use predetermined vertical angulations when employing the bisecting technique?
TRUE
Is the horizontal angulation determined in the same manner for both the bisecting and the paralleling techniques?
TRUE
Is the seating position of the patient important in using predetermined anatomical landmarks?
FALSE
Is the goal of accurate bisecting technique 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
To avoid conecut error when using the bisecting technique, where should the point of entry be?
The image receptor must be centered within the beam of x-radiation.
How should the patient be positioned to determine accurate and correct angles and points of entry?
The occlusal plane should be parallel to the floor and the midsagittal plane perpendicular to the floor.
How does the central ray of the x-ray beam intersect with the image receptor and the teeth of interest when using the bisecting technique?
The central ray of the x-ray beam should be directed at an imaginary bisector between the long axes of the teeth and the plane of the image receptor.
Why is it important for the radiographer to know how to apply both the paralleling and bisecting techniques?
The radiographer who possesses knowledge of both techniques is better able to produce diagnostic-quality radiographs under various conditions.
What must the radiographer do prior to confidently using predetermined vertical angulations when applying the bisecting technique?
The patient’s occlusal and midsagittal planes must be correctly positioned.
Name an image receptor holder that may be used with both the paralleling and the bisecting techniques.
The bite extension of the stabe holder.
What error results from excessive vertical angulation when taking periapical radiographs using the bisecting technique?
Excessive vertical angulation results in foreshortening of the image.
What error results from inadequate vertical angulation when taking periapical radiographs using the bisecting technique?
Inadequate vertical angulation results in elongation of the image.
Which technique for obtaining intraoral radiographs may be easier to use for children or adults with shallow palates?
The bisecting technique.
What is the preferred target-surface distance when using the bisecting technique?
The shorter (8 inch [20.5 cm]) PID.
How does the bisecting technique relate to the rule of isometry?
Theoretically, two isometric triangles are formed when the central ray is directed perpendicular to the bisector.
