Chapter 17 Flashcards
What happens if the arches are positioned too far back in the focal trough?
The anterior teeth will appear blurred and magnified.
What happens if the arches are positioned too far forward in the focal trough?
The anterior teeth will appear blurred and diminished in width.
What is the likely cause of a reversed smile (frown) in a panoramic image?
The patient’s chin was positioned too high.
What corrective action can avoid an image that mimics caries of the anterior teeth?
Have the patient close his or her lips on the biteblock.
Which statement about extraoral film is incorrect?
Film should slide across the intensifying screens when placing it in the cassette.
What is true regarding intensifying screens?
The thicker the emulsion, the faster the speed of the screen.
Is a panoramic radiograph often selected to identify caries?
FALSE
Is panoramic radiography based on the principles of tomography?
TRUE
Do most panoramic machines have wide focal troughs in the anterior region?
FALSE
Is the biteblock used to position the arches correctly in the focal trough?
TRUE
If the patient’s head is rotated to the right, do the teeth on the right appear magnified?
FALSE
If the patient’s chin is tipped up, does the image appear as an exaggerated smile?
FALSE
Will a frown appearance to the arches result when the patient’s chin is positioned too high?
TRUE
Will jewelry in the head and neck area produce artifacts on the panoramic image?
TRUE
Should the patient rest the tongue against the palate during exposure?
TRUE
Must careful loading of a flexible plastic sleeve cassette ensure that the film is completely seated?
TRUE
Is it necessary to use intensifying screens in film-based radiography?
TRUE
Do calcium tungstate or barium strontium sulfate emit green light when they absorb x-rays?
FALSE
Is the technique used to show detailed images of structures called tomography?
TRUE
Does the panoramic technique require more operator time than a full mouth series?
FALSE
Must the radiographer be skilled at setting the correct size of the focal trough?
FALSE
Do side positioner guides assist in locating the correct lateral dimension?
TRUE
Does the x-ray tube head move around the back of the patient?
TRUE
Do all panoramic images have between 10 and 30 percent image magnification?
TRUE
Is the focal trough of all panoramic radiographic machines three dimensional?
TRUE
What happens to the image if intensifying screens and film are not in tight contact?
The resultant image is blurry.
What type of gloves are required when handling extraoral film in the darkroom?
None.
How many intensifying screens are inside a cassette?
Two.
What is the front cover of a rigid extraoral film cassette constructed from?
Plastic.
What is the back cover of a rigid extraoral film cassette constructed from?
Metal.
Why should cassettes and intensifying screens be examined prior to use?
To check for light tightness and cleanliness.
What types of digital image receptors are available for panoramic imaging?
CCD and CMOS-APS solid-state sensors and PSP imaging plates.
Do extraoral films have an embossed identification dot?
No.
What are the steps for processing a PSP plate panoramic image?
The PSP plate is scanned to convert analog data into digital information.
What is the purpose of the head positioner guides when exposing panoramic images?
To position the patient correctly.
