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50 terms

Radiology ch 16, 17, 18, 19

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The _____ radiographic examination is used to examine the entire tooth (crown and root) and supporting bone
the periapical
the _____ is used to examine the interproximal areas of the crowns and bone height of the mandible and maxilla on one film
the interproximal examination
the ______ is used to examine large areas of the maxilla or the mandible an one image
Occlusal image examination
What are the two ways of obtaining periapical radiographs
paralleling and bisecting
What does CMRS stand for
Complete mouth radiograhic series
Define CMRS
(full mouth series, FMX) series of intraoral dental radiographs that show all the tooth bearing areas of the jaw
a total of ____ to ____ number of films may be included in a CMRS
14 to 20
how many films would be sufficient in a CMRS it the patient is endentulous
14 periapicals
define intersecting, perpendicular, parallel, and right angle
Intersecting: to cut across or through
Perpendicular: intersecting at or forming a right angle
Parallel: moving or lying in the same plane, always separated by the same distance and not intersecting.
Right angle: an angle of 90 degrees formed by two lines perpendicular to each other
According to the basic principles of the paralleling technique how is the film placed and how is the central ray directed
The receptor is placed in the mouth parallel to the long axis of the tooth being radiographed
the central ray of the x-ray beam is directed perpendicular(at a right angle) to the receptor and the long axis of the tooth
how do you achieve parallelism between the film and the tooth
to achieve parallelism between the tooth and the receptor, the receptor must be placed away from the tooth toward the middle of the oral cavity
there is an increased object receptor distance how will that affect the image?
image magnification and loss of definition will result, increased magnification
what will an increased target receptor distance compensate for
an increased target receptor distance will compensate for image magnifiation
which types of film holders are auto clavable, which is disposable
disposable: stabe bite blocks
auto clavable: XCP instruments, precision film holders, EEZEE grip, hemostate with bite blocks
are there any film holders that can be disinfected instead of autoclaved
no
which type of film holding device includes aiming rings that are in the alignment of the PID with the film
Rin XCP
Which size film is recommended for an adult periapical for the anterior teeth
Anterior size 1
posterior size 2
according to the book, which direction would a size one film be positioned when taking an adult anterior periapical, which direction would a size two film film be positioned when taking and adult posterior periapical
Size one is always positioned with the long portion of the receptor in a vertical (upright) direction
Size two is always placed with the long part of the receptor in a horizontal (sideways) direction
Which film are least likely to elicit gag reflex
Anterior placement
once a gag reflex is simulated what could the patient do so that he or she could normally tolerate
the patient may gag on receptor placement that might normally be tolerated, Have patient try placing the film in their mouth themselves then check to make sure the positioning is correct
with size 1 film a total of ____ anterior films are used in the paralleling technique with the size 2 film used in the anterior ____ number of films are used
Size one 8 films are used
size two 6 films are used
what does the author of your book recommend for an exposure sequence starting with
anterior premolar molar
how many posterior films are used with the paralleling technique
8 posterior placements may be used which include 4 maxillary exposures and 4 mandibular
If the patient has a shallow palate that creates a lack of parallelism a greater than ____ degrees requires a modification in technique
in a patient with a shallow palate tilting of the bite block occurs which results in a a lack of parallelism between the receptor and the long axis of the tooth
if lack of parallelism does not exceed 20 degrees the resulting image is generally accepted. When greater than 20 a modification technique is necessary
does the paralleling technique rely on a fixed vertical angulation? and does it produce a radiograhic image who dimensional distraction
the primary advantage of the parallelism technique is that it produces a radiograhic image WITHOUT dimensional distraction
When exposing a periapical, where should the dot be placed in the bite block? why
in the slot
When exposing the maxillary canine PA is it likely you will break the contact between the maxillary canine and the first maxillary premolar? why or why not
no it is not likely you will break the contact because the lingual cusp of the first premolar usually obscures the distal contact of the canine
Define the rule of isometry
the of isometry states that two triangles are equal if they have two equal angles and shake a common side
Where is the film placed when utilizing the bisecting angle technique
when utilizing the bisecting technique the receptor must be placed along the lingual surface of the tooth
the plane of the receptor and the long axis of the tooth form an angle where the receptor contacts the tooth
when utilizing the bisecting angle technique what angle is bisected
the angle that is formed at the contact of the receptor to the tooth
How is the central ray directed when utilizing the bisecting technique
the central ray is directed at a 90 degree angle
What may be used to hold the film in the bisecting technique? what is recommended to be used because it eliminates the use of the patients finger
Beam alignment devices may be used to stabalize the receptor
BAIS with collimators
what does BAIS refer to
bisecting angle instrument
What is the name of the commercially available film holders that are recommended for use with either the paralleling or bisecting technique
stabe bite blocks
what is the name of the commercially available film holders recommended for one time use
stabe bite blocks
which size film is traditionally use for the bisecting technique
size 2
which techniques use the same principles of horizontal angulation
paralleling, bisecting, and bite wing techniques all use the same principles of horizontal angulation
describe how the central ray is directed when utilizing the bisecting technique
the central ray is directed perpendicular to the imaginary bisector
Define foreshortened, how would the image appear on the receptor? what would cause an image to appear foreshortened? how would you correct this
foreshortened refers to images that appear shortened.
foreshortened images result from excessive vertical angulation is too steep, the image of the tooth appears shorter then the actual tooth. Also occurs if the central ray is directed perpendicular to the plane of the receptor rather than to the imaginary bisector.
to fix this, reduce the angulation
how far beyond the occlusal or incisal should the film be placed when using the bisecting technique
the occlusal end of the receptor must extend approx. one eighth of an inch beyond the incisal or occlusal surfaces
What does horizontal angulation refer to
postitioning teh PID and central beam in direction horizontal or side to side
what does vertical angulation refer to
positioning the PID vertical or up and down plane
Measured in degrees
What is a bite wing tab and how is it used
heavy paper board tab or loop that is fitted around an intraoral receptor and is used to stabilize the receptor during the procedure
when using, the bite wing is oriented in the bite loop so that the tab portion extends from the white side
how many size bite wing films are available
size 0: posterior teeth of children with primary dentition
size 2: posterior teeth in adults may be placed horizontally or vertically
size 3: longer and narrower than size 2 not recommended
which size film is used for bite wings only
size 3
which film is discouraged for bite wings
size 3 because overlapped contacts often result because the difference in the curvature of the arch between the premolar and molar areas
what size of film is recommended for bite wings
size 2
when determining vertical angulation if the PID is positioned above the occlusal plane and the central ray is directed downward, the vertical angulation is considered to be ____
positive
what is teh recommended exposure sequence for a patient who requires both PA and bite wings
all anterior then posterior then bite wings
what are vertical bite wings used for
to examine the level of alveolar bone in the mouth
most often used for post treatment follow ups