OMR Flashcards
how are congenitally missing teeth charted?
black vertical line or x through the tooth
how are previously extracted teeth charted?
blue vertical line or x through the tooth
how are existing composite resin restorations charted?
outline surfaces in blue
how are existing amalgam restorations charted?
fill in surfaces in blue
how are existing gold restorations charted?
cross hatch surfaces in blue
what is an odotogram
list all of the teeth for charting
how are existing porcelin/ ceramic crowns charted?
outline tooth in blue
what are 3 ways to maximize sharpness and resolution?
- use as small an effective focal spot as practical
- increase distance from focal spot to tooth with long open ended cylinder (aiming cylinder)
- minimize distance from tooth to image receptor (film next to tooth)
- further away, tooth closer to film
image size distortion (magnification) can be minimized by?
- increase focal spot to image receptor distance (aiming cone)
- decrease tooth to receptor distance (film placement)
image shape distortion can be minimized by?
- position image receptor (film) parallel to long axis or the tooth
- orient central ray (cone) perpendicular to the tooth and image receptor
what color is used in charting for treatment that needs to be completed?
red
how can shape distortion manifest?
foreshortening or elongation of the film image
when does foreshortening of the film occur?
when the central bean is perpendicular to the image receptor (film) but the tooth is not
-film is not parallel to long axis of the tooth
when does elongation of the film occur?
when the central beam is perpendicular to the tooth but not the image receptor
what is paralleling technique ?
central ray should be perpendicular to the long axis of both the tooth and the image receptor
what x-ray technique generates the least distortion and is the preferred method of capturing images when possible?
paralleling technique
what is the bisecting angle technique?
the central beam should be directed at a right angle to the imaginary place bisecting the angle formed by the image receptor (film) and the central axis of the tooth. The film is slightly tilted more.
-angle bisects (inbetween) the central axis of the tooth and the film
what is the result of the bisecting angle technique?
image of correct length but with distortions in tooth and height of alveolar crest
Object localization rule : SLOB rule?
Same Lingual- Opposite Buccal
if an object moves mesial or the same direction as you moved the tubehead, this it is _______ to the teeth?
lingual
if the object shifts to the opposite direction, distally it is located _______ to the teeth?
buccal
if the object does not shift, it is located _______ to the teeth
same plane
how to increase periapical coverage?
increase the angle of the x-ray head and cone by 5-15 degrees
To lessen distortion in a radiograph you can:
A. Increase distance between focal spot and image receptor
B. Decrease distance between object (tooth) and image receptor
C. Use paralleling technique
D. All of the above
D. All of the above
how many films are in a full mouth series of radiographs?
18 films- 14 periapicals and 4 bitewings
what number sensor is used for all radiographs?
2
what is the central x-ray entry point of the maxillary premolar region
point down from the pupil of the eye to mid cheek area
what is the central x-ray entry point for the maxillary cuspid region?
ala of the nose
what is the central x-ray entry point for the maxillary molar region?
point down from the outer canthus (corner) of the eye to mid cheek area
what do we want to see in the maxillary molar x-rays?
distal of 2nd premolar to the maxillary 3rd molar
When taking periapical radiographs of the upper bicuspids you do which of the following?
A. Position the cone parallel to the occlusal plane
B. Position the sensor such that it captures the cuspid back to the first molar
C. Angle the cone from the mesial in order to project the cuspid onto the sensor
D. Tip the patient back in the chair, mouth open, until the mandible is parallel with the floor
B. Position the sensor such that it captures the cuspid back to the first molar
radiopaque?
anything that blocks the transmission of x-rays
-photons are not reaching sensor b/c absorbed
is air and metal radiopaque or radiolucent?
air = radiolucent
metal - radiopaque
radiolucent?
permits the transmission of x-rays
what is more radiopaque, enamel or dentin?
enamel is more radiopaque
enamel is what percent mineral?
90%
-most dense natural substance in the body made of calcium phosphate
is dentin radiolucent or radiopaque?
what percent mineral?
- radiopaque
- 75% mineral
- makes up the largest portion of the hard structures of the tooth
- same opacity as bone
is cementum see radiographically?
seldom seen radiographically
-low contrast between it and dentin
is pulp radiopaque or radiolucent?
-radiolucent
lamina dura?
continuous with cortical bone at the alveolar crest
-surrounds the tooth locket with thick layer of dense bone
is the lamina dura radiopaque or radiolucent?
radiopaque
what can cause the lamina dura to appear more dense radiographically?
- passing of the x-ray bean at a tangent
- it is not any more mineralized than the surrounding bone
is the alveolar crest radiopaque or radiolucent?
radiopaque
how does the alveolar crest vary in the anterior and posterior?
anterior: pointed
posterior: flat and parallel line connecting the CEJ’s of adjacent teeth
cancellous bone also know as?
trabecular bone
where is cancellous bone located?
between the cortical plate
is the cancellous bone radiolucent or radiopaque?
radiopaque plates and rods surrounding radiolucent marrow pockets
what is the accepted distance of the alveolar crest to the CEJ?
1.5-2mm
what type of restorative materials appear radiolucent?
- silicate cements
- some composite resins
- porcelain
what type of restorative materials appear radiopaque?
- silver alamgam
- gold
- pins and posts
- calcium hydroxide
- gutta percha
- some composities
- stainless steal crowns
- ortho bands and appliances
- impants
This portion of the tooth makes up the bulk of the structure of the tooth and is about the same opacity as bone: A. Enamel B. Dentin C. Cementum D. Pulp
B. Dentin
where is the mental foramen typically located?
at the apex of the mandibular 2nd premolar
