intraoral projection

Question 1

BID-beam indicating device

Answer 1

collimates and directs X-ray beam (cone) (can also be rectangle)

Question 2

Central ray of x ray beam

Answer 2

define position of beam vertically and horizontally

Question 3

vertical angulation

Answer 3

movement of BID up or down in relation to occlusal plane

Question 4

horizontal angulation

Answer 4

movement of BID around patients head in relation to sagittal plane

Question 5

positive vs negative vertical angulation

Answer 5

positive=beam pointing down

negative=beam pointing up

Question 6

most accurate vertical angulation

Answer 6

BW’s

Question 7

what do bite wings eval?

Answer 7

• bone height
• interprox lesions
• depth of rest/caries
• assessment of rest margins

Question 8

FMX

Answer 8

20 radiographs
PA’s on top and bottom
BW in middle

Question 9

rules for PA

Answer 9

must show the entire crown and roots

2 mm beyond root apices

Question 10

rules for BW

Answer 10

equal distribution of both arches

Question 11

rules for canine

Answer 11

1. canine must be centered in image
2. 2 mm of apical bone visible above the root apex
3. lateral canine contact open

Question 12

head position for occlusal plane of teeth radiograph

Answer 12

parallel to floor

Question 13

sagittal plane radiograph head position?

Answer 13

perpendicular to floor

Question 14

paralleling technique

Answer 14

most anatomically accurate

-extension cone, right angle, long cone

Question 15

bisecting angle

Answer 15

inherit distortion

pt managment

Question 16

2 fundamental principles of paralleling technique

Answer 16

1. image receptor is positioned parallel to long axes of teeth
2. central ray of x ray beam is directed perpendicular to teeth and image receptor

Question 17

to obtain a parallel relationship bw teeth and image in maxillary teeth?

Answer 17

incisal edges/buccal cusps engage biteblock in first or second groove (outer edge of bite block)
-receptor in center of oral cavity

Question 18

in order to achieve parallelism between image receptor and teeth, the OBJECT RECEPTOR DISTANCE will have to be increased in the _______

Answer 18

maxillary arch (tooth placement in first or second groove)

Question 19

PA anterior instrument

Answer 19

straight ring

-anterior arm most bent

Question 20

PA posterior instrument

Answer 20

offset sing

horizontal block

Question 21

ring bitewing instrument

Answer 21

straight ring
no bends
looks like airplane

Question 22

to achieve parallel relationship bw teeth and image receptor in mandibular teeth—

Answer 22

incisal edges or buccal cusps should engage MIDDLE of biteblock

Question 23

correct horizontal angulation

Answer 23

image receptor placed parallel to lingual surfaces and beam should be directed thru contacts of teeth and perpendicular to image receptor

Question 24

correct horizontal angulation–

Answer 24

open contacts

Question 25

correct vertical angulation

Answer 25

results in radiographic image that is close to same length as the tooth

Question 26

incorrect vertical angulation

Answer 26

results in a radiographic image that is not the same length as the tooth - foreshortening - elongation

Question 27

foreshortened image

Answer 27

excessive vertical angulation

Question 28

elongated image

Answer 28

insufficient vertical angulation

Question 29

cotton rolls are never used with ---

Answer 29

bitewing technique

Question 30

never place a cotton roll where?

Answer 30

on same side as plate

Question 31

make sure image receptor is centered within ?

Answer 31

the ring

Question 32

cone cut

Answer 32

when the central ray is not directed through the center of the region being radiographed

Question 33

advantages of paralleling technique?

Answer 33

- accuracy (reduces distortion) - simplicity (eliminates need to determine horizontal and vertical angulation) - duplication (comparison of serial radiographs has validity)

Question 34

disadvantages of paralleling technique

Answer 34

- image receptor placement may be difficult | - discomfort

Question 35

typical results of paralleling tech

Answer 35

- no anatomic structures projected over roots - roots approx same length - cusp tips same height - alveolar crest below CEJ

Question 36

foreshortened image

Answer 36

- elongated palatal root - foreshortened buccal roots - alveolar crest not below CEJ - cusp tips not superimposed - zygomatic process and zygomatic bone projected over roots

Question 37

elongated image

Answer 37

- roots stretched off the image - crowns moved up in image - biteblock and alignment rod moved up in image

Question 38

bisecting angle technique

Answer 38

- plate must be placed along lingual - plane of plate and long axis form an angle at the point where plate contacts tooth - imaginary line bisects the angle formed by plate and long axis of tooth - central ray directed perpendicular to imaginary bisector

Question 39

advantages and disadvantages of bisecting tech

Answer 39

- helpful for gagging, small, shallow floor, large tongues | - image distortion

Question 40

what is ideal for patients with moderate to severe bone loss?

Answer 40

vertical bitewing

Question 41

vertical bitewing series

Answer 41

seven plates used to cover midline, canine, premolar, and molar areas

Question 42

bitewing plate holder

Answer 42

device used to position an intraoral plate in the mouth

Question 43

bitewing tab

Answer 43

heavy paperboard tab or loop fitted around an image receptor to stabilize it during exposure

Question 44

bitewing tech with tabs

Answer 44

- x ray beam is angled positively at 6-8 degrees | - center BID directly over image receptor

Question 45

diagnostic criteria for all intraoral radiographs

Answer 45

- density, contrast, definition, detail - least amount of distortion - FMX must include all tooth-bearing areas - PA--entire crowns and teeth+2mm - open contacts

Question 46

types of image receptor holders

Answer 46

styrofoam EEZEE-grip endoray unibite