Introduction to Radiographic Examinations

Question 1

radiolucent

Answer 1

structures of image that appears dark or black
lacks density
x-ray beam little or no resistance

Question 2

radiopaque

Answer 2

structures of the image that appears light or white
dense structure
absorbs or resists the passage of the x-ray beam

Question 3

3 types of intraoral radiographic examinations

Answer 3

periapical
interproximal
occlusal

Question 4

periapical examination

Answer 4

used to examine the entire tooth and supporting bone including apex of teeth
-paralleling
-bisecting

Question 5

interproximal examination

Answer 5

examine the crowns of both the maxillary and mandibular teeth on a single image
used to examine adjacent teeth and crestal bone levels
-bite-wing technique

Question 6

uses of periapical technique images

Answer 6

apical infection/inflammation/apical cysts, periodontal status, assess trauma to teeth and alveolar bone, assess presence and position on unerupted teeth, assess root morphology, endodontics

Question 7

bitewing technique

Answer 7

horizontal: alveolar bone limited
vertical: allow up to 1 cm more viewing area of bone than horizontal BW

Question 8

what technique is not recommended

Answer 8

interproximal technique full mouth series
useless for anterior teeth, cannot see apex of the root, posterior teeth are different because you cannot see them clinically

Question 9

occlusal examination

Answer 9

used to examine large areas of the maxilla or the mandible on one film, 3D characteristic
-occlusal technique
-patient occludes on receptor

Question 10

occlusal radiographs

Answer 10

larger and show full tooth development and placement, reveals entire arch of teeth in either upper or lower jaw

Question 11

extraoral examination

Answer 11

large areas of the skull or jaws
receptors placed outside mouth
-panoramic image (front view)
-cephalometric image (side view)

Question 12

full mouth x-rays (FMX)

Answer 12

provides diagnostic information
complements clinical examination
periapical and bitewing images
detects disease, foreign objects, retained roots

Question 13

receptors used in an FMX

Answer 13

size 1 receptor
used in anterior region
long portion in vertical direction
size 2 receptor
used in posterior region
long portion in horizontal direction

Question 14

full mouth series consists of

Answer 14

5 max anterior (#1 plates)
3 mand anterior (#1 plates)
4 max posterior (2 right, 2 left, #2 plates)
4 mand posterior (2 right, 2 left #2 plates)
4 bitewing radiograph (2 right, 2 left, #2 plates)

Question 15

diagnostic criteria

Answer 15

optimal density, contract, definition, detail
least amount of distortion possible, same shape and size as object being imaged
FMX includes images that show all tooth-bearing areas, dentulous and edentulous regions
periapical images show entire crowns and roots of teeth and 2 to 3 mm beyond root apices
bite-wing images show open contacts or interproximal tooth surfaces are not overlapped

Question 16

periapical radiographs

Answer 16

examines entire tooth including the apex of the tooth supporting structures
-2-3mm beyond apex
-highlights 1-3 teeth at a time

Question 17

prescription of dental radiographs

Answer 17

based on individual needs
-clinical evidence of generalized dental disease or a history of extensive dental treatment

Question 18

paralleling technique

Answer 18

used for both periapical and bitewing
creates most accurate representation of a tooth image
receptor positioned parallel to full length of tooth being radiographed

Question 19

long axis of the tooth

Answer 19

imaginary line that divides the tooth longitudinally into two equal halves

Question 20

central ray

Answer 20

central portion of the primary beam of x-radiation

Question 21

principles of paralleling technique

Answer 21

receptor is placed in the mouth parallel to the long axis of the tooth being radiographed
central ray of the x-ray beam is directed perpendicular to the film and the long axis of the tooth
a beam alignment device must be used to keep the receptor parallel with the long axis of the tooth

Question 22

principles of object-receptor distance paralleling technique

Answer 22

receptor must be placed away from the tooth
curvature of mouth makes the O/R distance increased to keep receptor parallel with long axis of tooth
image is magnified and loss of definition

Question 23

paralleling technique advantages

Answer 23

less distortion, cusps and root lengths more representative, less superimposition, improved image sharpness, length of teeth more easily measured, easy to learn, easy to duplicate

Question 24

paralleling technique disadvantages

Answer 24

can be difficult to place in a small mouth or shallow palate
discomfort

Question 25

beam alignment devices

Answer 25

used to position the receptor in the mouth and retain the receptor in position during exposure
reduces exposure, prevents cone cuts, held without patient’s finger, aids in alignment of x-ray beam, obtaining diagnostic radiographs of entire dental arches

Question 26

step-by-step procedures for paralleling technique

Answer 26

patient preparation
equipment preparation
exposure sequence for receptor placements
receptor placement for paralleling technique

Question 27

patient prep for paralleling technique

Answer 27

explain imaging procedures to patient
adjust chair
adjust headrest
lead apron

Question 28

equipment preparation

Answer 28

proper number and size of receptors placed in barriers
set exposure time
sterilized beam alignment device
identifying mark (a or o) placed in slot of biteblock

Question 29

exposure sequence

Answer 29

anterior, posterior, bitewing

Question 30

5 rules for paralleling technique

Answer 30

receptor placement: cover area of teeth
receptor position: parallel to long axis of tooth
vertical angulation: central ray perpendicular to receptor and long axis of tooth, right angle
horizontal angulation: central ray directed through teeth
receptor exposure: x-ray beam centered on receptor

Question 31

elongation paralleling technique

Answer 31

results from under-angulation of x-ray beam
increase vertical angulation
angulation of x-ray beam is less than the long axis plane of the teeth

Question 32

foreshortening

Answer 32

results from over-angulation of the x-ray beam
decrease positive vertical angulation for max
decrease negative vertical for mand
angulation of x-ray beam is greater than long axis plane of teeth

Question 33

shallow palate modifications in paralleling

Answer 33

receptor can become bent against palate
position receptor biteblock away from teeth
tip receptor holder so aiming ring moves up allowing patient to close their teeth on bite surface
cotton rolls on bite block of opposing arch
vertical angulation increased by 5 to 15 degrees more

Question 34

tori

Answer 34

maxillary torus: receptor must be placed on far side of the torus
mandibular tori: receptor must be placed between the tori and the tongue