Oral Radiology Glossary

Front 1

The direction or angle at which the central ray and PID of the xray machine are
aimed at the teeth and film

Back 1

Angulation

Front 2

front teeth of either jaw (incisors and canine teeth)

Back 2

Anterior

Front 3

the point or extremity of the tooth root (pi., apices)

Back 3

Apex

Front 4

a radiographic view that shows the crowns of the upper and lower posterior teeth
and the alveolar bone crest of the maxilla and mandible

Back 4

Bite-wings

Front 5

surface of the tooth towards the cheek

Back 5

Buccal

Front 6

the middle of the primary beam (=central beam)

Back 6

Central Ray

Front 7

a device that helps eliminate peripheral radiation

Back 7

Collimator

Front 8

an error in PID placement that results in part of the film being unexposed

Back 8

Cone Cutting

Front 9

the difference in density between adjacent (radiolucent and radiopaque) areas of an
image

Back 9

Contrast

Front 10

the degree of blackness of an image

Back 10

Density

Front 11

surface of the tooth towards the back of the mouth, away from the midline

Back 11

Distal

Front 12

an error in vertical angulation resulting in an image that appears to be too long

Back 12

Elongation

Front 13

identification dot; a circle on the corner of the xray film packet that corresponds
to a raised area on one side of the film. It is used to determine which side of the
film was struck by the xray

Back 13

Embossed Dot

Front 14

the amount of time the xray beam is released during the taking of one radiograph

Back 14

Exposure Time

Front 15

a radiographic technique in which the film is placed outside the mouth
during exposure

Back 15

Extraoral

Front 16

an error in angulation resulting in an image of reduced height

Back 16

Foreshortening

Front 17

the direction of the xray beam in the horizontal plane (i.e., parallel with the floor)

Back 17

Horizontal Angulation

Front 18

the cutting edge of the anterior teeth

Back 18

Incisal Edge

Front 19

a radiographic technique in which the film is placed inside the mouth during
exposure

Back 19

Intraoral

Front 20

1000 volts; the unit of measure for the penetrating power of the xray beam

Back 20

KiloVolt

Front 21

surface of the tooth towards the lips

Back 21

Labial

Front 22

surface of the tooth towards the tongue

Back 22

Lingual

Front 23

cylinder (PID) on xray machines where anode-film distance is 12 to 20 inches

Back 23

Long Cone

Front 24

lower jaw

Back 24

Mandible

Front 25

upper jaw

Back 25

Maxilla

Front 26

surface of the tooth towards the front; closest to the midline

Back 26

Mesial

Front 27

=Midline; an imaginary vertical line or plane passing through the center of the
body that divides it into right and left halves

Back 27

Mid-sagittal Plane

Front 28

1/1000 of an ampere, the unit of measure of quantity of radiation

Back 28

Milliampere

Front 29

surface of a premolar or molar that meets the opposing teeth in the closure of the
jaws (i.e., biting surface)

Back 29

Occlusal Surface

Front 30

superimposition of the image of one tooth over part of another, produced when the
central ray is not perpendicular to the film and teeth in the horizontal plane

Back 30

Overlapping

Front 31

around the apex of the tooth (used to refer to radiographs that show the crown,
root, and supporting structures of the tooth)

Back 31

Periapical

Front 32

Position Indicating Device; any device attached to the tubehead at the aperture to
direct the useful beam of radiation; long or short, cylindrical or rectangular, open
or closed (pointed) at tip

Back 32

PID

Front 33

teeth of either jaw behind the incisors and canines, i.e., premolars and molars

Back 33

Posterior

Front 34

the main flow of xrays from the xray machine

Back 34

Primary Beam

Front 35

structures that are permeable to xrays, producing black areas on radiographs

Back 35

Radiolucent

Front 36

structures that absorb xrays, producing light areas on radiographs

Back 36

Radiopaque

Front 37

xrays deflected from exposed tissue to adjacent tissue, or xrays deflected within the
tubehead; weaker than primary radiation

Back 37

Scattered Radiation

Front 38

cylinder (PID) on dental x-ray machines where anode-film distance is 9 inches or
less

Back 38

Short Cone

Front 39

angle made between the xray beam and a line parallel to the floor

Back 39

Vertical Angulation

Front 40

X-ray

Back 40

a high energy electromagnetic wave that can penetrate solid matter

Front 41

extension cone paralleling instrument (made by RINN)

Back 41

XCP

Front 42

long cone technique = right angle technique = paralleling technique.
This technique consists of placing the film packet parallel to the longitudinal axis
of the tooth and directing the central ray perpendicular to tooth and film packet.

Back 42

XCP Technique