bisecting technique Flashcards
rule of isometry states
two triangles are equal if they have two equal angles and share a common side
radiographer must visualize a plane that divides in half (bisects) this angle
imaginary bisector
SIZE 2 intraoral receptor is used for all periapical projections
anterior region- receptor placed in the vertical direction
posterior region-receptor placed in horizontal direction
phalangioma
if the finger was positioned in front of the film instead of behind it. The image shows the pt finger
incorrect horizontal angulation results in
overlapped contacts
proper horizontal angulations result in
open contacts
vertical angulation (va)
the positioning of the PID in a vertical or up and down plane
central ray directed differently depending on the technique used:
paralleling-
bisecting -
- perpendicular to film & long axis of the tooth
- perpendicular to imaginary bisector
vertical angulation positioning (maxilla)
positioned above the occlusal plane and the central ray
directed downward, IS POSITIVE
vertical angulation positioning (mandible)
positioned below the occlusal plane and the central ray,
directed upward, IS NEGATIVE
incorrect vertical angulation
foreshortened image
the image appears shortened, vertical angulation is too steep
incorrect vertical angulation
elongated image
the image appears too long, vertical angulation is too flat
rules for bisecting technique
receptor placement.
use size 2 for both anterior and posterior
rules for bisecting technique
receptor position
placed against the lingual surface, 1/8 inch beyond incisal or occlusal edge
rules for bisecting technique
VA
central ray must be perpendicular to the imaginary bisector
rules for bisecting
horizontal angulation
central ray must be directed between contact areas
rules for bisecting
receptor exposure
center x-ray beam on film so it’s all exposed
what teeth do you examine first
anterior, maxillary right
bitewing image includes
crowns of max and mand , interproximal areas of crestal bone
molar view
shows all molars and distal on 2nd premolar
premolar view
shows premolars and distal of canine & 1st molar
complete view
shows distal and of canines to retromolar pad
t/f; correct horizontal angulation is crucial for bitewings because they detect any decay
true
if contacts are overlapped on an image, then it is
non-diagnostic
0
posterior teeth of children
1
posterior teeth of children with mixed dentitions
2
posterior teeth in adults
3
longer and narrower and used only in bitewings
full mouth series
consists of PA and BW images
