Peri Apical Technique Flashcards
what is paralleling?
using holders to facilitate positioning
film parallel to tooth
accurate/reproducible image
what is bisected angle?
xray taken without use of holder
operator dependent
not reproducible
what is bisected angle used for?
patients who cant tolerate a holder
access is difficult
want to change position or shape of a tooth
technique of bisected angle?
film is placed as close to tooth as possible
operator observes the angulation of film relative to the tooth
operator bisects angle mode between the tooth and film and directs the x ray tube so the beam is at ninety degrees to the bisector
how to position the xray tube for bisected angle?
select angulation
position vertically - look from the side
position horizontally - look from the front
what happens to the image if the vertical angulation is too flat?
tooth appears elongated
what happens to the image if the horizontal angulation is too steep?
tooth appears shortened
bisected angle holder allows?
aid visualising angulations
reduce film bending
stabilise film
avoid irradiating finger
what are occlusal radiographs used for?
taken to show larger areas than possible on periapicals
used to demonstrate unerupted teeth, supernumerary teeth, cysts
technique of occlusal radiographs?
modified bisected angle technique
using set angulation
film placed in mouth head position, occlusal plane horizontal
insert film as far as can be tolerated
white side of film towards area to be imaged
xray beam angled to appropriate angulation for area to be imaged
anterior oblique occlusal maxilla angualtion?
65
lateral oblique occlusal maxilla ?
60-70
anterior oblique occlusal mandible
45
lateral oblique occlusal mandible
45
true occlusal mandible?
90
xray perpendicular to film
directly underneath chin
