Radiographic Localisation Flashcards
why is there a need for radiographic localisation
to determine the location of a structure or pathological lesion in relation to other structures
what are some clinical situations that would require radiographic localisation
position of unerupted teeth
supernumerary
location of roots/ canals
relationship of pathological lesions
trauma
soft tissue swellings
if you have a 2D image of a view and you want to know more about the 3D structures of it what should you do
take a right angle view
what is the premise of radiographic localisation
two views required
views at right angles in their projection geometry
when is horizontal or vertical tube shift used
when views are not at right angles
what is parallax
apparent change in the position of an object caused by a real change in the position of the observer
what is one of the premises of parallax
the objects furthest back move in the direction that we have changed our orientation to
how do we view radiographs
from the buccal aspect of the patient
why does viewing radiographs from the buccal aspect of the patient matter
the buccal aspect is closer to observer
what is the important parallax mnemonic to learn
Same
Lingual
Opposite
Buccal
as lingual is furthest away view
what is another mnemonic used for remembering which way objects go in parallax technique
PAL
my pal goes with me - PALatal
what do you need to identify for parallax technique
identify direction of tube movement
what do we want to know the location of
choose a reference
observe movement of the structure in correct direction
what are examples of horizontal tube shifts
equivalent views
2 x periapicals
2 x bitewings
2 x oblique occlusals
what are examples of vertical tube shift
different views
panoramic and oblique occlusal
panoramic and lower periapical
what is the term for different views of parallax localisation
vertical tube shift
