Radiology - Occlusal Radiographs Flashcards
what size of image receptor do we use for occlusal radiographs?
7x5cm
what kind of image receptor should we NOT use for an occlusal?
direct digital receptor
what are the 2 types of occlusals?
oblique
true/cross sectional
what types of occlusals are restricted to lower jaw use only?
true/cross sectional
When would we use an oblique occlusal?
when we cannot use a periapical;
trismus
gagging
large pathology
trauma
localisation with parallax
what technique do we use for oblique occlusals?
bisecting angle technique
describe the bisecting angle technique.
image receptor and object partly in contact but not parallel.
image receptor in in contact with the crowns but not the apices
don’t need to use image receptor holders
In the bisecting angle technique how do you alter the vertical angulation for proclined incisors?
increase
In the bisecting angle technique how do you alter the vertical angulation for retroclined incisors?
decrease
what head position does the patient need to be in for a oblique occlusal of the maxilla?
the mid sagittal plane should be perpendicular to the floor
the intrapupillary line = horizontal
and the ala-tragus line must be horizontal
what head position does the patient need to be in for a oblique occlusal of the mandible?
the mid sagittal plane should be perpendicular to the floor
the intrapupillary line = horizontal
the corner of the mouth/commissure of the lip to the tragus line must be horizontal
where is the centring point for a maxillary oblique occlusal?
1cm above the ala-tragus line
where is the centring point for a mandibular oblique occlusal?
through the lower border of the mandible
what size of image receptor do we use for true/cross-sectional radiographs?
occlusal size 50x70mm
periapical size
why would we use a true/cross-sectional radiograph? (4)
Detection of submandibular duct calculi
Assessment of buco-lingual position of unerupted teeth
Evaluation of pathological buccolingual expansion
Horizontal displacement of fractures
