Radiographic techniques 3 Flashcards
bisected angles technique
Film/image receptor as close to ? as possible.
Receptor will usually contact ? but be distant from ??.
Long axis of the tooth and film form an ? which is mentally bisected - ??
X-ray tube positioned so is ?* to ??
tooth
crown
root apex
angle
bisecting plane
90*
bisecting plane
what is the law of similar triangles?
use in bisecting angles technique
length of image = length of tooth
bisected angles technique
reasons for using bisected angles technique?
Patient can’t tolerate holder
Separate the roots of tooth
Overcome superimposition
Assessing root fractures
Localising unerupted teeth
Diagnosing apical pathology when the paralleling technique can’t be used
When its ok to have distorted view
when we want a bigger view than bisecting angles technique gives what radiographs do we take?
occlusal view
what technique is used to take oblique occlusals?
Modified bisecting angle technique
oblique occlusal views can be taken of Mandible and maxilla from
Anterior and lateral views
oblique occlusal views
Show teeth from ? to ?
? often occurs
? occurs of structures not in central area
? technique for patients
Has many different ?
crown
apex
distortion
superimposition
easy
names
how are oblique occlusals used to assess the relative position of pathology or unerupted teeth?
parallax views
when to request oblique occlusal radiographs?
Require a larger image than periapical
Patients who cant tolerate holder e.g. gag reflex/retch
Parallax views to help assess the relative position of pathology or unerupted teeth
mandibular occlusal views
Anterior oblique is often called ?
Film and long axis of incisors are at ? to each other
Bisected angle is ?
Beam is angled at 90* to the ?? and therefore hits the film at ?
45*
90*
45*
bisecting plane
45*
True mandibular occlusal film
Mandibular teeth are at ? to occlusal plane - especially ?
X-ray beams parallel to ????
X-ray beam ? to receptor
Not all teeth may be seen in cross section
Often taken to check for ???
Teeth look like ?
90*
anteriors
long axis of teeth
90*
submandibular duct calculi
buttons
what is localisation?
finding the exact location of an object that cant be seen clinically through assessing the relationship of one structure to another
indications for localisation
Unerupted teeth assessing buccal-palatal relationship to dental arch
Position of foreign bodies
Expansion/destruction of bone
Position of salivary calculi
Separating the multiple roots of teeth for RCT
Assessing the displacement of fractures
what are parallax views?
2 views/radiographs taken of same object with different angulation of beam
horizontal parallax
DPT and vertical parallax
