SA dental Radiography / Radiology

Question 1

What are the 2 different types of x-ray generators? +what are their pros/cons?

Answer 1

 Multidirectional generator head:
-Mobile head attached to stand/wall mounted
-Limitless positions – can set to angle needed
-Reduce movement during procedure
 Hand-held generator:
-Easier to store/set up in practice
-May see some movement during exposures
-Can be harder to set angles
-Care with setting up control zones and operator safety

Question 2

What are the 2 different types of dental radiography?

Answer 2

*Direct Dental radiography =
Image sent straight to computer, no processing needed
*Indirect dental radiography =
Digital film that needs to be processed after exposure

Question 3

What are advantages / disadvantages of direct dental radiography?

Answer 3

 Advantages:
-No need to move sensor between exposures – easier to correct positioning faults
-Faster= less GA time
-Sensor has long lifespan of use
-Sensor small, easy to move and store.
 Disadvantages:
-One size – doesn’t fit all well

Question 4

What are the advantages / disadvantages of indirect dental radiography?

Answer 4

 Advantages
-Size flexibility: Variety of shapes and sizes of films
-Films thin and easy to place into the mouth
 Disadvantages:
-Slower: removing the film to be processed
-Less accurate: For the same reason, harder to correct positioning faults
-Films susceptible to damage

Question 5

What needs to be assessed considering anatomy?

Answer 5

 Abnormal number or shape of roots
 Extra or ‘missing’ teeth

Question 6

What needs to be assessed considering pathology?

Answer 6

 Periodontitis
 Pulp necrosis
 Dental fractures
 Tooth resorption (FORLs)
 Supernumerary teeth
 Un-erupted teeth/dentigerous cysts

Question 7

What is the parallel technique used for?

Answer 7

Caudal mandible - premolars + molars

Question 8

What is the bisecting angle?

Answer 8

Sensor at angle to teeth - beam perpendicular to bisecting angle - between tooth root axis + sensor

Question 9

Why bother with a hard bisecting angle?

Answer 9

*Can radiograph teeth where a parallel technique is not possible
-Palate or other hard tissues in the way of sensor
-Opposite tooth would prevent parallel views with sensor outside the mouth

*Prevents image distortion from trying to take parallel views in hard to reach places
-Important to assess tooth roots and pulp cavities accurately

Question 10

What do you do if image isn’t fully on plate?

Answer 10

Move plate further into region of interest (in this case lower down in mouth)

Question 11

What do you do if area of interest is not within cone?

Answer 11

Plate and tube head need to be repositioned to include ROI

Question 12

What do you do if roots are elongated?

Answer 12

Angle too shallow – adjust tube head position

Question 13

What do you do if roots are compressed?

Answer 13

Angle too steep – adjust tube head position