Radiography

Question 1

Panoramic Positioning Errors:

Pt positioned too far back ->

Answer 1

BBBB

Back = Big, broad, blurred

Question 2

Panoramic Positioning Errors:

Pt positioned too far forwards ->

Answer 2

Minified teeth with narrow, skinny, spindly appearance

Teeth appear longer & narrower

Question 3

Panoramic Positioning Errors:

Pt Chin down ->

Answer 3

smiley face effect

Question 4

Panoramic Positioning Errors:

Pt Chin up ->

Answer 4

flattening of occlusal plane

anteriors - big and blurred

Question 5

Panoramic Positioning Errors:

Pt off centre

Answer 5

side closest to film -> Minified
side furthest from film -> magnified
Overlap -> non-diagnostic

Question 6

Writing a Radiographic Report

Answer 6

[Check correct patient & radiograph oriented correctly]

• Date
• Type of radiograph
• Image quality

- Periodontal 
Alveolar bone levels 
  if can see apex % root length 
  bitewings - bone loss measured in mm
Pattern of bone loss 
Calculus present 
Furcations 
Marginal widening 
Perio-endo lesions

• Cares
  Site
  Depth

Restorations
Mention heavily-retsored teeth
Must mention deficiencies/ overhangs/leaking

- Endodontic and periodical 
periapical radiolucencies
apical stars of crowned teeth 
widening of PDL space 
quality of root fillings (extruded/short from apex by how many mm) 

-Other
radiopacities
retained roots
unerrupted teeth past normal eruption date
degree of 3rd molar eruption, any abnormal angulation, root morphology and relation to ID canal

Question 7

What is quality assurance

Answer 7

planned and systematic execution of procedures to ensure high quality images of high diagnostic yield at a minimum radiation dosage

Question 8

Why quality assure?

Answer 8

Reduces necessity for retakes
Minimises radiation exposure to patient
Minimise costs
Minimise inconvenience
Save time
Ensure consistently adequate diagnostic information
Radiation doses to be controlled to be as low as reasonable practicable (ALARP principle of radiation protection)

Question 9

In the document ‘Guidance notes for dental practitioners on the safe use of X-ray equipment’ which encapsulates both of the ionising radiation regulations and elements of good practice they divide the QA chapter into these:

Answer 9

Essential QA procedures

• Image quality
  Excellent/Acceptable/Unacceptable
• Pt dose and xray equipment
• darkroom, films and processing
• training
• audits
  film reject analysis

Question 10

Testing of dental X-ray equipment

Answer 10

• Critical examination

Legal responsibility of installer
Installer must consult with Radiation Protection Advisor about nature, extent and results of examination
Mostly to do with keeping dose at a reasonable level, radiation protection safety features are in place, exposure control has been evaluated etc.

• Acceptance tests
  Responsibility of legal person
  RPA should be consulted
  Includes all parts of critical exam
  Measurement to determine whether equipment operating within agreed parameters
  Assessment of typical patient dose for comparison with Diagnostic Reference Levels
• Routine tests
  confirms no significant changes to description of equipment/location
  Main attention actual results but also to comparison with previous tests
  Identify and investigate trends that suggest deterioration

Most common method of carrying out the routine test:

The Dental monitoring service postal pack
supplied by NRPB (national radiological protection board)
Contents of monitoring pack: includes device which you make an exposure using your equipment, NRPB will send back the results after you have returned it to them