9 Justification and Interpretation

Question 1

What is dose?

Answer 1

the amount of radiation absorbed by the patient

Question 2

what are the recommended technique for diagnosing caries?

Answer 2

• bitewings (usually horizontal)
• paralleling periapicals

Question 3

If there is periodontal bone loss as well as possible caries, what technique would you consider?

Answer 3

• vertical bitewings

Question 4

what should we be able to see in bitewing radiographs?

Answer 4

• crowns of the teeth
• coronal portion of the roots
• contact points, with very little overlap
• the alveolar bone crest
• distinguish enamel from dentine
• the pulp chamber
• if restorations present, to be able to check for any overhangs or deficiencies at the margins

Question 5

What are the advantages of the paralleling technique?

Answer 5

• accurate images
• positioning device determines the angulations
• reproducible on different visits by different operators
• relative positions of the film, teeth and x-ray beam always maintained

Question 6

For high risk caries child patient, how often should they receive suitable radiographs?

Answer 6

6 months

Question 7

For moderate risk caries child patient, how often should they receive suitable radiographs?

Answer 7

annually

Question 8

For low risk caries child patient, how often should they receive suitable radiographs?

Answer 8

deciduous teeth - 12-18months
permanent teeth - 24 or more

Question 9

What is the trabecula pattern like in the mandible?

Answer 9

thick, close together, horizontally aligned

Question 10

What is the trabecula pattern like in the maxilla?

Answer 10

finer, more widely spaced, no obvious alignment pattern

Question 11

What are the 3 important landmarks when irradiating the peri-radicular region

Answer 11

PDL space - radiolucent line
Lamina dura - radiopaque line
Trabecula pattern and density of surrounding bone

Question 12

What are the limitations to interpreting radiographs of the peri-radicular region?

Answer 12

personal variation
contrast
resolution
superimposition

Question 13

How does initial acute inflammation appear radiographically?

Answer 13

no apparent changes
or
possible widening of PDL space

Question 14

How does initial spread of inflammation appear radiographically?

Answer 14

loss of lamina dura at the apex

Question 15

How does further inflammatory spread appear radiographically?

Answer 15

periapical bone loss

Question 16

How does initial chronic inflammation appear radiographically?

Answer 16

no bone destruction seen
or dense sclerotic bone periapically (sclerosing osteitis)

Question 17

How does chronic inflammation appear radiographically?

Answer 17

circumscribed, well defined, radiolucent area periapically with sclerotic bone surrounding
- radiolucency sometimes described as rarefying osteitis