special tests

Question 1

what are radiographs?

Answer 1

Images created using X-ray photons which pass through an object before interacting with a receptor

Question 2

what are the three types of interactions of x-rays with matter?

Answer 2

Transmitted (i.e. passes through unaltered)
Absorbed (i.e. stopped by the tissue)
Scattered (i.e. changes direction)

Question 3

which attributes of an x-ray contribute to attenuation of x-ray photons?

Answer 3

absorption and scattered

Question 4

what do radiographic images represent?

Answer 4

the pattern of attenuation of the x-ray photons after passing through matter

Question 5

what do the shades of grey of an x-ray correspond to?

Answer 5

the types of tissues the x-ray passes through

Question 6

what are the darker areas on an x-ray?

Answer 6

radiolucent- less attenuation of x-rays

Question 7

what are the lighter areas on an x-ray?

Answer 7

radiopaque- more attenuation of x-rays

Question 8

are the terms radiolucent and radiopaque relative or absolute?

Answer 8

relative

Question 9

why do we use x-rays?

Answer 9

to show anatomy and pathology not visible to the naked eye

Question 10

what is the most common use of x-rays in dentistry?

Answer 10

to assess caries- results in decreased radiodensity, appearing radiolucent compared to the rest of the tooth

Question 11

what are examples of intra-oral radiographs?

Answer 11

bitewing
periapical
occlusal

Question 12

what are examples of extra-oral radiographs?

Answer 12

panoramic
lateral cephalogram

Question 13

what is an example of cross-sectional radiograph?

Answer 13

cone beam compound tomograph

Question 14

describe bitewing radiography

Answer 14

side view of teeth
- shows crowns
- shows parts of roots
- shows interdental bone

• multiple images taken to reduce overlap to get a view of full teeth

Question 15

what is attenuation?

Answer 15

stopping of photons

Question 16

describe periapical radiography

Answer 16

full length view of particular tooth/teeth
- crown and entire root
- entire height of bone support around tooth
- one arch imaged at a time

Question 17

what type of tissues are x-rays taken of?

Answer 17

hard tissues- in dentistry= bone and teeth

Question 18

describe panoramic radiography

Answer 18

zoomed-out view of jaws
- entire dentition, jaws and mid-face
- can be full or sectional
- worse resolution than intra-oral

Question 19

describe occlusal radiography

Answer 19

view of one dental arch
- maxillary or mandibular
- taken at different angles- anterior/lateral, true/oblique
- allow teeth to be seen from different viewpoints

Question 20

describe cone beam computed tomography

Answer 20

cross-sectional imaging of teeth/jaws- 3D scan
- only used when routine dental imaging doesn’t work as more radiation, cost and lower resolution

Question 21

in a radiographic assessment what should be considered together?

Answer 21

visual and radiographic findings

Question 22

how should radiographs be arranged for viewing?

Answer 22

as if you were facing the patient
-Maxillary teeth along top / mandibular teeth along bottom
- Right sided teeth on left, left sided teeth on right
- Incisors towards the midline / molars towards the sides
- Occlusal planes towards the middle

Question 23

what is the curve of spee?

Answer 23

normal anatomical curvature of the occlusal plane- normally curves upwards posteriorly

Question 24

how do sinuses appear on radiogrpahs?

Answer 24

black