9. special tests - radiographs

Question 1

how are radiographs created?

Answer 1

x ray photons pass through an object before interacting with receptor

Question 2

what happens when x ray photons are transmitted?

Answer 2

pass through unaltered

Question 3

name 3 outcomes for x ray photons?

Answer 3

transmitted
absorbed
scattered

Question 4

what happens when x ray photons are absorbed?

Answer 4

stopped by tissue

Question 5

what happens when x ray photons are scattered?

Answer 5

change directions

Question 6

what 2 x ray interactions contribute to attenuation of x ray photons?

Answer 6

absorbed and scattered

Question 7

what is attenuation of x ray photons?

Answer 7

stops x ray photon from reaching receptor on other side

Question 8

what does the radiographic image represent?

Answer 8

the matter of attenuation of the x ray photons after they have passed through matter

Question 9

what do the shades of grey on a radiographic image correspond to?

Answer 9

type of tissue that the X-ray passed through

Question 10

is dentine lighter or darker than enamel on a radiographic image and why?

Answer 10

dentine is more dense than enamel therefor shows darker

Question 11

what does ‘radiolucent’ mean on a radiographic image?

Answer 11

• darker areas image
• less attenuation of x rays

Question 12

what does ‘radiopaque’ mean on a radiographic image?

Answer 12

• lighter areas on image
• more attenuation of x rays

Question 13

why do we use radiographs?

Answer 13

to show anatomy and pathology not visible to the naked eye

Question 14

how would caries show on a radiograph?

Answer 14

decreased radiodensity therefor appears radiolucent compared to rest of tooth

Question 15

name 3 common intra oral radiographs in dentistry?

Answer 15

bitewing
periodical
occlusal

Question 16

name 2 common extra oral radiographs in dentistry?

Answer 16

panoramic
lateral

Question 17

what is a common type of cross sectional radiograph in dentistry?

Answer 17

cone beam computed tomograph

Question 18

what does bitewing radiograph show?

Answer 18

provides a view of multiple side teeth
- shows crowns
- show part of the roots
- shows some interdental bone
- shows symmetry between upper and lower teeth

Question 19

how do you decide whether to take one or two bitewing radiographs per side?

Answer 19

• reason for the radiograph
• number of teeth present
• to reduce overlap between adjacent teeth

Question 20

what does a periodical radiograph show?

Answer 20

• crown and the entire root of tooth
• entire hight of bone support around tooth

Question 21

how many dental arches can be imaged in one periodical radiograph?

Answer 21

1

Question 22

what does a panoramic radiograph show?

Answer 22

provides zoomed out view of jaws
- shows dentin as well as jaws and mid face

Question 23

does intra oral or extra oral radiographs have better resolution?

Answer 23

intraoral

Question 24

describe features of occlusal radiography.

Answer 24

provides view of 1 dental arch (maxillary or mandibular)
can be taken at different angles (anterior/lateral and true/ oblique)

Question 25

when is cone beam computed tomography used?

Answer 25

only when rotten dental imaging can't provide the required information

Question 26

describe features on cone beam computed tomography compared to other types of radiography.

Answer 26

higher resolution dose lower resolution higher cost

Question 27

which type of radiography is 3D?

Answer 27

cone beam computed tomography

Question 28

how should you position radiographs when trying to view them?

Answer 28

as if you were facing the patient

Question 29

if the radiograph shows 3 roots what teeth could be shown?

Answer 29

upper molars

Question 30

if 1 root was shown on a radiograph what teeth could it be?

Answer 30

incisors canines some premolars

Question 31

if 2 roots were shown on a radiograph what teeth could it be?

Answer 31

some premolars lower molars

Question 32

what is the curve of spee?

Answer 32

normal anatomical curvature of the occlusal plane - curves upwards posteriorly

Question 33

what non dental anatomy can a radiograph of a maxillary show?

Answer 33

maxillary sinus nasal cavity maxillary tuberosity

Question 34

what non dental anatomy can a radiograph of a mandibular show?

Answer 34

inferior alveolar canal mental foramen inferior border of mandible external oblique ridge

Question 35

where does the mental foramen lie?

Answer 35

below premolars