part 1 - radiology

Question 1

what is electromagnetic radiation and which is most dangerous to humans

Answer 1

form of energy that can penetrate matter
- gamma rays are most dangerous

Question 2

what is the preferred wavelength for dental xrays

Answer 2

shorter wavelengths are preferred to dental xrays

Question 3

what are components of the tubehead and their purpose

Answer 3

metal housing - metal body that contains xray tube
insulating oil - prevents overheating by absorbing xrays
tubehead seal - made of leaded glass and keeps oil in tube
xray tube - where xrays are produced
transformer - alters voltage of electrical current

Question 4

what are the components of the xray tube and their purpose

Answer 4

cathode
- negative side
- contains tungsten filament in a cup made of molybdenum
- supplies electrons necessary to generate xrays

anode
- positice side
- tungsten target embedded in a large copper rod
- converts electrons into energy and xray photons

Question 5

what is kv

Answer 5

kilovoltage
- used to control penetrating power of xray beam
- 70-90 kvp is used
- controls quality of xrays

Question 6

what is mA

Answer 6

milliamperage
- controls number of electrons produced
- controls quantity of xray beams

Question 7

what is the denisity of an image

Answer 7

density refers to the overall darkness of an image and is controlled by the mA’s

Question 8

what is the maximal permissible dose for an occupational worker

Answer 8

5 rems a year

Question 9

what are the types of intraoral and extraoral exposure

Answer 9

bitewings
periapicals
occlusal
cone beam computed tomography
later cephalometric projection
posterior and anterior projection
panoramic imaging
tmj rad

Question 10

bitewings

Answer 10

shows crown and interproximal areas of max and mand teeth and crestal bone in one image

Question 11

periapical

Answer 11

shows entire tooth from occlusal surface to beyond the apex and periapical bone
- shows crown and roots of teeth, alveolar bone and apex of root

Question 12

occlusal

Answer 12

used to examine large areas of upper and lower jaw

Question 13

cone beam computed tomography

Answer 13

a three dimensional digital imaging method that rotates around a patient

Question 14

lateral cephalometric projection

Answer 14

used to evaluate facial growth, development, trauma, disease
- shows bone of the face, skull and soft tissue profile

Question 15

posterior anterior projection

Answer 15

used to evaluate facial growth, development, trauma, disease
- shows frontal and ethmoid sinuses, orbits, nasal cavities

Question 16

panoramic imaging

Answer 16

allows dentist to view entire dentition in a single imafe
- shows tmj, max sinuses, impacted teeth, jaw pathology, observe eruption patterns

Question 17

tmj radiography

Answer 17

used to examine bone and relationship of jaw joint
- cannot examine soft tissues

Question 18

what are landmarks of mandible seen in rad exposures

Answer 18

genial tubercles
lingual foramen
mental ridge
inferior border of mandible
mylohyoid ridge
mental forament

Question 19

what are landmarks of the maxilla that are seen in rad exposures

Answer 19

incisive foramen
nasal cavity
nasal septum
max sinuses
max tuberosity
coronoid process

Question 20

what are the principles of paralleling

Answer 20

• image receptor is placed in mouth
• image receptor is positioned parallel to long axis of tooth
• vertical angulation: central ray is directed perpendicular to image receptor
  horizontal angulation: central ray is directed through contact areas

Question 21

principles of bisecting

Answer 21

• film is directly placed against teeth making an angle
• making the film be at an angle not parallel

Question 22

rad errors

Answer 22

time and temp
- light / underdeveloped
- dark / overdevelopped
- cracked / reticulation of emulsion

chemical
- dark spots / developer spots
- white spots / fixer spots
- yellow colour / old developer

handling
- straight white border / developer cutoff
- straight black border / fixer cutoff
- white or dark areas / overlapped film
- white spots / air bubbles
- black crescent shape / fingernail artifact
- black fingerprint / fingerprint artifact
- black branches / static electricity
- white lines / scratched film

lighting
- black / light leak
- gray / fogged film

Question 23

advantages and disadvantages of digital

Answer 23

advantages
- immediate viewing
- less radiation
- no chemicals
- no processing errors

disadvantages
- convertion previous records
- learning software
- thickness of sensors

Question 24

advantages and disadvantages of analogue

Answer 24

advantages
- no need for electricity
- easier to have xrays and not be lost

disadvantages
- takes more time
- takes up more space

Question 25

what is equipment required for indirect digital imaging

Answer 25

psp plates
image receptor holder

Question 26

what equipment is required for direct digital imaging

Answer 26

image receptor
sensor

Question 27

what do restorations appear like on radiographs

Answer 27

radiopaque, white

Question 28

what are radiolucent structure on radiographs

Answer 28

• foramen
• dentin
• sinuses
• air pockets
• soft tissue

Question 29

what are radio[aque structures on radiographs

Answer 29

• enamel
• bone
• restoratoins
• metal
• cement
• jewelry

Question 30

types of images used to detect bone loss

Answer 30

• panoramic
• bitewings