Veterinary dental radiology

Question 1

dental findings

Answer 1

missing dentition, fractured teeth, abnormal periodontal pocket, evaluation of tooth viability, resorptive lesions, oral masses, draining tracts, nasal discharge

Question 2

radiation safety

Answer 2

gown, gloves, thyroid shield, eye protection, x-ray badge, 6 ft distance from beam

Question 3

radiology equipment

Answer 3

x-ray machine, tube, tubehead, machine setting, dial, angle adjustment, digital sensor, plate, film, positioning device, gauze, towels

Question 4

parallel technique

Answer 4

sensor, tooth root and tube are parallel
used for mandibular premolars and molars

Question 5

bisecting angle technique

Answer 5

used when you can’t lay film parallel to the tooth root
tooth root angle= root plane
plate parallel to the hard palette
bisecting angle is midway between the root plane and the plate plane
tube head at 90 degrees to bisecting angle

Question 6

proper film placement

Answer 6

place the film as near as possible to the teeth and oral mucosa to minimize distortion
large teeth: expose in 2 images (crown and root)

Question 7

foreshortening
troubleshooting

Answer 7

tube head too perpendicular to film/sensor which creates shorter roots
decrease angle to correct

Question 8

elongation
troubleshooting

Answer 8

tube head too parallel to film/sensor which creates longer roots
increase angle to correct
can be used in feline mandibular premolars and molars to throw zygomatic arch out of the way
horizontal elongation: tube head is rotated > 30 degrees horizontally

Question 9

under exposure
troubleshooting

Answer 9

if image is too light increase kVp to increase exposure

Question 10

over exposure
troubleshooting

Answer 10

if image is too dark decrease kVp to decrease exposure

Question 11

what is the best way to remember how radiograph over and under exposures look like?

Answer 11

it’s like toast
if the toast is too light you put it in longer
if the toast is too dark (burnt) you wouldn’t put it in the toaster as long

Question 12

missing intended structure
troubleshooting

Answer 12

if tooth/area of interest is not on the image, the sensor/film is not in the right position
film/sensor should be moved in the direction of the missing area
common when imaging large breeds with size 2 sensor
not all teeth of large breeds can be imaged on 1 view

Question 13

cone cut
troubleshooting

Answer 13

occurs when the tube head is not placed in the correct position to expose entire film/sensor resulting in a white area on the image

Question 14

brachycephalic
troubleshooting

Answer 14

none of the teeth are where they should be
often need to turn plates at different angles
using bisecting angles helps
often have less teeth
zygomatic arch is in the way

Question 15

dolichocephalic
troubleshooting

Answer 15

longer skull
large roots
multiple images needed for 1 tooth
zygomatic arch usually not an issue
landmarks are different

Question 16

canine maxillary: incisors

Answer 16

use bisecting angle
position tube: 60-65 degrees

Question 17

canine maxillary: canines

Answer 17

use bisecting angle
position tube: 45 degrees
considered a lateral oblique image

Question 18

canine maxillary: premolars

Answer 18

use bisecting angle
position tube: 45 degrees

Question 19

canine maxillary: premolars/molars

Answer 19

use bisecting angle to image the 4th premolar and molars
position tube: 45 degrees

Question 20

canine mandibular: incisors

Answer 20

use bisecting angle
position tube: 60-65 degrees

Question 21

canine mandibular: canines

Answer 21

use bisecting angle
position tube: 60-65 degrees
incisors can also be demonstrated

Question 22

canine mandibular: premolars

Answer 22

use bisecting angle
position tube: 45 degrees

Question 23

canine mandibular: molars

Answer 23

use parallel technique
position tube: 90 degrees

Question 24

feline maxillary: incisors

Answer 24

use bisecting angle
position tube: 60-65 degrees

Question 25

feline maxillary: canines

Answer 25

use bisecting angle
position tube: 45-60 degrees
considered lateral oblique technique

Question 26

feline maxillary: premolars/molars

Answer 26

use bisecting angle
position tube: 45 degrees
take zygomatic arch into consideration

Question 27

extra maxillary (extraoral) image in cats

Answer 27

position tube: 35-60 degrees to sensor
use shoot through technique to take image of the opposite side
reduces zygomatic arch blocking image

Question 28

how to take an extra maxillary image

Answer 28

1. place film/sensor on table and patient’s head on sensor with dental arch to be imaged down
2. place a radiolucent mouth gag (optional) to gently hold jaws apart
3. beam is angled through the mouth to create a bisecting angle which is approximately 30 degrees

Question 29

near parallel technique

Answer 29

lateral recumbency with target teeth up
sensor/film is placed across the mouth
beam is positioned almost parallel to the sensor

Question 30

feline mandibular: incisors

Answer 30

use bisecting angle
position tube: 60-65 degrees

Question 31

feline mandibular: canines

Answer 31

use bisecting angle
position tube: 60-65 degrees
typically included in incisor view

Question 32

feline mandibular: premolar

Answer 32

use bisecting angle to obtain 3rd premolar
position tube: 45 degrees
great technique to use to isolate 304 and 404

Question 33

feline mandibular: molars

Answer 33

use parallel technique to obtain 4th premolar and molars
easiest shot