Dentals - Intra-Oral

Question 1

what are the radiographic views for intra-oral ? - 3 points

Answer 1

peri-apicals
bitewings
occlusals

Question 2

what are the radiographic views for extra-oral? - 4 points

Answer 2

dental panormaic tomographic (OPGs)
cephalometry
lateral oblique jaw
CBCT

Question 3

how many teeth do most people have when fully developed?

Answer 3

32

Question 4

when do teeth begin to erupt

Answer 4

6 years old

Question 5

when have most permanent teeth erupted by?

Answer 5

12 years old

Question 6

wisdom teeth are the exception, when do these appear?

Answer 6

late teens / early twenties

Question 7

what are the order of teeth and how are they classified?

Answer 7

incisors - central and lateral
canines - cuspids
pre-molars - bicuspids
molars

Question 8

what is hypodontia?

Answer 8

where teeth are missing as they never erupted

Question 9

describe the dental pulp - 6 points

Answer 9

innermost part of the tooth
soft tissue rich with blood vessels and nerves
responsible for nourishing the tooth
pulp in the crown of the tooth is known as the pulp chamber
pulp canals transverse the root of the tooth
typically sensitive

Question 10

why are peri-apicals taken? - 2 points

Answer 10

to image the whole of the tooth including the bone around the apex of the root
to get detailed information about a selected tooth - e.g. in cases of tooth ache

Question 11

what is used in a peri-apical?

what else can be used?

Answer 11

intra-oral plates, a plate folder, a digital processor

intra oral sensor

Question 12

what are the two techniques that can be used to acquire a peri-apical image?

Answer 12

parallelling technique

bisecting angle technique

Question 13

why is a paralleling technique required?

Answer 13

the plate and tooth should be parallel to each other and close together - difficult because of shape of mouth

Question 14

what is the paralleling technique?

Answer 14

using anterior/posterior/bitewing holders to make the plate parallel to the tooth inside the mouth, bite down on it to hold in position, align tube to the outer circle and then the plate and the tube will be parallel

Question 15

what is the bisecting angle technique?

Answer 15

no film holder is used, the beam is positioned at 90 degrees to bisect the line halfway between the tooth and the film, film held in mouth by patient - difficult to judge, only used where there are difficulties with the paralleling technique

Question 16

what are the advantages of the bisecting angle technique? - 4 points

Answer 16

can be used in all parts of the mouth
gives a reasonable result
patient comfort
oral anatomy

Question 17

what are the disadvantages of the bisecting angle technique? - 6 points

Answer 17

prone to inaccuracy
incorrect angulation
coning off
magnification
higher skin dose
superimposition of zygoma

Question 18

what 5 things could go wrong with a peri-apical exam?

Answer 18

image elongated - angle too low
image foreshortened - angle too high
image coned off - not centrally positioned
film bending
errors with bisecting angle technique

Question 19

what are the advantages of the paralleling technique? - 4 points

Answer 19

accurate
minimal distortion
sharper image definition
reduces surface dose

Question 20

what are the disadvantages of the paralleling technique ? - 4 points

Answer 20

holder may be uncomfortable or difficult to position
shallow palate
strong gag reflex
oral anatomy

Question 21

what does a peri-apical image show? - 4 points

Answer 21

infection around the root
severe periodontal disease
caries (decay)
pathology - e.g. cysts

Question 22

image evaluation for peri-apicals - 6 points

Answer 22

no evidence of bending of the teeth in peri-apical region

no foreshortening or elongation of the tooth

no horizontal overlap - or if present, not overlap pulp/root canals

image should demo all tooth/teeth of interest (crown and root)

3mm of peri-apical bone visible to allow assessment of apical anatomy

good density and adequate contrast between the enamel and the dentine

Question 23

why are bite-wings taken? - 2 points

Answer 23

usually on a regular basis (6 months-2 years) to image crowns of teeth to look for caries
show the top of the alveolar bone to allow some assessment of periodontal disease

Question 24

how are bite-wings taken?

Answer 24

usually uses a tab attached to the plate (bitewing), film holders should now be used - care should be taken to position accurately

Question 25

what does bitewings using a film holder reduce?

Answer 25

positioning errors

Question 26

what do bitewings show? -4 points

Answer 26

caries
periodontal disease (slight loss of height of bone) - images turning film vertical
interproximal spaces
overhanging edges

Question 27

what can go wrong with bite-wings? - 2 points

Answer 27

incorrect angulation

most severe in the horizontal plane

Question 28

what can happen if the beam isn’t at a 90 degree angle?

Answer 28

teeth can overlap - should be able to see the surface of each tooth

Question 29

image evaluation for bite-wings? - 4 points

Answer 29

no foreshortening or elongation of teeth
no horizontal overlap - sometimes unavoidable due to overcrowding
3-4 and 7-8 spaces visible
periodontal bone levels visible

Question 30

why are occlusal views taken? - 4 points

Answer 30

to image pathology that will not fit on a peri-apical view such as
pathology involving teeth
buried teeth
#s of the jaw (combined with other views)

Question 31

what are the 3 different types of occlusal?

Answer 31

Maxillary - upper standard occlusal (shows buried teeth)
Upper oblique occlusal
Mandibular - lower standard occlusal, lower true occlusal (shows salivary stones/bone tumour), lower oblique occlusal