Lecture 6

Question 1

identification of the periodontium on radiographs

Answer 1

gingiva not visible
alveolar bone (cortical, cancellous, alveolar crest, lamina dura)
PDL space
cementum

Question 2

alveolar crest

Answer 2

surfaces of the bony crests are smooth and covered with a thin layer of cortical bone
thin white line
normal level is 2mm apical to the CEJ

Question 3

alveolar crestal bone anterior vs posterior

Answer 3

anterior: thin and pointed
posterior: rounded or flat

Question 4

crestal contour of the interdental bone

Answer 4

a good indicator of health
contour should be parallel to a line drawn between the CEJs of adjacent teeth

Question 5

horizontal crest contour

Answer 5

when the CEJs of adjacent teeth are of the same level, the crest of the interproximal bone will have a horizontal contour

Question 6

vertical/angular crest contour

Answer 6

when one of the adjacent teeth is tilted or erupted to a different height, the crest of the interproximal bone will have a vertical contour

Question 7

lamina dura

Answer 7

appears as a continuous white line around the tooth root
radiographically is continuous with cortical bone layer of the crest of the interdental septa

Question 8

periodontal ligament space

Answer 8

appears as a thin radiolucent line surrounding the tooth root
a widening of PDL space on radiograph indicates tooth mobility

Question 9

benefits of radiographs for periodontal evaluation

Answer 9

bony changes caused by disease: early signs of disease, direction of bone loss, furcation involvement
implant assessment
periodontal abscess
local factors

Question 10

early radiographic signs of disease

Answer 10

fuzziness in the crest of the interdental bone
widening of the PDLs
radiolucent lines in the interseptal bone

Question 11

periodontal disease and direction of bone loss is determined by

Answer 11

using the CEJ of adjacent teeth as points of reference

Question 12

horizontal bone loss direction

Answer 12

parallel to a line between CEJs of adjacent teeth

Question 13

vertical bone loss direction

Answer 13

greater bone loss on the interproximal aspect of one tooth than on the adjacent tooth

Question 14

types of periodontal pockets

Answer 14

suprabony
infrabony

Question 15

suprabony pocket

Answer 15

occurs when there is horizontal bone loss and the junctional epithelium, forming the base of the pocket, is located coronal to the crest of alveolar bone

Question 16

infrabony pocket

Answer 16

occurs when there is vertical bone loss and the junctional epithelium, forming the base of the pocket, is located below the crest of alveolar bone

Question 17

assessment of bone loss

Answer 17

stage I: <15% bone loss
stage II: 15%-33% bone loss within first third of root
stage III and stage IV: extending to middle third and beyond of root/vertical bone loss

Question 18

assessment of furcation involvement

Answer 18

early involvement not seen of a radiograph
furcation probe to assess clinically (Class I, II, III, IV)
furcations are easier to see on the mandible than maxilla
often greater than it appears on a radiograph

Question 19

radiographic sign of peri-implantitis

Answer 19

loss of radiodensity around the osseointegrated implant

Question 20

peri-implantitis alveolar bone changes

Answer 20

alveolar bone remodeling following the first year in function is normal (<2mm)
changes >2mm at any time point during or after the first year should be considered as pathologic

Question 21

calculus detection

Answer 21

large interproximal calculus deposits may be visible on a radiograph
large facial and lingual deposits may be visible if there is severe bone loss on the surfaces
the ability to visualize calculus on a radiograph depends on the degree of mineralization and angulation of the x-ray beam

Question 22

faulty restorations

Answer 22

can be detected on radiographs
can cause gingival inflammation, increase risk of periodontitis and alveolar bone resorption

Question 23

faulty contours

Answer 23

between the first and second molar restorations create an open contact that may cause food impaction

Question 24

radiographic signs of trauma from occlusion

Answer 24

widening of PDL
increased thickness of lamina dura
vertical bone loss
root resorption
used only as a supplemental aid in recognizing trauma

Question 25

pulpal abscess

Answer 25

an infection of the tooth pulp
caused by trauma, deep caries
requires root canal treatment
apical bone loss

Question 26

gingival abscess

Answer 26

limited to gingival margin

Question 27

periodontal abscess

Answer 27

gingiva and deeper structures
caused by trauma, or pre-existing periodontal disease

Question 28

pericoronal abscess

Answer 28

involves tissues around a partially erupted tooth

Question 29

extensive bone loss

Answer 29

crestal bone loss of 5mm or greater may cause the coronal bone to be poorly visualized or not seen at all on normal bitewing radiographs
as a result, vertical oriented bitewings may be used
long axis of the film is rotated 90 degrees

Question 30

limitations of radiographs

Answer 30

provide a 2D image of a 3D object
buccal alveolar bone can hide bone loss on the lingual aspect
palatal roots make furcation detection on the maxilla difficult
radiographs do not provide information about non-calcified components
radiographs do not show disease activity but they do show effects of the disease

Question 31

radiographs do not reveal the following

Answer 31

presence or absence of periodontal pockets
exact morphology of bone destruction
tooth mobility (early)
early furcation involvement
condition/height of the bone on the buccal and lingual surfaces
level of the epithelial attachment

Question 32

limitations of early bone loss detection

Answer 32

it must first be detected clinically with careful periodontal probing, not radiographically
by the time periodontal bone loss appears on a radiograph, it usually has progressed beyond the early stages of the disease
interseptal bony defects less than 3mm are not usually detectable radiographically