Lecture 1- Anatomy of Periodontium Flashcards
(95 cards)
1
Q
what are the 3 zones of the oral mucosa
A
- the gingiva and covering of the hard palate - masticatory mucosa
- dorsum of the tongue- specialized mucosa
- oral mucous membrane lining remainder of oral cavity
1
Q
what makes up the tissues of the periodontium
A
- gingiva
- cementum
- PDL
- alveolar bone
2
Q
what does the masticatory mucosa cover
A
alveolar bone and tooth root coronal to the CEJ
3
Q
what is masticatory mucosa divided into
A
marginal gingiva
- attached gingiva
- interdental areas
4
Q
what is the marginal gingiva
A
free or unattached, cufflike tissue surrounding the teeth on facial , lingual, and interproximal surfaces
5
Q
what is the gingival margin
A
- most coronal portion of the gingiva
- scalloped outline of teeth
6
Q
what is the gingival sulcus
A
-space formed by tooth and sulcular epithelium and the coronal end of the JE
7
Q
what sulcular measurements are WNL of gingival health
A
2-3mm
8
Q
where is the free gingival groove
A
divides free gingiva from attached gingiva
9
Q
what percentage of patients have free gingival groove
A
50%
10
Q
what part of the gingiva does the interdental gingiva belong to
A
free gingiva
11
Q
where is the interdental papilla
A
the interdental space
12
Q
how is the interdental papilla attached to the tooth
A
by the JE and CT fibers
13
Q
what is the gingival col
A
valley like depression of the interproximal contact areas
- connects lingual and buccal interdental papilla
14
Q
when is the gingival col absent
A
when the teeth are not in contact
15
Q
what is nonkeratinized epithelium susceptible to
A
inflammation and disease progression
16
Q
what is attached gingiva attached to and by what
A
attached to alveolar bone and cementum by CT fibers and epithelial attachment
17
Q
what are attached gingiva fibers demarcated by
A
-apically by the MGJ
- coronally by the base of the gingival sulcus
18
Q
what is the width of the attached gingiva
A
varies from 1-9 mm
19
Q
where is the widest aspect of attached gingiva and narrowest
A
maxillary central incisors and narrowest in premolar facial areas
20
Q
how do you measure attached gingiva
A
subtract width of gingival from periodontal pocket
21
Q
describe alveolar mucosa
A
- movable tissue, loosely attached to underlying alveolar bone
- thin, nonkeratinized epithelium
- separate from attached gingiva at the MGJ
- darker shade of red than gingiva due to blood supply
22
Q
what is the MGJ and where is it found
A
visible line where the pink keratinized gingiva meets the more vascular alveolar mucosa
- found on maxillary facial and mandibular facial and lingual areas
23
Q
describe gingiva microscopically
A
- stratified squamous epithelium and CT
- epithelium is mostly cellular in nature
- CT is less cellular and mostly composed of collagen fibers and ground substance
24
what is the function of the gingival epithelium
- physical barrier to infection
- protection of deep strucures
- participate actively in responding to infection in signlaing host response
- allows a selective interchange with oral environment
25
epithelium covering the free gingiva may be differentiated into the following:
- the oral/outer epithelium
- the sulcular epithelium
- the junctional epithelium
26
describe the sulcular epithelium
lines gingival sulcus, thin, non keratinized
27
what epithelium changes the most in the presence of bacteria
junctional epithelium
28
describe junctional epithelium
nonkeratinized epithelium surrounding and attaching to the tooth on one side and the gingival CT on the other side
29
where is junctional epithelium located
base of the sulcus/pocket
30
JE is more permeable to_____
cells and fluid
31
what does JE serve as a route of passage of
fluid and cells from the CT into the sulcus for bacteria/bacterial products from sulcus to CT
32
JE easily penetrated by ____ especially when _____
periodontal probe; gingiva is inflammed
33
what is the length of the JE
0.25-1.35mm
34
describe the color of the gingiva- attached/marginal
- generally coral pink
- produced by vascular supply and thickness/degree of keratinization
- presence of pigment containing cells
- lighter color in blond individuals with fair complexion than in dark complexioned dark haired individuals
35
describe the color of the alveolar mucosa
red
- smooth
- shiny
- epithelium is thinner and nonkeratinized
- blood vessels are more numerous
36
what is melanin responsible for
normal pigmentation of the skin, gingiva and remainer of the oral mucous membrane
37
melanin pigmentation in the oral cavity is prominent in______
black individuals
38
what does pigmentation in black individuals appear as
diffuse, deep-purplish discoloration or as irregularly shaped brown and light brown patches
39
size of the gingiva corresponds with:
the number of cellular/intercellular elements and vascular supply
40
what does the change in size of gingiva indicate
gingival disease
41
what does the contour of gingiva vary depending on
the shape of the teeth and alignment
42
what is gingival biotype
thickness of tissue
43
what is the shape of interdental gingiva governed by
contour of proximal tooth surfaces, location and shape of embrasures
44
interdental papilla can appear ____ or ____ depending on location
pyramidal; flattened
45
describe the consistency of gingiva and why
- firm and resilient except the free margin
- collagen fibers determine firmness of attached gingiva
- gingival fibers contribute to firmness of gingival margin
46
describe the surface texture of gingiva
- attached gingiva is stippled
- marginal gingiva is not stippled
47
where is stippling less prominent
on lingual than facial surfaces
48
how is stippling best viewed
drying the tissue
49
what are the ways to describe the quality of color of gingica
red, bright red, pink, cyanotic
50
what are the ways to describe the quality of contour
bulbous
- flattened
- punched out
- cratered
51
what are the ways to describe the quality of consistency
firm
- spongy
52
what are the ways to describe the quality of surface textrue
smooth
- shiny
- eroded
- stippling
53
describe cementum
-calcified connective tissue covering the roots of the teeth
54
what is the least mineralized of the calcified tissues of the tooth
cementum
55
what are the 2 types of cementum
acellular (primary) and cellular ( secondary) consisting of a caclified interfibrillar matrix and collagen fibrils
56
what is the function of the cementum
to attach fibers of the PDL to the tooth to seal the tubules of the root dentin
57
what is in cementum
no blood, lymph vessels of innervation noted
58
where is cementum deposited and during what stages of life
continuously deposited in the apical area of the root throughout life
59
describe acellular cementum
- first cementum formed
- covers approximately cervical third or half of the root
- does not contain cells
- formed before the tooth reaches the occlusal plane
60
describe cellular cementum
- formed after tooth reaches occlusal plane
- less calcified
- deposited throughout life of tooth
- deposited at intervals producing arrest lines
61
what is hypercementosis and where is it found
local abnormal thickening of parts of the cementum typically found in the apical region
62
what is hypercementosis a result of
- chronic inflammation of the tooth
- no opposing tooth
- additional eruption
- tooth becoming fused to surrounding alveolar bone proper
63
what are the 3 relationships involving and cementum that may exist at the CEJ
- space between the enamel and cementum with the dentin exposed occurs in 10% of cases
- end to end relationship of enamel and cementum occurs in 30% of cases
- cementum overlapping the enamel occurs in 60% of cases
64
what is the PDL
- fibrous connective tissue surrounding and attaching roots of teeth to bone
65
where is the PDL located
in periodontal space between the cementum and bone
66
what is PDL composed of
connective tissue cells and intracellular substance
67
what are sharpeys fibers
the fibers inserted into the cementum on one side and bone on the other
68
what are the 4 functions of the PDL and describe each
- supportive: anchors tooth to bone. sharpeys fibers
- formative: helps maintain biologic activity of bone and cementum
- nutritive: supplies nutrients and removes waste products via blood and lymph vessels
- sensory: capable of transmitting tactile pressure and pain sensations
69
how is PDL width seen
only in radiographs
70
what does PDL width depend on
age, stage of eruption, function of tooth and angle of film
71
what are the PDL fiber groups
gingival fiber groups and principal fibers
72
where are gingival fiber groups located
around the cervical are within the gingival tissue
73
what are the gingival fiber groups
- dentogingival fibers (free gingival)
- alveologingival fibers (attached gingival)
- circumferential fibers (circular)
- dentoperiosteal fibers (alveolar crest)
- transseptal fibers
74
where are principal fiber groups
surround the root
75
what are the principal fiber groups
- apical fibers
- oblique fibers
- horizontal fibers
- alveolar crest fibers
- interradicular fibers
76
where are the dentogingival fibers
from the cementum in the cervical region into the free gingiva to give support to the gingiva
77
where are the alveologingival fibers
from the alveolar crest into the free and attached gingival to provide support
78
where are the circumferential fibers
continuous around the neck of the tooth to help maintain the tooth in positionw
79
where are the dentoperiosteal fibers
from the cervical cementum over the alveolar crest to blend with fibers of the periosteum of the bone
80
where are the transseptal fibers
from the cervical area of one tooth across to an adjacent tooth on the mesial or distal only to provide resistance to separation of teeth
81
where ar apical fibers
from the root apex to adjacent surrounding bone to resist vertical forces
82
where are oblique fibers
from the root above the apical fibers obloquely towards the occlusal to resist vertical and enexpected strong forces
83
where are horizontal fibers
from the cementum in the middle of each root to adjacent alveolar bone to resist tipping of the tooth
84
where are the alveolar crest fibers
from the alveolar crest to the cementum just below the CEJ to resist intrusive forces
85
where are interradicular fibers
from cementum between the roots of multirooted teeth to the adjacent bone to resist vertical and lateral forces
86
what is alveolar bone and what is it made of
- bone that forms and supports the alveoli (tooth sockets)
- consists of alveolar bone proper and supporting bone
87
contour of the alveolar bone follows contour of the _____
CEJ and arrangement of the dentition
88
shape of the alveolar crest is generally ______
parallel to the CEJ of adjacent teeth' approximately 1.5mm-2mm apical to the CEJ
89
cortical plates are thicker in the _____
mandible
90
what does the alveolar bone surround
thin layer of bone that surrounds the root and gives attachment to the PDL
91
what is alveolar bone proper called in radiographic images
lamina dura or cribiform plate
92
what is the supportive alveolar bone
portion of alveolar process that surrounds the alveolar bone proper and gives support to the sockets
93
what are the types of supportive alveolar bone
- compact (cortical)
- cancellous or trabecular (spongy) bone
94
