Anatomy of the Periodontium Flashcards
(165 cards)
1
Q
What is periodontium?
A
Specialized connective tissue that provides support needed to maintain teeth in function
2
Q
What are the four main components of the periodontium?
A
gingiva
Cementum
Periodontal ligament
Alveolar bone
3
Q
What are the three zones of the oral mucosa?
A
- The gingiva & covering of the hard palate (masticatory mucosa)
- Dorsum of the tongue (specialized mucosa)
- Oral mucous membrane lining remainder of oral cavity
4
Q
What type of mucosa is on the dorsum of the tongue?
A
specialized mucosa
5
Q
What type of mucosa is the gingiva and covering the hard palate?
A
masticatory mucosa
6
Q
What is gingiva?
A
Masticatory mucosa that covers alveolar bone and tooth root coronal to the cementoenamel junction (CEJ)
7
Q
What are the three sections of the gingivia?
A
Marginal gingiva
Attached gingiva
Interdental areas
8
Q
__________ mucosa covers alveolar bone and tooth root coronal to the cementoenamel junction (CEJ)
A
Masticatory
9
Q
What is another name for marginal gingiva?
A
unattached gingiva
10
Q
What is the marginal gingiva?
A
Free, collar-like tissue surrounding the teeth on facial, lingual, and interproximal surfaces
11
Q
What type of epithielium is the marginal gingiva?
A
nonkeratinized epiethelium (but then she said parakeratinized before the first exam)
12
Q
What is the most coronal portion of the gingiva called?
A
gingival margin
- scalloped outline of teeth
13
Q
What are the characteristics of the gingival margin?
A
- about 1 mm wide
- forms the soft-tissue wall of the gingival sulcus
14
Q
What is the gingival sulcus?
A
- the shallow, natural space aroudn a tooth bounded by the surface of the tooth on one side and epithelium lining the free margin of the gingiva on the other side
15
Q
How should the gingival sulcus allow enterance for the periodontal probe?
A
- barely permits enterance
- sulcular measurements of 1-3 mm
16
Q
What is the clinical significance of the gingival sulcus?
A
helps to identify the health status of the sulcus; an important factor when accessing restorability of a tooth
17
Q
Boundaries of the gingival sulcus are the…
A
- sulcular epithelium
- tooth
18
Q
Sulcular epithelium is the ___________ continuation of keratinized epithelium covering the marginal gingiva
A
nonkeratinized
19
Q
What is the interdental gingiva (papilla) part of the gingiva?
A
- occupies the gingival embrasure space between 2 adjacent teeth (interproximal spaces)
20
Q
What part of the gingiva includes the interdental gingiva?
A
free gingiva
21
Q
What attaches the interdental gingiva to the tooth?
A
- JE (junctional epithelium)
- connective tissue fibers
22
Q
If a _____ space exists between 2 teeth-papilla will be flat or saddle-shaped
A
wide
23
Q
What is the gingival col?
A
valley-like depression of the interproximal contact areas
24
Q
Is the gingival col keratinized or non keratinized?
A
non-keratinized
25
If interdental space is ______ the papilla will be pointed or pyramidal
narrow
26
What does the gingival col connect?
lingual and buccal interdental papilla
27
The gingival col is ______ when teeth are not in contact
absent
28
____________ epithelium is susceptible to inflamation and disease progression
nonkeratinized
- mostly the gingival col
29
What does the free gingival groove divide?
free gingiva from attached gingiva
30
The free gingival groove is found in _____% of patients
50%
31
What type of epithelium is covering the free gingival groove?
keratinized epithelium
32
What type of epithelium is attached gingiva?
keratinized epithelium
33
What is attached gingiva?
- firm, resilient, tightly bound to underlying periosteum of aleolar bone
- continious with marginal gingiva
34
The _____ aspect of the attached gingiva extends to the relatively loose and movable alveolar mucosa
facial
35
The attached gingiva and alveolar gingiva transition is demarcated by the...
mucogingival junction (MGJ)
36
The width of the attached gingiva varies from...
1-9 mm
37
Where is the attached gingiva the widest in the facial aspect?
maxillary central incisors
38
Where is the attached gingiva the narrowest in the facial aspect?
mandibular premolar facial areas
39
Attached gingiva is not typically measured on what oral surface?
palate
40
Any changes in the width of attached gingiva results from changes at the ______ end
coronal
(recession)
41
What is the equation for measuring the width of attached gingiva?
total width of gingiva (from MGJ to GM) - PD = width of attached gingiva
42
When attached gingiva is diminished it results in...
gingival recession
43
What is the mucogingival junction (MGJ)?
visible line where the pink keratinized gingiva meets the more vascular alveolar mucosa
44
Where is mucogingival junction (MGJ) found?
- maxillary facial
- mandibular facial and lingual
45
What is the alveolar mucosa?
movable tissue, loosely attached to underlying alveolar bone
46
What type of epithelium is the alveolar mucosa?
- thin, soft, nonkeratinized epithelium
47
What is separated from the attached gingiva at the MGJ?
alveolar mucosa
48
Why is the alveolar mucosa a darker shade of red than gingiva?
rich blood supply (vascularization)
49
The gingiva is made of what?
- stratified squamous epithelium
- connective tissue (mostly composed of collagen fibers and ground substance)
50
What are the functions of the gingival epithelium?
- physical barrier to infection
- protection of deep structures
- allows a selective interchange with oral environment
- participate actively in responding to infection in signaling host response
51
How can you differentiate epithelium covering the free gingiva?
1. The oral (outer) epithelium
2. The sulcular epithelium
3. The junctional epithelium
52
What is the oral (outer) epithelium of the gingiva?
Covers the crest and outer surface of the marginal gingiva and the surface of attached gingiva
53
How thick is the oral (outer) epithelium?
0.2-0.3 mm
54
What are the four layers of the oral (outer) epithelium?
Basal layer
Prickle cell layer
Granular layer
Cornified layer
55
What type of epithelium is the oral (outer) epithelium?
Keratinized or parakeratinized, or combination of the two
56
What is the sulcular epithelium?
- Lines the gingival sulcus
- Extends from the coronal limit of the junctional epithelium to the crest of the gingiva margin
57
What type of epithelium is the sulcular epithelium?
Thin, nonkeratinized epithelium without rete pegs
58
Where does the sulcular epithelium extend?
Extends from the coronal limit of the junctional epithelium to the crest of the gingival margin
*short*
59
Why is sulcular epithelium important?
may act as a semipermeable membrane through which injurious bacterial products pass into the gingiva and seeps into the sulcus
60
Which is more permeable, sulcular epithelium or junctional epithelium?
junctional epithelium is more permeable
61
What is junctional epithelium?
Nonkeratinized epithelium surrounding and attaching to the tooth on one side, and the gingival connective tissue on the other side
62
What is the length of the junctional epithelium?
0.25-1.35 mm
63
What is another name for the base of the sulcus/pocket?
junctional epithelium
64
What is the function of the junctional epithelium?
Serves as route of passage of fluid and cells from the connective tissue into the sulcus for bacteria/bacterial products from sulcus to connective tissue
65
Can the junctional epithelium be penetrated by the periodontal probe?
yes, easily- especially when gingiva is inflamed
66
What epithelium is completely restored after pocket instrumentation or surgery, and it forms around implants?
junctional epithelium
67
What forms the junctional epithelium?
Formed by the confluence of the oral epithelium and the reduced enamel epithelium during tooth eruption
68
What are gingival fibers?
Connective tissue of the marginal gingiva is densely collagenous and contains a prominent system of collagen fiber bundles
69
What type of collagen are gingival fibers made of?
type I collagen
70
What are the functions of gingival fibers?
1. to brace the marginal gingiva firmly against the tooth
2. to provide the rigidity necessary to withstand the forces of mastication without being deflected away from the tooth surface
3. to unite the free marginal gingiva with the cementum of the root and the adjacent attached gingiva
71
What are the dentogingival fibers?
embedded in the cementum between the CEJ and crest of alveolar bone; fan outward into the attached and free gingiva; attach gingiva to the tooth apical to the epithelial attachment
72
What are the alveologingival fibers?
inserted in crest of alveolar process and splay out through lamina propria into the free gingiva
73
What are the circumferential fibers?
encircle each tooth in a cufflike fashion within the free gingiva
74
What are the dentoperiosteal fibers?
embedded in the same portion of the cementum as the dentogingival fibers, but extend apically over the alveolar crest after passing through the lamina propria and the periosteum
75
What are the transseptal fibers?
Embedded in the same portion of the cementum as the dentogingival and dentoperiosteal fibers; run a horizontal path from adjacent teeth
76
Because of the___________________, the connective tissue of the gingiva has remarkably good healing and regenerative capacity
high turnover rate
77
What should you look for clinically to understand the microscopic features?
color
size
contour
shape
consistency
surface texture
position
78
What is the color of the marginal and attached gingiva?
- when healthy should be coral pink
- presence of pigment-containing cells
79
Gingiva is _____ in individuals with fair complexions and hair and ______ in individuals with dark complexions and hair
lighter; darker
80
What is the color of the alveolar mucosa?
* Red
* Smooth
* Shiny
81
_________ is responsible for normal pigmentation of the skin, gingiva and remainder of the oral mucous membrane
Melanin
82
Melanin is present in all people, but it can be absent or severely diminished in...
albinos
83
Melanin pigmentation is ______ in individuals with dark skin tones
prominent
84
Melanin pigmentation in the oral cavity can appear as...
a diffuse, deep-purplish discoloration or as irregularly shaped brown and light-brown patches
85
_____ of gingiva corresponds with the number of cellular/intercellular elements and vascular supply
Size
86
Change in the size of gingiva indicates...
gingival disease (inflammation present)
87
_____ of gingiva varies depending on the shape of the teeth and alignment
contour
88
Marginal gingiva follows what outline?
scalloped
89
What is biotype?
thickness of gingiva
*varies
90
_____ of interdental gingiva guided by contour of proximal tooth surfaces, location, and shape of embrasures
Shape
91
Interdental papilla can appear as...
peaked/pointed in form or flattened depending on location and tooth contact points
92
What is the consistency of gingiva?
firm and resilient (except the free
margin)
93
What determine firmness of attached gingiva?
collagen fibers
94
What determines firmness of gingival margin?
gingival fibers
95
What is the surface texture of gingiva?
- stippled (best viewed by drying the tissue)
96
What type of gingiva should be stippled?
attached gingiva
- marginal gingiva is not stippled
97
Stippling is less prominent on which surface of the gingiva?
lingual
98
What are the four characteristics of gingiva for clinical assessment?
- color
- contour
- consistency
- surface texture
99
How Does Smoking Affect the Periodontium?
- causes vasoconstriction (affects immune system)
- impaires chemotaxis and phagocytosis
- decreases bone density
- leaves gingival tissues firm and fibrotic
100
What is the periodontal ligament (PDL) composed of?
Composed of a complex vascular and highly cellular connective tissue that surrounds the tooth root and connects it to the inner wall of the alveolar bone
*continuous with the connective tissue of the gingiva
101
What is the function of the periodontal ligament?
it communicates with the marrow spaces through vascular channels in the bone
- shock absorbers
102
When is the periodontal space diminished around teeth?
teeth that are not in function
and in unerupted teeth
103
When is the periodontal space increased in teeth?
teeth that have been subjected to hyperfunction
104
What is the most important element of the PDL?
principal fibers
105
Where are the principal fibers of the PDL located?
Located in periodontal space between cementum and bone
106
What are the principal fibers of the PDL made of?
Composed of connective tissue cells and intracellular substance
107
The principal fibers are inserted into the...
inserted into the cementum on one side and bone on the other are called: Sharpey’s fibers
108
What are the different general functions of the PDL?
- physical
- formative and remodeling
- nutritional and sensory
109
What are the physical functions of the PDL?
- Provision of a soft-tissue ‘casing’ to protect the vessels and nerves from
injury by mechanical forces
- Transmission of occlusal forces to the bone
- Attachment of the teeth to the bone
- Maintenance of the gingival tissues in their proper relationship to teeth
- Resistance to the impact of occlusal forces
110
What are the formative and remodeling functions of the PDL?
- The PDL and alveolar bone are exposed to physical forces in response to mastication, parafunction, speech and orthodontic tooth movement
- Cells of the PDL participate in the formation and resorption of cementum and bone which occur during physiologic tooth movement
- The PDL is constantly undergoing remodeling
- The rate of formation and differentiation of osteoblasts, cementoblasts, and fibroblasts affect the rate of formation of collagen, cementum, and bone
111
What are the nutritional and sensory functions of the PDL?
- PDL supplies nutrients to cementum, bone and gingiva by way of blood vessels; also provides lymphatic drainage
- PDL is highly vascularized tissue; the high blood vessel content may provide hydrodynamic damping to applied forces as well as high perfusion rates to the PDL
- PDL is abundantly supplied with sensory nerve fibers that are capable of transmitting tactile, pressure, and pain sensations via the trigeminal pathways
112
The rate of formation and differentiation of osteoblasts, cementoblasts, and fibroblasts affect the rate of formation of...
collagen, cementum, and bone
113
PDL supplies nutrients to cementum, bone and gingiva by way of...
blood vessels; also provides lymphatic drainage
114
PDL is highly vascularized tissue; the high blood vessel content may provide...
hydrodynamic damping to applied forces as well as high perfusion rates to the PDL
115
What does the PDL width depend on?
age, stage of eruption, function of tooth, and angle of film
116
What are the different principal fiber groups of the PDL?
- transseptal fibers
- apical fibers
- oblique fibers
- horizonal fibers
- alveolar crest fibers
- interradicular fibers
117
What are transseptal fibers?
extend interproximally over the alveolar bone crest and are embedded in the cementum of adjacent teeth
118
What are apical fibers?
from the root apex to adjacent surrounding bone to resist vertical forces
119
What are oblique fibers?
from the root above the apical fibers obliquely toward the occlusal to resist vertical and unexpected strong forces
120
What are horizontal fibers?
from the cementum in the middle of each root to adjacent alveolar bone to resist tipping of the tooth
121
What are alveolar crest fibers?
from the alveolar crest to the cementum just below the CEJ to resist intrusive forces
122
What are the interradicular fibers?
from cementum between the roots of multirooted teeth to the adjacent bone to resist vertical and lateral forces
123
What type of fibers are not on single rooted teeth?
interradiucular fibers
124
125
126
127
128
129
130
131
132
133
134
135
Does cementum have blood, lymph and innervation?
nah
136
What is the function of cementum?
to attach fibers of the PDL to the tooth (like cement); to seal the tubules of the root dentin
137
What are the two types of cementum?
2 types: acellular (primary) and cellular (secondary)
138
What is the least mineralized tissue of the tooth?
cementum
139
What is cementum?
Calcified, avascular mesenchymal tissue covering the roots of the teeth
140
What type of cementum is the first type formed?
acellular cementum
141
What cementum covers approximately the cervical third or half of the root?
acellular cementum
142
Which type of cementum is less calcified?
cellular cementum
143
Which cementum does not have cells?
Acellular cementum
144
When is the acellular cementum formed?
Formed before the tooth reaches the occlusal plane
145
When is cellular cementum deposited?
* Deposited throughout life of tooth
* Deposited at intervals, producing arrest lines
146
When is cellular cementum formed?
Formed after tooth reaches occlusal plane
147
What is the function of cellular cementum?
contains cells (cementocytes) in individual spaces (lacunae) that communicate with each other through a system of anastomosing canaliculi
148
What is hypercementosis?
* Local abnormal thickening of parts of the cementum
149
Where is hypercementosis usually seen?
apical region of the root
150
Hypercementosis may be found as a result of...
Chronic inflammation of the tooth
No opposing tooth
Additional eruption
Tooth becoming fused to surrounding alveolar bone proper
151
What are the three CEJ relationships that exist?
Space: 10%
End-to-end: 30%
Overlap: 60%
152
Understanding the relationship between the cementum and enamel junction is of clinical importance in...
scaling and root planing procedures
153
What is the alveolar process?
Bone that forms and supports the alveoli (tooth sockets)
154
When does the alveolar process form?
Forms when the tooth erupts to provide the osseous attachment to the forming PDL
155
When would the alveolar process be lost?
disappears gradually after the tooth is lost
156
What are the parts of the alveolar process?
Consists of alveolar bone proper and supporting bone
157
The contour of the alveolar bone follows the contour of what?
CEJ and arrangement of the dentition
158
Where is the alveolar process?
- approximately 1.5-2mm apical to the CEJ
- Shape of the alveolar crest is generally parallel to the CEJ of adjacent teeth
159
Cortical plates are usually thicker in the mandible or the maxilla?
mandible
160
Alveolar bone consists of...
two-thirds inorganic matter and one-third organic matrix
161
Does the form of the alveolar bone change during remodeling?
the alveolar bone is constantly changing its internal organization, it retains approximately the same form from childhood through adult life
162
Cancellous trabeculae between the two compact layers act as...
supporting alveolar bone
163
An external plate of cortical bone formed by...
haversian bone and compacted bone lamellae
164
The inner socket wall of thin, compact bone is called the...
alveolar bone proper
165
The alveolar bone proper has a series of openings through which what occurs?
through which neurovascular bundles link the PDL with the central component of the alveolar bone: the cancellous bone
