QUIZ 3 Periodontium 1 Flashcards
1
Q
the periodontal tissues are critical for the tooth to survive ___ over time
A
cyclical loading
2
Q
what are the tissues that invest and support the tooth?
A
the periodontium
3
Q
what are the 3 components of the periodontium?
A
- alveolar process
- cementum
- periodontal ligament
4
Q
the periodontium develops during a series of complex interactions of ___, ___, and ___
A
mesenchyme, HERS, and the dental follicle
5
Q
what type of joint is the periodontium?
A
gomphosis: fibrous peg-in-socket joint
6
Q
the alveolar process is formed by which type of ossification?
A
intramembranous ossification
mesenchyme direct to bone, no cartilage intermediate
7
Q
formation of the alveolar process occurs during which week of uterine life?
A
8th week
8
Q
describe the relationship between alveolar processes and tooth germs
A
- tooth germs are contained in the horseshoe-shaped grooves of the mandible and maxilla
- crypts develop around the tooth germs, such that they eventually form the sockest
9
Q
what are the cells involved in the formation of the periodontium?
A
- osteoblasts - make surrounding alveolar bone
- cementoblasts - make cementum
- PDL fibroblasts - make the PDL itself
- odontoblasts - make the rest of the root
- *all of these are epithelial derived tissues
10
Q
which 3 of the 4 types of mineralized tissues found in the oral cavity are contained in the periodontium?
A
bone, cementum, and dentin
11
Q
the alveolar processes develop substantially during ___, under the influence of the ___
A
- tooth eruption
- dental follicle
12
Q
T or F
the alveolar process is remodeled throughout life
A
true, as a result of posteruptive movement
13
Q
T or F
primary teeth and their permanent successors share the same bony crypt
A
false:
primary teeth have their own bony crypts, and then permanent teeth develop their own bony crypts as well
14
Q
compare the alveolar bone proper to the supporting alveolar bone
A
- alveolar bone proper
- compact bone
- cribriform plate, lamina dura
- supporting alveolar bone
- both compact AND trabecular bone
- cortical plates: compact bone component
- central spongiosa: trabecular bone component
15
Q
label this picture
A
- alveolar bone proper is the cortical bone that lines the tooth socket
- supporting alveolar bone includes the cortical plates (compact bone) and trabecular bone (central spongiosa)
16
Q
the alveolar bone proper is also known as what 3 other things?
A
- cribriform plate
- lamina dura
- bundle bone
17
Q
describe cribriform plate
A
anatomical term: cribrum = sieve; has volkmann’s canals running through it
18
Q
describe the lamina dura
A
radiographic term: area of PDL attachment
19
Q
describe bundle bone
A
histological term: sharpey’s fibers (PDL) embedded in bone
20
Q
describe the inner alveolar bone proper
A
- faces PDL directly
- remodeling rate may be high due to constant adaptation to tooth movements
- it primarily consists of woven bone, but lamellar bone is also present
- smooth surface in young individuals, but becomes rougher with age
21
Q
describe the outer alveolar bone proper
A
- faces away from the PDL
- lamellar bone, continuous with supporting alveolar bone
22
Q
supporting alveolar bone has what 3 components?
A
- cortical plate
- alveolar crest
- central spongiosa
23
Q
describe the cortical plate of supporting alveolar bone
A
- inner - lingual and palatal surface
- outer - labial and buccal surface
24
Q
describe the alveolar crest of the supporting alveolar bone
A
- junction of cortical plate and alveolar bone proper
- thinner in maxilla, thickest in premolar and molar region of mandible
25
describe the central spongiosa of supporting alveolar bone
* trabecular (spongy/cancellous) bone supporting alveolar bone proper and cortical plate
* marrow - red (hemopoeitic) in young, yellow in aged
26
spongiosa is more prevalent in the maxilla or mandible?
maxilla
27
the spongiosa is often ___ in the anterior region of both jaws
absent/diminished
28
what are the 4 functions of the alveolar process?
1. protection and structure of the socket for the tooth to rest in
2. attachment of sharpey's fibers of the PDL which are embedded in bone
3. support of tooth roots, especially facial/lingual
4. distribution of loading from the tooth and PDL to the surrounding bone
29
describe the two types of bone septa of alveolar processes
* interradicular septa
* bony septum between roots of a single tooth
* interalveolar septa
* bony septum between adjacent teeth
30
name the bone septa indicated by the arrows
31
development of the PDL occurs concomitant with ___ and ___ development
cementum and alveolar process
32
PDL develops after detachment/fragmentation of \_\_\_; starts off as unorganized \_\_\_
* HERS
* fibrillar short connective tissue
33
in the development of the PDL, ___ cells from the ___ differentiate into ___ which produce and organize ___ fibers, generally in an ___ orientation
* ectomesenchyme
* dental follicle
* fibroblasts
* collagen
* oblique
34
PDL fiber orientation changes with \_\_\_, based on what?
* eruption
* based on the relative positions of the tooth and alveolar crest
35
PDL fibers form from the CEJ in what direction?
apical
36
does remodeling of the PDL occur throughout life?
yes
37
developing cells of the PDL may prevent mineralization, which can prevent what?
ankylosis
38
the PDL is composed of what?
* fibroblasts, mesenchymal cells, epithelial cells, and macrophages
* osteoblasts, osteoclasts, and cementoblasts are also associated with the ligament on the adjacent mineralized surfaces
39
the PDL ranges in width between ___ and ___ mm. Width ___ with age.
* 0.15-0.38mm
* decreases
40
primarily, the PDL is ___ fibers, supported by a ___ matrix
* collagen
* non-collagenous protein
41
which collagen types are prevalent in the PDL?
type I, III, and XII
42
collagen types of the PDL are arranged in \_\_\_, which in turn are grouped into \_\_\_
* fibers
* bundles
43
individual collagen fibers of the PDL can be ___ while the overall bundle is \_\_\_, making a very ___ environment
* remodeled
* unchanged
* dynamic
44
the main elastic fiber of the PDL is \_\_\_
oxytalan
45
\_\_\_ is distributed extensively throughout the PDL and are largely associated with vasculature
oxytalan
46
oxytalan fibers of the PDL run vertically from ___ to \_\_\_, terminating in the \_\_\_
* cementum
* tooth apex
* neurovascular complex
47
\_\_\_ of the PDL possibly regulate vascular responses of the PDL (stretching these fibers increases exfiltration into the PDL)
oxytalan fibers
48
describe the ground substance of the PDL
* similar to other connective tissues
* 70% water
* increased hydrostatic pressure, possibly means greater ability to absorb loads
49
is the PDL well vascularized?
yes
50
which arteries supply the PDL?
superior/inferior alveolar arteries
51
arterioles that supply the PDL penetrate the \_\_\_
cribriform plate (penetrating arteries)
52
\_\_\_ teeth have more penetrating arteries generally and they are more prevalent in the ___ as opposed to the \_\_\_
* posterior
* mandible
* maxilla
53
arteries occupy loose connective "bays" in the PDL, called \_\_\_, tucked into the ___ fiber bundles
* interstitial areas
* principal
54
arrangement of blood vessels relative to the PDL is critical for \_\_\_
tissue healing/regeneration
55
nerves arrive at the PDL both ___ and through the \_\_\_
apically and through the cribriform plate
56
nerves of the PDL run ___ in relation to the tooth
axially
57
generally, concentration of nerve endings is greatest at the \_\_\_. what is the exception?
* tooth apex
* exception is upper incisors
* greater nerve density, especially in the coronal, labial part of the PDL
58
what are the 4 types of nerve endings of the PDL?
* free nerve endings
* ruffinis corpuscles
* coiled nerve endings
* spindle nerve endings
59
nerves of the PDL supply ___ innervation of the vasculature
sympathetic
60
describe the free nerve endings of the PDL
* most prevalent
* heavily branched
* nociceptive/mechanoreceptive
* these reach the cementum, and each innervates a region of the root
* some are associated with schwann cells
61
describe the ruffini corpuscles of the PDL
* bulbous dendritic endings
* associated with schwann cells and collagen fibers
* slow adapting mechanoreceptive fibers
* can be simple or compound
62
describe the coiled nerve endings of the PDL
* around mid-region of the PDL
* unknown function
63
describe the spindle nerve endings of the PDL
* surrounded by a fibrous capsule
* unknown function
* found apically
* relatively rare
64
what are the 5 main histological groups of PDL fibers (collagen fibers), and what are they grouped based on?
grouped based on their orientation
1. alveolar crest group
2. horizontal group
3. oblique group
4. apical group
5. interradicular group
65
describe the alveolar crest group of PDL fibers
attach just at the CEJ and run "outward" to attach into the alveolar socket rim
66
describe the horizontal group of PDL fibers
run from cementum at a right angle to the tooth into the alveolar crest
67
describe the oblique group of PDL fibers
most numerous, run at an oblique angle from the cementum most of the way down the root
68
describe the apical group of PDL fibers
from the root apex to the underlying bone
69
describe the interradicular group fo PDL fibers
only on multi-root teeth; they attach to the interradicular septum
70
PDL fiber bundles terminate in ___ or ___ and are attached to these structures via \_\_\_, which are embedded collagen fibers
* cementum or alveolar bone
* sharpey's fibers
71
the ___ is not part of the PDL proper, but is intimately associated with the periodontium
gingival ligament
72
the gingival ligament is composed of ___ fibers, which pass through the \_\_\_
* collagen
* oral lamina propria
73
the ___ gives the tooth a connection to surrounding soft tissues and neighboring teeth
gingival ligament
| (attachment of gingival margin)
74
what are the 5 main bundles that make up the gingival ligament?
1. dentogingival group
2. alveologingival group
3. circular group
4. dentoperiosteal group
5. transseptal fibers
75
describe the dentogingival group of the gingival ligament
* most numerous
* run from the cerivcal cementum to lamina propria of the free and attached gingivae
76
describe the alveologingival group of the gingival ligament
run from the alveolar crest (bone) to the lamina propria of free/attached gingivae
77
describe the circular group of the gingival ligament
circular band around the neck of the tooth, attaches to other fibers and the free gingiva
78
describe the dentoperiosteal group of the gingival ligament
run apically from cementum to the periosteum of the outer cortical plate
79
describe the transseptal fibers of the gingival ligament
* run from cementum just under the junctional epithelium, over the alveolar crest and into the cementum of an adjacent tooth
* significant cause of orthodontic relapse
80
what is the origin of osteoblasts?
surrounding mesenchymal tissues
81
what is the origin of cementoblasts?
ectomesenchymal cells
\*signaling from HERS influences ectomesenchymal cells to make cementoblasts
82
what is the origin of PDL fibroblasts?
signaling from HERS drives follicle cells/ ectomesenchmal cells to produce PDL fibroblasts
83
what is the origin of odontoblasts?
HERS signals the dental papilla to produce odontoblasts, which form the dentin part of the cemento-dentin junction
