The Periodontium I Flashcards Preview

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Flashcards in The Periodontium I Deck (89):
1

Define the periodontium

The tissues that invest and support the tooth

2

What are the 3 principle components of the periodontium?

1. Alveolar Process
2. Cementum
3. Periodontal LIgament

3

What is a Gomphosis?

Fibrous peg-in-socket joint

4

The periodontium develops during a series of complex interactions of ________, _____, and _______

1. Mesenchyme
2. HERS
3. Dental Follicle

5

What are the cells involved in the origin of the periodntium?

1. Osteoblasts
2. Cementoblasts
-HERS/Follicle cells
3. PDL fibroblasts
4. Odontoblasts

6

Where do osteoblasts come from in the periodontium?

Surrounding Mesenchymal tissues

7

Where do cementoblasts come from in the periodontium?

HERS/Follicle cells

*Ectomesenchymal cells

8

Where do PDL fibroblasts come from in the periodontium?

Follicle cells/Ectomesenchymal celss

9

What do Odontoblasts contribute to the periodontium?

Form dentin part of cemento-dental junction, and dental papilla

10

T/F the periodontium contains 3 out of 4 types of mineralized tissues found in the oral cavity

True

11

How does the alveolar process form?

Intramembranous ossification

*Mesenchyme direct to bonef, no cartilage intermediate

12

When does the alveolar process form?

During the 8th week of uterine life

13

__________ are contained in horseshoe-shaped grooves of the mandible and maxilla

Tooth germs

14

What develops around tooth germs that eventually forms the sockets?

Crypts

15

Alveolar Processes develop substantially during _______, under the influence of ______

1. Tooth eruption
2. Dental follicle

16

T/F Alveolar processes are remodeled throughout life

True

*Post-eruptive movement

17

What is an anodontic individual?

People whose alveolara process development is impaired

18

What kind of bone is alveolar bone proper?

Compact bone

*Cribiform plate, lamina dura

19

Supporting alveolar bone is what type of bone?

Both compact and trabecular

20

What is the compact component of supporting alveolar bone?

Cortical plates

21

What is the trabecular portion of supporting alveolar bone?

Central Spongiosa

22

What are the 3 main descriptors associated with Alveolar bone proper?

1. Cribiform plate
2. Lamina dura
3. Bundle bone

23

T/F Cribiform plate has volkmann's canals running through it

True

24

What is the lamina dura?

Radiographic term for alveolar bone proper: area of PDL attachment

25

What is bundle bone?

Histological term for alveolar bone proper: Sharpey's fibers (PDL) embedded in bone

26

T/F There is an inner and outer aspect ot alveolar bone proper

True

*inner is towar the PDL

27

Describe the remodeling rate of the inner alveolar bone proper

May be high due to constant adaptation to tooth movements

28

Because of its higher rate of remodeling, inner alveolar bone proper primarily consits of ______ bonne but _______ is also present

1. Woven bone
2. Lamellar bone

29

Describe the texture of the surface of inner alveolar bone proper as it changes with age

Smooth surface in young individuals, but becomes rougher with age

30

Describe the outer alveolar bone proper

-Lamellar bone
-Continuous with supporting alveolar bone

31

What are the 3 main parts of supporting alveolar bone?

1. Cortical plate
2. Alveolar crest
3. Central spongiosa

32

What are the two parts to the cortical plate?

1. INNER: Lingual and palatal surface
2. OUTER: Labial and buccal surface

33

Describe the alveolar crest

-Junction of cortical plate and alveolar bone proper
-Thinner in maxilla
-Thickest in premolar and molar region of mandible

34

What are the 2 components associated with the central spongiosa?

1. Trabecular (spongy/cancellous) bone supporting alveolar bone proper and cortical plate
2. Marrow: red (hemeopoietic) in young, yellow in aged

35

Spongiosa is more prevalent in the ________ than in the __________

1. Maxilla
2. Mandible

36

The spongiosa is often absent or diminished in what part of both jaws?

The anterior region

37

What are the 4 functions of Alveolar bone?

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

38

The Bone septa is divided into what two parts?

1. Interradicular septum
2. Interalveolar septum

39

What is the interradicular septum?

Bony septum between roots of a single tooth

40

What is the interalveolar septum?

Bony septum between adjacent teeth

41

Periodontal ligament development occurs concamitant with _______ and _______ development

1. Cementum
2. Alveolar process

42

The periodontal ligament develops after ______, and starts of as ________

1. Detachment / fragmentation of HERS
2. Unorganized, fibrillar short connective tissue

43

What develops from the dental follicle and differentiate into fibroblasts which produce and organize collagen fibers, and are generally oriented in an oblique manner?

Ectomesenchyme cells that form PDL

44

PDL fiber orientation changes with ______

eruption

45

PDL fibers form from the CEJ in what direction?

apically

46

The PDL fiber orientation changes with eruption. What is that change based on?

The relative positions of the tooth and alveolar crest

47

T/F Remodeling of the PDL occurs throughout life

True

48

Developing cells of the PDL may also prevent _________, preventing _______

1. Mineralization
2. Ankylosis

49

What is the width of the PDL?

Between .15mm to .38mm

*decreases with age

50

The PDL is composed of what type of cells?

Composed of:
1. Fibroblasts
2. Mesenchymal cells
3. Epithelial cells and macrophages

*Osteoblasts, osteoclasts and cementoblasts are also associated with the ligament on the adjacent mineralized surfaces

51

Primarily the PDL is ________, supported by a ________

1. Collagen fibers
2. Non-collagenous protein matrix

52

What types of collagen are in the PDL?

Type I, III, XII

53

Describe the arrangement of Collagen in the PDL

Arranged in fibers, which in turn are grouped into bundles

*Individual fibers can be remodeled while the overall bundle is not changed, making a very dynamic environment

54

The main elastic fiber of the PDL is _______

Oxytalan

*NOT mature elastin

55

Oxytalan is distributed extensively throughout the _____ and are largely associated with _______

1. PDL
2. Vasculature

56

Describe the orientation of Elastic fibers in the PDL

Fibers run vertically from cementum to the tooth apex, terminating in the neurovascular complex

57

T/F Elastic fibers (Oxytalan) Possible regulate vascular responses of the PDL

True

*Stretching these fibers increases exfiltration into the PDL

58

Describe the ground substance of the PDL

-Similar to other connective tissues
-70% water
-Increased hydrostatic pressure, possibly means greater ability to absorb loads

59

T/F the PDL is well vascularized

True

60

What supplies the PDL with blood?

Superio/inferior alveolar arteries

61

In the vasculature of the PDL, arterioles penetrate the ________

Cribiform plate

*called penetrating arteries

62

Where do you typically see more Penetrating arterioles?

Posterior teeth have more of them generally and they are more prevalent in the mandible as opposed to the maxilla

63

In the vasculature of the PDL, arteries occupy loose connective tissue 'bays' in the PDL, called ______

-Interstitial areas

*Tucked into the principle fiber bundles

64

What is the arrangement of blood vessels in the PDL critical for?

Tissue healing/regeneration

65

How do nerves arrive to innervate the PDL?

Both apically and through the cribiform plate

66

Nerves innervating the PDL run _______

Axially in relation to the tooth

67

Generally the concentration of nerve endings is greatest in the _______. With the exception of ________

1. Tooth apex
2. Upper Incisors
*Greater nerve density, especially in the coronal, labial part of PDL

68

T/F PDL has sympathetic innervation of the vasculature

True

69

What are the 4 types of nerve endings of PDL innervation?

1. Free nerve endings
2. Ruffini's Corpuscles
3. Coiled nerve endings
4. Spindle nerve endings

70

Describe the Free nerve endings of PDL innervation

-Most prevalent
-Heavily branched
-Nociceptive and mechanoreceptive
-These reach the cementum and each innervates a region of the root
-Some are associated with schwann cells

71

Describe the Ruffini's corpuscles in PDL innervation

-Bulbous dendritic endings
-Associated with schwann cells, and are associated with collagen fibers
-Slow adapting mechanoreceptive fibers
-Can be simple or compound

72

Describe Coiled nerve endings in PDL innervation

-Around mid-region of the PDL
-Unknown Function

73

Descdribe Spindle nerve endings in PDL innervation

-Surrounded by a fibrous capsule
-Unknown function
-Found apically and are relatively rare

74

Name the 5 main histological groups of PDL fibers

1. Alveolar Crest group
2. Horizontal group
3. Oblique group
4. Apical group
5. Interradicular group

*based on orientation

75

Describe the alveolar crest group

Attach just at the CEJ and run 'outward' to attach into the alveolar socket rim

76

Describe the horizontal group

Run from cementum at a right angle to the tooth into the alveolar socket

77

Describe the Oblique group

-Most numerous
-Run at an oblique angle from the cementum most of the way down the root

78

Describe the apical group

From the root apex to the underlying tissue

79

Describe the interradicular group

Only on multi-root teeth, they attach to the interradicular septum

80

The 5 types of PDL fibers terminate in _________ or ________ and are attached to these structures via ________ which are embedded in ______

1. Cementum
2. Alveolar Bone
3. Sharpey's fibers
4. Collagen fibers

81

T/F The gingival ligament is part of the PDL proper

False,

*But they are intamitely associated with the periodontium

82

T/F Gingival ligament is composed of collagen fibers which pass through oral lamina propria

True

83

What does the gingival ligament do for the teeth?

Gives the tooth a connection to surrounding soft tissues and neighboring teeth (attachment of gingival margin)

84

Name 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

85

Describe the dentogingival group

-Most numerous
-Run from cervical cementum to lamina propria of the free attached gingivae

86

Describe the alveologingival group

-Run from the alveolar crest (bone) to the lamina propria of free/attached gingivae

87

Describe the Circular group

-Circular band around the neck of the tooth
-Attaches to other fibers and the free gingiva

88

Describe the dentoperiosteal group

-Run apically from cementum to the periosteum of the outer cortical plate

89

Describe the transseptal fibers

-Run from cementum just under the junctional epithelium, over the alveolar crest and into the cementum of adjacent tooth
-Significant cause of orthodontic relapse