1. Chapter 2 Periodontium /Periodontal Tissues （牙周组织）

2. Introduction The gingiva（牙龈） The periodontal ligament（牙周膜）
The alveolar process (牙槽突)

3. The Gingiva located around the necks of teeth
keratinized epithelium(角化上皮)
function during mastication

4. The periodontal ligament
suspend the tooth in the socket
provide a cushion against occlusal forces
provide a delicate sense of touch and pressure
carry oxygen and nutrition

5. The alveolar process the bony extension of the mandible & maxilla
provide the necessary support for the teeth
an attachment for periodontal ligament fibers
compensate for tooth movement

6. Cementum an attachment for periodontal ligament fibers
provide compensation for occlusal wear
protect the sensitive dentin

7. Objective
Histologic structures and function of the periodontal tissues
the gingiva
the periodontal ligament
the alveolar bone

8. Part I Gingiva

9. Introduction
Position: around the necks of teeth
Color: pink

10. Surface Anatomy The free gingiva(游离龈) The attached gingiva(附着龈)
Interdental papilla
Free gingiva
Attached gingiva
The free gingiva(游离龈)
The attached gingiva(附着龈)
The interdental papilla(牙间乳头)

11. Free Gingiva Boundaries Coronally: the gingival margin
Apically: the free gingival groove, 1.0~1.5mm
(游离龈沟，GG)

12. Free Gingiva Gingival sulcus(龈沟) : 0.5~3mm
Gingiva sulcus
Gingiva sulcus
Gingival sulcus(龈沟) : 0.5~3mm
coronally: the gingival margin
bottomly: the junctional epithelium
the inner margin: the tooth surface
the outer surface: sulcular epithelium

13. Attached Gingiva
Position: between the free gingiva & the alveolar mucosa
the free gingiva: the free gingival groove
the alveolar mucosa: mucogingival junction

14. Stipple orange peel appearance the absence:
an initial sign of pathology

15. Interdental Papilla
Position: on the inter-proximal areas of the crowns on the labial and lingual surfaces
Shape: wedge-shaped

16. The col
interproximal to the vestibular and oral cavity surfaces of the interdental papilla
a concave area
anteriorly: like a pyramid
posteriorly: be flattened
plaque and calculus form: sign of inflammation

17. Histological Structure
The surface epithelium
Lamina propria
rete epithelium ridges

18. The surface epithelium
the margin of
the gingiva
the sulcular epithelium
the epithelium attachment
stratified squamous epithelium

19. keratinized, parakeratinized, or nonkeratinized

20. Gingival epithelium: % of cases Surface cell Stratum granulosum
nucleus Keratinized No Present Nonkeratinized Yes None Parakeratinized Partially None

21. pigment granules: basal layer, melanocyte

22. The sulcular epithelium
thin
lack keratinization

23. The col thin nonkeratinized
extensions into the underlying connective tissue

24. The junctional epithelium
Definition:
a seal between the epithelium and the tooth, thin

25. Characteristics
the basement membrane is smooth

26. a smaller tonofilament-to-cytoplasmic ratio
desmosomes is four times less - molecules of high molecular weight can migrate into the surface
rough endoplasmic reticulum & Golgi apparatus are highly developed - protein synthesis & glycosylation.

27. the attachment: cuticle & hemidesmosome
attachment plaque
tonofilaments
lamina lucida and lamina densa
cellular fibrils

28. high rate of cell turn over: the attachment between epithelium and tooth is dynamic

29. disturbance of the epithelial attachment: deepen of the gingival sulcus, form periodontal pocket

30. the relation between the gingiva and the tooth: changes constantly by age
20 or 30 year old: enamel
40 year old or later: cementoenamel junction
Elderly: cementum

31. Lamina Propria
The gingiva fibers

32. dentogingival group: the cervical cementum - the lamina propria
alveologingival group: the alveolar crest - the lamina propria
circular group: circle the tooth
dentoperiosteal group: the cementum - the periosteum of the alveolar bone
transseptal group: the cementum - the cementum of the neighboring teeth

33. elastic fibers: the walls of larger blood vessels
fibroblasts, macrophages, lymphocytes and plasma cells.

34. Vascularity and Nerves
highly vascular: the branches of the alveolar arteries

35. well innervated: touch endings, temperature and pain receptors

36. Summary
The free gingiva. The attached gingiva, and the interdental papilla
The free gingiva groove: separate the free and attached gingiva
The mucogingival junction:
separate the gingiva and the alveolar mucosa

37. The gingival epithelium : keratinized

38. The epithelial attachment:
cuticle, hemidesmosome

39. Lamina propria: fiber groups - dentogingival, alveolar gingival, circular, dentoperiosteal, and transseptal
No submucosa

40. Highly vascular and well innervated

41. Periodontal Ligament

42. Introduction
The terms:
periodontal ligament / periodontal membrane

43. Position: between the cementum and the alveolar bone proper
Thickness: 0.15~0.38mm, the thinnest part - the midroot

44. The collagen fiber bundles
Highly cellular
Rich nerve and blood supply.

45. Histological Structure
dense connective tissue
composed of fibers, cells, and stroma

46. Fibers Principal fibers the bundles of collagenous fibers
between the cementum and alveolar bone proper

47. Sharpey’s fibers:
the embedded portions of principal fibers

48. Space fibers the loose connective tissue
between the principal fiber bundles
contain the blood vessels, lymphatics, and nerves

49. The groups of the principal fiber bundles
the alveolar crest fibers
the horizontal fibers
the oblique fibers
the apical fibers
the interradicular fibers

50. Principal Fibers Group name Location of attachment. Function
Principal Fibers Group name Location of attachment Function Alveolar crest Cervical root to alveolar crest of Resist vertical and
alveolar bone proper intrusive force Horizontal Midroot to adjacent alveolar Resist horizontal
bone proper and tipping force Oblique Apical one third of root to Resist vertical and
adjacent alveolar bone proper intrusive force Apical Apex of root to fundic alveolar Resist vertical forces
bone proper Interradicular Between roots to alveolar bone Resist vertical and
proper lateral movement

51. Oxytalan fibers transmission electron microscopic observation
fine fibers

52. the special stains
part of the support system of the principal fibers.

53. Summary
Position: between the root surface and the alveolar bone proper
Thickness: fairly constant

54. Principal fibers Alveolar crest Horizontal Oblique Apical
Interradicular

55. Oxytalan fibers: fine fibers aid in the support of the ligament

56. Next Class Hour
The cells, vascular, lymphatic, and neural supply of periodontal ligament
The histological structure of alveolar bone

57. Thanks!