periodontium

Question 1

gomphosis

Answer 1

• cementum
• PDL
• alveolar bone
• gingiva

Question 2

enamel organ is derived from

Answer 2

oral ectoderm

Question 3

after mineralization, ameloblasts

Answer 3

shrink from columnar to cuboidal cells

-become part of the “reduced enamel epithelium”

Question 4

what eventually surrounds the enamel

Answer 4

reduced enamel epithelium

Question 5

2 cell types of REE

Answer 5

1. reduced ameloblasts (cannot divide)

2. external cells (can divide)

Question 6

external cells of REE eventually give rise to

Answer 6

junctional epithelium

Question 7

proliferation steps

Answer 7

• proliferative cells (basal, adjacent to gingiva ct) migrate up
• ameloblasts displaced and eventually all are exfoliated
• JE replaces REE, from coronal end downwards

Question 8

3 parts of gingival epithelium

Answer 8

• oral epithelium
• sulcular epithelium
• junctional

Question 9

oral epi

Answer 9

-Keratinized or para keratinized

Question 10

sulcular epi

Answer 10

NON-keratinized

-permeable => allow flow of GCF

Question 11

junctional epi

Answer 11

• base of sulcus
• joins gingiva to tooth
• 0.71-1.35mm
• 15 - 30 cells thick (coronal
• 4-5 cells thick (apical)
• NON-keratinized

Question 12

cells attach to tooth surface (enamel) by

Answer 12

hemi desmosomes

Question 13

in disease state, the gingival fibers

Answer 13

migrate down as the bone gets destroyed

Question 14

can grow a new attachment after a disease

Answer 14

long junctional epi

*only on root surface below CEJ

Question 15

muco-gingival junction

Answer 15

marks the change from NK to K

-between alveolar mucosa (NK) and attached gingiva (K)

Question 16

biologic width

Answer 16

distance between level of bone and CEJ

Question 17

biologic width

Answer 17

JE + connective tissue attachment

Question 18

5 types of gingival fibers

Answer 18

1) dentogingival
2) alveologingival
3) circular
4) dentoperiosteal
5) transeptal

Question 19

dentogingival

Answer 19

• most numerous

- cementum to free and attached gingiva

Question 20

alveologingival

Answer 20

alveolar crest to free and attached gingiva

Question 21

circular

Answer 21

goes around the soft tissue of the tooth

Question 22

dentoperiosteal

Answer 22

cementum, over the alveolar crest, and into bone

Question 23

transeptal

Answer 23

between teeth

Question 24

5 types of PDL fibers

Answer 24

• alveolar crest
• horizontal
• oblique
• apical
• interradicular

Question 25

alveolar crest

Answer 25

cementum below CEJ downward towards alveolus

Question 26

horizontal group

Answer 26

(below alveolar crest) goes to bone

Question 27

oblique

Answer 27

- most numerous | - cementum upward to alveolar bone

Question 28

apical

Answer 28

apical cementum to alveolar bone

Question 29

interradicular

Answer 29

between roots of multirooted teeth (molars)

Question 30

white opaque layer that shows up on radiograph

Answer 30

lamina dura

Question 31

PDL

Answer 31

found -between cementum and inner cortical plate of alveolar bone -specialized CT that provides supportive, nutritive, and sensory function

Question 32

osteoclasts and odontoclasts are derived from

Answer 32

blood borne macrophages

Question 33

how is PDL formed

Answer 33

- unorganized CT initially - short fiber bundles extend - ligament mesenchymal cells secrete TYPE I COLLAGEN which assemble into bundles - remodled into PDL (from CEJ downwards)

Question 34

2 ways of classifying cementum

Answer 34

cellular connotation or fibrillar connotation

Question 35

cellular connotation

Answer 35

1) acellular | 2) cellular

Question 36

acellular cementum

Answer 36

- no cells | - provides attachment

Question 37

cellular cementum

Answer 37

- cementocytes | - adaptive role

Question 38

fibrillar connotation

Answer 38

1) intrinsic 2) extrinsic 3) mixed 4) afibrillar

Question 39

intrinsic

Answer 39

- fibers made by CEMENTOBLASTS | - parallel to cementum surface

Question 40

extrinsic

Answer 40

- sharpey's fibers - continuous with PDL - made by PDL FIBROBLASTS - perpendibular to cementum surface - tooth anchorage

Question 41

mixed

Answer 41

both extrinsic and intrinsic

Question 42

afibrillar

Answer 42

no type I collagen fibers

Question 43

cementum types

Answer 43

1) acellular afibrillar (AAC) 2) acellular extrinsic fiber (AEFC) 3) cellular intrinsic 4) cellular mixed

Question 44

acellular afibrillar cementum (AAC)

Answer 44

- no fibrils or cementocytes - produced by CEMENTOBLASTS - pre-eruptive enamel maturation - CORONAL cementum

Question 45

acellular extrinsic fiber cementum (AEFC)

Answer 45

- type I collagen, part of sharpeys fibers and continuous with PDL - made by FIBROBLASTS - densely packed - pre and post eruptive - CERVICAL 2/3 OF ROOT - TOOTH ANCHORAGE

Question 46

cellular intrinsic fiber

Answer 46

- cementocytes - intrinsic fiber (made from CEMENTOBLASTS) - pre and post - SITES OF REPAIR

Question 47

cellular mixed

Answer 47

- APICAL THIRD OF ROOT AND FURCATIONS - cementoblasts trapped => cementocytes - intrinsic run between extrinsic (not as dense) - extrinsic more irregular path - CEMENTOBLASTS AND FIBROBLASTS