EX2; Periodontium Development Flashcards Preview

May14 Oral Histology > EX2; Periodontium Development > Flashcards

Flashcards in EX2; Periodontium Development Deck (36):
1

What structures does the periodontium include

cementum
PDL
bony socket
gingiva facing the tooth; junctional and sulcular epithelium

2

This is the calcified material that covers the root dentin

cementum

3

This is largely composed to collagen fibers which are embedded on one end to the cementum and the other to the periodontium

PDL

4

All but which structure serves a role in the attachment of the tooth

sulcular gingiva

5

True or False
the tooth root develops after the crown

True

6

What guides root growth

Hertiwig's epithelial root sheath

7

The initiation of root dentinogenesis slightly precedes what

periodontal development

8

What is the inductive signal from HERS for odontoblast differentiation

TGF-β and/or laminin5

9

Once dentin in the root begins to be laid down, what occurs

HERS separates from root dentin
osteobalsts, cementoblasts, PDL fibroblasts differentiate and migrate to their appropriate locations

10

What is the order in which the blast cells secrete their substance

cementoblasts and osteoblasts secrete their organic matrix (type 1 collagen) first
PDL fibroblasts secrete their organic collagen matrix

11

The organic matrices of cementum and bone are secreted before what begins

mineralization

12

How does the PDL become entrapped in the cementum and bone

it intermingles with the unmineralized matrices and then is locked in during mineralization

13

All of periodontal development is occurring as what is happening

the tooth is erupting

14

What changes in orientation does the PDL undergo as the tooth is erupting

starts out in an oblique orientation with the end in the cementum apically, then it becomes more horizontal, then obliquely again with the cementum more coronal

15

In which direction does the periodontium grow

from the CEJ to the root apex

16

This type of cementum is mainly acellular and is located on the coronal 2/3 of the tooth

primary cementum

17

This type of cementum is mainly cellular and located on the apical 2/3

secondary cementum

18

When is secondary cementum formed

after at least half of the root is completed and about the time the tooth emerges from the oral cavity

19

Which type of cementum is more important in serving an attachment function

primary cementum

20

Along the advancing root edge, what is there a continuous layer of

predentin extending between the future DCJ and the pulp

21

A little coronal to the developing root, the root dentin begins to mineralize, creating what

two separate unmineralized parts of dentin (predentin and non-mineralized dentin at the future DCJ)

22

At what orientation to the DCJ are the cementum collagen "fiber fringe" laid down

right angles

23

The cementum fiber fringe extends into what, then what occurs

extends into the unmineralized dentin matrix and upon mineralization the fiber fringe is embedded in the dentin matrix

24

The firm attachment between the cementum and dentin is a consequence of what

the fact that collagen fibers of these two tissues intermingle prior to mineralization

25

As primary cementum is laid down, cementoblasts do what

retreat toward the future PDL; they do not become entrapped in the forming matrix (hence, acellular)

26

Fragmented HERS remain in the PDL as what

epithelial rests of Mallasez

27

What are the similarities between the formation of primary and secondary cementum

similarity; formed in the same way regarding the fringe and dentin mingling prior to mineralization
difference; cementoblasts become trapped in the cementum matrix (hence, cellular)

28

Sulcular epithelium arises from what

embryonic oral epithelium

29

Junctional epithelium arises from what

reduced enamel epithelium

30

The periodontium structures arise from which portion of the tooth germ

dental follicle

31

There is a debate over this cell regarding of whether it came from ectomesenhyme (NCC) dental follicle or epithelial; HERS

cementoblasts

32

What is the general consensus regarding the origin of cementoblasts

cementum-forming cells may be derived from both the dental follicle and HERS

33

These are secreted growth factors implicated in cementoblast induction

BMPs; bone morphogenetic proteins

34

These are transcription factors implicated in cementoblast differentiation

RunX

35

These are extracellular matrix molecules implicated in cementogenesis

bone sialoprotein and osteopontin; both secreted from cementoblast about the same time as the initial collagen matrix; role in mineralization

36

This is secreted by cementoblasts and plays a role in cementoblast adhesion to root dentin surface and cementum mineralization

bone sialoprotein (BSP)