EX1; Odontogenesis Flashcards Preview

May14 Oral Histology > EX1; Odontogenesis > Flashcards

Flashcards in EX1; Odontogenesis Deck (46):
1

*The formation of tooth tissue from stem cells originates in which germ layer

ectoderm

2

When does odontogenesis begin

the 6th embryonic week

3

What are the two basic tissues that arise from the ectoderm germ layer involved with tooth development

epithelium and mesenchyme

4

This is the formation of dentin

dentinogenesis

5

This is the formation of enamel

amelogenesis

6

This is the formation of cementum

cementogenesis

7

What is the order in which tooth tissue from

dentin
enamel
cementum

8

What are the epithelial stages

epithelial dental lamina
epithelial bud
epithelial cap
epithelial bell (organ)

9

What does the epithelial tissue develop within

a mesenchymal tissue environment

10

What is the tooth germ stage

odontogenic epithelial and mesenchymal tissue combine inducing specificity to become the formative cells or dentin, enamel, cementum, and pulp

11

*What are the three parts of the tooth germ

enamel bell (organ)
dental papilla
dental follicle

12

*What tissues make up the parts of the tooth germ

enamel bell (organ) = epithelium
dental papilla and follicle = mesenchyme

13

During which week do the vestibular and primary dental lamina from

6th embryonic week

14

Which arch is a half a week behind the other in terms of development

maxillary is a 1/2 week behind the mandible

15

This invagination of epithelium descending into the mesenchyme appears along the facial aspect

vestibular lamina

16

This invagination of epithelium descending into the mesenchyme appears along the lingual aspect

primary dental papilla

17

True or False
Upon development, the vestibular and primary dental lamina continue posteriorly within the mesenchyme as continuous epithelial bands

True

18

What occurs in the center to the vestibular lamina

cell death; leaving the space as the vestibule

19

What do cells arising from the primary dental lamina (primary and secondary) become

odontogenic epithelial part of a tooth germ

20

Cells at the deep end of the primary dental lamina where a tooth is destined to be will develop into what

epithelial "knobs" or epithelial bud

21

Each epithelial bud is surrounded by what

mesenchymal tissue

22

When do the primary buds of central incisors form

6 weeks in utero

23

When do primary buds of second molars form

8 weeks in utero

24

When do permanent buds of first molars form

4 months in utero

25

When do permanent buds of central incisors form

5 months in utero

26

When do permanent buds of second molars form

10 months postnatally

27

When do permanent buds of third molars form

5 years postnatally

28

A total of how many epithelial buds arise from the primary dental lamina

16; 10 primary teeth and 6 permanent molars

29

On which side of the primary dental lamina does the secondary dental lamina arise

lingual

30

What specific structure is located in the epithelial cap

enamel knot

31

What is the purpose of the enamel knot

it is a concentration of epithelial cells that is the signaling center determining if the tooth will develop into an anterior or posterior tooth

32

What does the epithelium arrange into during the bell (organ) stage

4 distinct cell layers given names according to position within the bell and the cell morphology

33

What are the four distinct epithelial cell layers of the enamel organ

inner epithelial layer
stratum intermedium
stellate reticulum
outer epithelial layer

34

Where does the secondary dental lamina arise from

primary dental lamina (NOT the oral epithelium)

35

This is an epithelial enamel organ and a closely associated ectomesenchymal tissue that is continuous from around the epithelium to within the epithelium

tooth germ

36

*What does the inner epithelial cells differentiate into

ameloblasts

37

After the formulation of enamel, the ameloblasts along with other layers of the enamel organ come together over the surface of the enamel as what

a protective structure; reduced enamel epithelium

38

*What do the undifferentiated (stem) cells of the dental papilla become

odontoblasts
fibroblasts
reserve cells

39

What tissue does the dental papilla become

pulp

40

*What do the undifferentiated (stem) cells of the dental follicle become

cementoblasts
fibroblasts
osteoblasts
reserve cells

41

What tissue does the dental follicle become

periodontal ligament of the periodontium

42

The enamel organ is attached to both mesenchymal parts of the tooth germ via what

a basal lamina

43

What occurs at the cervical loop of the enamel organ

where the inner and outer cell layers merge

44

When the inner and outer epithelial layers merge at the cervical loop, they form what

a double epithelial layer celled Hertwigs epithelial root sheath

45

What is the function of Hertwig's epithelial root sheath

determines root dentin outline
determines number of root canals of tooth

46

What parts of the tooth germ are avascular or vascular

avascular = enamel organ
vascular = dental papilla and follicle