Lecture 2- Odontogenesis

Question 1

odontogenesis begins in the … embryonic week

Answer 1

6th

Question 2

odontogenesis is the formation of tooth tissue from … cells originating in … primary germ layer

Answer 2

stem

ectoderm

Question 3

two basic tooth tissues that arise from the ectoderm primary germ layer that are involved in tooth development are… and…

Answer 3

epithelium and mesenchyme

Question 4

the 4 epithelial stages are

Answer 4

1. epithelial dental lamina
2. epithelial bud
3. epithelial cap
4. epithelial bell

Question 5

3 parts of a tooth germ

Answer 5

1. enamel organ (bell): epithelium
2. dental papilla: mesenchyme
3. dental follicle: mesenchyme

Question 6

The primary dental lamina appears in the …. embryonic week and consists of two epithelial invaginations called… and…

Answer 6

vestibular lamina

and primary dental lamina

Question 7

the primary epithelial buds appear…. in utero

Answer 7

6-8 wks

Question 8

the central incisor primary buds appear at… in utero

Answer 8

6 weeks

Question 9

the second molar primary buds appear at… in utero

Answer 9

8 weeks

Question 10

The permanant epithelial buds appear …. to…

Answer 10

4 months in utero to 5 years postnatal

Question 11

the first molar permanent buds appear…

Answer 11

4 months in utero

Question 12

the central incisor permanent buds appear….

Answer 12

5 months in utero

Question 13

The second molar permanent buds appear….

Answer 13

10 months postnatally

Question 14

The 3rd molar permanent buds appear

Answer 14

5 years postnatally

Question 15

a total of … epithelial buds arise from the primary dental lamina of each arch

Answer 15

16

10 primary teeth and 6 permanent molars

Question 16

Each succedaneous tooth (primary tooth) has its own … that arises from the lingual side of the primary dental lamina

Answer 16

secondary dental lamina

Question 17

in the epithelial cap stage there is a concentration of epithelial cells that is a ….. which determines if the tooth is going to be anterior or posterior

Answer 17

signaling center

Question 18

the … stage has 4 distinct layers

Answer 18

epithelial bell stage

Question 19

what are the 4 layers of the epithelial bell stage from inside out

Answer 19

1. inner epithelial layer
2. stratum intermedium epithelial layer
3. stellate reticulum epithelial layer
4. outer epithelial layer

Question 20

secondary dental lamina arises from… not…

Answer 20

primary dental lamina

not oral epithelium

Question 21

the enamel organ is avascular or vascular?

Answer 21

avascular

Question 22

the dental papilla is avascular or vascular

Answer 22

vascular

Question 23

the dental follicle is vascular or avascular

Answer 23

vascular

Question 24

after formation of enamel, the ameloblasts and other layers come together come together to form

Answer 24

reduced enamel epithelium

Question 25

the dental papilla becomes the ...

Answer 25

pulp

Question 26

the dental papilla has undifferentiated cells (stem cells) that become

Answer 26

odontoblasts, fibroblasts, reserve cells

Question 27

the dental follicle becomes the

Answer 27

periodontal ligament

Question 28

the stem cells of the dental follicle become...

Answer 28

cementoblast, fibroblast, osteoblast and reserve cells

Question 29

ameloblasts come from which layer of the tooth germ

Answer 29

inner epithelial layer

Question 30

the enamel organ is attached to both mesenchymal parts of the tooth germ by a

Answer 30

basal lamina

Question 31

the outer and inner layers of the enamel organ come together, at cervical loop, forming a double epithelial layer called....

Answer 31

Hertwig's epithelial root sheath

Question 32

Hertwigs epithelial root sheath has 2 main functions

Answer 32

1. determine root dentin outline | 2. determines number of root canals of tooth

Question 33

The pulp came from the dental papilla, what 2 formative cell types arose from its stem cells?

Answer 33

odontoblasts and fibroblasts

Question 34

The periodontal ligament came from the dental follicle and what 3 formative cell types arose from its stem cells?

Answer 34

cementoblasts fibroblasts osteoblasts