Ex 1- Odontogenesis

Question 1

_______ is the formation of tooth tissues from stem cells originating in the ________ primary germ layer

Answer 1

Odontogenesis

Ectoderm

Question 2

Odontogenesis begins in the ______ embryonic week

Answer 2

6th

Question 3

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

Answer 3

Epithelium

Mesenchym

Question 4

_______ is the formation of dentin tissue

Answer 4

Dentinogenesis

Question 5

______ is the formation of enamel tissue

Answer 5

Amelogenesis

Question 6

_____ is the formation of cementum tissue

Answer 6

Cementogenesis

Question 7

Formative levels of the odontogenic epithelial and mesenchymal tissues appear ______ tooth mineralized tissue

Answer 7

before

Question 8

What is the order in which tooth tissues form?

Answer 8

dentin
enamel
cementum

Question 9

What are the two histologic stages of odontogenesis?

Answer 9

epithelial stage

tooth germ stage

Question 10

What are the 4 stages of the epithelial stage?

Answer 10

1. epithelial dental lamina
2. epithelial bud
3. epithelial cap
4. epithelial bell (enamel organ)
   * epithelial bell stage- epithelium is 4 distinct layers

Question 11

The _____ ______ stage is when odontogenic epithelial and mesenchymal tissues combine inducing specificity to become formative cells of dentin, enamel, cementum, and pulp tissues

Answer 11

Tooth germ

Question 12

What are the three parts of the tooth germ?

Answer 12

Enamel organ (bell)
Dental papilla
Dental follicle
* give rise to the specialized cells that form tooth tissues

Question 13

What tissues make up the 3 parts of the tooth germ?

Answer 13

• epithelium- enamel organ

- mesenchyme- dental papillla + follicle

Question 14

During the ___ embryonic week, two epithelial invaginations appear (vestibular lamina + primary dental lamina) in the lower anterior region of the lower jaw and later in the week the upper jaw

Answer 14

6th

Question 15

The epithelial invaginations descend into the underlying mesenchymal tissue (ectomesenchyme) and continue _______ within the mesenchyme as continuous epithelial bands

Answer 15

posteriorly

Question 16

The ______ arch is 1/2 week behind the _____ arch in terms of development

Answer 16

maxillary

mandibular

Question 17

The facial band is called ______ lamina

Answer 17

vestibular

Question 18

The lingual band is called ______ ____ lamina

Answer 18

primary dental

Question 19

In the most facial epithelial band, _______ lamina, cell death will occur in the center leaving a space known as the ______

Answer 19

vestibular

vetibule

Question 20

In the lingual most epithelial band is the odontogenic ______ ______ lamina, cells arising from this lamina (primary and secondary) become the odontogenic ________ part of a tooth _____

Answer 20

primary dental
epithelium
germ

Question 21

Cells at the deep end of the dental lamina, where a tooth is destined to form, will develop into epithelial knobs, each known as an _____ _____ which is surrounded by _______ tissue

Answer 21

epithelial bud

mesenchymal

Question 22

What is the first mineralized tissue of a tooth?

Answer 22

Dentin

Question 23

Epithelial bud cells are continuous with cells of the ____ _____ ____

Answer 23

primary dental lamina

Question 24

Primary buds of central incisors form ___ weeks in utero

Answer 24

6

Question 25

Primary buds of second molars form ___ weeks in utero

Answer 25

8

Question 26

How many primary buds are there per arch?

Answer 26

10

Question 27

Permanent buds of first molars form __ months in utero

Answer 27

4

Question 28

Permanent buds of central incisors form __ months in utero

Answer 28

5

Question 29

Permanent buds of second molars form __ moths postnatally

Answer 29

10

Question 30

Permanent buds of third molars form __ years postnatally

Answer 30

5

Question 31

There is __ primary dental lamina per arch and __ secondary dental lamina per arch for each succedaneous teeth

Answer 31

1 | 10

Question 32

A total of __ epithelial buds arise from the primary dental lamina of each arch: __ primary teeth and __ permanent molars

Answer 32

16 10 6

Question 33

Each succedanous tooth has its own _______ dental lamina that arises from the _____ side of the primary dental lamina

Answer 33

secondary | lingual

Question 34

During the cap stage epithelial cells of the cap concentrate to form an ______ _____ which acts as a _______ _____

Answer 34

enamel knot | signaling center

Question 35

The _____ _____ determines if a tooth will develop to become an anterior or posterior tooth

Answer 35

signaling center

Question 36

During the epithelial bell stage the epithelial cap undergoes growth and develops into a ___ shaped epithelial structure called an ______ ______

Answer 36

enamel organ

Question 37

At the bell stage, the epithelium is arranged into ___ distinct cell layers; given names according to position within the bell and cell morphology

Answer 37

4

Question 38

What are the 4 distinct epithelial cell layers of the enamel organ from inner to outer?

Answer 38

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

Question 39

The ____ _____ layer becomes ameloblasts

Answer 39

inner epithelial

Question 40

Secondary dental lamina is _______ to the primary tooth germ. ___ secondary lamina arise in each arch. ___ for each secondary toth

Answer 40

lingual 10 1

Question 41

Secondary dental lamina arises from _____ _____ lamina NOT the oral epithelium

Answer 41

primary dental

Question 42

____ ____ is the epithelial enamel organ and a closely associated __________ tissue that is continuous from around the epithelium to within the epithelium

Answer 42

tooth germ

Question 43

What are the 3 distinct parts of the tooth germ?

Answer 43

- enamel organ- epithelium - dental papilla- ectomesenchyme - dental follicle- ectomesenchyme

Question 44

The ____ ____ is avascular. Inner epithelial cells differentiate into _______ specialized epithelial cells

Answer 44

enamel organ ameloblasts *epithelia is avascular*

Question 45

After the formation of enamel is complete, the ameloblasts, along with other layers of the enamel organ come together over the surface of the enamel as a protective structure called ______ _______ ____

Answer 45

reduced enamel epithelium

Question 46

The _____ ____ is vascular. Its undifferentiated (stem) cells become ____, ____, and _____ ____

Answer 46

dental papilla odontoblasts fibroblasts reserve cells

Question 47

Dental papilla ultimately becomes ____ tissue of the tooth. _____ are the most numerous cells in the ____ tissue

Answer 47

pulp fibroblasts pulp

Question 48

The dental follicle is avascular. Its stem cells become ______, ____, _____, and _____ ____

Answer 48

cementoblasts fibroblasts osteoblasts reserve cells

Question 49

The dental follicle ultimately becomes the ______ _____ of the periodontium

Answer 49

periodontal ligament

Question 50

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

Answer 50

basal lamina

Question 51

The light, acellular layer between odontoblasts and ameloblasts is the site of the future ______ junction (___)

Answer 51

dentinoenamel junction | DEJ

Question 52

The __ cell layers of enamel organ come together to form a stratified epithelial layer over the enamel surface called ______ _______ epithelium that protects the enamel from surrounding connective tissue until the tooth enters the ______ _____

Answer 52

4 reduced enamel oral cavity

Question 53

The ______ _____ at the rim of the epithelial bell (enamel organ) is where inner and outer cell layers merge

Answer 53

cervical loop

Question 54

Outer and inner layers come together at the cervical loop forming a double epithelial layer called ______ ______ ______ _____

Answer 54

Hertwig's epithelial root sheath

Question 55

Hertwig's epithelial root sheath has what 2 functions?

Answer 55

- Determines: - root dentin outline - # root canals of toth

Question 56

What part of the germ layer and what formative (blast) cell types arose from pulp stem cells?

Answer 56

Dental papilla - odontoblasts - fibroblasts

Question 57

The periodontal ligament was from what part of the germ layer and what 3 formative (blast) cell types arose from its stem cells?

Answer 57

Dental follicle - fibroblasts - cementoblasts - osteoblast

Question 58

Osteoblasts come from _____ cells while osteoclasts come from _____ _____

Answer 58

stem | bone marrow

Question 59

What parts of the tooth germ are avascular and vascular?

Answer 59

Enamel organ- avascular | Dental papilla + follicle- vascular

Question 60

The dental papilla of the primary first molar forms the secondary dental papilla of the permanent first _______

Answer 60

premolar