1 - Tooth Development

Question 1

When is the 1st sign of tooth development?

Answer 1

6-7 weeks in utero

Question 2

Deciduous teeth begin to calcify when?

Answer 2

13-20 weeks in utero

Question 3

When have all deciduous teeth begin to calcify?

Answer 3

18-20 weeks in utero

Question 4

Deciduous teeth erupt when?

Answer 4

6-30 months

Question 5

What is the 1st part of the tooth to calcify?

Answer 5

Crown

Question 6

What are the stages of tooth development?

Answer 6

1. Crown formation
2. Root formation
3. Supporting structure formation

Question 7

What arch is where the majority of teeth originate from?

Answer 7

1st arch

Question 8

Teeth are particular from what process?

Answer 8

Medial-nasal process

Question 9

The primary epithelial band corresponds to what?

Answer 9

Future dental arches

Question 10

This is a horseshoe shaped band that corresponds to future dental arches

Answer 10

Primary epithelial band

Question 11

The primary epithelial band gives rise to what?

Answer 11

1. Dental lamina
2. Vestibular lamina

Question 12

What is expressed where the tooth bud will form?

Answer 12

Shh → epithelia
Pax9 → mesenchyme

Question 13

The neural crest mesenchyme induces _____ to become the dental lamina

Answer 13

Oral ectoderm

Question 14

What are the stages of crown formation?

Answer 14

Initiation → bud stage → cap stage → bell stage → enamel/dentin/pulp

Question 15

In what stage do epithelial cells show no major changes?

Answer 15

Bud stage

Question 16

What hormones are involved in placode formation (ectoderm thickening)?

Answer 16

Shh, Lef-1, Eda-Edar

Question 17

Shh, Lef-1, Eda-Edar are in what stage?

Answer 17

Bud stage

Question 18

The enamel organ and dental papilla are formed in what stage?

Answer 18

Cap stage

Question 19

Do we see epithelial growth in the Cap stage?

Answer 19

Yes

Question 20

In what stage do we see the tooth germ?

Answer 20

Cap stage

Question 21

What does the tooth germ consist of?

Answer 21

1. Enamel organ
2. Dental papilla

Question 22

What are the outer and inner parts of the dental papilla?

Answer 22

Outer = dentin
Inner = pulp

Question 23

In what stage do we see Enamel knot formation?

Answer 23

Cap stage

Question 24

This is a key signaling center that consists of a cluster of non-dividing cells determines cusp formation?

Answer 24

Enamel knot

Question 25

What does the enamel knot determine?

Answer 25

Cusp formation

Question 26

This is the enamel of the tooth

Answer 26

Enamel organ

Question 27

Cells in the enamel organ synthesize what into the ECM?

Answer 27

Glycosaminoglycans

Question 28

In what stage do we see glycosaminoglycans?

Answer 28

Cap stage

Question 29

What synthesize glycosaminoglycans?

Answer 29

Cells of the enamel organ (IEE & OEE)

Question 30

What do glycosaminoglycans do?

Answer 30

Hydrophilic and pull water into the enamel organ

Question 31

You get stellate reticulum formation by what and in what stage?

Answer 31

Glycosaminoglycans pulling water in Cap stage

Question 32

What do glycosaminoglycans form?

Answer 32

Stellate reticulum cells

Question 33

In what stage does the stratum intermedium form?

Answer 33

Bell stage

Question 34

What stage does the crown attain full size and shape?

Answer 34

early Bell stage

Question 35

Permanent detention forms _____ to the deciduous dentition

Answer 35

Lingual

Question 36

The IEE and OEE are found in what stage?

Answer 36

Bell stage and cap

Question 37

These will differentiate into ameloblasts

Answer 37

IEE

Question 38

What will make odontoblasts and ameloblasts?

Answer 38

IEE

Question 39

The site of what determines future cusp formation?

Answer 39

IEE differentiates

Question 40

The junction of the IEE and OEE is called the

Answer 40

Cervical loop

Question 41

This is the future site of the CEJ

Answer 41

Cervical loop

Question 42

Dental papilla will form what?

Answer 42

Dentin Pulp

Question 43

Dental follicles will form what?

Answer 43

Cementum Periodontium

Question 44

In what stage do you see Tome’s process?

Answer 44

Secretory stage Amelogenesis

Question 45

What breaks and then separates the tooth from oral epithelium?

Answer 45

Dental lamina

Question 46

What proteins are associated with the secretory stage ameloblasts?

Answer 46

Amelogenin Ameloblastin Enamelin

Question 47

What are the proteases in secretory stage ameloblasts?

Answer 47

Enamelysin Kallikrein

Question 48

In the secretory stage ameloblasts, what do they form?

Answer 48

Enamel rods and Inter-rod

Question 49

This is the 1st layer of dentin formed

Answer 49

Mantle dentin

Question 50

What are the characteristics of Mantle dentin?

Answer 50

1. 1st formed 2. Hypomineralized 3. Only in the crown of the tooth

Question 51

This is formed during tooth development at 4um/day

Answer 51

Primary dentin

Question 52

This dentin is formed after tooth eruption

Answer 52

Secondary dentin

Question 53

This dentin is produced in response to injury to protect the pulp

Answer 53

Tertiary dentin

Question 54

IEE and OEE from the cervical loop proliferate downwards to form what?

Answer 54

Hertwig’s root sheath

Question 55

What happened to HERS before cementum?

Answer 55

Most of it is removed before cementum is laid down

Question 56

The hertwig’s root sheath is also the site of what?

Answer 56

CEJ

Question 57

Differentiation of cementoblasts are from what?

Answer 57

HERS Dental follicle cells

Question 58

Remnants of hertwig’s are called

Answer 58

Epithelial rests of Malassez

Question 59

What are the kinds of Cementum?

Answer 59

Acellular = line the root Cellular = bottom of the root

Question 60

What are the periodontal ligament fibers?

Answer 60

1. Transseptal ligament 2. Alveolar crest group 3. Horizontal group 4. Oblique group 5. Apical group 6. Interradicular group