Lec 7: Development of Dentition & Nolla's

Question 1

The primitive oral cavity is also called as?

Answer 1

Stomatodeum

Question 2

The primitive oral cavity is lined by?

Answer 2

Stratified squamous epithelium

Question 3

The lining of the stomatodeum is called as?

Answer 3

Oral ectoderm

Question 4

The primitive oral cavity establishes connection with the foregut at what week of gestation?

Answer 4

4th week

Question 5

This structure limits the stomatodeum, separating it from the foregut, until it ruptures at 4th week of gestation.

Answer 5

Buccopharyngeal membrane

Question 6

The first indication of tooth formation is seen at what week?

Answer 6

6th week of gestation (1st trimester)

Question 7

At the 6th week, the oral ectoderm proliferate into the underlying ectomesenchyme to form what horseshoe-shaped structure?

Answer 7

Dental lamina

Question 8

The primary teeth develop directly from?

Answer 8

Dental lamina

Question 9

The permanent successor teeth develop from?

Answer 9

Successional lamina / lingual extension of dental lamina

Question 10

The permanent molars develop from?

Answer 10

Distal extension of dental lamina

Question 11

Also known as the lingual extension of the dental lamina.

Answer 11

Successional lamina

Question 12

At this stage, the enamel organ resembles a small bud, surrounded by the condensation of ectomesenchymal cells.

Answer 12

Bud stage

Question 13

During the bud stage, what are the cells seen in the enamel organ?

Answer 13

1. peripherally located low columnar cells
2. centrally located polygonal cells

Question 14

At this stage, the enamel organ proliferates to form a cap over the dental papilla. The dental papilla and dental sac become well defined.

Answer 14

Cap stage

Question 15

During the cap stage, the enamel organ differentiates to form three epithelial cells, which are?

Answer 15

1. Inner enamel epithelium
2. Stellate reticulum
3. Outer enamel epithelium

Question 16

In this stage, there is an uneven proliferation of cells, resulting in deepening of the undersurface of the epithelial cap.

Answer 16

Early bell stage

Question 17

What is the layer formed between the IEE and stellate reticulum during early bell stage?

Answer 17

Stratum intermedium

Question 18

How many epithelial cell types does the enamel organ exhibit during early bell stage?

Answer 18

4 types

Question 19

The IEE differentiates into tall columnar cells called?

Answer 19

Ameloblasts

Question 20

These cells secrete enamel.

Answer 20

Ameloblasts

Question 21

The peripheral cells of the dental papilla differentiate into?

Answer 21

Odontoblasts

Question 22

These cells form dentin.

Answer 22

Odontoblasts

Question 23

At this stage, odontoblasts form a layer of dentin and then the ameloblasts begin to secrete enamel matrix.

Answer 23

Advance bell stage

Question 24

The deposition of enamel and dentin continues until?

Answer 24

Crown formation is complete

Question 25

Root formation begins once the dentin and enamel reach the?

Answer 25

Future cementoenamel junction

Question 26

The cervical portion of the enamel organ gives rise to the?

Answer 26

Hertwig’s epithelial root sheath

Question 27

This structure molds the shape of the roots and initiates radicular dentin formation.

Answer 27

Hertwig’s epithelial root sheath

Question 28

Eruption of a tooth generally begins when __________ of the root is formed.

Answer 28

two-thirds

Question 29

Root formation is usually completed ________ after the eruption of tooth.

Answer 29

1–3 years

Question 30

Physiological process involving the dental lamina and bud stage.

Answer 30

Initiation

Question 31

Physiological process involving the bud and cap stage.

Answer 31

Proliferation

Question 32

Physiological process involving the early bell stage.

Answer 32

Histodifferentiation

Question 33

Physiological process involving the advanced bell stage.

Answer 33

Morphodifferentiation

Question 34

Physiological process involving the formation of enamel and dentin matrix.

Answer 34

Apposition

Question 35

Mineralization begins around at what week of gestation in primary dentition?

Answer 35

14th week

Question 36

Mineralization occurs first in the?

Answer 36

Central incisors

Question 37

The permanent tooth germs begin to form around what month of intrauterine life?

and their mineralization commences at ____?, beginning in the ______?

Answer 37

4th–5th month
birth
first molars

Question 38

Radiographic studies of tooth formation consider what three basic stages?

Answer 38

Beginning of calcification, Crown completion, Root completion

Question 39

Nolla’s Stage 1?

Answer 39

Absence of crypt

Question 40

Nolla’s Stage 2?

Answer 40

Initial calcification

Question 41

Nolla’s Stage 3?

Answer 41

1/3 of crown completed

Question 42

Nolla’s Stage 4?

Answer 42

2./3 of crown completed

Question 43

Nolla’s Stage 5?

Answer 43

Crown almost completed

Question 44

Nolla’s Stage 6?

Answer 44

Crown completed

Question 45

Nolla’s Stage 7?

Answer 45

1/3 of root completed

Question 46

Nolla’s Stage 8?

Answer 46

2/3 of root completed

Question 47

Nolla’s Stage 9?

Answer 47

Root almost completed

Question 48

Nolla’s Stage 10?

Answer 48

Apical end of root completed

Question 49

At what stage of Nolla’s classification do the eruption of tooth commence?

Answer 49

Stage 8 (2/3 of root completed)