Development of Dentition & Nolla’s Stage

Question 1

DECIDUOUS TEETH AGE OF ERUPTION

Answer 1

recite from reference

Question 2

PERMANENT TEETH AGE OF ERUPTION

Answer 2

recite from reference

Question 3

The primitive oral cavity or __________ is lined by stratified squamous epithelium called ____________.

Answer 3

stomatodeum
oral ectoderm

Question 4

The primitive oral cavity establishes connection with the foregut at __________ of gestation when the ______________, which is limiting the stomatodeum, ruptures.

Answer 4

4th week
buccopharyngeal membrane

Question 5

The first indication of tooth formation is seen at about _______ of gestation when oral ectoderm proliferate into the underlying ectomesenchyme to form horseshoe-shaped ___________ at the future upper and lower dental arches.

Answer 5

6th week
dental lamina

Question 6

The primary teeth develop directly from the ___________; while the permanent successor teeth develop from a ___________ of dental lamina called successional lamina. The permanent molars, which do not have deciduous predecessors develop from a ____________ of the dental lamina.

Answer 6

dental lamina
lingual extension
distal extension

Question 7

STAGES OF TOOTH DEVELOPMENT

Answer 7

BUD STAGE
CAP SATGE
EARLY BELL STAGE
ADVANCE BELL STAGE
ROOT FORMATION
HERTWIG’S EPITHELIAL ROOT SHEATH

Question 8

The enamel organ at first resembles a small bud, which is surrounded by the condensation of ectomesenchymal cells.

Answer 8

BUD STAGE

Question 9

• During bud stage, the enamel organ consists of peripherally located _________ and centrally located ______.

Answer 9

low columnar cells
polygonal cells

Question 10

• The enamel organ then proliferates to form a cap over the dental papilla. The dental papilla and dental sac become well defined.

Answer 10

CAP SATGE

Question 11

• The enamel organ differentiates to form three epithelial layers namely:

Answer 11

1) Inner dental / inner enamel epithelium
2) Stellate reticulum
3) Outer dental / outer enamel epithelium

Question 12

• The enamel organ acquires a bell shape due to uneven proliferation of its cells, resulting in deepening of the undersurface of the epithelial cap.

Answer 12

EARLY BELL STAGE

Question 13

• Another cell layer forms between the inner dental epithelium and the stellate reticulum called _________________. Thus, the enamel organ at bell stage exhibits four different types of epithelial cells.

Answer 13

stratum intermedium

Question 14

• The inner dental epithelium differentiates into tall columnar cells called ___________, which later secrete _________.

Answer 14

ameloblasts
enamel

Question 15

• The peripheral cells of the dental papilla differentiate into __________ under the organizing influence of inner dental epithelium, which later form ______.

Answer 15

odontoblasts
dentin

Question 16

• First, odontoblasts form a layer of dentin and then the ameloblasts begin to secrete enamel matrix. The deposition of enamel and dentin continues until the crown formation is complete.

Answer 16

ADVANCE BELL STAGE

Question 17

• Root formation begins once the dentin and enamel reach the future _____________.

Answer 17

cementoenamel junction

Question 18

• The cervical portion of the enamel organ gives rise to the ____________, which molds the shape of the roots and initiates radicular dentin formation.

Answer 18

Hertwig’s epithelial root sheath

Question 19

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

Answer 19

two-thirds

Question 20

• Root formation is usually completed _______ after the eruption of tooth.

Answer 20

1–3 years

Question 21

These physiological processes are: (5)

Answer 21

1. Initiation – dental lamina and bud stage
2. Proliferation – bud and cap stage
3. Histodifferentiation - early bell stage
4. Morphodifferentiation - advanced bell stage
5. Apposition - formation of enamel and dentin matrix

Question 22

dental lamina and bud stage

Answer 22

Initiation

Question 23

bud and cap stage

Answer 23

Proliferation

Question 24

early bell stage

Answer 24

Histodifferentiation

Question 25

advanced bell stage

Answer 25

Morphodifferentiation

Question 26

formation of enamel and dentin matrix

Answer 26

Apposition

Question 27

Mineralization begins around ___________of gestation in primary dentition and occurs first in the central incisors.

Answer 27

14th week

Question 28

The permanent tooth germs begin to form around _______ month of intrauterine life and their mineralization commences ______, beginning in the first molars.

Answer 28

4th– 5th
at birth

Question 29

RADIOGRAPHIC STUDIES OF TOOTH FORMATION CONSIDER THREE BASIC STAGES:

Answer 29

I. Beginning of calcification
II. Crown completion
III. Root completion

Question 30

CROWN STAGES:

Answer 30

Stage 1: Absence of crypt
Stage 2: Initial calcification
Stage 3: 1/3 of crown completed
Stage 4: 2/3 of crown completed
Stage 5: Crown almost completed
Stage 6: Crown completed.

Question 31

ROOT STAGES:

Answer 31

Stage 7: 1/3 of root completed
Stage 8: 2/3 of root completed
Stage 9: Root almost completed
Stage 10: Apical end of root completed.v