Tooth Development

Question 1

origin of all tooth structures (tissues and cells)

Answer 1

1. Surface ectoderm forms the ameloblasts and enamel respecitvely
2. Ectomesenchyme from neural crest cells and give rise to the cementocytes which form the cementum, pdl, and alveolar bone
3. Ectomesenchyme forming the odontoblasts which produce dentin

Question 2

primary epithelial band will form when? what is it?

Answer 2

Day 37 of development.

This is a proliferation of the epithelium at the site of the future dental arches.

Question 3

subdivisions of the primary epithelial band form what and when does this occur?

Answer 3

Day 42-48 of development and will form

1. dental lamina
2. vestibular lamina

Question 4

dental lamina

Answer 4

appears around day 42-48 in development and will form from the primary epithelial band.

Question 5

vestibular lamina

Answer 5

forms from the primary epithelial band and will proliferate and break down forming the vestibule or open cavities in the oral cavity

Question 6

enamel origin

Answer 6

ameoloblasts - ectoderm

Question 7

odontoblasts

Answer 7

produce dentin from odontoblasts which are derived from neural crest cells

Question 8

cementocytes

Answer 8

give rise to the alveolar bone, pdl, and cementum

derived from neural crest cells

Question 9

ectomesenchyme

Answer 9

neural crest cell invaded mesencyme

Question 10

physiological break site in epithelium

Answer 10

when the dental lamina and lateral lamina break down in the developing tooth bud forms we have a physiological break with the oral epithelium

Question 11

oral mucosa is what type of tissue?

Answer 11

oral ectoderm

Question 12

proliferation of oral ectoderm and mesenchyme?

Answer 12

bud stage - no structural changes occur

Question 13

origin of stellate reticular cells?

Answer 13

oral ectoderm

Question 14

tooth germ composition

Answer 14

enemal ogran, dentil papilla, dental sac

Question 15

cytodifferentiation and histodifferentiation begins when?

Answer 15

in cap stage - largely in end of cap stage and beginning of bell stage

Question 16

when is the enamel knot noticeable and what is its function?

Answer 16

in the cap stage and is thought of as a proliferating center and cell signaling center which coordiantes the crown form of the tooth

Question 17

4 regions in the bell stage and where are they found?

Answer 17

1. outer enamel apithelium
2. inner enamel epihtelium
3. stellate reticulum layer
4. stratum intermedium layer
   WITHIN THE ENAMEL ORGAN