tooth development

Question 1

complete the process

stomadeum –> –>

Answer 1

stomadeum –> oral epithelium –> dental lamina

Question 2

what are epithileal-mesenchymal interactions?

Answer 2

• dental lamina secretes growth factor
• induces expression of TF
• leads to differentiation of mesenchyme

Question 3

what signifies the start of odontogenesis?

Answer 3

appearance of dental lamina

Question 4

the tooth is formed from the combo of? (2)

which arch?

Answer 4

• NC cells
• mandibular epithelium

1st arch

Question 5

finish the process

oral epithelium –> –> –> –>

Answer 5

oral epithelium –> dental lamina –> bud –> cap –> stage

Question 6

the differentiation of _____ _____ occurs in the bud stage

when does the bud form?

what tethers the bud?

Answer 6

• dental lamina
• bud forms after epithileal incursion into mesenchyme
• lateral lamina (part of dental lamina) tethers the bud

Question 7

describe asynchronous tooth development

Answer 7

1st: anterior mandible
2nd: anterior maxilla

moves anterior to posterior in both jaws

Question 8

what are the abnormalities in the bud stage?

Answer 8

• microdontia

- macrodontia

Question 9

what are the 3 enamel layers in the cap stage

Answer 9

• outer enamel epithelium
• stellate reticulum
• inner enamel reticulum

Question 10

tooth germ consists of? (3)

Answer 10

• enamel organ
• dental papilla
• dental follicle

Question 11

dental follicle consists of?

Answer 11

• cementum
• PDL
• alveolar bone

Question 12

dental follicle is formed by

Answer 12

dental papilla

Question 13

what makes up the cervical loop?

Answer 13

• outer enamel epithelium

- inner enamel epithelium

Question 14

finish:***

IEE –> –>

Answer 14

IEE –> ameloblasts –> enamel

Question 15

where is enamel laid down? what direction does it move?

where is dentin made? where does it move?

Answer 15

enamel

• laid down on cusp
• moves away from the DEJ

dentin

• made ar crown
• moves inward

Question 16

finish

dental papilla –> –>

Answer 16

dental papilla –> odontoblasts –> dentin

Question 17

what do the peripheal cells of the dental papilla face? what do the inner cells form?

Answer 17

periphreal: face the IEE

inner cells: form the pulp

Question 18

inner cells of dental follicle form?

outer cells form?

Answer 18

inner –> cementoblasts –> cementum

outer –> PDL
- contribute to alveolar bone formation

Question 19

what are the abnormalities in the cap stage?

Answer 19

• dens in dente
• fusion
• gemination

Question 20

what is morphodifferentiation? histodifferentiation?

Answer 20

morpho: enamel organ takes shape of incisor, canine, molar
histo: ameloblasts and odontoblasts acquire phenotype

Question 21

what happens in HERS?

Answer 21

• joining of IEE and OEE

- initiates root formation

Question 22

what is the 1st important thing that happens in the bell stage?

Answer 22

• dental lamina disintegrates, separating tooth from oral epithelium
• tooth continues development
• before tooth can function, it reestablishes a connection with the oral epithelium by formation of the junctional epithelium
• posteriormost extent of dental lamina does not disintegrate, but elongates posteriorly. gives rise to 12 buds, the precursors to permanent molars

Question 23

2nd important thing that happens in bell stage?>

Answer 23

crown pattern and number of cusps on tooth is established following folding of IEE

Question 24

all tooth structures are _____ in origin except ____

Answer 24

all tooth structures are neural crest cell in origin except enamel