Tooth Eruption

Question 1

primary teeth start to form at when?

Answer 1

6 weeks

Question 2

Primary teeth start to erupt when?

Answer 2

6 months

Question 3

what is the 1st primary tooth to erupt?

Answer 3

lower a

Question 4

1st permanent tooth erupts when?

Answer 4

6 years

Question 5

3 reasons for teeth not erupting

Answer 5

Impacted

Not there at all
- Common with lateral incisors, lower 5s and wisdom teeth

Something is in the way
- Delayed loss of primaries or supernumeries

Question 6

Tooth eruption - the movement of a tooth from developmental position in the jaw to functional position in occlusion
Eruptive movements continue throughout life

Question 7

what is active eruption?

Answer 7

tooth moving

Question 8

what is passive eruption?

Answer 8

uncovering of the tooth by apical gingivae migrating -> tooth static

Question 9

Teeth move as ? grows

? teeth move from lingual/palatal position

Answer 9

jaw

successional

Question 10

how does primary tooth extraction lead to delayed eruption? use the example of a lower E extracted in a 4/5yr old

Answer 10

If remove lower Es in 4/5yr old, the 5 isn’t developed and the area heals with bone over, the 5 now has to go through a lot more bone compared to if the E was there -> delayed eruption

Question 11

what 2 things are thought to drive eruption?

Answer 11

Pull - by PDL fibroblasts

Push - hydrostatic pressure

Question 12

how do PDL fibroblasts drive eruption?

Answer 12

Fibroblasts move cervically on eruption

Question 13

how does hydrostatic pressure drive eruption?

Answer 13

Pressure below the tooth is higher than above

Parasympathetics
- Stimulate parasympathetics -> vasoconstriction -> less hydrostatic pressure -> slows eruption
- Remove parasympathetics -> vasodilation -> increase pressure -> increased eruption rate

Question 14

For a tooth to erupt ?? occurs coronally and ?? occurs apically
- ?? regulates ? formation and bone resorption
○ Osteoclasts formation from ? is promoted by ? and ?

?? promotes bone formation promoted by ?

Answer 14

bone resorption
bone formation

coronal follicle
osteoclast

monocytes
RANK
RANKL

apical follicle
BMP-2 (bone morphogenic protein)

Question 15

bloodless eruption

Proliferation of ???

Degradation of ? in oral ?

Fusion of ??? and ??

?? forms through oral epithelial ?? and reduced enamel epithelium ?

Reduced enamel epithelium forms ??

Answer 15

reduced enamel epithelium

collagen
mucosa

reduced enamel epithelium
oral epithelium

epithelial pathway
cell death
degradation

junctional epithelium

Question 16

Question 17

what happens to the primary tooth for exfoliation?

Answer 17

Primary tooth resorption through odontoblasts

Question 18

Question 19

Post eruptive movements

Accommodate for ?

Compensate for ??

Accommodate for ??

Following extraction of ??

Answer 19

growth
occlusal wear
approximal wear
opposing teeth