Tooth Eruption Flashcards
primary teeth start to form at when?
6 weeks
Primary teeth start to erupt when?
6 months
what is the 1st primary tooth to erupt?
lower a
1st permanent tooth erupts when?
6 years
3 reasons for teeth not erupting
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
Tooth eruption - the movement of a tooth from developmental position in the jaw to functional position in occlusion
Eruptive movements continue throughout life
what is active eruption?
tooth moving
what is passive eruption?
uncovering of the tooth by apical gingivae migrating -> tooth static
Teeth move as ? grows
? teeth move from lingual/palatal position
jaw
successional
how does primary tooth extraction lead to delayed eruption? use the example of a lower E extracted in a 4/5yr old
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
what 2 things are thought to drive eruption?
Pull - by PDL fibroblasts
Push - hydrostatic pressure
how do PDL fibroblasts drive eruption?
Fibroblasts move cervically on eruption
how does hydrostatic pressure drive eruption?
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
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 ?
bone resorption
bone formation
coronal follicle
osteoclast
monocytes
RANK
RANKL
apical follicle
BMP-2 (bone morphogenic protein)
bloodless eruption
Proliferation of ???
Degradation of ? in oral ?
Fusion of ??? and ??
?? forms through oral epithelial ?? and reduced enamel epithelium ?
Reduced enamel epithelium forms ??
reduced enamel epithelium
collagen
mucosa
reduced enamel epithelium
oral epithelium
epithelial pathway
cell death
degradation
junctional epithelium
