Tooth eruption & comparison Flashcards
By what age should all deciduous teeth have erupted?
by 2.5 - 3 years
What is the general rule about deciduous teeth eruption?
Lowers before uppers, except for lateral incisors
How long does complete apexogenesis taken after decidious tooth eruption?
around 1.5 years after eruption
What is the eruption pattern in deciduous teeth?
1 2 4 3 5
A B D C E
When do upper deciduous central incisors erupt?
8-12 months
When do upper deciduous lateral incisors erupt?
9-13 months
When do upper deciduous canines erupt?
16-22months
When do upper deciduous first molars erupt?
13-19months
When do upper deciduous second molars erupt?
23-33 months
When do lower deciduous central incisors erupt?
6-10 months
When do lower deciduous lateral incisors erupt?
10-16 months
When do lower deciduous canines erupt?
17-23 months
When do lower deciduous first molars erupt?
14-18 months
When do lower deciduous second molars erupt?
23-31 months
Between what ages is the ‘mixed dentition stage’?
6-11 years
What is the general rule for permanent tooth eruption?
Lowers before uppers except 2nd premolars
What is the eruption pattern for upper permanent teeth?
6 1 2 4 5 3 7 8
What is the eruption pattern for lower permanent teeth?
6 1 2 3 4 5 7 8
In permanent teeth, how long after eruption does it take for root formation to complete?
3 years
When do upper permanent central incisors erupt?
7-8 years
When do upper permanent lateral incisors erupt?
8-9 years
When do upper permanent canines erupt?
11-12 years
When do upper permanent first premolars erupt?
10-11 years
When do upper permanent second premolars erupt?
10-12 years
When do upper permanent first molars erupt?
6-7 years
When do upper permanent second molars erupt?
12-13 years
When do upper permanent third molars erupt?
17-21 years
When do lower permanent central incisors erupt?
6-7 years
When do lower permanent lateral incisors erupt?
7-8 years
When do lower permanent canines erupt?
9-10 years
When do lower permanent first premolars erupt?
10-12 years
When do lower permanent second premolars erupt?
11-12 years
When do lower permanent first molars erupt?
6-7 years
When do lower permanent second molars erupt?
11-13 years
When do lower permanent thirds molars erupt?
17-21 years
How do deciduous crowns differ from the crowns of permanent teeth?
- primary incisors are smaller in root & crown proportions
- primary molars are wider mesiodistally than permanent premolars which replace them
- Primary molar crowns are more bulbous
- primary teeth are usually whiter in colour
How do deciduous and permanent teeth differ re: roots?
- primary roots tend to be narrower
- primary molar roots are longer & more slender, they tend to flare apically to allow room inbetween for developing permanent tooth crowns
How do deciduous and permanent teeth differ re: pulps?
- Primary dentition have relatively large pulp chambers
- pulp horns of primary dentition extend high occlusally - hence pulpal exposure more likely
How do deciduous and permanent root canals differ?
- Primary root canals tend to be ribbon shaped
- primary root canals are clinically impossible to clean completely
How do deciduous and permanent hard tissues differ?
- coronal dentine is much thinner than permanent
- primary enamel is relatively thin and has a consistent depth
How do deciduous and permanent occlusions differ?
- anterior spacing is desired (= no crowdin in permanent dentition)
- deciduous incisors are upright, permanent incisors are proclined, leading to an increase in A-P archlength
What is leeway space in deciduous teeth?
Extra space mesio-distal space occupied by primary molars, wider than the replacing permanent pre-molars
- usually equates to 1.5mm eather side in upper arch, 2.5mm lower arch
