Anatomy and Development Flashcards
what are the differences between primary and permanent teeth?
primary teeth are whiter
pulp to crown ratio bigger in primary teeth
primary teeth are more bulbous
primary roots are more divergent
contact point in primary teeth is bigger
when do primary teeth start to erupt?
6 months
what primary teeth erupt first?
lower central incisors
when is the primary dentition complete?
2 1/2 years
when does the mixed dentition begin?
6 years
what are the first permanent teeth to erupt?
lower central incisors
what teeth do you get from 6-8 years?
incisors and 1st molars
what teeth do you get at age 10?
lower canines and 1st premolars
what teeth do you get at age 11?
upper canines and 2nd premolars
what teeth do you get at age 12?
2ns permanent molars
when is the permanent dentition established?
12
what is the curve of spee?
curvature of the mandibular occlusal plane
where does the curve of splee begin?
tip of lower incisors
what does the curve of splee follow?
buccal cusps of posterior teeth
where does the curve of splee end?
anterior mandibular ramus
when do primary teeth begin to develop?
day 28 in utero
what happens to the continuous plate of epithelium on maxilla and mandible at day 37?
thickens
in early development what plays an important role in shaping dental arches?
tongue
what are features of primary dentition?
spaced anteriors
primate spaces
shallow overjet and overbite
class I molar relationship
in the primary dentition, what molar is the widest?
mandibular
why is there spacing of the primary dentition?
mesio-distal width of permanent incisors is 7.6mm greater in the max arch and 6mm greater in the man arch.
why is there leeway space?
mesio-distal width of C D E is greater than the 3 4 5
whats the effect of early loss of primary teeth?
Formation of fibrous tissue over the erupting tooth – delayed eruption.
However,
If the developing permanent tooth has 1/3 to 2/3 of the root formation completed there will be accelerated eruption.
describe a class I incisor relationship
lower incisor edges occlude with the upper central incisor central plateaus.
describe a class II div 2 incisor relationship
- Lower central incisor edges sit posteriorly relative to the upper central incisor central plateaus.
- The upper central incisors are either proclined, or of an average inclination.
- Often an increased overjet.
describe a class II div 2 incisor relationship
- Lower central incisor edges sit posteriorly relative to the upper central incisor central plateaus.
- Upper central incisors are retroclined.
- Minimal overjet
describe a class III incisor relationship
- Lower central incisor edges sit anteriorly relative to the upper central incisor central plateaus.
- Overjet is reduced or reversed.
