Developing dentition

Question 1

describe the development of primary dentition

Answer 1

6 weeks: tooth development 
3/4 months: tooth germs form
3/6 months: calcification starts
7 months: the first tooth erupts (normally lower A's) 
8 months: lower and uppers A's erupt 
1 year: all incisors erupted 
18 months: D's erupt 
2 years: C's erupt 
3 years: full set of primary dentition

Question 2

state the features of primary teeth

Answer 2

• root completion takes up to 1 or 1 and a half years after tooth eruption
• present until ~6 YO
• frequently incisor spacing (a good thing)
• mixed dentition after 6 years
• symmetrical development is v important

Question 3

describe the development of permanent dentition

Answer 3

• age 6: an eruption of permanent dentition, usually 6’s erupt, then lower 1’s
• 10 years: all permanent incisors come through, D’s and E’s start to be lost
• 12 years: all primary teeth replaced (upper c’s last to be replaced)
• 13 years: 7’s erupt
• 18/19: 8’s erupt
• 21: full set of permanent teeth

Question 4

what are some eruption problems?

Answer 4

• asymmetrical development
• natal teeth: eruption at birth, should be removed as its too sharp for the mother
• delayed eruption

Question 5

what are some causes for a delayed eruption?

Answer 5

• down’s syndrome
• trauma
• abnormal path of eruption
• crowding
• early deciduous loss and bone formation