L61. Development of Dentition

Question 1

Give the definition of orthodontics.

Answer 1

Diagnosis and treatment of occlusal abnormalities

Question 2

Briefly describe primary dentition.

Answer 2

Eruption = 6 months to 3 years
Lowers before uppers
a-b-d-c-e

Question 3

Give the ages at which primary teeth erupt.

Answer 3

a - 6m
b - 7m
d - 12m
c - 18m
e - 24m

Question 4

What should be present in primary dentition

Answer 4

Spacing

Question 5

Give the age guidelines for mixed dentition.

Answer 5

6-13 years

Question 6

Which teeth erupt at age 6?

Answer 6

Lower 1s

All 6s

Question 7

Which teeth erupt at age 7?

Answer 7

Upper 1s

Lower 2s

Question 8

Which teeth erupt at age 8?

Answer 8

Upper 2s

Question 9

Which teeth erupt at age 11?

Answer 9

Lower 3s

All 4s

Question 10

Which teeth erupt at age 12?

Answer 10

Upper 3s
All 5s
All 7s

Question 11

What is a crossbite?

Answer 11

When a tooth/teeth sit in the wrong plane

Question 12

Where does arch length increase?

Answer 12

Behind first primary molar to accommodate adult 6,7 and 8.

Question 13

What is transposition?

Answer 13

Tooth is in the wrong place, eg canine and incisor are switched.