Disorders of Teeth

Question 1

3 stages of tooth development

Answer 1

• pre eruptive (crown formation)
• pre-functional (tooth eruption)
• funcitonal (maintenance of occlusion)

Question 2

3 processes of pre-eruptive tooth development

Answer 2

• initiation (dental lamina + tooth germs)
• morphogenesis (shape of tooth)
• histogenesis (mineralised hard tissues)

Question 3

define eruption

Answer 3

the process by which a tooth moves from its developmental position to a functional position in the mouth

Question 4

when does eruption begin in terms of tooth development

Answer 4

once root of tooth begins to form

Question 5

primary teeth eruption dates

Answer 5

6-9 months: As
7-10 months: Bs
12-16 months: Ds
16-20 months: Cs
23-30 months : Es

Question 6

permanent teeth eruption dates

Answer 6

6: 6,1
7: 2
8: 2
9: lower 3
10: 4,5
11: upper 3
12: 7
18: 8s

Question 7

• TOOTH ERUPTION TABLE

genetic cause of cherubism

Answer 7

• genetic autosomal dominant

- SH3BP2 gene, chromosome 4

Question 8

most common teeth affected by impaction

Answer 8

• rare in primary dentition

- most common teeth affected: 8s,lower 4s/5s, upper 3s

Question 9

teeth affected by reimpaction

Answer 9

Es (normally lower)

Question 10

define

a. hyperdontia
b. supernumary teeth
c. supplemental teeth

Answer 10

a. hyperdontia: too many teeth
b. supernumerary teeth: extra teeth, abnormal shape
c. supplemental teeth: extra teeth, normal shape

Question 11

prevalence of supernumerary teeth

Answer 11

1-3% population (permanent dentition)

F>M

Question 12

3 types of supernumerary teeth

Answer 12

• mesiodens: in midline
• paramolar: buccal
• distomolar: behind upper 8s

Question 13

teeth affected by supplemental teeth

Answer 13

Upper 2>lower 5> upper 5