first permanent molars ortho

Question 1

when is the best time to extract the 6

Answer 1

• Age 8 ½ to 10 yrs
• Class I occlusion
• Mild incisor crowding
• all permanent teeth present
  bifurcation of the lower 7 is visible
  lead to spontenous space closure

Question 2

implications for loss of 1st permanent molar

Answer 2

disturbs occlusion (can affect how other teeth come into position)
orthodontic tx prolonged and difficult (risk of decalcification , devitalisation root resorption of teeth around)
patients may be unsuitable for prolonged tx
assess if all permanent teeth present

Question 3

occlusion disturbance after extraction of 6

Answer 3

7 eruption path difference
problem with lower - tends to :
- 1)	tilts mesially
2)	rotates mesio-lingually
3)	leans lingually
4)	upper 6 over eruption

• can get plaque retention , not enough space for bridge, 5 may distalise

Question 4

factors which influence succsess

Answer 4

degree of crowding
upper or lower (lower more problems with occlusion)
timing of extraction
balancing or compensating extractions

Question 5

what does extraction timing depend on

Answer 5

quality of the molars

Question 6

when is immediate extraction indicated

Answer 6

symptomatic teeth

all permanent teeth in

Question 7

what happens if the lower 6s removed prematurley

Answer 7

minimal spontaneous space closure

5 moves distally

Question 8

other favourable factors when to extract 6 for spontaneous space closure

Answer 8

lower 5 engaged in bifurcation of E
lower 7 medially angulated
lower 8 present

Question 9

balancing extractions

Answer 9

extraction in same arch opposite side

but little effe t on the midline as very far back, generally not done unless GA to relieve extracting

Question 10

compensating extractions

Answer 10

extraction in the opposite arch on the same side

need to check if upper 6 will over erupt

Question 11

alveolar necking

Answer 11

narrowing of bone
can be width way
harder to close space
tooth moves through cancellous bone therefore without much will struggle, hard to place implant too

Question 12

factors to consider prior to ex

Answer 12

degree of crowding
hypodontia
different effects for upper vs lower
appropriate timing of extraction
never balance but consider compensating