first permanent molar

Question 1

What are implications of losing the first permanent molar?

Answer 1

Disturbs occlusion
Prolonged ortho tx (pts may be unsuitable, also risks become prolonged too)
Assess if all permanent teeth present

Question 2

Why is it more of a problem to extract a lower 6 over an upper 6?

Answer 2

Usually the 7 drops into place for the upper due to a different eruption path

The 7 in the lower arch would-
1. Tilt mesially
2. Rotate mesio lingual
3. Lean lingually
4. Over erupt (upper 6)
The 5 might tilt back
Leaves little spaces- difficult to clean, can’t place tooth
If upper 6 over erupts it stops movement of 7

Question 3

How do you hold the 7s in place?

Answer 3

With a TPA
Trans palatal arch

Question 4

What are factors influencing the success of extracting 6s?

Answer 4

1. Degree of crowding (too much space=teeth get lost on way to eruption)
2. Upper or lower
3. Timing of extraction
4. Balancing/compensating

Question 5

What is alveolar necking?

Answer 5

When a tooth is extracted the width of the bone decreases so theres a thin ridge (even vertical collapse)

Makes space difficult to close as tooth can’t move through and can’t place implant

Question 6

Do you extract straight away or not?

Answer 6

If you temporise and retain, it can act as a space maintainer for ortho tx

If v poor prognosis and causing problems, extract straight away

If x too late- minimal spontaneous space closure
If x too early- 5 moves distally (behind E)

Question 7

What are favourable factors that indicate the ideal timing to extract 6s?

Answer 7

Once you can see the dentine bifurcation of 7s, you know that the eruption path is favourable

Lower 5 engaged in bifurcation of E
Lower 7 mesially angulated
Lower 8 present

Question 8

What is balancing/compensating?

Answer 8

Balancing= extraction in same arch on opposite side

Compensating= extraction in opposite arch on same side

Compensating preferable to avoid over eruption of upper 6
Never balance

Question 9

What should you do if they have poor prognosis of 6 but they’re a class II?

Answer 9

Large OJ
Extract molars early
Correct class II w functional appliance
OR
Retain and incorporate into ortho tx

Question 10

What should you do if they have poor prognosis of 6 but they’re a class III?

Answer 10

Seek opinion
Delay ortho tx to assess mandibular growth
Timing of x can be altered if orthognathic surgery planned