Extractions

Question 1

What are the reasons for extraction?

Answer 1

1. Create space to relieve crowding
2. Space to correct the incisor relationship - usually overjet reduction
3. Provision of anchorage to move teeth

Question 2

How do extractions relieve crowding?

Answer 2

The relieve crowding without the need for arch expansion or incisor proclination, which take teeth out the soft tissue neutral zone

Question 3

What do you extract to reduce overjet?

Answer 3

Premolars. make space for incisor retraction

Question 4

What is loss of anchorage?

Answer 4

When premolars are extracted, incisors not only move distally, but posterior teeth move mesially due to the effect of equal and opposite force

Question 5

What does headgear ?

Answer 5

Provide anchorage to prevent posterior teeth moving forward, so as to maintain space to sufficiently retract incisors

Question 6

Which factors influence the choice of extraction of teeth for orthodontics?

Answer 6

1. Dental health - caries, perio, trauma

2. The amount of space and anchorage required ie extracting teeth nearer to the problem creates more space and anchorage

Question 7

Why extract 4s over 5s

Answer 7

4s better if you need more space and when there is more anterior crowding or a bigger overjet to correct

Question 8

Mild crowding

Answer 8

1-4mm (Non-extraction or extract 5s)

Question 9

Moderate crowding

Answer 9

5-8 mm (extract 4s or 5s)

Question 10

Severe crowding

Answer 10

9+ mm (extract 4s)

Question 11

Do you plan upper or lower arch extractions first?

Answer 11

Lower arch. You plan upper arch extractions to fit around the upper arch

Question 12

What happens if the lower arch is non-extraction?

Answer 12

The upper arch is either non-extraction or upper premolar extraction, If upper premolars are extracted, the molars will finish class 2