extractions in ortho

Question 1

What is space needed?

Answer 1

Relieves crowding
Corrects incisor relationships (reduce OJ, camouflage in class II)I
Corrects over bite
Corrects centre line
Anchorage

Question 2

How can space be created?

Answer 2

Expansion
Extraction
Interdental reduction/stripping (with a disc)

Question 3

How can you have expansion?

Answer 3

3 directions-
Lateral- eg. quad helix
Anterior- causes bimaxillary proclination (issue w appearance, stability- out of zone of equilibrium, perio)
Posterior- eg. head gear

Question 4

What are the principles of extraction?

Answer 4

1. Condition of teeth
2. Location of crowding
3. Position of teeth (crown/apices)
4. Appliance tx proposal

Patient attitude

Question 5

What is the choice of extraction?

Answer 5

Most common- pre molars

First molar- if poor prognosis, however leaves large space so bring 7s forward which takes long time

Second molar- v rare but if poor p., impacted 8s, can’t resolve anterior crowding
Third molar- for a mandibular osteotomy (6 months before)

Centrals- v rare, if poor p.
Laterals- poor p., symmetry, severely displaced

Canines (most likely to be ectopic and weird position)- if gross displacement, if poor candidate for ortho

Question 6

What do you do with a previous loss of upper central incisor?

Answer 6

1. Preserve the space
2. Close space (crown the lateral)

Question 7

What are the problems with lower incisor extractions?

Answer 7

Compromises occlusion
Increased OJ and OB
Increased upper crowding

Works for class III camouflage

Question 8

What are problems with canine extractions?

Answer 8

UPPER- 4 and 2 aren’t designed to be in contact w each other so poor aesthetics

LOWER- poor contact between 2 and 4

Question 9

Why is extraction of first premolars popular?

Answer 9

Good anchorage balance
Close to anteriors so good to help their malocclusion

Question 10

What are problems with first premolar extractions?

Answer 10

May give too much space (7mm per tooth)
May affect pt profile (little evidence)

Question 11

Are second premolar extractions suitable?

Answer 11

Changes anchorage balance- more teeth anterior
Used in mild cases- close space from behind, bring posteriors forward as large anchor unit anteriorly

Question 12

What are alternative options of extraction?

Answer 12

ASYMMETRIC- within/between arches, depends on malocclusion and anchorage