Extractions in Ortho

Question 1

How can space be created w/o XLA?

Answer 1

Expansion

Question 2

What directions can expansion occur?

Answer 2

Lateral, anterior, posterior

Question 3

What does anterior expansion cause?

Answer 3

Bimaxillary proclination

Question 4

Problems bimaxillary proclination?

Answer 4

If significant: appearance
Stability: zone of stability - if out of zone forces not balanced - higher chance relapse
Periodontal health: occlusal forces - if proclined force doesn’t act via whole tooth

Question 5

Problems with expanding in posterior direction w/o XLA?

Answer 5

Not enough room for teeth to erupt

7s/8s can become impacted

Question 6

Reasons for XLA in orthodontic?

Answer 6

Crowding
Correct incisor relationship
Overbite correction
Correct centrelines

Question 7

Thought behind removing teeth for overbite correction?

Answer 7

Posterior teeth XLA

Auto-rotation of mandible

Question 8

What are 5 principles of XLA in ortho?

Answer 8

1. Condition of teeth (poor prognosis XLA)
2. Location crowding
3. Position of teeth (crowns/ apices)
4. Appliance tx proposed
5. Pt attitude - OH

CLPAP

Char Likes Partying At Paris

Question 9

What teeth are most commonly extracted?

Answer 9

Premolars

Question 10

What to consider when thinking about condition of teeth?

Answer 10

Always take out teeth w/ worse prognosis - even if not ideal for mechanics or prolongs tx
If pink tinge laterals - likely buccal impacted canine causing root resorption
If poor prognosis laterals - may take out other for symmetry

Question 11

How to tx plan if pt had previous loss of upper incisors?

Answer 11

Space maintenance

1. Prosthetics - build into appliance (maintain space and aesthetic)
2. Restorative tx - bridge/ implant

Space closure
1. Not as common - gives poor aesthetic due to morphological discrepancies

Question 12

Thoughts about extractions of incisors?

Answer 12

Centrals - very rarely indicated - only if poor prognosis

Laterals - poor prognosis/ symmetry or severely displaced

Question 13

What to consider when thinking about location of crowding?

Answer 13

Remove teeth in area of crowding

If remove laterals in class II can help
If remove laterals in class I - can increase overjet

Question 14

Problems with lower incisor extractions?

Answer 14

Can compromise occlusion, increase overjet and overbite, increase upper crowding

Question 15

Benefit and disadvantages of canine XLA?

Answer 15

Adv: if grossly displaced or need quicker tx

Disadvantages:

1. Upper arch - space between 2 and 4 open = poor aesthetic
2. Lower arch - poor contact 2 and 4

Question 16

Adv of premolar extractions?

Answer 16

1. Good anchorage balance
2. Retract anterior teeth
3. Bring posterior teeth forward
4. Allows option to bring buccal segment anterior

ARPB
Alex Run Past Beth

Question 17

Which premolar more ideal?

Answer 17

1st premolar

XLA 2nd premolar not as effective - change anchorage balance

Question 18

Problems w/ XLA premolars?

Answer 18

May give too much space - 7mm per tooth

Possible effect pt profile

Question 19

When extract first molar?

Answer 19

Poor prognosis

But can extend tx time

Question 20

When extract second molars?

Answer 20

Third molars impacted
Poor prognosis
Can’t be used to resolve anterior crowding