Extractions in orthodontics

Question 1

What is the only alternative to extraction?

Answer 1

Expansion
Anterior - procline incisors
then distalise using headgear

Question 2

What is the problem with anterior proclination?

Answer 2

causes bimaxillary proclination:
Affects the appearance, stability, periodontal health
reduces the prognosis of teeth

Question 3

What causes relapse with anterior proclination?

Answer 3

Lips push force back

Question 4

What can happen to posterior teeth if have early non-extraction treatment?

Answer 4

7’s and 8’s can be impacted

Question 5

When may you take out 3rd molars?

Answer 5

In 3 out of 4 cases where teeth have not been removed during treatment there are good reasons for removing wisdom teeth in mid-late teens

Question 6

What are the reasons for extraction?

Answer 6

Relieve crowding 
Correct incisor relationship - reduce an overjet/camouflage in class III
Overbite correction 
To correct the centrlines 
Anchorage

Question 7

What are the principles of extractions in orthodontics?

Answer 7

1. Condition of teeth
2. location of crowding
3. Position of the teeth (crowns/apices)
4. Appliance treatment proposed - patient attitude

Question 8

What is a compromised extraction pattern?

Answer 8

When have to take out the teeth with poor prognosis rather than the ideal teeth (premolars)

Question 9

What does a clinical pink spot mean?

Answer 9

Root resorption

Question 10

If lose an upper central incisor what can be done with the space?

Answer 10

Preserve the space with space maintainer

Close the space - crown on the lateral incisor

Question 11

When would you extact central incisors?

Answer 11

Rarely indicated

If have poor prognosis

Question 12

When would you extract lateral incisors?

Answer 12

Poor prognosis
For Symmetry
If severely displaced

Question 13

When would you extract the tooth close to crowding?

Answer 13

Class III camouflage
Relief of crowding
LR2 displaced

Question 14

What are the problems with lower incisor extractions?

Answer 14

Compromise the occlusion
Increases the overjet and overbite
Increases upper crowding

Question 15

When are canines extracted?

Answer 15

Gross displacement 
Quicker treatment (than alignment if ectopic)

Question 16

What are the problems with canine extractions in the upper arch?

Answer 16

Upper arch: space between 2 and 4 opens, poor aesthetics
Lower arch: poor contact between 2 and 4
Canines have the biggest root and last the longest

Question 17

Why are 1st premolars good to extract?

Answer 17

Good anchorage balance
Good for correction of class II and class III and anterior crowding as close
Dont eant to extract anteriors because of aesthetics
Can do mesial movement of 5’s and 6’s to close space

Question 18

What are the problems with 1st premolar extractions?

Answer 18

May give too much space - 7mm per tooth
Possible effect on patient profile - poor treatment planning and poor mechnics
No evidence

Question 19

What is the problem with extraction of 2nd premolars?

Answer 19

Changes anchorage balance
Take out upper 5’s, more mesial movement of molars - less space anteriorly, more anterior teeth to distalise
Larger anchor unit anteriorly - determined by having a larger root SA anteriorly

Question 20

Why extract 1st molars? Problems?

Answer 20

Removes teeth of poor prognosis

Larger teeth, takes longer to close the space, need to retract all the teeth to resolve any crowding

Question 21

When to extract 2nd molars?

Answer 21

If 3rd molars are impacted
7’s of poor prognosis
Cannot be used to releive anterior crowding - in lower arch have nothing to distalise the 6’s

Question 22

What are the alternative asymmetric extractions?

Answer 22

Within the arch
Between the arches
Depends on the malocclusion - if class II usually extract upper 4 and lower 5

Question 23

How does the appliance treatment proposed have an effect on extractions?

Answer 23

If using a removable appliance then can only tip teeth, dont extract any teeth