Introduction to Orthodontics Fifth Year

1. Therapeutic Extraction

2. Outline

Indications:
ِِTo relieve crowding.
To correct anteroposterior dental arch relationship.
To improve facial esthetics.

Consideration in Therapeutic Extraction:
Condition of the teeth.
Position of the teeth.
Degree and position of the crowding.
April 28, 2012
Dr. Ahmed Basyouni
2

3. Outline
 Choice
of teeth for Extraction:
Incisors:
Canines:
First premolars:
Second premolars:
First permanent molar:
Second permanent molar:
Third molar:
April 28, 2012
Dr. Ahmed Basyouni
3

4. Indications
A. To relieve crowding
B. To correct anteroposterior dental arch
relationship
C. To improve facial esthetics.
April 28, 2012
Dr. Ahmed Basyouni
4

5. A. To relieve crowding:
If the dentition is too large to fit in the
dental arch without irregularity, it is necessary
to reduce the dentition size by extraction of
teeth. It is not normally accepted to increase
size of the dental arch, except in certain cases,
because this would not be tolerated by oral
musculature.
April 28, 2012
Dr. Ahmed Basyouni
5

6. A. To relieve crowding:
CLASS I EXTRACTION CASE
WITH SEVERE CROWDING
April 28, 2012
Dr. Ahmed Basyouni
6

7. B. Extraction for correction anteroposterior
dental arch relationship:
It is frequently necessary to remove teeth to give
space for correction of discrepancies in arch
relationship. For example, in Class II relationship,
when upp. Arch is too far forward in relation to
lower. The upp. anterior segment is moved back
during treatment, after extraction to provide space
for retraction of the anterior teeth.
April 28, 2012
Dr. Ahmed Basyouni
7

8. B. Extraction for correction anteroposterior dental arch relationship:
CLASS II, div. 1
subdivision right,
MALOCCLUSION
EXTRACTION CASE
EXTRACTION OF
UPPER FIRST PREMOLARS
+
LOWER SECOND
PREMOLARS
April 28, 2012
Dr. Ahmed Basyouni
8

9. C. Extraction for improvement of facial
esthetics:
It is usually done in cases of Class I Angle’s
malocclusion with bimaxillary dentoalveolar
prognathism.
April 28, 2012
Dr. Ahmed Basyouni
9

10. C. Extraction for improvement of facial esthetics:
CLASS I EXTRACTION CASE
CROWDING
DENTAL PROTRUSION
April 28, 2012
Dr. Ahmed Basyouni
10

11. Consideration in Therapeutic Extraction



Condition of the teeth
Position of the teeth
Degree and position of the crowding
April 28, 2012
Dr. Ahmed Basyouni
11

12. 
Condition of the teeth:
Fractured, hypoplastic, badly carious teeth and teeth
with extensive restoration, all more favourable for
extraction than sound healthy teeth. Tooth condition
is the overriding factor, even treatment would be
more difficult or prolonged.
April 28, 2012
Dr. Ahmed Basyouni
12

13. 
Position of the teeth:
Grossly malposed teeth would be difficult to align are
often the teeth of choice for extraction. In particular,
position of the apex of the tooth must be considered,
as it is usually more difficult to move the apex than to
move the crown.
April 28, 2012
Dr. Ahmed Basyouni
13

14. 
Degree and position of the crowding:
If crowding is located in one part of the arch, it would
be more favourable, if extraction carried out in that
part, rather than in remote uncrowded part. However,
this principle is not considered a rule, e.g. crowding
of the incisors is usually relieved by extraction of
premolars. This usually gives more pleasing final
appearance, and occlusal balance than removal of the
incisors.
April 28, 2012
Dr. Ahmed Basyouni
14

15. Choice of teeth for Extraction

Incisors:
1. Upper central incisors are rarely extracted for relief
of crowding, unless their condition is the overriding
factor (severely fractured). In such cases, lateral
incisors may be aligned and crowned to simulate
missing central incisors.
The usual reason for removing upper lateral incisors
are:
a) Severe malposition of the tooth.
b) Malformation of the tooth.
April 28, 2012
Dr. Ahmed Basyouni
15

16. Choice of teeth for Extraction
Incisors:
2. Lower incisors, as a rule removal of a lower
incisor from an imbricated arch is to be
avoided as this will result in increased curve of
spee, over-eruption of anterior teeth and
decrease of the inter-canine width. But,
extraction of a lower incisor can be made if it
is the only tooth outside the arch alignment
and / or there is gum stripping and lacking of
supporting alveolar bone around the tooth.
April 28, 2012
Dr. Ahmed Basyouni
16

17. Choice of teeth for Extraction
Incisors:
April 28, 2012
Dr. Ahmed Basyouni
17

18. 
Canines:
Upper canine is removed only, if it is severely
malpositioned or impacted. This may be
developmental malposition or due to severe
crowding. Position of the apex is the prime
consideration.
April 28, 2012
Dr. Ahmed Basyouni
18

19. April 28, 2012
Dr. Ahmed Basyouni
19

20. 
First premolars:
The first premolar is the tooth most commonly
removed for relief of crowding. It is positioned near
the center of each quadrant of the dental arch and is
therefore near the site of crowding. Another
important factor, second premolar has same shape
and makes a similar contact with the canine. So, loss
of the first premolar does not affect quality of contact
between teeth.
April 28, 2012
Dr. Ahmed Basyouni
20

21. First premolars:
April 28, 2012
Dr. Ahmed Basyouni
21

22. 
Second premolars:
Removal of second premolar for relief of crowding is
usually undertaken when the tooth is itself
malpositioned through crowding. As it erupts after
first premolar and first permanent molar, it may be
completely blocked out from the dental arch.
April 28, 2012
Dr. Ahmed Basyouni
22

23. Second premolars:
Class II, Extraction treatment
EXTRACTION OF
UPPER FIRST PREMOLARS +
LOWER SECOND PREMOLARS
April 28, 2012
Dr. Ahmed Basyouni
23

24. 
First permanent molar:
Not usually the tooth of choice for extraction. If
extraction is necessary due to caries, two situations
exist which control timing of the extraction:
a) if no space is required for alignment of the anterior
segment, extraction should be carried out before
second molar erupts.
b) if space is required for alignment of the anterior
segment, extraction should be carried out after
eruption of the second molar.
April 28, 2012
Dr. Ahmed Basyouni
24

25. First permanent molar:
April 28, 2012
Dr. Ahmed Basyouni
25

26. 
Second permanent molar:
The second permanent molar is not often removed for
the relief of crowding. It is sometimes, removed when
first permanent molars have moved forward leaving
insufficient space for eruption of second premolars.
Removal of second molar will allow distal movement
of first molar to increase premolar space. In general,
extraction of second molar does not allow much
spontaneous relief of crowding but may relieve third
molar impaction if third molar is not severely inclined
mesially.
April 28, 2012
Dr. Ahmed Basyouni
26

27. 
Third molar:
Extraction of third molars has been advocated by
some orthodontists to prevent or relief potential
crowding in the dental arch specially in the incisor
area.
April 28, 2012
Dr. Ahmed Basyouni
27

28. Serial Extraction

Indication:
Class I malocclusion with severe crowding of
upper & lower permanent incisors in the mixed
dentition stage.
April 28, 2012
Dr. Ahmed Basyouni
28

29. Serial Extraction

Contraindication:
1. Congenital missing second premolars.
2. Extensive caries of permanent first molars.
April 28, 2012
Dr. Ahmed Basyouni
29

30. Serial Extraction
Timing

At 8 years old:
Extract
C
C
For eruption 2
2
April 28, 2012
C
C
2
2
Dr. Ahmed Basyouni
30

31. Serial Extraction

At 9 years old:
Extract
D
D
3
3
For eruption
April 28, 2012
Dr. Ahmed Basyouni
31

32. Serial Extraction

At 10 ½ years old:
Extract
D
For eruption 4
April 28, 2012
D
4
Dr. Ahmed Basyouni
32

33. Serial Extraction

At 11 years old:
Extract
E
E
For eruption 5
4
April 28, 2012
E
E
5
4
Dr. Ahmed Basyouni
33

34. Serial Extraction

At 11 ½ years old:
Extract
4
4
For eruption
4
4
3
3
5
April 28, 2012
5
Dr. Ahmed Basyouni
34

35. Summary

Indications:
A. To relieve crowding
B. To correct anteroposterior dental arch
relationship
C. To improve facial esthetics.

Consideration in Therapeutic Extraction:
Condition of the teeth
Position of the teeth
Degree and position of the crowding
April 28, 2012
Dr. Ahmed Basyouni
35

36. Summary

Choice of teeth for Extraction:
Incisors:
Canines:
First premolars:
Second premolars:
First permanent molar:
Second permanent molar:
Third molar:
April 28, 2012
Dr. Ahmed Basyouni
36

37. Serial Extraction



Indication:
Contraindication:
Timing:
April 28, 2012
Dr. Ahmed Basyouni
37

38. April 28, 2012
Dr. Ahmed Basyouni
38