This document discusses extraction procedures in orthodontic treatment. It begins by defining extraction as the painless removal of teeth from their socket. Extractions may be needed to address tooth-arch length discrepancies, correct sagittal inter-arch relationships, or due to abnormal tooth size/form. Different extraction procedures are discussed, including balancing, compensating, enforced, and therapeutic extractions. Factors in choosing which teeth to extract include arch length issues, jaw growth, tooth condition, and facial profile. Common teeth extracted for orthodontic reasons are premolars, as their removal provides space while maintaining occlusion. Other teeth may be extracted depending on the specific orthodontic needs of each case.
2. CONTENTS
INTRODUCTION
THE NEED FOR EXTRACTION
DIFFERENT EXTRACTION PROCEDURES
CHOICE OF TEETH FOR EXTRACTION
CONCLUSION
BIBLIOGRAPHY
3. INTRODUCTION
Painless removal of teeth from its socket is termed as
Extraction.
The nature of malocclusion and the age of the
patient may be important factors in deciding whether
extraction needed or not.
Extractions in orthodontics include serial extraction
as an interceptive procedure and therapeutic
extractions as a space gaining procedure. To extract or
not to extract has always been and will always remain a
controversy in orthodontics.
4. THE NEED FOR EXTRACTION
I. ARCH LENGTH- TOOTH MATERIAL DISCREPANCY
Ideally the arch length and tooth material should be in
harmony with each other. The sizes of the dentition and
arch length are usually genetically determined. The
presence of tooth material in excess of the arch length can
result in crowding of teeth or proclination of anteriors.
In many cases the tooth material-arch length
disproportion cannot be treated by increasing the arch
length. Hence reduction of tooth material is the only
alternative. Extraction of one or more teeth is required in
case of severe tooth material - arch length discrepancy.
5. Signs of arch length deficiency
Absence of physiologic spacing in the primary dentition .
Ectopic eruption of teeth .
Localized gingival recession in the lower anterior .
Malpositioned or impacted lateral incisors that erupt
palatally out of the arch.
Markedly irregular or crowded upper and lower anteriors
Lower anterior flaring .
Unilateral or bilateral premature loss of deciduous
canine with midline shift.
6. II. CORRECTION OF SAGITTAL INTER-ARCH
RELATIONSHIP
In a Class I malocclusion it is preferable to extract in
both the arches because it is not advisable to discourage
the development of only one arch more than the other.
In most Class II cases, abnormal upper proclination, it is
advisable to extract teeth only in the upper arch . In case
of lower arch crowding it is advisable to extract in both
arches
Class III cases are usually treated by extracting teeth only
in the lower arch or by extraction in both arches
7. III. ABNORMAL SIZE AND FORM OF TEETH
Teeth that are abnormal in size or form may
necessitate their extraction in order to achieve
satisfactory occlusion. Such anomalies include
macrodontia, severely hypoplastic teeth, dilaceration
and abnormal crown morphology.
IV. SKELETAL JAW MALRELATIONS
Severe skeletal malrelationship of the jaws may not be
satisfactorily treated using orthodontic appliances
alone. Surgical resective procedures along with
extraction maybe required.
8. DIFFERENT EXTRACTION PROCEDURE
1 Balancing extractions
2 Compensating extractions
3 Enforced extractions
4 Wilkinson extractions
5 Therapeutic extractions
1 )Balancing Extractions
Balancing extractions may be defined as the removal of a tooth on the opposite
side of the same arch (although not necessarily the antimere) in order to
preserve symmetry.
2)Compensating Extractions
Removal of the equivalent tooth in the opposing arch to maintain buccal
occlusion. In some Class I crowding cases, it is necessary to extract in both the
arches to maintain lateral symmetry.
9. Compensating extractions preserve inter arch
relationship by allowing the posterior teeth to drift
forward together.
3)Enforced Extractions
These extractions are carried out because they are
necessary as in the case of grossly decayed teeth, poor
periodontal status, fractured tooth, impacted tooth,
etc.
4)Wilkinson Extraction
Wilkinson advocated extraction of all the four first
permanent molars between the age of 8½ and 9 years.
The basis for such extractions is the fact that first
molars are highly susceptible to caries.
10. The other benefits of extracting first molars at an
early age are:
o To avoid third molar impactions by providing
additional space for their eruption.
o To reduce crowding in the arch
Wilkinson's extractions are not usually carried out
because of various drawbacks as
o First molar extraction offers limited space for
crowding correction
o Adjacent teeth tip into the extraction space
5)Therapeutic Extractions
These are extractions carried out for the purpose of
treatment.
11. CHOICE OF TEETH FOR EXTRACTION
Choice of teeth to be extracted depends on local
conditions which include:
- Direction and amount of jaw growth
-Arch length tooth material discrepancy
-State of soundness, position and eruption of teeth
- Facial profile
- Age of patient
-The entire dentition
12. I EXTRACTION OF UPPER INCISORS
An unfavourably impacted upper incisor that cannot be
brought to normal alignment.
A buccally/lingually blocked out lateral incisor with good
contact between the central incisor and canine can be extracted
If one of the lateral incisors is congenitally missing, the
opposite lateral may have to be extracted in order to maintain
arch symmetry.
A grossly carious incisor that cannot be restored may have to
be sacrificed.
Malformations of incisor crowns that cannot be restored by
prosthesis may necessitate their extraction
Trauma or irreparable damage to incisors by fracture may
indicate their removal.
An incisor with dilacerated root cannot be efficiently moved by
orthodontic therapy. It is hence preferable to extract them.
13.
14. II EXTRACTION OF LOWER INCISORS
Extraction of lower incisors should as far as possible be
avoided.
o Narrowing of lower inter-canine width
o Retroclination of lower incisors
o Deep bite
o Re-appearance of crowding. This leads to a collapse of
the lower arch.
o The reduction in lower inter-canine width often leads
to a secondary reduction in upper inter-canine width
resulting in upper anterior crowding
15.
16. INDICATIONS
A. If one of the incisors is completely out of the arch
with good inter-dental contact between the rest of the
teeth .
B. A lower incisor that was traumatized, or exhibiting
severe caries, gingival recession or bone loss may have a
poor prognosis.
C. Presence of severe arch length deficiency is often
characterized by the presence of fan shaped flaring out
of the lower incisor crowns
D. In mild Class III cases with lower incisor crowding,
one of the lower incisors may be extracted to achieve
normal overjet, overbite and to relieve crowding.
E. Treatment of Class I cases with moderate lower labial
segment crowding of up to 5 mm (i.e. the size of a lower
incisor) may be treated with loss of a lower incisor.
17. III EXTRACTION OF CANINES
Not frequently extracted
Extraction of canine causes
- Flattening of face
- Altered facial balance
- Change in expression
- Contact between the premolar and lateral incisor is
rarely satisfactory.
18.
19. INDICATIONS
A. Unfavourably impacted canines or canines that have
erupted in unusual locations may have to be removed.
B. A canine that is completely out of the arch with
reasonably good contact between the lateral incisor and
first premolar is an indication for its extraction
C. Premature shedding of a deciduous canine usually
indicates the extraction of its fellow on the opposite side
of the arch to restore symmetry.
D. In Class II cases if the lower deciduous canines are
shed early, the upper deciduous canines should also be
removed so as to avoid worsening of the post-normalcy
(Class II tendency).
E. In Class III cases if the upper deciduous canines are
shed early, it may necessitate the extraction of the lower
deciduous canines to avoid worsening of the pre
normalcy (Class III tendency)
F. Deciduous canines may be extracted as a part of serial
20. IV EXTRACTION OF FIRST PREMOLARS
The first premolars are the most commonly extracted
teeth as part of orthodontic treatment.
The reason for their extraction is as follows:
A. Their location in the arch is such that the space
gained by their extraction can be utilized for
correction both in the anterior as well as the posterior
region.
B. The contact that results between the canine and
second premolar is satisfactory.
C. The extraction of the first premolar leaves behind a
posterior segment that offers adequate anchorage for
the retraction of the six anterior teeth.
21.
22. The following are some of the indications for first
premolar extraction:
A. They are the teeth of choice for extraction to
relieve moderate to severe anterior crowding of the
upper or lower arch
B. The first premolars are extracted for correction
of moderate to severe anterior proclination as in a
Class II, division 1 malocclusion or a Class I
bidental protrusion
23. V EXTRACTION OF SECOND PREMOLARS
INDICATIONS
A. The extraction of second premolars instead of the first
premolars results in the anchorage of the anterior
segment being strengthened. Thus an environment is
created that favours mesial movement of the posterior
teeth. The second premolars are usually extracted to treat
mild anterior crowding. The remaining space can be
closed by controlled mesial movement of the molars.
B. The second premolars are usually extracted when 4-5
mm of anchorage loss is deliberately desired.
C. Whenever the second premolars are unfavourably
impacted, it is preferred to extract them rather than the
first premolars
D. If extractions are to be undertaken in open bite cases,
it is preferable to extract the second premolars as their
extraction encourages deepening of the bite.
24. E. In case of grossly carious or deeply filled second
premolars, it is wise to extract them and preserve the
first premolars.
25. VI EXTRACTION OF FIRST MOLARS
Extraction of the first permanent molars is avoided for
the following reasons:
A. The extraction of the first molar does not give
adequate space in the incisor region.
B. The extraction of the first molar results in deepening
of the bite.
C. The second premolar and molar may tip into the
extraction space.
D. Mastication may be affected.
INDICATIONS
A. Minimal space requirement for correction of mild
anterior crowding or mild proclination.
B. Grossly decayed molar or heavily filled teeth.
C. Open bite cases can benefit from extraction of first
molar, as there is a tendency for the bite to deepen after
extraction of first molars
26. VII EXTRACTION OF SECOND MOLARS
INDICATIONS
A. To prevent third molar impaction: The removal of
second molars has been advocated for the prevention of
lower third molar impaction. The cases that benefit from
such extractions are those where the third molars are
upright or not tipped mesially more than 30°. Upper
second molar extraction if carried out prior to the
eruption of the third molars, results in satisfactory third
molar position.
B. To relieve impaction of second premolar: The
premature loss of second deciduous molars is usually
followed by forward drift of the first permanent molars
leaving inadequate space for the second bicuspids to
erupt. The extraction of second molars in such cases may
allow the distal movement of the first permanent molars
thereby offering sufficient space for the second
premolars to erupt.
27. C. Lower incisor crowding: Very mild crowding in the
anterior part of the arch can be relieved by extraction
of the second molars. Some authors suggest that
extraction of second molars minimizes anterior
imbrication and crowding
D. To enable distalization of first molars: In cases
where the first permanent molars are to be distalized,
the extraction of second molars can benefit the
procedure.
E. Open bite cases: The extraction of the second
molars deepens the bite. Thus they can be considered
in open bite cases.
28. VIII EXTRACTION OF THIRD MOLARS
Extraction of third molars during orthodontic
treatment does not yield space that can be used for
decrowding or reduction of proclination.
Third molars are extracted for other reasons as follows:
I. Grossly impacted
II. Grossly malformed
III. Eruption of third molars cause late lower anterior
crowding.
29. CONCLUSION
Orthodontic tooth extraction should always be
planned with consideration of width and length of the
face ,the oral hygiene , carious activity , periodontal
involvement , malformed crown , length and health of
the root of the teeth , prognosis of the impacted tooth
, supernumeraries and hypodontia.