2. Introduction
Painless removal of teeth from its
socket is termed as Extraction. It is one of
the most common methods of gaining
space in the arch.
3. Need For Extraction
• Arch length – tooth material discrepancy :-
Ideally the arch length and tooth material should be in
harmony with each other. If the dentition is too large to fit in
the dental arch without irregularity, it may be necessary to
reduce the dentition size by the extraction of teeth. It is not
normally acceptable to increase the dental arch size, because
the increased dental arch dimension would not be tolerated
by the oral musculature.
4. • Correction of Sagittal Interarch 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 with abnormal upper proclination, it is
advisable to extract teeth only in the upper arch and to retract the
maxillary incisors and canines. In case of the lower arch crowding it
is advisable to extract in both the arches.
Class III cases are usually treated by extracting teeth only in
the lower arch to discourage the forward growth of mandibe.
5. • Extraction for the Relief of Crowding :-
Condition of the teeth - Fractured, hypoplastic, grossly carious
teeth, root canal treated teeth and teeth with large
restorations are preferred for extraction over healthy teeth.
Position of the crowding - Crowding in one part of the arch is
more readily corrected if extractions are done in that part
rather than a remote area of the arch. The first premolar,
positioned in the centre of each quadrant, is usually near the
area of crowding whether in the anterior or buccal segment.
Hence, it is also the tooth most frequently extracted along
with orthodontic treatment.
Position of the teeth - Grossly malpositioned teeth which arc
difficult to align may often be the teeth of choice for
extraction.
7. • 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.
• Compensating Extractions :-
In this procedure extraction of teeth are
carried out in opposing arches to maintain buccal occlusion. In
some Class I crowding cases, it is necessary to extract in both
the arches to maintain lateral symmetry. Compensating
extractions preserve inter-arch relationship by allowing the
posterior teeth to drift forward together.
8. • Phased Extractions :-
It may be possible to effect a change in molar
occlusion by extracting in one arch only, or a few months
earlier than in the other. Thus extractions done in phases, so
called as Phased Extractions.
• 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.
9. • Wilkinson Extraction :-
Wilkinson advocated extraction of all the four first
permanent molars between the age of 8 ½ & 9 years. The basis
of it is the fact that first molars are highly susceptible to caries.
The other benefits of extracting first molars at an early age are:-
– To avoid third molar impactions by providing additional
space for their eruption.
– To reduce crowding in the arch.
Wilkinson‘s extractions are not usually carried out because of various
drawbacks as
—first molar extraction offers limited space for crowding
correction.
—2nd bicuspid & 2nd molar rotate & may tip into the
extraction space.
10. • Stobies Extractions :-
Extractions of two premolars at the same time.
• Serial Extractions :-
Concept was introduced by Kjellgren.
Nance is known as the Father of serial Extractions.
It is defined as Extractions of certain deciduous teeth and
permanent teeth in selected cases to overcome crowding. Usual
sequence of extraction is primary canines, primary first molars &
first premolar.
• Driftodontics :-
This concept is applicable when extraction of the
permanent teeth are done without appliance therapy. Teeth have a
natural tendency to drift into the extraction space.
Extraction of the lower first premolars are often
associated with spontaneous decrowding of lower anteriors. Such
spontaneous decrowding by drifting of teeth is referred to as
Driftodontics, & is less frequent in upper arch.
11. CHOICE OF TEETH FOR EXTRACTION
Choice of teeth to be extracted depends on local
conditions which include:
• Direction and amount of jaw growth.
• Discrepancy between size of dental arches and basal
arches.
• State of soundness, position and eruption of teeth.
• Facial profile.
• Degree of dentoalveolar prognathism.
• Age of patient.
• State of dentition as a whole.