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.
In orthodontics, there are two major reasons to extract
To provide space to align the remaining teeth in the
presence of severe crowding.
To allow teeth to be moved so that protrusion can
be reduced or so skeletal class II or class III problems
can be camouflaged.
The alternative to extraction in treating dental
crowding is to expand the arches.
The alternative for skeletal problems is to correct the
jaw relationship, by modifying growth or surgery.
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.
Arch length - tooth material discrepancy - may result in
spacing or crowding.
May be due to arch length deficiency.
Tooth material excess - Necessitates extraction.
Less than 4mm arch length discrepancy extraction rarely
5-9 mm arch length discrepancy - non extraction or
extraction, depends on the details of both the hard- and
soft-tissue characteristics of the patient and on how the
final position of the incisors will be controlled.
10 mm or more: extraction almost always required.
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 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 mandible.
Extraction for the Relief of Crowding:-
Extraction for the relief of crowding will
be governed by:
The condition of the teeth
The position of the crowding
The position of the teeth
Fractured, hypoplastic, grossly carious teeth & teeth with
large restorations would be more favorable for extraction
than sound, healthy teeth.
The main consideration is the long term prognosis for the
tooth & the secondary consideration is the appearance of
Abnormal size and form of teeth- may necessitate their
extraction in order to achieve satisfactory results. Eg:
macrodontia, severe hypoplasia , dilaceration and
abnormal crown form.
If crowding is located in one part of the dental arch, it will be
more readily corrected if extractions are carried out in that
part of the arch.
However, crowding of incisors is usually relieved by
extraction of premolars, thus giving a more pleasing final
appearance and occlusal balance.
First premolar, positioned in the center of each quadrant is
usually near the area of crowding.
Teeth which are grossly malpositioned and would be difficult
to align, are often the teeth of choice for extraction.
The position of the apex of the tooth must be considered, as
it is usually more difficult to move the apex than to move the
Removal of a tooth on the opposite side of the same
arch (although not necessarily the antimere) in order to
preserve symmetry. Designed to eliminate centre line
displacements that will require fixed appliances for their
later correction. Balancing extractions are not necessary if
the dental arch is spaced.
Removal of the equivalent tooth in the opposing
arch to maintain buccal occlusion. In a class I
occlusion with crowding in some cases, extraction is
the only treatment needed. Here, the arches being
equal sizes, it would be necessary to extract in both
arches to maintain lateral symmetry ie., a tooth
would need to be removed from four quadrants of
the jaws. Compensating extractions preserve inter
arch relationship by allowing the posterior teeth to
drift forward together.
Wilkinson has advocated the extraction of the 4 first
permanent molars between the ages of 8 ½ and 9
½ years in selected cases on account of their
susceptibility to caries.
He believed that this provided additional space for
third molars and the resulting relief from over
Favors the preservation from caries of the
Drawbacks ofWilkinson Method:
1. Excessive drifting of lower second premolars.
2. Second premolars and second molars rotate
frequently as they erupt following extraction.
3. Deprives operator of adequate anchorage for
4. second molars erupt with mesial tilting to contact
second premolars resulting in inter dental space
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.
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 de-crowding of lower anteriors.
Such spontaneous de-crowding by drifting of teeth is
referred to as Driftodontics, & is less frequent in upper arch.
Extractions carried out for the purpose of treatment.
An interceptive orthodontic procedure usually initiated in the
early mixed dentition when one can recognize and anticipate
potential irregularities in the dentofacial complex.
It is designed to avoid the development of a fully matured
malocclusion in the permanent dentition in severely crowded
Planned extraction of certain deciduous teeth and later
specific permanent teeth in an orderly sequence and
predetermined pattern to guide the erupting permanent
teeth into a more favorable position.
1) Class I malocclusion showing harmony and balance between
skeletal and muscular systems.
2) Arch length deficiency compared to tooth material as
indicated by one of the following cardinal clues:-
Absence of physiologic spacing.
Midline shift of mandibular incisors due to displaced lateral
Uni/ bilateral premature loss of deciduous canines with
Abnormal or asymmetric primary canine root resorption.
Markedly crowded or irregular upper or lower anteriors.
Lingual eruption of lateral incisors.
Mesial eruption of canine over lateral incisors.
Flaring of lower anteriors
Abnormal eruption direction and eruption sequence.
Localized gingival recession of lower incisors.
Class II/Class III malocclusions with skeletal abnormalities.
Class I malocclusion where lack of space is slight and
teeth are only slightly crowded.
When fixed appliance cannot be used to avoid arch
technique of serial extraction:
1. NANCE METHOD:
Sequence of Extraction: (D4C)
1. Deciduous first molars.
2. First Premolar.
3. Deciduous canine.
dewel's method:(CD4) 3 Stages
1. Early extraction of deciduous canines to provide space for
the incisors to assume correct alignment at the expense of
the space for permanent canines.
2. Extraction of the first deciduous molars to permit early
eruption of 1st premolars, especially in mandibular arch where
normal sequence is for deciduous canines i.e., between 9 & 10
3. Extraction of the first premolars to allow space for the
permanent canines to erupt in the spaces formerly occupied
by first premolars.
tweed's method (D4C)
When the patient is between the ages of 7 ½ - 8½ years. Serial
extraction is performed as follows:-
a) Extract all 4 deciduous 1st molars at the age of 8 years. If
mandibular permanent incisors are not blocked out or
severely crowded, Tweed advised maintaining the deciduous
canines in position so that eruption of permanent canine will
not be hastened.
b) When the I premolar teeth erupt to about the level of the
crest of the alveolar mucosa they are extracted.
c)The deciduous canines are also extracted at this time.
Treatment is more physiologic as it involves guidance of teeth
into normal positions using physiologic forces.
It eliminates/ reduces the duration of multi banded fixed
Lesser retention period at completion of treatment.
More stable results; tooth material and arch length are in
Requires clinical judgment. No single approach can be
Treatment time is prolonged; spread out over 2-3 years.
Patient co-operation is vital.
As extraction spaces close gradually, patient has a tendency
to develop tongue thrust.
Choice of teeth to be extracted depends on local conditions
Direction and amount of jaw growth.
Discrepancy between size of dental arches and basal arches.
State of soundness, position and eruption of teeth.
Degree of dentoalveolar prognathism.
Age of patient.
State of dentition as a whole.
The incisors are rarely extracted as a part of orthodontic
therapy, especially the maxillary central incisors
▪ Unfavorably impacted maxillary incisors that cannot be
brought into normal alignment within the arch.
▪ If one of the lateral incisor is congenitally missing,
opposite lateral incisor may be extracted to maintain
▪ Grossly carious incisor that cannot be restored.
▪ Fracture or irreparable damage to incisors by fracture
▪ Incisor with dilacerated root
It is often very tempting to extract a lower incisor to
relieve crowding particularly when its confined to the
anterior segment but its extraction should be avoided as
far as possible because it causes:-
a. Remaining anterior teeth tend to imbricate.
b. Although crowding may be relieved in the short
term, forward movement of buccal teeth leaves incisor
contacts and positions less than ideal.
However, in a few well defined cases, extraction of lower
incisors may be appropriate-
a. When one incisors is completely excluded from the
arch and there are satisfactory approximal contacts
between other incisors.
b. Poor prognosis for mandibular incisors trauma, caries,
bone loss, gingival recession.
c. Lower incisor is severely malpositoned.
The permanent canines are important teeth and are not
frequently extracted as part of orthodontic treatment.
Extraction of canines can cause:-
Flattening of face
Altered facial balance
Change in facial expression.
Some of the conditions under which the canines may have to be
1. Canines highly susceptible to ectopic eruption or impaction
2. Canine that is completely out of the arch with reasonably good
contact between lateral incisor and first premolar
3. premature shedding of a deciduous canine usually indicates
extraction of its fellow on opposite side of the arch
4. Deciduous canines may be extracted as apart of serial extraction
It is the tooth most commonly extracted as part of
orthodontic therapy especially for the relief of crowding
1. It is positioned near the centre of each quadrant of
the dental arch and since is near the site of crowding i.e
space gained by their extraction can be utilized for
correction both in anterior and posterior region.
2. First premolars extraction is least likely to upset
molar occlusion and is the best alternative for
maintaining vertical dimension.
3. The contact that results between
canine and the second premolar is
4. First premolar extraction leaves
behind a posterior segment that
offers adequate anchorage for
retraction of the 6 anterior teeth.
indications for extraction:
1. When second premolar is excluded
completely from the arch due to forward
drift of first permanent molars after early
loss of deciduous second molars.
2. In mild anterior crowding cases, second
premolar extraction is preferred over first
premolar as space closure and vertical
control is easier after anterior alignment.
The first permanent molar has been esteemed as
untouchable from the very beginning of the history of
orthodontics; it is considered as the consistence of the
dentition always at its right position in the arch.
Extraction of first molars is avoided because-
It does not give adequate space in the incisor region.
Deepening of bite.
Poor contact relation between second premolar and
Second premolar and second molar may tip into
Mastication is affected.
Lower second molar is often not removed for the relief of
crowding. Its position at the end of the dental arch means that
it is usually removed from the site of crowding and is not itself
actually malpositioned through crowding.
But extraction may be indicated in the following cases:-
To relieve impaction of second premolars-
To relieve impaction of mandibular third molars-
When permanent second molars are impacted
Extraction of third molars during orthodontic treatment
does not yield space that can be used for de crowding or
reduction of proclination.
Indication for III molar extractions:-
Grossly impacted third molars that are unable to erupt
into ideal position:
The erupting mandibular third molars have been
implicated to be the cause of late lower anterior
crowding, although the evidence is not clear cut
Malformed third molars which interfere with normal
occlusion should be extracted.