Extraction in orthodontics /certified fixed orthodontic courses by Indian dental academy

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Extractions in
Orthodontics
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

"To extract or not to extract" may not have quite the significance of
"To be or not to be," but for 100 years it has been a key question in
planning orthodontic treatment.
There are two major reasons to extract teeth:
(1) To provide space to align the remaining teeth in the presence of
severe crowding,
(2) To allow teeth to be moved (usually, incisors to be retracted) so
protrusion can be reduced or so skeletal Class II or Class III problems
can be camouflaged.
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The Great Extraction Controversy of the 1920s
Edward Angle struggled with both facial esthetics and stability of result as potential
complications in his efforts to achieve an idealized normal occlusion.
Systematized and organized.
Suggested extractions in earlier works.(1887).
By 1907, strongly opposed extractions.
His dogmatic views dominated for next 30yrs in America
Calvin case argued in favour of extractions

The Re-introduction of Extraction in Mid-Century
By the 1930s, relapse after non-extraction treatment was frequently
observed. At this time soon after Angle's death, one of his last students,
Charles Tweed, decided to re-treat with extraction a number of his
patients who had experienced relapse.
Four first premolar teeth were removed and the teeth were aligned and
retracted. Tweed's dramatic public presentation of consecutively
treated cases with premolar extraction caused a
revolution in American orthodontic thinking and led to the
widespread reintroduction of extraction into orthodontic
therapy by the late 1940s.
Raymond Begg in Australia, also concluded that non-extraction
treatment was unstable

Breeding experiments with animals, of which Stockard's widely
publicized results from crossbreeding dogs were most influential,
showed conclusively that malocclusion could be inherited
Rather than developing the (non-existent)
It appeared that it was necessary for the orthodontist to recognize
genetically determined disparities between tooth size and jaw size, or to
acknowledge that the lack of proximal wear on teeth produced tooth
size-jaw size discrepancies during development. In either case,
extraction was frequently necessary.
By the early 1960s, more than half the American patients undergoing
orthodontic treatment had extraction of some teeth.

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• Increased ability to move teeth under better control:
ever-expanding choice of extraction.
Factors affecting choice of extraction
1. Treatment objectives
2. Type of malocclusion
3. Esthetics (large chin button, prominent nose)
4. Growth pattern.
5. Conditions of teeth.(caries, multifilled teeth,
impacted, ectopic, severe rotation)
6. Health of supporting tissues.

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Facial profile alteration:
– Maxi retraction of U&L anteriors: 4s (laterals)
– Lesser retraction in lower face: U4s and L5s
– Less overall retraction: 5s or 6s.
Deep anterior overbite:
– Closer.( Mechanically easier to level, as spaces are
closed). incisors – min time and effort.
Open bite:
– 5 or 6 Xn. Accentuate the curve of Spee.
GRABER: Removal of 5s in mandibular arch preferable.
‘.’ reduces the tendency of relapse of openbite &lingually
inclined incisors seen occasionally with Xn of 4s.

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Extraction of Ist premolars.
ADVANTAGES :
• Erupts before any other post teeth, after 6.
• Eruptive sequence : Xn at proper time.
• Strategically located close to the incisors.
• Center of each half of arch .’. Ant & post crowding.
• Protraction of molars not required.
• 4 Xn adequate anchorage for retraction of 6 teeth.
• Contact b/w canine and 2nd
premolar satisfactory.

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1. Convex profile with
severe crowding.
2. Class II div I with deep
anterior bite.
3. Class I with severe
crowding.
4. Class I with bimaxillary
protrusion.
Indications for I st premolar extraction:

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Indications for I st premolar extraction.

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Extraction of 2nd
premolars:
History:
Henry(1965)
1.mild degree of crowding & excellent profile.
2.No crowding and fullness of lips.
Begg: unless carious or poorly formed.
Nance: Ist person.Mild discrepancy.
Avoids dished-in-face & less tendency for relapse.
Carey: 2.5-5mm

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• DEWEL: Xn creates more space in borderline cases, closed
by reducing the anchorage value of buccal segments
• LOGAN:
• U4 more esthetic than 5
• Contact b/w 4 and 6 tended to stay closed.
• Reduced possibility of buccal/lingual furrows in Xn
site ‘.’ of rapid closure.
• Closure of ant open bite, by reducing post vertical
dimension.
• De CASTRO: 3 independent segments.
– 5s Xed only post segment shortened.
– 4s Xed, both segments shortened- functional
integrity of the dentition.

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INDICATIONS FOR 2ND
PREMOLAR EXTRACTION
1.Good profile+mild crowding
2.flat profile+moderate crowding
3.Class II div 1 on skeletal class I
+mild crowding.
4. Mild Class III inter-arch
relation+mild crowding in U arch.
5.Congenitally missing,impacted.
6. Grossly destructed/heavy restn.
7. Abnormal root morphology.
8. Open bite.

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Extraction of 2nd
premolars:
ADVANTAGES:
1. Original facial contours
retained without reduction of
lip profile.

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Ist Molar Extraction:
• Avoided:
Not provide adequate space in the ant region.
5 & 7 may tip in the Xn space.
Deepening of bite.
Masticatory efficiency.

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Carious- beyond restorationCarious- beyond restoration
RC Treated, - than a perfectly good premolar.RC Treated, - than a perfectly good premolar.
Multi filled teeth- crown.Multi filled teeth- crown.
Premature Xn of 6, to preserve symmetry.Premature Xn of 6, to preserve symmetry.
Facial considerations: large chin buttons&/ prominentFacial considerations: large chin buttons&/ prominent
nosenose
(4- dished-in)(4- dished-in)
((rationale: farther back less facial change)rationale: farther back less facial change)
Open bite cases.Open bite cases.
Indications:

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Ist Molar Extraction:
• Not to allow U7 locked behind L7.
Horizontal elastics – until danger of locking has passed.
• Mesially inclined 7, lesser degree of anchor bend.
Wilkinson’s Extraction: 1942
8 ½ to 9 ½ yrs. Extraction of all Ist molars.
Basis:
•Additional space for eruption of 8s.
•Crowding of lower arch minimized.
•Disadvantages-

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Single arch extraction – U 6 or what to do when
non extraction treatment fails.
Raleigh Williams. AJO 1979
• Class II div 1 with perfect lower arch alignment but growth
expectation inadequate.
• Class II div 1 active growth over. Pt non cooperative.
• Class II div 1 with good lower arch over basal bone, with
some growth expectation.
• Class II div 1 with mild open bite.

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• Problems with Xn of 4s:
• Tipping, opening of space (5 small to fill the space)
• Mesial tipping of 6, hanging palatal cusp
Avoided with 6 Xn.
• Good molar relation.
• U 4 occlude with L4
• 8s erupt normally.
• Min patient cooperation
• Stable results.
• Tuberosity not crowded.
• Results similar to nonext.
• Rx duration is reduced.
• Profile maintained.

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2nd
MOLAR EXTRACTION:
• David W.Liddle- AJO 1977
• Malocclusion: potential force by developing 7,8.
• Xn of 7s to intercept this forward force.
• 4 Xn: treating the effect and not the cause.
– 10-12mm of space :satisfies arch length problem, not
apparent when patient smiles.
– 91% 7 Xn.
• 6 move distally in response to pressure.

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2nd
MOLAR EXTRACTION:
ADVANTAGES AND INDICATIONS
• Disimpaction of 3rd
molars, faster eruption
• Prevention of “dished-in” at the end of facial growth
• Prevention of late incisor imbrication
• Facilitation of 1st
molar distalization
• Distal movement only as needed to correct the overjet
• Fewer “residual”spaces at the end of Rx
• Less likelihood of relapse
• Good functional occlusion
• Good mandibular arch form
• Overbite reduction.

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Indications:
Chipman:
• Xn 7 - caries, ectopic, rotated.
• Mild – moderate discrepancy with good profile.
• Crowding in tuberosity area ,with a need for distal
movement of 1st
molar.
Lehman - preconditions
• 8 in favorable angulation 15-30*angle to the long axis of
the 1st
molar.
• Normal in size/shape & root area is sufficient w.r.t 2nd
molar.
• No congenitally missing teeth.

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Disadvantages:
• Too much tooth substance removed in Cl I malocclusion
with mild crowding.
• Location far from area of concern.
• No help in correction of A-P discrepancy without patient
cooperation .
• Possible impaction of 3rd
molars even with 2nd
molar Xn
• Unacceptable positions of erupted 3rd
molars –second, late
stage of fixed therapy.
• 9-20% missing 3rd
molars.

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Timing for mandibular 2nd
molar extraction:
• Kokich:
1. 3rd
molar crowns completely formed, Xn before
roots begin to develop
2. 30*to the occlusal plane
3. 3rd
molars in close proximity to 2nd
molar-drift.
Halderson, Huggins, Lehman and Smith.
Before radiographic evidence of root formn.(12-14yrs)
Consensus opinion: as soon as 2nd
molar erupts.
angulation.

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3rd
Molar Extraction:
• Xn to prevent lower anterior crowding?
• Distal movement of 6,7– impaction of 8.
• Xn of 8 before retracting.
Contraindications:
• 1st
or 2nd
molars are extracted.

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Incisor Extraction:
• Mandibular incisors- therapeutic value
• 1st
sign of incipient malocclusion
• Difficult to treat as they relapse easily.
• Not a new idea.
• Jackson (1904)
• Riedel : Xn of 2 lower
Incisors-arch form without
Expn of intercanine width
• Angle:
Inexcusable.disharmony b/w
Occlusal planes, abnormal overbite

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Incisor extraction:
Indications:-
• For mandibular incisors:
• Extreme crowding / protrusion.
• Gingival recession & loss of
overlying bone on labial surface.
• Lateral incisors severely # in young
children.
• Rarely-discrepancy in sizes of U &
L incisors themselves, 1 incisor can
be removed.
• Reidel- Rx time reduced.
• min facial change.

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Incisor extraction:
Advantages:
1. Maintains/ reduces intercanine
width
2. General arch form is maintained
– greater stability
3. Retention period- less
4. Anterior segments can be
retracted readily if need be.
5. Immediate solid tooth support
of entire buccal segments.
6. Easy reduction of overbite-
intrusion, reshaping
7. Mechanotherapy is simplified.
Space closure quick. www.indiandentalacademy.com

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Incisor extraction:
Disadvantages:-
• Reopening of space . Central Incisor.
• Danger of creating a tooth size discrepancy.
• Reidel- 2 mandi incisors Xed to maintain
intercanine width.
• 1 incisor Xn- deepbite- if normal tooth size
relationship is present before Xn.
• Color difference of canine.

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Upper Incisor Extraction:
• Rarely indicated.
• Unfavorable impaction of U incisor.
• Bu/Li blocked out lateral, with good contact b/w central
and canine.
• Congenital missing of 1 lateral incisor
• Dilacerated tooth.
• Gardiner et al:
– U crowding, mesial displacement of root apices
of U3 - Xn of lateral incisor.

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Summarize:
• Incisor Xn rare.
• Possibility must always be considered.
• Careful planning with diagnostic setup

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Extraction of Canines:
• Not extracted. Profile.
• Long path of eruption.
– Conditions where indicated:
• Impossible to bring in alignment.
• Gross displacement Bu/Li
• 4 in contact with 2 & does not show palatal cusp.
Decision : position of apex.

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The Effect of Different Extraction sites upon
incisor retraction. Raliegh Williams et al AJO 1976
• Relation b/w root surface area and Xn site selection upon
incisor retraction.
• Efficient mechanotherapy.
• Diagnostic line.
• Larger the root surface area, greater the resistance to
movement.

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Non extraction 1.5mm
1st
molars u&l 6.0mm
U4 and L5 8.7mm
1st
premolars 9.2mm
1st
premolars
&1st
molars 16.9mm

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Conclusion:
• Location of the Xn site-
–Root surface area.
–Predict incisor retraction.
• Should be considered in diagnosis, so that a
desired Rx goal for the final position of incisors
within the facial profile can be achieved.

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• Orthodontic treatment may include extractions of
any tooth in the arch.
• Based on sound diagnosis, treatment objectives.

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Extraction in orthodontics /certified fixed orthodontic courses by Indian dental academy

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