Extraction in Ortho

8/4/2019 Extraction in Ortho

1/40

EXTRACTIONS IN

ORTHODONTICS


2/40

CONTENTS

1. INTRODUCTION2. HISTORY3. CRITERIA FOR EXTRACTION4. CHOICE OF TEETH FOR EXTRACTION

1. INCISOR

2. CUSPIDS3. PREMOLARS4. FIRST MOLARS5. SECOND MOLARS6. THIRD MOLARS

5. BEGGS VIEW REGARDING EXTRACTIONS6. WHICH TEETH TO EXTRACT AND WHEN


3/40

INTRODUCTION

Extractions in orthodontics remains arelatively controversial area.

It is not possible to treat all malocclusions

without taking out any teeth.Extractions of specific teeth are required inthe various presentations of malocclusion.

In some situations careful timing ofextractions may result in spontaneouscorrection of the malocclusion.


4/40

HISTORY

The role of extraction in orthodontics wasrecognised by John Hunter (1771) in his NaturalHistory of Teeth.

Spooner advised (1839) the extraction of four

premolars or Ist molar when defective.

Farrar (1888) considered judicious extractions asessential prerequisites for prevention and

correction of irregularities.


5/40

The question of extraction was published first by CalvinS Case in 1911 in Dental Cosmos.

He contradicted views as compared to Dr. Dewey + Dr.Cryer & Dr. E.H.Angle .

According to Case following rules were to be followedfor extraction:

1. Never extract teeth for the purpose of makingthe operation of correction easier

2. No teeth should ever be extracted except incases of excessive protrusions producing decided

facial deformities

According to Case in every patient in which dentofacialprotrusions can be corrected without extraction weshould strive to produce a normal occlusion.


6/40

According to Angle, full complement of teethshould be preserved as it will only produce the

true facial result for that individual.

At that time most theories of malocclusion putforward were explained by process of nature

Even Angle in 1910 believed that variousabnormalities of jaws were due to defect inbending process by nature.

David Liddle in 1977 says clearly that one of themost important early lessons in orthodontics isthat one should never try to move a tooth untilthere is a place for it.


7/40

CRITERIA FOR EXTRACTION(Salzmann)

1. The labial lingual dental arch relationship to thefacial plane

1. With little crowding2. Lingually placed arches3. Gonial angle being 125 or less

2. The size of the gonial angle - short ramus andextremely obtuse gonial angle , incisor

procumbency in relation to F-H plane is morepronounced.

3. The axial inclination of mandibular incisors and

there effect on Frankfurt mandibular incisorangle.


8/40

4. The type and degree of irregularity andcrowding present in the dental arches.

5. The direction of jaw growth.

6. The relative difference in the size of the basalarches i.e. basal arch length.

7. The thickness and distribution of the softtissues covering the facial bones


9/40

CHOICE OF TEETH FOR EXTRACTION

It depends on local conditions which include:1. The direction and amount of jaw growth.

2. Discrepancy between the size of dental arches and

the basal arches.3. The state of soundness, position, eruption of teeth

4. The facial profile .

5. The degree of alveolo-dental prognathism.6. The age of the patient .

7. The state of dentition as a whole.


10/40

Factors affecting choice of extraction

1. Treatment objectives

2. Medical history

3. Type of malocclusion

4. Esthetics (large chin button, prominentnose)

5. Conditions of teeth.(caries, multi-filledteeth, impacted, ectopic, severe rotation)

6. Health of supporting tissues.


11/40

Incisor

Inter-canine distance of the maxillary and

mandibular teeth should be considered

when contemplating extraction of incisorteeth


12/40

MAXILLARY INCISOR

IndicationsRarely indicated.

Unfavorable impaction of Upper incisor.

Buccal or palatally blocked out lateral,

with good contact b/w central and canine.

Congenital missing of 1 lateral incisorDilacerated tooth.

Severely fractured lateral incisors


13/40

MANDIBULAR INCISORS:Indications

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.

(Boltons Discrepancy)

Presence of supplemental teeth


14/40

A supplementary

incisor ispresent

Supplementaryincisor removalresulted inspontaneouscorrection of

crowding


15/40

Advantages:

1. Maintains/ reduces intercanine width2. General arch form is maintained greater

stability

3. Retention period- less

4. Anterior segments can be retracted readilyif 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.


16/40

Disadvantages:-

Reopening of space especially if mandibular

Central Incisor are extracted.

Danger of creating a tooth size

discrepancy.

Color difference of canine.


17/40

Contraindication: (drawbacks)

In instances of minimal crowding spacestend to open between canines and centralsor canine and laterals, these spaces initiatefood impaction which is embarrassing andesthetics is unpleasant.

Anatomic differences in shape of the

mandibular canines as compared tomandibular lateral incisors


18/40

CANINES

Extraction of canine for orthodontictreatment should be avoided as

1. It may cause flattening of face.

2. Change in facial expression.

3. Contact between lateral incisor and

premolar is not stable.

4. Act as ideal abutment teeth


19/40

Indications for extraction of canine

Ectopic eruption ( palatal / buccal/ lingual)

Ankylosed canine

Impacted canineSevere dilaceration cases

Impacted canine

Ectopic eruption of canine


20/40

Severely crowded case where all four canines were extracted. The

resulting occlusion giving acceptable contact between lateral incisor

and first premolar and improved arch form


21/40

Premolars

Premolars are the most commonly extracted teethin orthodontics.

Factors that determine which upper bicuspidshould be extracted

Anchorage needsTooth size and shapeRestorations or cariesExtreme upper bicuspid mal-position.


22/40

INDICATION FOR FIRST PREMOLAR

If second deciduous molar is lostprematurely and before eruption of I stpermanent molar.

When disproportion exists between thedental base and teeth the root apices may allbe in abnormal position and crowding will be

manifested especially into the incisor teeth.


23/40

All first premolars have been extracted in this case


24/40

INDICATION FOR SECOND PREMOLAR

If they are unsound. ( carious or multi-filled)

Their position in the arch is such that

extended orthodontic tooth movement wouldbe needed to bring them into line and Ist

premolars are already in satisfactory position

When considerable mesial movement of

molars required.


25/40

Maxillary second premolar have been extracted in this case


26/40

Correction of open bite with extraction of second premolar

Continued..

In open bite malocclusions

Abnormal root structure of IInd premolar

Congenitally absent 1 or 2 or 3 IInd

premolar


27/40

FIRST MOLAR

First molar extraction should be avoided :

1. causes deepening of bite2. mastication may be affected

3.offers only limited space inrelieving crowding of the incisor teeth.4. IInd premolar and IInd permanentmolars frequently rotate as they

erupt following the loss of Ist molar.5. deprives the operator of adequateanchorage.


28/40

INDICATION FOR FIRST MOLAR

Carious- beyond restoration

RC Treated, - than a perfectly goodpremolar.

Multi filled teeth- crown.

Premature extraction of first molar, topreserve symmetry.

Facial considerations: large chin buttons&/prominent nose a removal of premolar mayresult in Dished in appearance.

Open bite cases.


29/40


30/40

First molar were extracted justafter the optimal time, beforethe fixed appliance treatment.OPG how gross caries in leftfirst molar and heavyrestorations in right firstmolars.


31/40

WILKINSONS EXTRACTION

Wilkinson advocated extraction of all the 4 Istpermanent molars between the age of 81/2- 9 years

Basis:

First molars are highly susceptible to caries.

Additional space for eruption of third molars.

Crowding of lower arch minimized

Disadvantages :Adjacent teeth tip into extraction spacePrincipal anchorage unit for orthodonticappliances is lostLimited space for crowding correction


32/40

SECOND MOLARS

Criteria for extraction of second molar(Chipman)

Delayed eruption of second molarsSize, shape and root area of maxillary third

molars should be sufficient to serve in place ofsecond molars.Maxillary tuberosity should be insufficient to

accommodate all third molarsAttempt to bring second molars into occlusionwould cause relapse of treated dentitionSeverely cariousMaxillary third molars in favourable angulation.


33/40

Contraindications

1. Maxillary third molars are too high in the

tuberosity or show delayed eruption.

2. Poor angulation of third molars in relationto second molars

3. Undersized third molars, crown or roots

4. Absence of third molar tooth bud


34/40

Advantages

1. Relieves crowding in both anterior and posteriorsegments simultaneously.

2. Increased vertical dimension,3. Contacts remain intact throughout the arch

4. More posterior teeth are available for chewing5. Stability is greatly enhanced as the giganticforward thrust of second molars is replaced bythe thirds

6. Treatment time is made easier, shorter and far

more dependable7. Treatment method using this technique avoids

the use of elastics and eliminate the need forheadgear and prolonged use of fixed retainers


35/40

THIRD MOLARS

Impacted third molars that show evidence ofinterfering with treatment or retention or they maybe the cause of reflex pain or infection should beextracted.

Malformed third molars which interfere withocclusion should be extracted after or duringorthodontic treatment if they interfere with distalmovement of maxillary dental arch or with retention

after treatment.

Contraindication: 1st or 2nd molars are extracted.


36/40

BEGGS VIEW REGARDING EXTRACTIONS

According to Begg four first premolars shouldbe the most common teeth to be extracted, asthe extraction of first premolars makes betterorthodontic treatment possible than does theextraction of four first molars. This is because:First premolars are closer to the anterior toothregion where tooth crowding is most liable tooccur.The appliance therapy is more easily and

successfully performed if first premolars areremoved i.e. if teeth that are close to theanterior teeth are the one extracted.


37/40

First molars should not be extracted because :Site of extraction is far from the site of toothcrowdingRelapse of the treatment is more likely asmesial migration of ten teeth instead of only sixbrings a greater amount of anterior translationafter treatment

Extraction of second premolar should also beavoided unless they are carious or faulty in theirformation because :Their extraction may lead to relapse ofcrowding due to mesial migration force fromeight teeth is more powerful than from six.


38/40

WHICH TEETH TO EXTRACT AND WHEN

First premolars should be extracted after thecanines and incisors have erupted sufficientlyfor orthodontic bands to be placed. Butexceptions to this rule are:

Early removal in case of impacted secondpremolar due to mesial migration of firstpermanent molar after premature loss ofsecond deciduous molar.

In case of vertically impacted canineOtherwise first premolars should not beextracted more than 3 weeks before startingorthodontic treatment.


39/40

In patients with erupting permanent incisors andmolars with teeth that may be excessively largeandjaw size inadequate, the amount of space forremaining permanent teeth left is insufficient, inthese cases first molars should be extracted assoon as they erupt to reduce the force of mesialmigration that causes crowding and protrusion in

anterior region. But this is highly contradicted.

There may be many instances when teeth other

than these which orthodontist would choose tohave extracted have to be extracted because ofdental caries. These are known as Mutilation Cases


40/40

Extraction in Ortho

Documents

Transcript of Extraction in Ortho