An overview of class 2 & class 3 treatment plan

An Overview Of Class II &An Overview Of Class II &
Class III TreatmentClass III Treatment
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CONTENTS OF CLASS IICONTENTS OF CLASS II
TREATMENTTREATMENT
 IntroductionIntroduction
 The shift in emphasis from molars to incisors.The shift in emphasis from molars to incisors.
 The concept of ‘ideal’ incisor position inThe concept of ‘ideal’ incisor position in
treatment planning.treatment planning.
 Planned incisor position.Planned incisor position.
 The limitations of orthodontics.The limitations of orthodontics.
 The surgical/non-surgical decision in Class IIThe surgical/non-surgical decision in Class II
treatment.treatment.
 Identifying severe Class II cases.Identifying severe Class II cases.

 The four-stage treatment planning processThe four-stage treatment planning process
 PIP components in Class II treatmentPIP components in Class II treatment
 Upper incisor movement in Class II casesUpper incisor movement in Class II cases
 Positioning of lower incisors in Class IIPositioning of lower incisors in Class II
casescases

AN OVERVIEW OF CLASS IIIAN OVERVIEW OF CLASS III
TREATMENTTREATMENT
 IntroductionIntroduction
 The four-stage treatment planning processThe four-stage treatment planning process
 PIP components in Class III treatmentPIP components in Class III treatment
 Upper incisor movement in Class IIIUpper incisor movement in Class III
treatmenttreatment
 Lower incisor movement in Class III casesLower incisor movement in Class III cases

The shift in emphasis from MolarsThe shift in emphasis from Molars
to Incisorsto Incisors
 When angle introduced his classification inWhen angle introduced his classification in
the late 1920 s, orthodontics focusedthe late 1920 s, orthodontics focused
primarily on the molar relationship asprimarily on the molar relationship as
Class I, Class II, or Class III.Class I, Class II, or Class III.
 Non-extraction treatment & expansion wasNon-extraction treatment & expansion was
generally the treatment of choice.generally the treatment of choice.
 In the 1940s Tweed moved the emphasisIn the 1940s Tweed moved the emphasis
to the lower incisors, with extractionto the lower incisors, with extraction
treatment becoming more prevalent.treatment becoming more prevalent.

 This was clearly a reaction against theThis was clearly a reaction against the
shortcomings of non-extraction treatment.shortcomings of non-extraction treatment.
 The emphasis on the lower incisors, withThe emphasis on the lower incisors, with
minimized emphasis on the upper incisors,minimized emphasis on the upper incisors,
was due to the fact that surgical correctionwas due to the fact that surgical correction
was not available at the time, nor waswas not available at the time, nor was
improved facial appearance with functionalimproved facial appearance with functional
appliances.appliances.
 The majority of orthodontic cases requireThe majority of orthodontic cases require
changes in incisor position.changes in incisor position.
 In addition to ‘tooth alignment’, most casesIn addition to ‘tooth alignment’, most cases
require more challenging ‘denture-require more challenging ‘denture-
positioning’ procedures.positioning’ procedures.

The concept of ‘ideal’ incisorThe concept of ‘ideal’ incisor
position in treatment planningposition in treatment planning
 Today, it is possible to base treatmentToday, it is possible to base treatment
planning on the position of the upperplanning on the position of the upper
incisors, instead of using the molars or theincisors, instead of using the molars or the
lower incisors as a starting point.lower incisors as a starting point.
 At the start of treatment planning, it isAt the start of treatment planning, it is
possible to envision an ‘ideal’ position forpossible to envision an ‘ideal’ position for
the upper incisors.the upper incisors.

Planned Incisor PositionPlanned Incisor Position
 PIP may be defined as: The intended end-PIP may be defined as: The intended end-
of-treatment position for upper incisors.of-treatment position for upper incisors.
 In some cases, the perceived ideal upperIn some cases, the perceived ideal upper
incisor position will be a realistic treatmentincisor position will be a realistic treatment
goal, & can become the PIP for that case.goal, & can become the PIP for that case.
 In other cases, the ideal incisor positionIn other cases, the ideal incisor position
may not be a realistic goal.may not be a realistic goal.

 In such cases, the perceived ideal incisorIn such cases, the perceived ideal incisor
position has to be adjusted to reflect theposition has to be adjusted to reflect the
limiting features of the case.limiting features of the case.
 Then a PIP has to be accepted which is notThen a PIP has to be accepted which is not
ideal, but which is acceptable for the case.ideal, but which is acceptable for the case.

The limitations of orthodonticsThe limitations of orthodontics
 Skeletal disproportion, cannot be resolvedSkeletal disproportion, cannot be resolved
by orthodontics alone.by orthodontics alone.
 It is important to identify such cases, andIt is important to identify such cases, and
consider a surgical/orthodontic solution inconsider a surgical/orthodontic solution in
order to achieve an acceptable PIP.order to achieve an acceptable PIP.

The surgical/non-surgical decisionThe surgical/non-surgical decision
in Class II treatmentin Class II treatment
 The soft tissue cephalometric analysis, orThe soft tissue cephalometric analysis, or
STCA, has been advocated by Arnett et al asSTCA, has been advocated by Arnett et al as
an aid for orthodontists & surgeons in treatmentan aid for orthodontists & surgeons in treatment
planning.planning.

It recommends analysis using a True Vertical Line (TVL) through subnasale,It recommends analysis using a True Vertical Line (TVL) through subnasale,
with natural head posture.with natural head posture.
Only seven measurements from the STCA are included here.Only seven measurements from the STCA are included here.
The upper incisor torque is measured relative to the maxillary occlusal planeThe upper incisor torque is measured relative to the maxillary occlusal plane
& the lower incisor torque relative to the mandibular occlusal plane.& the lower incisor torque relative to the mandibular occlusal plane.
In this diagram, projected to true vertical line (TVL):In this diagram, projected to true vertical line (TVL):
Soft tissue ‘A’ point,Soft tissue ‘A’ point,
upper lip anterior,upper lip anterior,
lower lip anterior,lower lip anterior,
soft tissue ‘B’ point,soft tissue ‘B’ point,
soft tissue pogonion.soft tissue pogonion. www.indiandentalacademy.comwww.indiandentalacademy.com

Identifying severe Class II casesIdentifying severe Class II cases
 It is important to recognize those Class II casesIt is important to recognize those Class II cases
which have a major skeletal disproportion at thewhich have a major skeletal disproportion at the
time of assessment.time of assessment.
 For such individuals, it will be necessary toFor such individuals, it will be necessary to
consider a surgical/orthodontic solution.consider a surgical/orthodontic solution.
 Treatment on the basis of orthodontics aloneTreatment on the basis of orthodontics alone
should be discarded as a possibility, unlessshould be discarded as a possibility, unless
there is a real prospect, in a growing individual,there is a real prospect, in a growing individual,
of achieving favorable skeletal change withof achieving favorable skeletal change with
functional appliances.functional appliances.

 Solution A- orthodontic masking of a mild ClassSolution A- orthodontic masking of a mild Class
II. If the skeletal Class II discrepancy is mild, itII. If the skeletal Class II discrepancy is mild, it
may be decided to follow a treatment planmay be decided to follow a treatment plan
based on orthodontics alone.based on orthodontics alone.
 The orthodontist will provide correction byThe orthodontist will provide correction by
‘masking’ the underlying Class II discrepancy‘masking’ the underlying Class II discrepancy
with dental compensation.with dental compensation.
 This will involve slight retroclination of upperThis will involve slight retroclination of upper
incisors &/or proclination of lower incisors.incisors &/or proclination of lower incisors.
Good patient cooperation with Class II elasticsGood patient cooperation with Class II elastics
&/or headgear will normally be needed in this&/or headgear will normally be needed in this
type of treatment. Treatment should lead to atype of treatment. Treatment should lead to a
good dental & an acceptable facial outcome.good dental & an acceptable facial outcome.

Good correction achieved by
dental compensation assisted
by small amount of favorable
growth.
Mild class II case

 Solution B- attempted orthodontic masking ofSolution B- attempted orthodontic masking of
a more severe Class II skeletal problem.a more severe Class II skeletal problem.
 If the underlying skeletal Class II discrepancyIf the underlying skeletal Class II discrepancy
is moderate to severe, a treatment planis moderate to severe, a treatment plan
based on orthodontics alone carries risks.based on orthodontics alone carries risks.
 If the orthodontist attempts correction of theIf the orthodontist attempts correction of the
bite by ‘masking’ the Class II discrepancy withbite by ‘masking’ the Class II discrepancy with
dental compensation, there is a probability ofdental compensation, there is a probability of
over-retraction of the upper incisors & a veryover-retraction of the upper incisors & a very
unfavorable change in facial profile. This alsounfavorable change in facial profile. This also
leaves the upper & lower incisors in a positionleaves the upper & lower incisors in a position
which is unsuitable for successfulwhich is unsuitable for successful
orthognathic surgery, if this is to be providedorthognathic surgery, if this is to be provided
later.later. www.indiandentalacademy.comwww.indiandentalacademy.com

 Further orthodontic treatment will beFurther orthodontic treatment will be
required to decompensate the anteriorrequired to decompensate the anterior
teeth, so that maximum benefit can beteeth, so that maximum benefit can be
obtained from surgery.obtained from surgery.

 Solution C- combined orthodontic & surgical correction of a severeSolution C- combined orthodontic & surgical correction of a severe
Class II/I malocclusion.Class II/I malocclusion.
 The theoretical situation C is the same at the start as situation B.The theoretical situation C is the same at the start as situation B.
 However, the severe Class II problem has been corrected byHowever, the severe Class II problem has been corrected by
combined surgery & orthodontics.combined surgery & orthodontics.
 The favorable change in facial profile is clearly seen in the blackThe favorable change in facial profile is clearly seen in the black
Arnett measurements in the right diagram. Although patients areArnett measurements in the right diagram. Although patients are
anxious to avoid surgery, it may offer the best possible outcome inanxious to avoid surgery, it may offer the best possible outcome in
dental & facial terms for severe cases, & it is appropriate to informdental & facial terms for severe cases, & it is appropriate to inform
the patient of this.the patient of this.

THE FOUR-STAGE TREATMENTTHE FOUR-STAGE TREATMENT
PLANNING PROCESSPLANNING PROCESS
 Setting a PIP for upper incisorsSetting a PIP for upper incisors
 The lower incisorsThe lower incisors
 The remaining lower teethThe remaining lower teeth
 The remaining upper teethThe remaining upper teeth

Stage 1- Setting a PIP for theStage 1- Setting a PIP for the
upper incisorsupper incisors
 What is the ideal position for the upper incisorsWhat is the ideal position for the upper incisors
in the face in terms of A/P position, torque, &in the face in terms of A/P position, torque, &
vertical positioning?vertical positioning?
 Can ideal upper incisor position be achieved?Can ideal upper incisor position be achieved?
 If not, can an acceptable incisor position beIf not, can an acceptable incisor position be
achieved by orthodontics alone, or is itachieved by orthodontics alone, or is it
necessary to consider maxillary surgery?necessary to consider maxillary surgery?
 In this way, a PIP is determined for the case.In this way, a PIP is determined for the case.

Stage 2- The lower incisorsStage 2- The lower incisors
 The second stage of treatment planning concerns theThe second stage of treatment planning concerns the
lower incisors, & how to position them in goodlower incisors, & how to position them in good
relationship to the PIP for the upper incisors.relationship to the PIP for the upper incisors.
 If this is cannot achieved by orthodontics alone, it willIf this is cannot achieved by orthodontics alone, it will
be necessary to modify the PIP for the upper incisors,be necessary to modify the PIP for the upper incisors,
or consider mandibular surgery.or consider mandibular surgery.

Stage 3- The remaining lower teethStage 3- The remaining lower teeth
 The third treatment planning stage concernsThe third treatment planning stage concerns
lower arch crowding or spacing, & the extractionlower arch crowding or spacing, & the extraction
decision. How can the rest of the lower teeth bedecision. How can the rest of the lower teeth be
positioned to fit the planned lower incisorpositioned to fit the planned lower incisor
position,& will extractions be needed.position,& will extractions be needed.

 The dental VTO can be used at this stage ofThe dental VTO can be used at this stage of
the planning process, to reach a correctthe planning process, to reach a correct
extraction decision.extraction decision.
 The primary factors are crowding, Curve ofThe primary factors are crowding, Curve of
Spee,& midlines.Spee,& midlines.
 The secondary factors are expansion,The secondary factors are expansion,
distalization of molars, inter-proximal enameldistalization of molars, inter-proximal enamel
reduction, & ‘E’ space.reduction, & ‘E’ space.

Stage 4- The remaining upper teethStage 4- The remaining upper teeth
 Finally, in the treatment planning process,Finally, in the treatment planning process,
it is necessary to decide how to positionit is necessary to decide how to position
the rest of the upper teeth correctly. Howthe rest of the upper teeth correctly. How
will crowding or spacing be dealt with,&will crowding or spacing be dealt with,&
what treatment mechanics will bewhat treatment mechanics will be
needed?needed?
 The dental VTO will confirm the requiredThe dental VTO will confirm the required
tooth movements for upper canines &tooth movements for upper canines &
molars.molars.

PIP COMPONENTS IN CLASS IIPIP COMPONENTS IN CLASS II
TREATMENTTREATMENT
For each case, it is necessary to set a PIPFor each case, it is necessary to set a PIP
as a treatment goal which will result in theas a treatment goal which will result in the
upper incisors having correct A/P &upper incisors having correct A/P &
vertical positioning with appropriatevertical positioning with appropriate
torque.torque.
It consists of 3 components:It consists of 3 components:
 A/P componentA/P component
 Torque componentTorque component
 Vertical componentVertical component

The antero-posterior component ofThe antero-posterior component of
PIP in the Class II treatmentPIP in the Class II treatment
 Traditionally in orthodontics the upper incisorTraditionally in orthodontics the upper incisor
A/P position has been related to the APo lineA/P position has been related to the APo line
with a conventional cephalometric value ofwith a conventional cephalometric value of
+6mm.+6mm.

 The Arnett analysis relates upper incisorThe Arnett analysis relates upper incisor
position to a true vertical line (TVL),& theposition to a true vertical line (TVL),& the
term MXI-TVL, which is the linearterm MXI-TVL, which is the linear
measurement from the tip of the uppermeasurement from the tip of the upper
incisor to the true vertical line.incisor to the true vertical line.
 The male central incisor tip is ideallyThe male central incisor tip is ideally
-12mm to the line & the female is at -9mm.-12mm to the line & the female is at -9mm.

The torque component of PIP inThe torque component of PIP in
Class II TreatmentClass II Treatment
 In traditional orthodontics treatmentIn traditional orthodontics treatment
planning, upper incisor torque is related toplanning, upper incisor torque is related to
the maxillary plane with a cephalometicthe maxillary plane with a cephalometic
value of 110 to 115 degrees being goal .value of 110 to 115 degrees being goal .

 The Arnett analysis relates upper incisorThe Arnett analysis relates upper incisor
torque to the maxillary occlusal plane, &torque to the maxillary occlusal plane, &
has slightly different values for males &has slightly different values for males &
females.females.

The vertical component of PIP inThe vertical component of PIP in
Class II TreatmentClass II Treatment
 The Arnett analysis quantifies the verticalThe Arnett analysis quantifies the vertical
positioning of upper incisors,& requires anpositioning of upper incisors,& requires an
overbite 3mm, with upper incisor exposure beingoverbite 3mm, with upper incisor exposure being
4mm below the relaxed upper lip in males &4mm below the relaxed upper lip in males &
5mm in females.5mm in females.

UPPER INCISOR MOVEMENT INUPPER INCISOR MOVEMENT IN
CLASS II TREATMENTCLASS II TREATMENT
It is helpful to first plan the upper incisor correction,&It is helpful to first plan the upper incisor correction,&
then plan the lower incisor correction. This allowsthen plan the lower incisor correction. This allows
clear & systemized organization of treatmentclear & systemized organization of treatment
mechanics. Treatment mechanics may be :-mechanics. Treatment mechanics may be :-
 Mesial movement of upper incisorsMesial movement of upper incisors
 Distal movement of upper incisors in cases with upperDistal movement of upper incisors in cases with upper
anterior spacinganterior spacing
 Distal movement of upper incisors after upperDistal movement of upper incisors after upper
premolar extractionspremolar extractions
 Distal movement of upper incisors in non-extractionDistal movement of upper incisors in non-extraction
cases without spacingcases without spacing
 Control of upper incisor torqueControl of upper incisor torque
 Vertical control of incisorsVertical control of incisors

Mesial movement of upper incisorsMesial movement of upper incisors
in Class II treatmentin Class II treatment
 In Class II/2 cases, the upper incisors areIn Class II/2 cases, the upper incisors are
typically too far back.typically too far back.
 In the modern thinking, which is concernedIn the modern thinking, which is concerned
more with the incisor position in the face, themore with the incisor position in the face, the
Class II molar relationship (which AngleClass II molar relationship (which Angle
emphasized) is secondary to the retroclinedemphasized) is secondary to the retroclined
upper & lower incisors.upper & lower incisors.
 During leveling &aligning of the upper arch, theDuring leveling &aligning of the upper arch, the
upper incisors move mesially, closer to theupper incisors move mesially, closer to the
PIP,& the Angle’s classification becomes ClassPIP,& the Angle’s classification becomes Class
II/I.II/I. www.indiandentalacademy.comwww.indiandentalacademy.com

 In adolescent treatment Class II/I case canIn adolescent treatment Class II/I case can
normally be corrected by conventionalnormally be corrected by conventional
orthodontics, but in some cases mandibularorthodontics, but in some cases mandibular
surgery will be required.surgery will be required.
 The required mesial change in upper incisorThe required mesial change in upper incisor
position is achieved mainly by tooth movement.position is achieved mainly by tooth movement.
 In orthodontic cephalometry, the SNA is usedIn orthodontic cephalometry, the SNA is used
to record the position of the maxillary skeletalto record the position of the maxillary skeletal
base,& therefore this may suggest that mesialbase,& therefore this may suggest that mesial
movement of the maxilla has contributed to themovement of the maxilla has contributed to the
improved A/P position of the upper incisors.improved A/P position of the upper incisors.

 The opening stages of ClassII/2 cases may beThe opening stages of ClassII/2 cases may be
managed in two ways:managed in two ways:
1.Upper arch treatment may be started first, with no1.Upper arch treatment may be started first, with no
appliance placed on the lower teeth. After reaching theappliance placed on the lower teeth. After reaching the
rectangular steel working wire in the upper arch, therectangular steel working wire in the upper arch, the
lower appliance may then be placed, & lower levelinglower appliance may then be placed, & lower leveling
commenced.commenced.
2.Upper & lower fixed appliances may be placed from2.Upper & lower fixed appliances may be placed from
the outset, with an upper acrylic bite plate being wornthe outset, with an upper acrylic bite plate being worn
for the opening few months, to free the bite & preventfor the opening few months, to free the bite & prevent
damage to the lower brackets.damage to the lower brackets.
Bendbacks should be 1mm distal to molar tubesBendbacks should be 1mm distal to molar tubes
during leveling & aligning to allow arch length toduring leveling & aligning to allow arch length to
increase.increase.

Distal movement of upper incisorsDistal movement of upper incisors
in cases with upper anteriorin cases with upper anterior
spacingspacing
 Sliding mechanics are used, on a normalSliding mechanics are used, on a normal
working steel rectangular wire,& active tiebacksworking steel rectangular wire,& active tiebacks
achieve the necessary retraction & spaceachieve the necessary retraction & space
closure, sometimes augmented by a light four-closure, sometimes augmented by a light four-
link anterior elastic chain.link anterior elastic chain.
 It is necessary to ensure that good lower archIt is necessary to ensure that good lower arch
leveling has been achieved .leveling has been achieved .
 Appropriate anchorage support from an upperAppropriate anchorage support from an upper
palatal bar, a sleeping headgear, or Class IIpalatal bar, a sleeping headgear, or Class II
elastics may be needed.elastics may be needed. www.indiandentalacademy.comwww.indiandentalacademy.com

 If there is anterior spacing, sliding mechanicsIf there is anterior spacing, sliding mechanics
on a 0.019/0.025 steel rectangular wire may beon a 0.019/0.025 steel rectangular wire may be
used to retract incisors & close spaces.used to retract incisors & close spaces.
 Archwire hooks should be close to upper lateralArchwire hooks should be close to upper lateral
incisor brackets, to avoid impingement ontoincisor brackets, to avoid impingement onto
canine brackets as the space closes.canine brackets as the space closes.

after upper premolar extractionsafter upper premolar extractions
 Where possible, lower premolarWhere possible, lower premolar
extractions are generally avoided in Classextractions are generally avoided in Class
II/1 cases, because of the need toII/1 cases, because of the need to
maintain a mesial position for lowermaintain a mesial position for lower
incisors.incisors.
 If four premolars need to be taken, it isIf four premolars need to be taken, it is
often appropriate to choose upper firstoften appropriate to choose upper first
premolars & lower second premolars, topremolars & lower second premolars, to
assist treatment mechanics.assist treatment mechanics.

 A small number of cases may be treated to aA small number of cases may be treated to a
Class II molar relationship, following extractionClass II molar relationship, following extraction
of two upper premolar.of two upper premolar.
 Sliding mechanics are used to retract upperSliding mechanics are used to retract upper
incisors after premolar extractions, on a normalincisors after premolar extractions, on a normal
working steel rectangular wire.working steel rectangular wire.
 The retraction force is delivered from activeThe retraction force is delivered from active
tiebacks.tiebacks.
 A small amount of additional torque may needA small amount of additional torque may need
to be bent into the anterior region of the upperto be bent into the anterior region of the upper
rectangular wire in the incisor region,& excessrectangular wire in the incisor region,& excess
retraction force should be avoided.retraction force should be avoided.

 Appropriate anchorage support from either anAppropriate anchorage support from either an
upper palatal bar, a sleeping headgear, orupper palatal bar, a sleeping headgear, or
Class II elastics may be needed, or from aClass II elastics may be needed, or from a
combination of these.combination of these.
 It is necessary to ensure that good lower archIt is necessary to ensure that good lower arch
leveling has been achieved before, so that theleveling has been achieved before, so that the
overbite is minimal,& lower incisors will notoverbite is minimal,& lower incisors will not
interfere with the retraction process.interfere with the retraction process.

in non-extraction cases withoutin non-extraction cases without
spacingspacing
 In some Class II/1 cases, it may beIn some Class II/1 cases, it may be
decided that the treatment should be on adecided that the treatment should be on a
non-extraction basis,& that the uppernon-extraction basis,& that the upper
buccal segments need to be movedbuccal segments need to be moved
distally, to allow subsequent retraction ofdistally, to allow subsequent retraction of
the upper incisors toward PIP.the upper incisors toward PIP.
 If the movement is minimal, first molarIf the movement is minimal, first molar
rotation solves most of the problem.rotation solves most of the problem.

 A headgear & sliding jig are helpful in thisA headgear & sliding jig are helpful in this
situation.situation.
 However, when the required movement isHowever, when the required movement is
3mm or more, this becomes a challenging3mm or more, this becomes a challenging
situation for the patient & orthodontist ,situation for the patient & orthodontist ,
irrespective of the treatment mechanics inirrespective of the treatment mechanics in
use.use.

Control of upper incisor torqueControl of upper incisor torque
In June 2000, Fastlight presented aIn June 2000, Fastlight presented a
discussion on the facial ‘tetragon’discussion on the facial ‘tetragon’
consisting of four angles:consisting of four angles:
 Upper incisor to palatal planeUpper incisor to palatal plane
 Lower incisor to mandibular planeLower incisor to mandibular plane
 Inter-incisal angleInter-incisal angle
 Maxillary/Mandibular plane angleMaxillary/Mandibular plane angle

 Upper incisor to palatal planeUpper incisor to palatal plane
 Lower incisor to mandibular planeLower incisor to mandibular plane
 Inter-incisal angleInter-incisal angle
 Maxillary/Mandibular plane angleMaxillary/Mandibular plane angle

By dividing the tetragon in half, two trianglesBy dividing the tetragon in half, two triangles
are formed. The upper triangle has angles asare formed. The upper triangle has angles as
follows:follows:
 Palatal plane to occlusal planePalatal plane to occlusal plane
 Upper incisors to palatal planeUpper incisors to palatal plane
 Upper incisors to occlusal planeUpper incisors to occlusal plane

The lower triangle has angles as follows:The lower triangle has angles as follows:
 Mandibular plane to occlusal planeMandibular plane to occlusal plane
 Lower incisors to occlusal planeLower incisors to occlusal plane
 Lower incisors to mandibular planeLower incisors to mandibular plane

 Viewing the dental complex in this mannerViewing the dental complex in this manner
provides excellent information on incisorprovides excellent information on incisor
torque,& demonstrates that different normalstorque,& demonstrates that different normals
need to be used, depending on the underlyingneed to be used, depending on the underlying
skeletal pattern.skeletal pattern.
 Anterior torque compensation is typicallyAnterior torque compensation is typically
necessary in high-angle Class I cases,& innecessary in high-angle Class I cases,& in
cases with Class II or Class III skeletal bases,cases with Class II or Class III skeletal bases,
unless it is planned to use surgery to correctunless it is planned to use surgery to correct
the skeletal pattern as part of treatment.the skeletal pattern as part of treatment.

 Incisor torque is controlled by the action of theIncisor torque is controlled by the action of the
rectangular 0.019/0.025 wire in the 0.022/0.028rectangular 0.019/0.025 wire in the 0.022/0.028
bracket slots.bracket slots.
 The MBT bracket system has been designed toThe MBT bracket system has been designed to
reduce the amount of wire bending needed.reduce the amount of wire bending needed.
 Despite this advance in bracket design, whereDespite this advance in bracket design, where
necessary the orthodontist needs to accept thenecessary the orthodontist needs to accept the
possible need to introduce bends into the steelpossible need to introduce bends into the steel
rectangular wire, to add or reduce incisorrectangular wire, to add or reduce incisor
torque, according to the requirements oftorque, according to the requirements of
individual cases.individual cases.

Vertical control of incisorsVertical control of incisors
 There is a need to open deep bite & to close anteriorThere is a need to open deep bite & to close anterior
open bite.open bite.
 Upper incisor exposure relative to upper lip (Arnett)Upper incisor exposure relative to upper lip (Arnett)
should be kept in mind.should be kept in mind.
 Early in Class II/2 treatment, considerable upperEarly in Class II/2 treatment, considerable upper
incisor intrusion occurs during the leveling process, asincisor intrusion occurs during the leveling process, as
progressively heavier wires are placed.progressively heavier wires are placed.
 Later, at the rectangular wire stage, in Class II/2 &Later, at the rectangular wire stage, in Class II/2 &
other treatments, upper incisors can be slightlyother treatments, upper incisors can be slightly
intruded, either by curve in the archwire or by the useintruded, either by curve in the archwire or by the use
of ‘J’ hook headgear, or by a combination of these.of ‘J’ hook headgear, or by a combination of these.

 An attempt may be made to extrude the upperAn attempt may be made to extrude the upper
incisors relative to the lip line .incisors relative to the lip line .
 A steel rectangular 0.019/0.025 wire with 2 or 3A steel rectangular 0.019/0.025 wire with 2 or 3
mm of anti-Spee curve is tied into the lowermm of anti-Spee curve is tied into the lower
arch.arch.
 An upper wire of 0.014 round steel is thenAn upper wire of 0.014 round steel is then
placed, with a 3mm positive Curve of Spee.placed, with a 3mm positive Curve of Spee.
 Up-and-down anterior elastics (50gm) can thenUp-and-down anterior elastics (50gm) can then
be expected to produce some upper incisorbe expected to produce some upper incisor
extrusion.extrusion.

POSITIONING OF LOWERPOSITIONING OF LOWER
INCISORS IN CLASS II CASESINCISORS IN CLASS II CASES
 Control of the A/P position of lower incisorsControl of the A/P position of lower incisors
 Movement of lower incisors in the mandibular boneMovement of lower incisors in the mandibular bone
 Favorable change in mandibular length or positionFavorable change in mandibular length or position
 Mandibular growthMandibular growth
 Augmentation of mandibular position with functionalAugmentation of mandibular position with functional
appliances?appliances?
 Orthopedic vertical control of the maxilla?Orthopedic vertical control of the maxilla?
 Unfavorable condylar changes, causing reducedUnfavorable condylar changes, causing reduced
mandibular lengthmandibular length
 Unfavorable condylar repositioning of the mandibleUnfavorable condylar repositioning of the mandible

Control of the Antero-PosteriorControl of the Antero-Posterior
position of lower incisorsposition of lower incisors
 In Class II treatment, the challenge is normallyIn Class II treatment, the challenge is normally
to bring the lower incisors sufficiently forward toto bring the lower incisors sufficiently forward to
coordinate them with the PIP for the uppercoordinate them with the PIP for the upper
incisors, as determined in Stage 1 of theincisors, as determined in Stage 1 of the
treatment planning.treatment planning.
 The lower incisor A/P position relative to theThe lower incisor A/P position relative to the
upper incisors can be changed by three mainupper incisors can be changed by three main
factors:factors:
1.Movement of lower incisors in the mandibular1.Movement of lower incisors in the mandibular
bone.bone. www.indiandentalacademy.comwww.indiandentalacademy.com

2.A change in the length of the mandible.2.A change in the length of the mandible.
3.A change in the A/P position of the3.A change in the A/P position of the
mandible, due to changes in the positionmandible, due to changes in the position
of the condyles in the fossae.of the condyles in the fossae.

Movement of lower incisors in theMovement of lower incisors in the
mandibular bonemandibular bone
 Mesial bodily movement of lower incisor isMesial bodily movement of lower incisor is
normally not possible due to anatomy of bonenormally not possible due to anatomy of bone
in lower incisor area. Therefore, any mesialin lower incisor area. Therefore, any mesial
movement of the lower incisor tip is mainly as amovement of the lower incisor tip is mainly as a
result of a change in torque.result of a change in torque.
 A rule of thumb limit for this proclination is 100A rule of thumb limit for this proclination is 100°°
to mandibular plane as set in the Class IIto mandibular plane as set in the Class II
mandibular triangle.mandibular triangle.
 As these arbitrary limits are exceeded, thereAs these arbitrary limits are exceeded, there
comes a perceived risk of instability, poorcomes a perceived risk of instability, poor
esthetics, or gingival problems.esthetics, or gingival problems.

 In Class/1 cases with Class II skeletal bases, it isIn Class/1 cases with Class II skeletal bases, it is
becoming more acceptable to procline lower incisorsbecoming more acceptable to procline lower incisors
beyond the traditional 95beyond the traditional 95°° to mandibular plane &to mandibular plane &
+2mm to APo.+2mm to APo.
 Conventional orthodontic thinking was against this,Conventional orthodontic thinking was against this,
because of the risk of gingival recession & relapse.because of the risk of gingival recession & relapse.
 However, gingival recession or periodontalHowever, gingival recession or periodontal
disadvantage has been shown not to occur & relapsedisadvantage has been shown not to occur & relapse
can be controlled with bonded retainers.can be controlled with bonded retainers.
 Geometrically, every 2.5Geometrically, every 2.5°° of proclination moves theof proclination moves the
lower incisor edges forward by 1mm (resulting inlower incisor edges forward by 1mm (resulting in
space gains of 2mm for every 2.5space gains of 2mm for every 2.5°° of proclination).of proclination).

 Consequently, because of this space gain inConsequently, because of this space gain in
Class II treatment, lower premolar extractionsClass II treatment, lower premolar extractions
are not normally needed.are not normally needed.
 The 6 degree torque feature in the MBT lowerThe 6 degree torque feature in the MBT lower
incisor bracket is helpful in preventingincisor bracket is helpful in preventing
excessive lower incisor proclination.excessive lower incisor proclination.
 A well-aligned lower arch with a 0.019/0.025A well-aligned lower arch with a 0.019/0.025
steel rectangular wire tied in place cansteel rectangular wire tied in place can
therefore often be used to support Class IItherefore often be used to support Class II
elastics for upper incisor retraction, if the caseelastics for upper incisor retraction, if the case
needs this.needs this.

Favorable change in the length orFavorable change in the length or
position of the mandibleposition of the mandible
 Lower incisor mesial movement, relative toLower incisor mesial movement, relative to
upper incisor PIP will be augmented if there is aupper incisor PIP will be augmented if there is a
favorable change in the length of the mandiblefavorable change in the length of the mandible
& hence a mesial change in ‘B’ point.& hence a mesial change in ‘B’ point.
 This assists treatment mechanics & in mostThis assists treatment mechanics & in most
cases enhances facial profile.cases enhances facial profile.
 Also, less lower incisor proclination will beAlso, less lower incisor proclination will be
needed if ‘B’ point moves forward duringneeded if ‘B’ point moves forward during

 An increase in mandibular length isAn increase in mandibular length is
therefore desirable for most Class IItherefore desirable for most Class II
cases, but it is questionable whether therecases, but it is questionable whether there
is any procedure which the orthodontistis any procedure which the orthodontist
can follow which will achieve this.can follow which will achieve this.

Mandibular growthMandibular growth
 For growing individuals it is necessary toFor growing individuals it is necessary to
estimate the likely quantity & direction ofestimate the likely quantity & direction of
mandibular growth.mandibular growth.
 Generally low-angle cases show moreGenerally low-angle cases show more
favorable change in ‘B’ point than average-favorable change in ‘B’ point than average-
angle or high-angle cases.angle or high-angle cases.
 More favorable late mandibular growth canMore favorable late mandibular growth can
be expected in growing boys than in girls.be expected in growing boys than in girls.
(Riolo M et al 1974)(Riolo M et al 1974)

Augmentation of mandibularAugmentation of mandibular
position with functional appliances?position with functional appliances?
 The use of a functional appliance in the mixedThe use of a functional appliance in the mixed
dentition often produces a substantial &dentition often produces a substantial &
pleasing change for a young patient with apleasing change for a young patient with a
Class II malocclusion, with consequentClass II malocclusion, with consequent
improvement in the facial appearance.improvement in the facial appearance.
 The reason for this pleasing change is thatThe reason for this pleasing change is that
functional appliances have the potential tofunctional appliances have the potential to
produce dental & skeletal change.produce dental & skeletal change.

 They have the potential to procline lowerThey have the potential to procline lower
incisors, retrocline upper incisors, favorablyincisors, retrocline upper incisors, favorably
modify mandibular growth,& restrict maxillarymodify mandibular growth,& restrict maxillary
growth.growth.
 Over the years, there has been muchOver the years, there has been much
discussion & research to establish whetherdiscussion & research to establish whether
functional appliances can consistently increasefunctional appliances can consistently increase
the final length of the mandible, beyond what itthe final length of the mandible, beyond what it
would have been without the functionalwould have been without the functional
appliance.appliance.
 This is a difficult topic to investigate,& atThis is a difficult topic to investigate,& at
present the research evidence does not confirmpresent the research evidence does not confirm
that it is possible to modify the quantity ofthat it is possible to modify the quantity of
mandibular growth using functional appliances.mandibular growth using functional appliances.

 Despite this, many orthodontists feel thatDespite this, many orthodontists feel that
functional appliances have a useful place in thefunctional appliances have a useful place in the
management of Class II/1 malocclusions,management of Class II/1 malocclusions,
because they produce a substantial earlybecause they produce a substantial early
improvement for the patient,& can reduce theimprovement for the patient,& can reduce the
amount of treatment needed in the fixedamount of treatment needed in the fixed
appliance phase.appliance phase.
 InIn 1998, Pancherz et al1998, Pancherz et al investigated 98 Classinvestigated 98 Class
II/1 malocclusions treated with the HerbestII/1 malocclusions treated with the Herbest
appliance, to assessappliance, to assess ‘effective condylar growth’.‘effective condylar growth’.
This term was used to describe the summationThis term was used to describe the summation
of the condylar remodeling, glenoid fossaof the condylar remodeling, glenoid fossa
remodeling,& condylar repositioning changes.remodeling,& condylar repositioning changes.

 In individuals with anterior mandibularIn individuals with anterior mandibular
autorotation, they found relatively more forwardautorotation, they found relatively more forward
change in chin position.change in chin position.
 In individuals with posterior mandibularIn individuals with posterior mandibular
autorotation, they found relatively moreautorotation, they found relatively more
backward change in chin position.backward change in chin position.
 In practical terms, if a functional appliance is toIn practical terms, if a functional appliance is to
be used in a case, it is helpful to use it in thebe used in a case, it is helpful to use it in the
late mixed dentition. At this time, there is plentylate mixed dentition. At this time, there is plenty
of growth available,& it is possible to moveof growth available,& it is possible to move
straight into the fixed appliance phase, as thestraight into the fixed appliance phase, as the
functional appliance phase ends.functional appliance phase ends.

 If the functional appliance is introduced in theIf the functional appliance is introduced in the
early mixed dentition, it can be difficult & timeearly mixed dentition, it can be difficult & time
consuming to manage the inevitable retentionconsuming to manage the inevitable retention
phase before fixed appliances can be placed.phase before fixed appliances can be placed.
 Some functional appliance effects may occurSome functional appliance effects may occur
during the use of Class II elastics in a fullyduring the use of Class II elastics in a fully
bracketed fixed appliance case.bracketed fixed appliance case.
 For example, this ‘functional effect’ is frequentlyFor example, this ‘functional effect’ is frequently
seen when Class II elastics are used in theseen when Class II elastics are used in the
second phase of a Class II/2 treatment in asecond phase of a Class II/2 treatment in a
growing individual.growing individual.

Favorable condylar repositioning ofFavorable condylar repositioning of
the mandiblethe mandible
 In a few cases, the mandible may be positionedIn a few cases, the mandible may be positioned
distally at the start of treatment,& then thedistally at the start of treatment,& then the
condyles can be expected to reposition morecondyles can be expected to reposition more
mesially into a centered position, as treatmentmesially into a centered position, as treatment
progresses.progresses.
 For e.g. in some Class II/2 treatments, there isFor e.g. in some Class II/2 treatments, there is
the chance of a small but favorable mesialthe chance of a small but favorable mesial
movement of ‘B’ point after the case has beenmovement of ‘B’ point after the case has been
converted to a Class II/1 malocclusion,converted to a Class II/1 malocclusion,
although this is difficult to confirm with researchalthough this is difficult to confirm with research
evidence.evidence. www.indiandentalacademy.comwww.indiandentalacademy.com

Orthopedic vertical control of theOrthopedic vertical control of the
maxillamaxilla
 Although this is discussed as a method ofAlthough this is discussed as a method of
achieving mesial movement of point B , thereachieving mesial movement of point B , there
seems to be little evidence that this is a usefulseems to be little evidence that this is a useful
orthodontic treatment procedure.orthodontic treatment procedure.
 It is difficult to achieve vertical control of theIt is difficult to achieve vertical control of the
maxilla orthodontically.maxilla orthodontically.

Unfavorable condylar changes,Unfavorable condylar changes,
causing a reduction in the length ofcausing a reduction in the length of
the mandiblethe mandible
 Effective shortening of the mandible can occurEffective shortening of the mandible can occur
in some cases, due to changes in the condylarin some cases, due to changes in the condylar
regions of the mandible.regions of the mandible.
 In some instances, this will be identified asIn some instances, this will be identified as
being due to idiopathic condylar resorption.being due to idiopathic condylar resorption.
 This condition is fortunately rare, but can resultThis condition is fortunately rare, but can result
in unfavorable downwards & backwardsin unfavorable downwards & backwards
movement of ‘B’ point in response to changesmovement of ‘B’ point in response to changes
in the condylar region.in the condylar region.
 It is predominantly seen in female patients.It is predominantly seen in female patients.www.indiandentalacademy.comwww.indiandentalacademy.com

 Idiopathic condylar resorption occurs mainly inIdiopathic condylar resorption occurs mainly in
females. It is not well understood,& fortunatelyfemales. It is not well understood,& fortunately
is rare. It can be unilateral. It causes ais rare. It can be unilateral. It causes a
reduction in the length of the mandible,& this inreduction in the length of the mandible,& this in
turn results in an increase in overjet & anteriorturn results in an increase in overjet & anterior
openbite.openbite.

Unfavorable condylar repositioningUnfavorable condylar repositioning
of the mandibleof the mandible
 During initial leveling & aligning of some ClassDuring initial leveling & aligning of some Class
II/1 malocclusions, the condyles, mayII/1 malocclusions, the condyles, may
reposition distally, giving a substantial &reposition distally, giving a substantial &
unfavorable change in ‘B’ point.unfavorable change in ‘B’ point.
 This results from a situation where centricThis results from a situation where centric
occlusion & centric relation are not coincidentalocclusion & centric relation are not coincidental
at the start of treatment.at the start of treatment.
 Roth has advocated the early use of an acrylicRoth has advocated the early use of an acrylic
splint to identify these individuals & establishsplint to identify these individuals & establish
true mandibular position before commencingtrue mandibular position before commencing
treatment.treatment. www.indiandentalacademy.comwww.indiandentalacademy.com

AN OVERVIEW OF CLASS IIIAN OVERVIEW OF CLASS III
TREATMENTTREATMENT

INTRODUCTIONINTRODUCTION
Successful treatment of Class III cases depends onSuccessful treatment of Class III cases depends on
identifying the true nature of the malocclusion,& onidentifying the true nature of the malocclusion,& on
evaluating any probable growth changes. Theevaluating any probable growth changes. The
following are relevant to the management of thesefollowing are relevant to the management of these
cases:cases:
 Accurate record-taking-displacementsAccurate record-taking-displacements
 Mandibular prognathism or maxillary retrognathism?Mandibular prognathism or maxillary retrognathism?
 The timing of Class III treatmentThe timing of Class III treatment
 Making the correct surgical/non-surgical decisionMaking the correct surgical/non-surgical decision
 The posterior ‘squeezing out’ effect of molar crowdingThe posterior ‘squeezing out’ effect of molar crowding
 The use of Class III elasticsThe use of Class III elastics

Accurate record-taking-Accurate record-taking-
displacementsdisplacements
 If there is a mandibular displacement betweenIf there is a mandibular displacement between
centric relation (CR) & centric occlusion (CO),centric relation (CR) & centric occlusion (CO),
this needs to be identified & accuratelythis needs to be identified & accurately
recorded at the record-taking appointment.recorded at the record-taking appointment.
 Displacement can be a major factor inDisplacement can be a major factor in
determining a surgical versus non-surgicaldetermining a surgical versus non-surgical
decision for some patients.decision for some patients.

 Mandibular displacements are frequently foundMandibular displacements are frequently found
in Class III malocclusions. They need to bein Class III malocclusions. They need to be
identified and accurately recorded.identified and accurately recorded.

 A waxbite is required to accurately record theA waxbite is required to accurately record the
A/P position of the mandible, with condylesA/P position of the mandible, with condyles
centered. In this way, accurate treatmentcentered. In this way, accurate treatment
planning will be possible, based on recordsplanning will be possible, based on records
taken with the treatment at the CR position.taken with the treatment at the CR position.

Mandibular prognathism orMandibular prognathism or
maxillary retrognathismmaxillary retrognathism
 Early in Class III treatment planning, it is necessary toEarly in Class III treatment planning, it is necessary to
decide whether the case has a prognathic mandible ordecide whether the case has a prognathic mandible or
a retrognathic maxilla, or a combination of these twoa retrognathic maxilla, or a combination of these two
possibilities.possibilities.
 In many cases, this will be clear from visualIn many cases, this will be clear from visual
examination of the patient & the radiograph.examination of the patient & the radiograph.
 There are several methods of conventionalThere are several methods of conventional
cephalometric analysis to assess A/P skeletalcephalometric analysis to assess A/P skeletal
discrepancy.discrepancy.
 For e.g. SNA,SNB,& ANB can be compared withFor e.g. SNA,SNB,& ANB can be compared with
Michigan normals for a male or female of the sameMichigan normals for a male or female of the same
age.age. www.indiandentalacademy.comwww.indiandentalacademy.com

 This method has accepted shortcomings, butThis method has accepted shortcomings, but
has been a mainstay indicator of skeletalhas been a mainstay indicator of skeletal
disproportion for many years.disproportion for many years.
 McNamara suggested dropping a line fromMcNamara suggested dropping a line from
Nasion perpendicular to Frankfort horizontal toNasion perpendicular to Frankfort horizontal to
evaluate the position of ‘A’ point & ‘B’ point, asevaluate the position of ‘A’ point & ‘B’ point, as
a useful indicator of skeletal discrepancy.a useful indicator of skeletal discrepancy.
 The Arnett analysis uses a true vertical lineThe Arnett analysis uses a true vertical line
(TVL) as a facial reference & it is(TVL) as a facial reference & it is
recommended as a more sophisticated &recommended as a more sophisticated &
accurate method of deciding the needs of theaccurate method of deciding the needs of the
case.case.

The timing of Class III treatmentThe timing of Class III treatment

Early correction of mandibularEarly correction of mandibular
displacementsdisplacements
 These should be identified at dental age 8 or 9,These should be identified at dental age 8 or 9,
soon after the adult incisors erupt.soon after the adult incisors erupt.
 This incisor relationship has the potential toThis incisor relationship has the potential to
restrict maxillary development & encouragerestrict maxillary development & encourage
mandibular growth, thereby worsening themandibular growth, thereby worsening the
Class III problem.Class III problem.
 This is similar to the effect of a functionalThis is similar to the effect of a functional
appliance in Class II treatment.appliance in Class II treatment.
 Normally, such displacements can be correctedNormally, such displacements can be corrected
by simple tooth movements,& it is important forby simple tooth movements,& it is important for
treatment to be provided at an early age.treatment to be provided at an early age.

 Subsequently, unrestricted maxillarySubsequently, unrestricted maxillary
development can resume, & if thedevelopment can resume, & if the
condyles are centered in the fossae, thiscondyles are centered in the fossae, this
will eliminate the potential ‘functionalwill eliminate the potential ‘functional
appliance’ effect of the original mandibularappliance’ effect of the original mandibular
displacement.displacement.

Maxillary retrognathismMaxillary retrognathism
 Growing patients who present with maxillaryGrowing patients who present with maxillary
retrognathism should be considered for earlyretrognathism should be considered for early
expansion & development of the maxilla.expansion & development of the maxilla.
 This may involve the use of rapid maxillaryThis may involve the use of rapid maxillary
expansion & a reverse headgear.expansion & a reverse headgear.
 Subsequently, a palatal bar can be used toSubsequently, a palatal bar can be used to
stabilize the skeletal change, & then full fixedstabilize the skeletal change, & then full fixed
appliance treatment can be commenced atappliance treatment can be commenced at
approximately 12 years of age.approximately 12 years of age.

Borderline surgical casesBorderline surgical cases
 In some cases with mandibular excess, theIn some cases with mandibular excess, the
diagnosis will suggest that mandibular surgerydiagnosis will suggest that mandibular surgery
may be needed.may be needed.
 It is helpful to delay orthodontic treatment forIt is helpful to delay orthodontic treatment for
such cases, if possible.such cases, if possible.
 This will allow assessment of growth patterns,This will allow assessment of growth patterns,
using regular cephalometric radiographs, sousing regular cephalometric radiographs, so
that a more informed surgical/non-surgicalthat a more informed surgical/non-surgical
decision can be reacheddecision can be reached

Class III surgical casesClass III surgical cases
 Some cases are clearly Class III surgicalSome cases are clearly Class III surgical
cases from the outset, & should not becases from the outset, & should not be
treated until all growth has ceased , Maytreated until all growth has ceased , May
be beyond the age of 20 years in males &be beyond the age of 20 years in males &
a little earlier in females.a little earlier in females.

The surgical/non-surgical decisionThe surgical/non-surgical decision
in Class III treatmentin Class III treatment
It is important to recognize those Class III casesIt is important to recognize those Class III cases
which have a major skeletal disproportion,which have a major skeletal disproportion,
either at the time of assessment, or whereeither at the time of assessment, or where
there is a probability of unfavorable growth.there is a probability of unfavorable growth.
Treatment on basis of orthodontics aloneTreatment on basis of orthodontics alone
should be delayed, or discarded as possibility.should be delayed, or discarded as possibility.
The same seven measurements will beThe same seven measurements will be
considered, for cases where it is assumed thatconsidered, for cases where it is assumed that
the upper-& mid-thirds of the facial profiles arethe upper-& mid-thirds of the facial profiles are
close to ideal,& that the upper incisors are wellclose to ideal,& that the upper incisors are well
positioned.positioned. www.indiandentalacademy.comwww.indiandentalacademy.com

 Solution A-a surgical/orthodontic correction toSolution A-a surgical/orthodontic correction to
an ideal result. If it is determined thatan ideal result. If it is determined that
mandibular surgery will be required, then themandibular surgery will be required, then the
surgeon will normally wait until all growth hassurgeon will normally wait until all growth has
finished, which may be as late as 22 years offinished, which may be as late as 22 years of
age in males.age in males.
 The surgeon will then require the orthodontistThe surgeon will then require the orthodontist
to decompensate the incisors.to decompensate the incisors.
 Correction will be achieved by A/P realignmentCorrection will be achieved by A/P realignment
of the mandible &/or maxilla, with transverseof the mandible &/or maxilla, with transverse
correction of the maxilla if necessary.correction of the maxilla if necessary.
 This should lead to an optimal facial & dentalThis should lead to an optimal facial & dental
result.result. www.indiandentalacademy.comwww.indiandentalacademy.com

 If a combined surgical & orthodontic solution isIf a combined surgical & orthodontic solution is
used to treat this case, a close-to-ideal facialused to treat this case, a close-to-ideal facial
profile & dental outcome should be possible. Aprofile & dental outcome should be possible. A
6-mm mandibular set-back will result in6-mm mandibular set-back will result in
measurements to true vertical line (TVL) whichmeasurements to true vertical line (TVL) which
are within 1 SD of the ideal.are within 1 SD of the ideal.

 Situation B-orthodontic masking of a mild ClassSituation B-orthodontic masking of a mild Class
III skeletal case. If the underlying skeletalIII skeletal case. If the underlying skeletal
discrepancy is mild, it may be decided to followdiscrepancy is mild, it may be decided to follow
a treatment plan based on orthodontics alone.a treatment plan based on orthodontics alone.
 This will allow correction to be commencedThis will allow correction to be commenced
much earlier,& the patient will be informed ofmuch earlier,& the patient will be informed of
the possibility of late mandibular growth.the possibility of late mandibular growth.
 The orthodontist will then solve the problem byThe orthodontist will then solve the problem by
‘masking’ the underlying Class III discrepancy‘masking’ the underlying Class III discrepancy
by dental compensation.by dental compensation.
 This will involve proclination of upper incisorsThis will involve proclination of upper incisors
&/or retroclination of lower incisors.&/or retroclination of lower incisors.

 Good patient cooperation with Class IIIGood patient cooperation with Class III
elastics and/or a face mask will normallyelastics and/or a face mask will normally
be needed in this type of treatment.be needed in this type of treatment.
 This should lead to an acceptable dental &This should lead to an acceptable dental &
facial outcome without the need forfacial outcome without the need for
orthognathic surgery, which patients wishorthognathic surgery, which patients wish
to avoid.to avoid.

 In this mild Class III case, a treatment plan canIn this mild Class III case, a treatment plan can
be based on orthodontic tooth movements tobe based on orthodontic tooth movements to
mask the slight underlying skeletal discrepancy.mask the slight underlying skeletal discrepancy.
This can lead to a good dental outcome, &This can lead to a good dental outcome, &
some improvement in facial profilesome improvement in facial profile
measurement. In this theoreticalmeasurement. In this theoretical
representation, the upper incisors wererepresentation, the upper incisors were
proclined 2 degrees & the lowers wereproclined 2 degrees & the lowers were
retroclined 8 degrees.retroclined 8 degrees.

 Situation C- late mandibular growth. After orthodonticSituation C- late mandibular growth. After orthodontic
masking of a mild Class III malocclusion, latemasking of a mild Class III malocclusion, late
mandibular growth can occur, especially in males.mandibular growth can occur, especially in males.
 This is a difficult situation to manage.This is a difficult situation to manage.
 Sometimes the patient will find the late change inSometimes the patient will find the late change in
dental & facial outcome acceptable,& seek no furtherdental & facial outcome acceptable,& seek no further
 However, if mandibular surgery is deemed necessary,However, if mandibular surgery is deemed necessary,
there is limited scope for facial improvement from thethere is limited scope for facial improvement from the
surgery, because of the dentally compensated teeth.surgery, because of the dentally compensated teeth.
 The incisors will need to be decompensated byThe incisors will need to be decompensated by
orthodontics before surgery, if there is to be an optimalorthodontics before surgery, if there is to be an optimal
benefit from the surgery.benefit from the surgery.

 In some cases, late mandibular growth occursIn some cases, late mandibular growth occurs
after the type of treatment shown in ‘B’ above.after the type of treatment shown in ‘B’ above.
This is difficult to manage. If a decision is madeThis is difficult to manage. If a decision is made
to carry out mandibular surgery, it is oftento carry out mandibular surgery, it is often
necessary to provide further orthodonticnecessary to provide further orthodontic
treatment to decompensate the incisors, beforetreatment to decompensate the incisors, before
the surgery.the surgery.

The posterior ‘squeezing out’ effectThe posterior ‘squeezing out’ effect
of molar crowdingof molar crowding
 The theory suggests that a squeezing out effectThe theory suggests that a squeezing out effect
can occur because of crowding in the molarcan occur because of crowding in the molar
regions, which can contribute to an anteriorregions, which can contribute to an anterior
open-bite malocclusion in a mandible with pooropen-bite malocclusion in a mandible with poor
vertical growth in the ramus area.vertical growth in the ramus area.
 Alternatively, good ramus growth can lead to aAlternatively, good ramus growth can lead to a
Class III malocclusion.Class III malocclusion.
 This concept is not well understood,& has notThis concept is not well understood,& has not
been fully investigated.been fully investigated.

 However, some carefully selected Class IIIHowever, some carefully selected Class III
cases & some open-bite cases respond well tocases & some open-bite cases respond well to
a treatment approach involving second molara treatment approach involving second molar
extractions.extractions.
 This suggests some validity to the theory of aThis suggests some validity to the theory of a
squeezing out effect.squeezing out effect.

 Posterior ‘squeezing out effect’ can be relievedPosterior ‘squeezing out effect’ can be relieved
by extraction of second permanent molars inby extraction of second permanent molars in
selected cases, which is helpful to treatmentselected cases, which is helpful to treatment
mechanics.mechanics.

Class III mechanicsClass III mechanics
 Inter-maxillary Class III elastics are mostInter-maxillary Class III elastics are most
helpful in orthodontic (non-surgical) correctionhelpful in orthodontic (non-surgical) correction
of Class III cases.of Class III cases.

 They tend to produce lower incisorThey tend to produce lower incisor
retroclination, upper incisor proclination,& A/Pretroclination, upper incisor proclination,& A/P
correction of the molar relationship.correction of the molar relationship.
 All components of the Class III elastic force canAll components of the Class III elastic force can
therefore be helpful in reaching treatment goalstherefore be helpful in reaching treatment goals
in average or low angle cases.in average or low angle cases.
 With Class III elastics the vertical componentsWith Class III elastics the vertical components
may be perceived as disadvantageous inmay be perceived as disadvantageous in
higher angle cases.higher angle cases.

 This shows the force vectors involved in theThis shows the force vectors involved in the
use of Class III elastics. In low angle deepuse of Class III elastics. In low angle deep
cases all four vectors are helpful. However, incases all four vectors are helpful. However, in
the high angle Class III cases with an openbitethe high angle Class III cases with an openbite
tendency, upper molar extrusion is contra-tendency, upper molar extrusion is contra-
indicated. This can be counteracted with aindicated. This can be counteracted with a
palatal bar.palatal bar.

The four stage treatment planningThe four stage treatment planning
process for Class III casesprocess for Class III cases
The treatment planning sequence is similarThe treatment planning sequence is similar
to the Class II method. The four stages into the Class II method. The four stages in
planning are described below:planning are described below:
 Setting a PIP for the upper incisorsSetting a PIP for the upper incisors
 The lower incisorsThe lower incisors
 The remaining upper teethThe remaining upper teeth
 The remaining lower teethThe remaining lower teeth

Stage 1-Setting a PIP for the upperStage 1-Setting a PIP for the upper
incisorsincisors
 The first stage in Class III treatment planningThe first stage in Class III treatment planning
concerns upper incisor position. It is necessaryconcerns upper incisor position. It is necessary
to determine an ideal position & then decideto determine an ideal position & then decide
whether it can be achieved. If not, a modifiedwhether it can be achieved. If not, a modified
position may be appropriate, which is less thanposition may be appropriate, which is less than
ideal, but acceptable. In this way a ‘plannedideal, but acceptable. In this way a ‘planned
incisor position’, or PIP, is determined.incisor position’, or PIP, is determined.

Stage 2-The lower incisorsStage 2-The lower incisors
The second stage of treatment planningThe second stage of treatment planning
involves positioning of the lower incisors. Thisinvolves positioning of the lower incisors. This
is frequently a key concern in Class III casesis frequently a key concern in Class III cases
with mandibular excess.with mandibular excess.
..

It is possible to position the lower incisors inIt is possible to position the lower incisors in
good relationship to the PIP for the uppergood relationship to the PIP for the upper
incisors? Can we achieve the required lowerincisors? Can we achieve the required lower
incisors position by orthodontics alone? Inincisors position by orthodontics alone? In
Class III cases with mandibular excess, this isClass III cases with mandibular excess, this is
frequently the key question, especially infrequently the key question, especially in
growing individuals Often the answer will begrowing individuals Often the answer will be
‘probably, provided growth will not be‘probably, provided growth will not be
unfavorable’.unfavorable’.
Alternatively, the answer may be ‘possibly, butAlternatively, the answer may be ‘possibly, but
there is concern about future growth, and it isthere is concern about future growth, and it is
preferable to wait this to express itself.preferable to wait this to express itself.

Stage 3-The remaining upper teethStage 3-The remaining upper teeth
 In the discussion on Class II treatment planningIn the discussion on Class II treatment planning
3 of the process concerned the remaining lower3 of the process concerned the remaining lower
teeth, followed by stage 4- the remaining upperteeth, followed by stage 4- the remaining upper
teeth.teeth.

 In Class III treatment planning theIn Class III treatment planning the
opposite applies.opposite applies.
 It is beneficial to evaluate the remainingIt is beneficial to evaluate the remaining
upper teeth at stage 3.upper teeth at stage 3.
 If upper premolar extractions areIf upper premolar extractions are
necessary (usually second premolars)necessary (usually second premolars)
then it is normally logical to extract lowerthen it is normally logical to extract lower
first premolars, in a Class III case.first premolars, in a Class III case.

 The third stage therefore involves decidingThe third stage therefore involves deciding
how to position the rest of the upper teeth tohow to position the rest of the upper teeth to
fit the PIP for the upper incisors.fit the PIP for the upper incisors.
 It normally assists Class III treatmentIt normally assists Class III treatment
mechanics if upper arch extractions can bemechanics if upper arch extractions can be
avoided.avoided.
 The dental VTO will confirm the requiredThe dental VTO will confirm the required
movement of molars & canines.movement of molars & canines.

Stage 4-the remaining lower teethStage 4-the remaining lower teeth
 How can the rest of the lower teeth beHow can the rest of the lower teeth be
positioned to fit the lower incisor position?positioned to fit the lower incisor position?
 Does the case require lower extractions to dealDoes the case require lower extractions to deal
with lower arch crowding, or to allow sufficientwith lower arch crowding, or to allow sufficient
retraction of the lower incisors?retraction of the lower incisors?
 Lower premolar extractions assist in theLower premolar extractions assist in the
retraction of lower incisors, & are helpful toretraction of lower incisors, & are helpful to
Class III treatment mechanics in many cases.Class III treatment mechanics in many cases.
 The dental VTO can be used to reach a correctThe dental VTO can be used to reach a correct
decision.decision.
 In some Class III marginal extractions cases,In some Class III marginal extractions cases,
second molars may be considered.second molars may be considered.www.indiandentalacademy.comwww.indiandentalacademy.com

 The final stage of Class III treatmentThe final stage of Class III treatment
planning. It is necessary to assess lowerplanning. It is necessary to assess lower
arch crowding or spacing,& decide how toarch crowding or spacing,& decide how to
position the rest of the lower teeth to fit theposition the rest of the lower teeth to fit the
planned lower incisor position.planned lower incisor position.

PIP Components In Class IIIPIP Components In Class III
TreatmentTreatment
 For each Class III case, it is necessary to set a PIP asFor each Class III case, it is necessary to set a PIP as
a treatment goal which will result in the upper incisorsa treatment goal which will result in the upper incisors
having correct antero-posterior & vertical positioning,having correct antero-posterior & vertical positioning,
with appropriate torque.with appropriate torque.
 As with Class II cases, before reaching a decisionAs with Class II cases, before reaching a decision
about a suitable goal, it is first necessary to analyzeabout a suitable goal, it is first necessary to analyze
the existing position of the incisors, using eitherthe existing position of the incisors, using either
conventional cephalometry or the Arnett analysis.conventional cephalometry or the Arnett analysis.
 The same approach & values should be used whenThe same approach & values should be used when
analyzing the pre-treatment upper incisor position foranalyzing the pre-treatment upper incisor position for
Class III cases.Class III cases.

 For each Class III case, at the start ofFor each Class III case, at the start of
treatment planning it is necessary totreatment planning it is necessary to
establish a PIP which will result in upperestablish a PIP which will result in upper
incisors having correct A/P & verticalincisors having correct A/P & vertical
positioning, with appropriate torque.positioning, with appropriate torque.

Upper Incisor movement In ClassUpper Incisor movement In Class
III TreatmentIII Treatment
 Having set a PIP for a case, controlledHaving set a PIP for a case, controlled
upper incisor movement will be needed toupper incisor movement will be needed to
reach the goal.reach the goal.
 It is helpful to plan the upper incisor toothIt is helpful to plan the upper incisor tooth
movements in isolation,& then considermovements in isolation,& then consider
the lower tooth movements.the lower tooth movements.
 The lower arch may be disregarded at thisThe lower arch may be disregarded at this
stage, except as a possible source ofstage, except as a possible source of
anchorage when using Class III elastics.anchorage when using Class III elastics.

 If a Class III case requires mesial movementIf a Class III case requires mesial movement
of upper incisors, it can be achieved in twoof upper incisors, it can be achieved in two
ways:ways:
1.By proclination & mesial movement of upper1.By proclination & mesial movement of upper
incisors within the available bone. Manyincisors within the available bone. Many
Class III cases require mesial movement ofClass III cases require mesial movement of
upper incisors, to keep pace with the growingupper incisors, to keep pace with the growing
mandible. When upper incisors aremandible. When upper incisors are
proclined forwards, each 2.5proclined forwards, each 2.5°° of proclinationof proclination
creates approximately 1mm of space percreates approximately 1mm of space per
side, or 2mm in total.side, or 2mm in total.

For this reason upper premolar extractions areFor this reason upper premolar extractions are
not advisable in many Class III cases. If uppernot advisable in many Class III cases. If upper
premolars are extracted it can be difficult orpremolars are extracted it can be difficult or
impossible to procline upper incisors.impossible to procline upper incisors.
2. By mesial movement of the maxillary bone2. By mesial movement of the maxillary bone
result of normal growth or orthodonticresult of normal growth or orthodontic
procedures.procedures.

Mesial movement of upper incisorsMesial movement of upper incisors
within the bonewithin the bone
 During tooth leveling with the opening wires,During tooth leveling with the opening wires,
there is a tendency for upper incisors to movethere is a tendency for upper incisors to move
mesially due to bracket tip.mesially due to bracket tip.
 In Class III cases, this is normally beneficial,&In Class III cases, this is normally beneficial,&
moves the upper incisors towards PIP.moves the upper incisors towards PIP.
 Likewise, at the rectangular HANT & theLikewise, at the rectangular HANT & the
rectangular steel wire stages, the A/Prectangular steel wire stages, the A/P
expansion & torque effects tend to produceexpansion & torque effects tend to produce
beneficial changes for most Class III cases.beneficial changes for most Class III cases.
 This can be further augmented by the use ofThis can be further augmented by the use of
Class III elastics.Class III elastics. www.indiandentalacademy.comwww.indiandentalacademy.com

Limits to mesial movement of upperLimits to mesial movement of upper
incisorsincisors
 The risks lie in two areas:The risks lie in two areas:
1.Excessive proclination: It is necessary to avoid1.Excessive proclination: It is necessary to avoid
excessive proclination of the upper incisors,excessive proclination of the upper incisors,
otherwise unaesthetic appearance &otherwise unaesthetic appearance &
inadequate function will result. As a generalinadequate function will result. As a general
rule, proclination of the upper incisors beyondrule, proclination of the upper incisors beyond
120120°° to the maxillary plane should be avoided,to the maxillary plane should be avoided,
although there is individual variation. In somealthough there is individual variation. In some
cases, less proclination than 120cases, less proclination than 120°° may bemay be
appropriate. Gingival recession & long clinicalappropriate. Gingival recession & long clinical
crowns can result from excessive proclination.crowns can result from excessive proclination.

 Excessive proclination of upper incisorsExcessive proclination of upper incisors
beyond 120beyond 120° to the maxillary plane should° to the maxillary plane should
be avoided as a general rule, althoughbe avoided as a general rule, although
there is individual variation.there is individual variation.

2.Failure to fully achieve a positive overjet: this2.Failure to fully achieve a positive overjet: this
can be due to the forward position of the lowercan be due to the forward position of the lower
incisors, or other reasons, & the resulting biteincisors, or other reasons, & the resulting bite
can be difficult to manage. If this is allowed tocan be difficult to manage. If this is allowed to
persist, then there is a risk of enamel damagepersist, then there is a risk of enamel damage
&/or root resorption. Accordingly, it is unwise to&/or root resorption. Accordingly, it is unwise to
attempt to correct a Class III incisor relationshipattempt to correct a Class III incisor relationship
by orthodontic procedures alone, unless it isby orthodontic procedures alone, unless it is
clear from the outset that full correction can beclear from the outset that full correction can be
achieved, & a near normal overjet obtained.achieved, & a near normal overjet obtained.

 It is unwise to attempt to correct the Class IIIIt is unwise to attempt to correct the Class III
relationship by orthodontists alone, unless itrelationship by orthodontists alone, unless it
is clear that a normal overjet can beis clear that a normal overjet can be
achieved. A persistent edge-to-edge bite canachieved. A persistent edge-to-edge bite can
be associated with root resorption &/orbe associated with root resorption &/or
enamel damage.enamel damage.

Mesial movement of maxillary boneMesial movement of maxillary bone
due to growthdue to growth
 Maxillary growth cannot be relied on as aMaxillary growth cannot be relied on as a
useful factor in correction of Class IIIuseful factor in correction of Class III
malocclusions.malocclusions.
 Generally in this type of case, maxillaryGenerally in this type of case, maxillary
growth will not be favorable or helpful ingrowth will not be favorable or helpful in
reaching the PIP for the upper incisors.reaching the PIP for the upper incisors.

Mesial movement of maxillary boneMesial movement of maxillary bone
due to orthodontic treatmentdue to orthodontic treatment
 In growing individuals who have maxillary deficiency,In growing individuals who have maxillary deficiency,
consideration can be given to treatment proceduresconsideration can be given to treatment procedures
which will encourage orthopedic change within thewhich will encourage orthopedic change within the
maxillary bone.maxillary bone.
 These can include rapid maxillary expansion,& theThese can include rapid maxillary expansion,& the
use of reverse headgear, but there is muchuse of reverse headgear, but there is much
controversy & uncertainty surrounding the effect &controversy & uncertainty surrounding the effect &
stability of this type of treatment.stability of this type of treatment.
 However, there is some evidence in the literatureHowever, there is some evidence in the literature
that favorable mesial change in the maxilla can bethat favorable mesial change in the maxilla can be
produced, thereby assisting in mesial movement ofproduced, thereby assisting in mesial movement of
the upper incisors toward PIP.the upper incisors toward PIP. www.indiandentalacademy.comwww.indiandentalacademy.com

 If favorable orthopedic change can beIf favorable orthopedic change can be
achieved in the maxilla, this assists inachieved in the maxilla, this assists in
mesial movement of upper incisors towardsmesial movement of upper incisors towards
PIP.PIP.

LOWER INCISOR MOVEMENT INLOWER INCISOR MOVEMENT IN
CLASS III CASESCLASS III CASES
 Distal movement of the lower incisors canDistal movement of the lower incisors can
be achieved by distal movement of thebe achieved by distal movement of the
teeth within the mandibular bone, or byteeth within the mandibular bone, or by
distal movement of the mandible itself,distal movement of the mandible itself,
when there is a displacement.when there is a displacement.
 Unfavorable mesial movement of theUnfavorable mesial movement of the
lower incisors can occur because oflower incisors can occur because of
mandibular growth.mandibular growth.

Distal movement & retraction of theDistal movement & retraction of the
lower incisors within the mandibularlower incisors within the mandibular
bonebone
 In most non-surgical Class III treatments, it isIn most non-surgical Class III treatments, it is
helpful to retract & retrocline the lower incisors.helpful to retract & retrocline the lower incisors.
 This can compensate for mild mandibularThis can compensate for mild mandibular
prognathism or mild maxillary retrognathism, &prognathism or mild maxillary retrognathism, &
hence mask the underlying skeletalhence mask the underlying skeletal
discrepancy.discrepancy.
 Retraction & retroclination beyond a figure ofRetraction & retroclination beyond a figure of
approximately 80approximately 80° to the mandibular plane is° to the mandibular plane is
undesirable, because of the risk of dehiscenceundesirable, because of the risk of dehiscence
&/lack of bone support for the over-retracted&/lack of bone support for the over-retracted
incisors.incisors. www.indiandentalacademy.comwww.indiandentalacademy.com

..
As a general rule, retraction &As a general rule, retraction &
retroclination of lower incisorsretroclination of lower incisors
beyond 80° to the mandibular planebeyond 80° to the mandibular plane
is undesirableis undesirable

 Also, dental esthetics & function will beAlso, dental esthetics & function will be
adversely affected.adversely affected.
 Although 80° is a good rule of thumb, In someAlthough 80° is a good rule of thumb, In some
cases a limit of 85° may be appropriate, & acases a limit of 85° may be appropriate, & a
case-by-case assessment is recommended.case-by-case assessment is recommended.
 The required retraction & retroclination of theThe required retraction & retroclination of the
lower incisors is normally achieved with thelower incisors is normally achieved with the
assistance of Class III elastics, & treatmentassistance of Class III elastics, & treatment
mechanics are easier in cases where lowermechanics are easier in cases where lower
teeth have been extracted.teeth have been extracted.

 Lower first premolar extractions are mostLower first premolar extractions are most
favorable in assisting lower incisor distalfavorable in assisting lower incisor distal
movement, but loss of lower second incisorsmovement, but loss of lower second incisors
can also be considered.can also be considered.
 If the lower arch is managed on a non-If the lower arch is managed on a non-
extraction basis, Class III mechanics can beextraction basis, Class III mechanics can be
used to produce some retraction &used to produce some retraction &
retroclination of the lower incisors.retroclination of the lower incisors.
 This can produce distal tipping of the lowerThis can produce distal tipping of the lower
premolars & molars, which in turn reduces thepremolars & molars, which in turn reduces the
available space for the lower third molars.available space for the lower third molars.
 Early removal of lower third molars can beEarly removal of lower third molars can be
considered in some cases.considered in some cases.www.indiandentalacademy.comwww.indiandentalacademy.com

 A non-extraction approach to Class IIIA non-extraction approach to Class III
treatment may not achieve sufficient lowertreatment may not achieve sufficient lower
incisor movement for the needs of the case.incisor movement for the needs of the case.
 Correction of the malocclusion may beCorrection of the malocclusion may be
possible, but not over-correction.possible, but not over-correction.
 Thus, there is no provision in the result for anyThus, there is no provision in the result for any
late growth changes, which occur relativelylate growth changes, which occur relatively
frequently in Class III cases, especially amongfrequently in Class III cases, especially among
male patients.male patients.

Distal movement of mandibularDistal movement of mandibular
bone - distal repositioningbone - distal repositioning
 In many Class III cases, there is a mesialIn many Class III cases, there is a mesial
displacement of the mandible at the start of thedisplacement of the mandible at the start of the
 As treatment progresses, the mandibleAs treatment progresses, the mandible
repositions distally, to a position with therepositions distally, to a position with the
condyles centered in the fossae.condyles centered in the fossae.
 This favorable change can be predicted at theThis favorable change can be predicted at the
treatment planning stage,& is a useful adjuncttreatment planning stage,& is a useful adjunct
to distal movement of the lower incisors withinto distal movement of the lower incisors within
the facial complex.the facial complex.

Distal movement mandibular bone-Distal movement mandibular bone-
restriction of growth?restriction of growth?
 In the past, much attention was given to theIn the past, much attention was given to the
use of orthopedic devices, such as chin caps,use of orthopedic devices, such as chin caps,
to restrict mandibular growth in Class III casesto restrict mandibular growth in Class III cases
with mandibular prognathism.with mandibular prognathism.

 Clinical experience & research evidenceClinical experience & research evidence
combine to suggest that there is littlecombine to suggest that there is little
advantage in using orthopedic measures toadvantage in using orthopedic measures to
attempt to restrict the final length of theattempt to restrict the final length of the
mandible.mandible.
 Accordingly, the authors have abandonedAccordingly, the authors have abandoned
the use of chin caps & similar devices.the use of chin caps & similar devices.

Mesial movement of mandibularMesial movement of mandibular
bone - Class III growthbone - Class III growth
 This is a major factor in the treatment &This is a major factor in the treatment &
subsequent retention of Class III patients,subsequent retention of Class III patients,
especially males.especially males.
 Any case which appears to have substantiallyAny case which appears to have substantially
unfavorable Class III growth patterns should beunfavorable Class III growth patterns should be
carefully monitored before making acarefully monitored before making a
commitment to correction by orthodontic meanscommitment to correction by orthodontic means
alone.alone.

 If a decision is made to treat the malocclusionIf a decision is made to treat the malocclusion
with orthodontics alone, every patient should bewith orthodontics alone, every patient should be
informed of the unpredictable nature of Class IIIinformed of the unpredictable nature of Class III
growth, & of the implications of any unfavorablegrowth, & of the implications of any unfavorable
growth which may occur in the retention period.growth which may occur in the retention period.
 Unfavorable growth can be difficult to manageUnfavorable growth can be difficult to manage
for the post-orthodontic patient, & thereforefor the post-orthodontic patient, & therefore
care should be taken to identify those casescare should be taken to identify those cases
which should be managed surgically from thewhich should be managed surgically from the
outset.outset.

 In particular, irreversible extraction decisionsIn particular, irreversible extraction decisions
should not be made too early.should not be made too early.
 Unfavorable Class III growth can be difficult toUnfavorable Class III growth can be difficult to
manage for the post-orthodontic patient.manage for the post-orthodontic patient.

An overview of class 2 & class 3 treatment plan

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