Early treatment of class ii malocclusion /certified fixed orthodontic courses by Indian dental academy

EARLY TREATMENT OF CLASS II
MALOCCLUSIONS IN ORTHODONTICS

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

TREATMENT PLANNING IN CLASS-II MALOCCLUSION
Angles class-II malocclusion forms a major part of an orthodontic
practice. More than half of all the treated malocclusions in US are the
class-II malocclusions. There had been a dramatic change in trend in
the management of these malocclusions.
In the early 80's class-II treatment comprised of functional appliance
like the activator and guide planes and / or camouflage treatment
with the usual upper 4's, lower 5's extraction and fixed appliances.
But the results obtained were not satisfactory in all cases. Then came
an array of functional appliances from Balter's bionator (1956) to the
present day Twin Block (1977, Clark). Functional jaw orthopaedics
became the mainstay in orthodontic practice in India in the early
90's. Now the present trend is a two-phase treatment- with the first
phase comprising of functional jaw orthopaedics to correct the
skeletal abnormality followed by a second phase of fixed appliances
in which non-extraction treatment forms an important entity.


Recent technological advances like the digital photography,
computerized diagnostic aids, morphing and warping to evaluate the
treatment outcome along with an array of adjuncts like molar
distalizing appliances, Niti palatal expanders, new generation wires,
sophisticated mandibular protraction devices and magnets have
enabled the orthodontist to choose the right prescription for his case.
Treatment planning in orthodontics starts with an ethical
understanding of the Doctor / patient relationship. Previously the
orthodontists chose and planned the preferred treatment and patient
either accepted or rejected it. The present concept is to outline the
patients problems use inputs to establish priorities in dealing with the
problem, present reasonable alternatives and explain risk / benefits.


The orthodontist must:
1.

Recognize the various
Dentofacial deformity.

characteristics

2.

Define the nature of problem including the etiology if possible.

3.

Design a treatment strategy based on specific needs and desires
of the individual.

4.

Present the treatment strategy to the patient. Computers have
facilitated communication with the patients through graphic
imaging and to visualize facial effects of treatment before final
treatment decisions are made. This allows the orthodontist to
design the face first and measure what is needed to get there.


of

malocclusion

and

TREATMENT MODALITIESThese include:
1.

Redirection of facial growth through functional alteration of
dentoalveolar eruption pattern or jaw growth (functional
appliance treatment).
2.
Dentofacial orthopaedics in which dentofacial growth is
altered through the application of the forces sufficient in
magnitude to retard / redirect maxillary or maxillo
mandibular growth.
3.
Repositioning the teeth through orthodontic tooth
movement.
4.
Surgical orthodontic treatment. The treatment modality
depends on the:
1.
Nature of the problem
2.
Severity of the problem.
The range of correction that can be accomplished through each of
these modalities can be assessed from the envelope of discrepancy.

Class II Treatment –Historical
Finger pressure

Wire frame work extending down from the Lingual Arch Advancing and Stimulating
Mandibular growth
Retraction of Max Teeth also affects Max Growth
Restraining Max Growth-with Head gear- succeeds in producing Differential in
favor of Mandible- only if mandible grows
Functional Appliances:-1930
Idea of forcing the lower jaw forward that would stimulate Mandibular growth and
Correct Class II
The Incisal capping of the appliance gave better resistance to forward
displacement and controlling eruption of lower incisors Moves the lower teeth
forward and upper teeth back- like Class II Elastics


Diagnosis:
1.

A database, which comprises of

Patient questioning

The diagnosis of the problem is arrived by formulating a–
a.
b.
c.
d.

Elicit the chief problem (functional/esthetics).
Brief medical history
Family history
Social and behavioral history

2. Clinical evaluation - I-Extra oral, II-Intra oral
I.
Extra oral:
a.
Profile, frontal
b.
Functional
II.

Intraoral


3.

Evaluation of diagnostic records
a.
Study casts
b.
Radiographs
c.
Facial and intra oral images.

In treating a potential class-II patient functional examination is very
crucial but commonly over looked.


Functional Examination
It is an appraisal of the functional status of each patient before any
form of orthodontic therapy is instituted.
Diagnostic exercises recommended during mixed dentition period to
assess possibility of treatment with functional appliances are:
1.
2.

Determination of postural rest position of the mandible and
the interfering free way space.
Examination of TMJ
a.
Function
b.
Dysfunction
c.
Condylar movement

Assessment of functional status of the lips, cheeks and the tongue
with particular attention to the nose. They play an important role in
dentofacial abnormalities.
First the patients natural head position is determined because in
postural rest position the synergistic and antagonistic muscular
components are in dynamic equilibrium and their balance is
maintained.

Then the postural rest position is assessed by:
a.
b.
c.
d.

Phonetic exercises
Command methods
Non-command methods
Combined approach

Registration of the postural rest position:
a.

Direct intra oral method

b.

Direct extra oral method
Soft tissue - a.
b.

c.

Nasion,
Menton

Indirect extra oral method:
1.
2.
3.
4.

Cephalometric
Electro myography
Cine flurography
Kinesiography

Lateral cephalograms are taken under identical
exposure and patient positioning.
1. Postural rest position.
2. Initial contact
3. Full habitual occlusion
Two measurements can be performed:
a.
b.

Recording hinge movements in vertical plane
Assessing sliding or translatory action in sagittal plane


Evaluation of path of closure from postural rest to
occlusion in the saggital plane
.
1.

True class-II malocclusions: In class-II malocclusions without
functional disturbance the path of closure from rest to occlusion is
straight up and forward with a hinge movement of the condyles in
glenoid fossa. These are true class-II malocclusions.

2.

In class-II malocclusions with functional disturbance: from initial
contact to full occlusion the condylar action is both rotatory and
slides backward (posterior shift). This is most common in cases of
excessive over bite. Here the class-II malocclusion appears most
severe than it actually is sagitally.

3.

If the mandible is anteriorly displaced : from the initial contact
and the cusps guide the mandible into a forward position the
class-II is actually more severe than it appears.


Vertical evaluation
A. True deep bite - Large free way space
B. Pseudo deep bite.
In true deep bite cases a large inter occlusal clearance is caused
by infra occlusion of posterior segments resulting from lateral
tongue posture or tongue thrust habit. Elimination of
environmental factors and functional therapy gives good results.
The prognosis is good in a true deep bite case if vertical growth
pattern is present.
In pseudo deep bite cases with horizontal growth pattern the
possibility of the correction with functional appliances is limited,
hence the prognosis is poor.
Combination ofI. true deep bite and horizontal growth pattern,
II. Pseudo deep bite and vertical growth patternlimited prognosis can be expected.

When the patients jaw is moved from postural rest
to habitual occlusion the midline of the
mandible is observed.
Two types of deviations are observed.
A. Laterognathy
B. Lateroocclusion
Laterognathy: The center of the mandible is not aligned
into the midline of the face in rest and occlusion. There is a
true neuromuscular or. anatomical asymmetry. (True cross
bite). Here the prognosis is unfavourable.
Lateroocclusion: Here the mandibular midline coincides at
rest and deviates in habitual occlusion. This is a functional
and not a true occlusion. Here the prognosis is good.


Examination of TM joint and condylar movement:
To check if any dysfunction is present already and if the TM joint
structure is abnormal at the start, to avoid the possibility of
exacerbation
Symptoms of TM Joint problems:
•
Clicking and crepitus.
•
Sensitivity in condylar region and masticatory muscles
•
Functional disturbance (hypo mobility or limitation of
movement, deviation).
•
Radiographic evidence of morphological and positional
abnormalities.


Assessment of Stomatognathic dysfunction:
•
•
•
•
•
•

Mouth breathing
Bruxism
Thumb and finger sucking
Tongue thrusting
Lip biting
Abnormal deglutition

Examination of Lips:
A. Clinically
B. Lateral cephalogram
Examination of respiration
Mouth breathing


ASSESSING GROWTH DIRECTIONS
The bones that constitute the face descend down and at the same
time move forwards. This means there is a vertical growth and
anteroposterior growth. When both are balanced there is smooth
downward and forward movement of the facial skeleton. The
mandible rotates both clockwise and anti-clockwise during this
process. Increase in clockwise growth results in excessive vertical
growth. Counter clockwise growth results in deficiency of vertical
growth.


Vertical elements of growth
The frontonasal and frontomaxillary sutures which produce an
increase in the distance from nasion to anterior nasal spine makes
the maxillary molar and posterior nasal spine to move away from
the base of the skull. The growth of the posterior alveolar process
causes the molar teeth to move away from the palatal plane.
Growing of the mandibular posterior alveolar process caused the
molars to move away occlusally.
If the vertical element of this growth is more than the condylar
growth the chin moves downwards and backwards. If the sum of all
the vertical components are less than the vertical growth of the
condyle the chin grows forwards and upwards.
With this above knowledge we proceed to treatment planning.


APPLIANCES MODULES OF THE EARLY SYNERGISTIC
TREATMENT CONCEPT
The concepts of treatment are ultimately more important than the
actual appliances utilized. The appliances described are recommended
as the result of personal experience and highly satisfactory results
related to
(1) ease of use;
(2) patient comfort;
(3) minimum demand for patient cooperation;
(4) minimum chair time;
(5) cost effectiveness;
(6) resistance to breakage;
(7) minimum iatrogenic side effects;
(8) minimum non-scheduled appointments or patient problems;
(9) hygiene;
(10) ease of fabrication;
(11) predictability and stability of results and
(12) minimum risks.


Class II Treatment.- When?---Early Treatment Deciduous Dentition - 2 to 7 years of age
 Mixed Dentition - 8 to 11 years, when the dentition is mixed in nature
 Transition Dentition - 11 to 12 years, just before the eruption of all
second bicuspids- all the second deciduous standing
 Late Treatment- Adolescent/ Early Perm Dent 12 to 17 years
 Very Late Treatment- Adult Therapy
Characteristics can be detected to predict certain Un /and Favorable
patterns of Growth
But Accurate Growth Predictions are simply not possible to for the
children who need it the most!


A. Treatment planning for orthodontic problems in primary
dentition.
B. Treatment planning for orthodontic problems in early mixed
dentition period.
i.
ii.

Moderate
Severe

C. Treatment planning for orthodontic problems in adolescence (Late
mixed and early permanent dentitiion)
1.
2.
3.
4.

Alignment problem
Transverse problem
Anteroposterior problem
Vertical problem

D. Treatment planning for orthodontic problems in adults


Treatment planning for orthodontic problems in primary
dentition (Age 3-6 years)
A.
Space maintenance in primary molar area
B.
Incisor protrusion due to concomitant habits – severe cases
habit breaking appliance can be instituted in the late primary
dentition
-Incisor retrusion like in Class II division II situations are
attended to prevent shift
C.
Posterior crossbite: Frequently caused by sucking habits that
cause constriction in the primary canine region. Treatment
includes grinding of canines to eliminate deflective contacts or
expansion may be considered
D.
Anteroposterior discrepancy: A distal step has to be identified
at this stage and growth modification is attempted only in
severe
cases as continuing growth complicates the problem
E.
Vertical discrepancy
1.
Deep bite – no treatment
2.
Open bite due to habits to be corrected by appropriate
appliances
3.
Skeletal open bite – no treatment

Treatment planning in early mixed dentition
1.

Moderate problems

2.

Severe problems

Moderate Problems: These are associated with the dental
malocclusions which are dealt with habit breaking appliances,
space maintainers and expansion appliances depending on the
nature of the problem.
Severe Problems: In Mixed dentition can, be broadly grouped into
a.

Skeletal problems

b.

Dentofacial problem relating to. incisor protrusion

c.

Space problems - 5mm or more.


Timing of Early Treatment ?
The benefit of Early Treatment, particularly in avoiding extraction of permanent
teeth, is no longer in question. Optimal timing of treatment in late mixed dentition
would correspond to the time just before the loss of second deciduous second
molar
Joseph Ghafari

Periodontal Standpoint
……..that less damage to periodontal tissues and roots would occur if a greater
portion of the orthodontic and skeletal modification were accomplished in the
mixed dentition in moderate to severe malocclusions
Robert Boyd


Timing of Early Treatment ?
….it seems safe to say that, within the the preadolescent period, there is little to
be gained from precisely timing early treatment to coincide with any particular
maturational event.
It seems likely that there is quite a wide window of opportunity for growth
modification during preadolescent period.
Tulloch, Proffit & Phillips

Timing of Early Treatment??
There is near unanimity in the merits of Early treatment
But there is difference of opinion in Timings of Early treatment
Two views
Before the shedding of second deciduous molars (10 to 12 years)
Even earlier ( 8 to 10 years)


Aims & Objectives of Early Treatment
Control of first perm. molar when deciduous molars are being shed --timely
utilization of ‘E’ space
Development of ideal arch form utilizing the potential for orthodontic/
orthopedic expansion as a means to gain space
Establish ideal incisal inclination early to achieve ideal Alignment

Early Treatment- Objective
Early Treatment Procedures provide greater opportunity for ‘Non Extraction
Therapy’ to survive Better use of Growth Potential
Patient gets wider and broader Smile, Greater Stability of achieved results

Early Treatment.--Personal Preference
Phase I to start
Girls 9 to 10 years, Boys 9 1/2 to 10 1/2 years
(with an intervening rest phase of no treatment between Phase I and II
of 0 months to 24 months)


Two Phase Therapy
Consensus to start the Early treatment for most Class II patients in Late Mixed
Dentition. By this even though one may not be treating at peak growth velocity,
it has a growth - freeing effect when treatment is instituted at this age
This results in two relatively short phases of treatment
Duration of Phase I & II Tx.

Phase I
Maximum of 15 months, whether or not full correction is achieved. (average
10months)

Phase II
Started when all perm. teeth mesial to first perm. molars have erupted, and
carried on till all the second molars have erupted and aligned


Indications of Early Tx.
Class II cases
-With arch-length discrepancies and contracted arches
Goals of Early Treatment
■ Resolution of Skeletal Discrepancy with growth modification
methods
■ Establishment of Class I Molar
■ Ideal Incisor Relationship,
O- Jet & O- Bite
■ Creation of Space for All Permanent Teeth
How to achieve your goals?
By the use of ‘simple’ and ‘user-friendly appliances, which are versatile, to
achieve your set targets ,within the specified time


Contraindications of Early Treatment
-

- Class I and Class II cases with:
- Severe Bimaxillary proclination
- Extreme arch length deficiency with severe anterior crowding-Both
situations needing definite extraction therapy in Phase II treatment


The appliances of choice most commonly used in our
practice have been divided into those considered to
be principally
(1) Orthopedic;
(2) Functional;
(3) Orthodontic or tooth moving and
(4) Retentive.


ORTHOPEDIC APPLIANCES (FORCES)
RPE – Direct Bonded Rapid Palatal Expansion Appliance
A bonded palatal expansion appliance with occlusal coverage that
disarticulates the teeth and the incorporation of two expansion
screws is highly recommended. Use of two screws permits patient
specific differential anterior / posterior sutural expansion.
Sufficient and stable skeletal expansion of the maxillary canine
area is essential avoid mandibular anterior dental relapse. Such
expansion appears to be stable and greatly reduces the incidence
of relapse in both the upper and lower anterior dental segments.
(Please note that patients treated in our practice over a period of
years do not demonstrate the high percentage of lower anterior
dental relapse documented by Littie et al at the University of
Washington)


DAE – Dual Arch Expansion Appliance
This appliance, designed to expand both the maxilla and
mandible at the same time, requires a carefully executed
registration bite and detailed models of both the upper and lower
teeth. The appliance must be fabricated from the “salt and
pepper” technique. It is important that the lower impression is
deep and lingually accurate. The lingual flanges should be long
and exceed the freeway space by 5-10 mm.
Important: While the DAE has been listed under “Orthopedic
Appliances”, it has an important and defined “functional”
component that must not be overlooked.


Even though it is almost never the appliance of choice in such
cases, caution in the use of DAE should be exercised if the
patient demonstrates any Class III tendencies. The RPE is
ideal for such cases. If, at the same time, mandibular
expansion is indicated, it can best be achieved by the
concurrent and synchronized use of a mandibular Schwarz or
McNamara type appliance.


Registration bite:
The registration bite should be taken with carefully heated horseshoe
shaped roll of Columbus Dental Red Base Plate Wax #93553 (available
through Summit Orthodontic Services). It is important that it be taken
in the patient’s centric, and the wax should be about two millimeters
thick in the molar area to permit space for the acrylic overlay of the
teeth.
Note: When using the prescribed wax, a good method of determining
proper opening is to hold the wax bite up to the light. There should be
some reduction in the occlusal thickness where light passes through
more readily.


Bite Planes (BP) With or Without Expansion
The use of removable bite planes either with or without expansion is
imperative to keep the maxillary and mandibular teeth disarticulated
following the use of an RPE or DAE, if a sagittal discrepancy still
prevails. The appliances, if utilized with expansion, have an orthopedic
effect. As with the DAE, they also have a functional effect, the result of
disarticulation of the teeth, eruption of the buccal quadrants, and
release of the mandible permitting natural reposturing.

Note: In “high angle” cases, both upper and lower posterior teeth

must be indexed (flat plane) to prevent additional eruption of teeth.


MANAGEMENT OF MANDIBULAR DEFICIENCY
Functional appliances form the main stay for treatment of mandibular
deficiency in growing children. The following criteria can be used
for case selection:
1.
2.
3.
4.
5.

Individuals with growth potential
Retrognathic mandible
Deep bite
Low mandibular plane angle
Favourable VTO
The functional concept employs carefully designed removable
appliance in an effort to achieve harmonious development of dento
facial structures by eliminating unfavourable myofunctional and
occlusal factors and improving the functional environment of the
developing dentition. This concept flourished and became the basis
of functional therapy for over a century resulting in the
development of wide range of functional appliances.


Removal Functional Appliances
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

Bite plate
Monobloc
Activator
Bionator
Modified activator
Functional regulator
Palate free activator
Twinblock
Functional Magnetic System
Mandibular Growth Advancer


Average changes brought about by functional appliance therapy(WOODSIDE; METARUS;ALTUNA)
Condylar growth amounts- lto3mm (mandible outgrows maxilla by
l±0.5 mm}
Fossa growth and adaptation-0.5 to 1 mm
Eliminating functional retrusion-0.5 to 1 mm
More favourable growth direction (trabecular angle) 0.5 to 1 mm
With holding of downward and forward maxillary arch movement- l to
2 mm
Differential upward and forward eruption of lower buccal segments1.5 to 2.5 mm
Head gear effect – l to 2 mm


Similar studies by Vangerall & Harvold (1985) on activator, frankell
appliance by FRANKELL (1987) have shown favourable changes
with functional appliances.
FRANK WEILAND & BERGT INGERVALL compared the effects of
herren activator, activator-headgear & jasper jumper and
demonstrated higher percentage of success with jasper jumper.
Recently Twin block appliance has become popular due to its
versatility and patient compliance.
The cephalometric changes brought about by this appliance include
an increase in mandibular unit length (condylion to gnathion) by
6.5mm with increase in ramal height (2/3) and body length (1/3)
( MILLS & MECULLOCH.)


PROBLEMS OF MAXILLARY DENTOALVEOLAR POSITION IN LATE
MIXED & PERMANENT DENTITION:
Simple Problems:
1. Retraction utility arch (Ricketts) for protruded incisors in class-2
div-1.
2. Protrusion utility arch in class 2 div -2 followed by functional jaw
orthopaedics.
Complex Problems:
1. PROTRUSION OF THE ENTIRE MAXILLARY ARCH-retraction of all
upper anteriors with extraction of upper first bicuspids.
2. Extra oral traction with headgear


In class II mesially migrated molars with straight profile molar
distallization is attempted. This is especially successful before the
eruption of II molars.

The distallization devices are

1.
2.
3.
4.
5.
6.
7.

Pendulum appliance (Hilgers 1992)
Distal Jet (Carano et al 1996)
Modified Nance arch with niti coils or wire (Gianelly 1991)
Magnetic appliance (Gianelly 1989)
Jones Jig (Jones and White 1992)
Lokar distallizing appliance
Molar distallizing bow (Jerkel and Rakosi 1991).

Fixed functional appliances
1. Herbst
2. Herbst with High pull headgear
3. MARS appliance
4. Jasper Jumper
5. Mandibular Protraction application
6. Universal bite jumper
7. Churrojumper


Rational & Logic of Early Treatment
Target Disorders / Discrepancies
Tooth Size / Arch Length
Skeletal / Dental / Alveolar
Combination of the above
Time Bound Treatment Program
No Treatment Overruns even if Phase I Objectives are not Achieved

Appliances used in Early Treatment
Head gears/Chin cups/Max. protractors
Functional appliances
Rapid Maxillary Expansions
Utility arches, Trans Palatal Arches, Nance’s buttons
Lingual arches--Wilson’s Arches
Slow expansions of maxilla/ mandible


Utility Arch
Incisal Segment, Ant. Vertical Leg( 6 to 8 mm height),
Vestibular Section, Post Vertical Leg (3 to 4 mm height)
Molar Segment -Distal Tip, Toe-in, & Buccal Root TorqueUtility
Arch‘V’ Bend mesial to Molar
Crown Labial / Root Lingual Moment & Intrusive Force at Incisors
Larger Crown Distal / Root Mesial Moment & Extrusive Force at
MolarUtility Arch can be used as a Torquing Arch‘V’ Bend more
towards Incisors
Crown Labial / Root Lingual Moment more pronounced –Lingual
Root Torque at Incisors, Extrusive Force at Incisors, Intrusive
Force at MolarUses of Utility ArchesStabilization & Maintenance
of Space during Transition Dentition
Intrusion/Extrusion/Derotation/ Retraction/Proclination of Incisors


Skeletal Problem:
A class II Malocclusion can develop due to the following factors.
1. Prognathic maxilla with normal mandible.
2. Retrognathic mandible with normal maxilla.
3. Combinations.
According to a cephalometric study by MCNAMARA (1981), the
position of the maxilla was normal in majority of class II
individuals and mandible was retrusive.
In those individuals when the position of maxilla was abnormal,
the maxilla was retrusive rather than protrusive.
In-patients with increased lower anterior facial height and high
mandibular plane angle, both maxilla and mandible were retrusive.


MANAGEMENT OF MAXILLARY PROGNATHISM
Management is by extraoral traction by
a. Facebows - attached to splint or upper molar bands
b. Head gears-force of 450-550gm should be worn for minimum of
14hrs/ day.
Cervical Pull Head Gear:
-

Indicated in-patients with decreased vertical dimension.
Outer bow lies above the plane of occlusion to direct force through
center of resistance and prevent distal tipping of molars.
Numerous studies by KLOEHEN {1953}; GRABER {1955};
POULTON {1967}; WATSON .{1972} and WEISLANDER (1975}
have shown that the forward movement of maxilla can be inhibited
through the use of this type of appliance. Cervical traction
increases vertical dimension through the extrusion of molars.
Timing of cervical pull headgear should he based on skeletal
maturation to achieve maximum orthopaedic affect (Kopecky and
Fishman)

High Pull Head Gear
-

Indicated in patients with increased vertical dimension
Face bow is anchored to an occipital anchoring unit to produce
vertically directed force.
High pull headgear can decrease vertical growth of maxilla
thus allowing autorotation of the mandible.
Mauric Firouz and Ravindra Nanda Demonstrated that when
the force was directed at the levels of Trifurcation of maxillary molars
significant distal movement and intrusion of molars was
achieved along with restoration of vertical and horizontal
maxillary growth.

Medium Pull Head Gear
-

Indicated in average angle cases


Management in adolescent period:
Camouflage treatment: Beyond the adolescent growth spurt to correct
a skeletal problem teeth should be displaced relative to their
supporting bone to compensate for the underlying jaw
discrepancy. This is termed as camouflage treatment.
Indications for class-II camouflage treatment:
1.
2.
3.
4.

Too old for successful growth modification.
Mild to moderate skeletal class-II.
Reasonably good alignment of teeth.
Good vertical facial proportions - neither very short nor very long
face.


Camouflage - Contra-indications
1. Severe Class II with Vertical Displacial
2. Extreme & Severe Crowding with Protrusion -Where Ext. space
used up for Alignment
3. With Remaining Good Growth potential
4. Non- Growing with more than Moderate Dis.placia- Surgical
Camouflage vs Surgery
5. Classic case of mature 14 yr old with full cusp Class II with 10
mm OJ & Mandibular Deficiency- Max Premolar Ext. & Ret of
Ants
6. Surgical Mandibular Advancement Past The Growth/
Careful Tx plan/ Too severe for Camouflage > 10 mm Overjet
7. Mandible short, Lower teeth protrusive
8. Deficient Chin, and/or Long Face
9. Lower Incisor Position/Protrusion


Extractions in Class-II
1.
Extraction of upper first bicuspids only with lower nonextraction
2.
Extraction of upper first bicuspids and lower second bicuspids
3.
Extraction of upper and lower first bicuspids in cases with
severe lower crowding.
4.
Distalization of molars with extraction of second molar. Upto
4mm of distal movement of first molar is possible by extraction of
second molars. Thus an ideal case for second molar extraction is a
patient with less than a full cusp class-II.
This concept was put
forward by WITZIG AND SPHAL.


Second molar extraction has the following advantages:
A.
B.
C.
D.
E.
F.

Simplified mechanical treatment
Less need for patient co-operation in some cases
Reduced incidence of late lower incisor crowding
Avoidance of third molar impaction
Easier first molar distalization
Increased long term stability of the result. (Richardson)

Disadvantages of the second molar extractions are:
1.

Inadequate space is created to deal with significant anterior
crowding or protrusion.
2. Delay while awaiting third molar eruption.
3. Possible need to upright lower third molars in some cases at a
difficult time for the patient.
4. Difficulty in keeping contact with the patient to achieve third molar
uprighting.
The present trend is to incorporate fixed functional appliance or twin
block along with fixed appliances.

Combined surgical and orthodontic treatmentWhen Is Surgery Indicated?

- When severe skeletal or very severe Dentoalveolar problems are
too severe to correct by Orthodontics alone
When Camouflage - dental compensations to mask skeletal
dicrepancy- may produce poor facial estheticsSurgical Tx.Indications
-Adult Patients , With little remaining growth
Younger patients with Extremely severe or progressive Deformity
Good General health statusSurgical - Treatment Planning
Dental CompensationsMost Skeletal problems are with some
Dental CompensationsCamouflage & Surgical Preparation would
need opposite Tooth movements
Camouflage in Definite Surgical cases to be avoided unless a Good
Outcome

Pre-surgical orthodontics - Goals:
1.

Alignment of arch segments and make them compatible

2.

To establish the anteroposterior and vertical position of incisors
- Extraction pattern:
Dental compensations are removed. Extractions may be needed
in the lower arch i.e., lower 4's and non-extraction in the upper
or upper 5's.
Stabilizing arch wires are placed.
Surgical movements are simulated on the recent cephalogram
and the functional and esthetic balance is evaluated and if
satisfactory results are achieved these surgical movements are
duplicated on models and inter occlusal surgical splint is
fabricated.

3.


Surgical Procedures:
1. Maxillary excess - Le Fort-I Osteotomy
2. Mandibular deficiency - Saggital split ramus Osteotomy
3. Deficient chin - advancement genioplasty

Post-surgical Orthodontics
Timing: Post-surgical orthodontics can be initiated 3 to 4 weeks
after the release of immobilization Stabilizing arch wires are
removed and replaced by working arch wires with light vertical
forces till a good stable occlusion is achieved.


Distraction Osteogenesis - Deficient Mandible
Distraction Osteogenesis is a biological process of new bone formation
between surfaces of bone segments gradually separated by
incremental traction. Though this technique was practiced earlier it
was revolutionized by Ilizarov in 1989, with his technique for limb
lengthening. In 1992, McCarthy was the first to clinically apply an
external device to the mandible and in 1994, he developed and intra
oral mandibular distraction device.
In congenital mandibular deficiency, a multiplanar distraction is
required. Following a single or double osteotomy, it is possible to
distract both vertically and horizontally using Bi-Directional distractor.
This in very severe mandibular hypoplasia where ramus and body are
affected, this procedure results in rapid distraction as well as
development of mandibular angle.
Conclusion: With such a wide range of treatment modalities and
appliances listed out for class-II malocculsion it is at the hands of a
skilled orthodontist to appropriately time and choose the right
treatment according to individual patient needs.


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