Class 2 malocclusion /certified fixed orthodontic courses by Indian dental academy

Maxillary excess( A-P
and Vertical)

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




Excessive growth of the maxilla in children with class II
malocclusion often has a vertical as well as an
anteroposterior component (downward and forward
growth)
The effect is to prevent mandibular growth from being
expressed anteriorly



The goal of the treatment is to restrict growth of the
maxilla while the mandible grows into a more prominent
and normal relationship with it


 Although

the application of extra oral
appliance is the obvious approach,
Functional appliance can be used in
excessive vertical growth


Principles in the use
of head gear


Development of head gear
 Extra

oral force in the form of head gear was
used by the pioneer orthodontists of the late
1800s
 By 1920 angle and his followers stopped
using head gear ( class II elastics)
 It was after world war II, Silas Kloehn’s
impressive results with head gear treatment
of Class II malocclusion

•

The greatest and most significant
changes occurs in the
Zygomaticotemporal and
Zygomaticomaxillary sutures

 Compressive

force inhibit sutural growth by
producing resorption at the sutural bony
margins

 In

pre-adolescent child, extra oral appliances
are always applied to the first molar

 To

be effective should be worn regularly for
at least 10-12 hrs per day

 Early

evening to next morning

 Current

recommended force 12 to 16 ounces
or 350 to 450 gms per side

INDICATIONS
 Anteroposterior

maxillary excess, or maxillary

protrusion.
 Normal

mandibular skeletal and dental
morphology

 When

there is continued active mandibular
growth, primarily disposing the mandible in a
forward, rather than downward direction.

Selection of head gear type
1.

Head gear anchorage location

2.

Head gear attachment to dentition

3.

Bodily movement or tipping of teeth or
maxilla is desired


 The

length and position of the outer
head gear bow and the form of
anchorage determine the vector of
force and its relation to the center of
resistance of the tooth


Selection of head gear

P. Parietal, O. Occipital, C. Cervical

Long face (skeletal open bite)
vertical maxillary excess
Two major diagnostic criteria
 Short

mandibular ramus

 Rotation

of the palatal plane (more posterior
growth) Most common
Restraining maxillary vertical development&
Encouraging antero -posterior mandibular growth

 Children

with excessive face height generally
have normal upper face and elongation of
max and mand posteriors

 Unfortunately,

vertical growth extends into
the adolescent and post adolescent years
Active retention


Hierarchy of effectiveness in
long-face class II treatment
HP Headgear to functional with biteblocks
Bite blocks on functional appliances
High-pull headgear to maxillary splint
High-pull headgear to molars

Spontaneous correction of
Class II malocclusion
 Traditionally,

clinicians viewed class II
malocclusion as primarily a saggital and
vertical problem

 Most

Class II malocclusion in mixed dentition
patients are associated with max constriction.
(max width less than 31mm)


Mandible

Maxilla



Reichenbach and Taatz used the example
foot and shoe

Class II Problems in
Adolescents(12-15yrs)


Four major approaches
1.
2.
3.
4.

Growth modification with head gear or
functional appliances
Distal movement of maxillary molars,
and eventually entire upper dental arch
Retraction of maxillary incisors into a
premolar extraction space, and
A combination of retraction of the upper
teeth and forward movement of the lower
teeth

Growth modification in
adolescents
 Growth

modification would be more
successful when more growth remains
 As a general guideline, even in the most
favorable circumstances it is unlikely that half
of the changes needed to correct Class II
malocclusion in an adolescent would be
gained by differential growth ( 3-4mm from
differential mandibular growth )

 Head

gear is compatible with fixed
appliances but most functional appliances
are not.
 If a functional appliances is desirable for
adolescent treatment, often a fixed functional
that allows brackets on the incisor teeth is the
best choice.


Fixed Vs Removable
functional appliance


 There

are very few studies that have
evaluated the effectiveness of removable and
fixed function appliances that have followed
the effectiveness of removable and fixed
functional appliances to completion with fixed
appliance (Phase 1 and Phase 2).


Kevi’ O Brien et al (AJO 2003)
compared twin block and herbst appliance
The results of this study revealed
Phase 1 treatment (O’Brien 2003) is more rapid with
Herbst but overall duration of treatment is similar to that
with Twin Block


There are no differences in the dental and skeletal
effects of treatment between the two appliances


The

skeletal effects with both the appliances were
clinically insignificant

one phase Vs two
phase treatment


 To

examine whether functional appliances
are effective in human patients prospective
randomized clinical trials were undertaken at
the university of Florida, Pennsylvania and
north Carolina by Timothy wheeler, Joseph
Ghatari and Cemillet Tuloch respectively.


Florida study (AJO DO-1998)
Keeling, wheeler et al


Children aged 9 years at the start of treatment was
randomly assigned to control, Bionator and
Headgear with Biteplates. Cephalograms were
obtained initially, after cl I molar was obtained or 2
years had elapsed. The data revealed that both
Bionator and headgear treatment corrected cl II
molar relationship; reduced overjet and apical base
discrepancies. The skeletal changes that occurred
were stable; however the partime retention protocol
used in this study was not effective in preventing
dental relapse

The

same patients were followed through phase II
treatment and in the fine report in 2003 (AJO DO-2003)
There

was no significant differences in the final score
when patients who wore their headgear or bionator as a
retention appliance between phase 1 and phase 2
treatment were compared with patients who did not wear
any appliance during this period
Most

of the changes in PAR scores came from the
finished results achieved regardless of the protocol or initial
severity of the malocclusion.
Patients

who undergo 2 phase orthodontic treatment do
not achieve better results than patients who undergo 1
phase treatment.

University of Pennsylvania study – Ghatfari et al
AJO DO 1998


Ghatari et al conducted a prospective randomized
clinical study to compare the treatment effects of
headgear versus Frankel functional regulator in early
treatment of cl II div/ malocclusion in prepubertal
children. The results revealed that both headgear and
functional regulator were effective in treatment of cl II
div/ malocclusion. The headgear had a distal effect on
the maxilla and first molars but not the maxillary
incisors. The functional regulator retrained the growth
of the maxilla and resulted in retroclination of the
maxillary incisors, a more forward position of the
mandible and a proclination of the mandibular
incisors. There were no significant differences in the
mandibular length when the two appliances were
compared.

University of North Carolina
study
 Tulloch,

profit, Philip et al initiated a
randomized controlled clinical trial in1997 in
growing patients with cl II malocclusion.
Patients were randomly assigned to one of the
three groups.
 Group I received headgear treatment,
 Group 2 received functional appliance
 Group 3 received no treatment.

The significant findings of this study widely
publishing between 1997 and 2004 are as follows
 There was no difference between the groups in

the ANB angle either at start or after phase 2
treatment.
There was no differences in the quality of dental occlusion
between the children who had early treatment and those
who did not


There was approximately the same distribution of successes
and failures with and without early treatment.





Early treatment did not reduce the percentage of children
needing extraction of premolars or other teeth during
phase 2 treatment.

Early treatment did not influence the eventual need
for Orthognathic surgery.


There

was very little differences in the time both groups
spent wearing fixed appliances.


 In

conclusion there is very little evidence in
the literature to suggest the two phase
treatment can significantly modify growth
or eliminate the need for protracted phase
two treatment nor can it be justified to
result is fewer extractions or avoidance of
orthognathic surgery. Early phase one
treatment is beneficial in reducing the
incidence of incisors trauma and may be
useful in correction of eruption
disturbances.

Correction by tooth
movement


1.

Distal movement of maxillary molars,
and eventually entire upper dental arch

2.

Retraction of maxillary incisors into a
premolar extraction space, and

3.

A combination of retraction of the upper
teeth and forward movement of the lower
teeth

2) MOLAR
DISTALIZATION


Indications for Molar distalization


End on molar relationship
with mild to moderate space
requirement



Cases with less than a full
cusp class II molar
relationship




Good soft tissue profile



Borderline cases



Mild to moderate space
discrepancy with missing 3rd
molars/2nd molars not yet erupted





Axial inclination : Mesially
angulated upper molars



Normal or Hypodivergant
growth pattern



Late mixed dentition with
mild crowding of anteriors


Treatment timing :


Perhaps best time to initiate distalization is
late mixed dentition and it may be too late
after eruption of second molar.



Canines and premolars follow molars as
they moved distally.



Vertical growth helps : it is much easier to
tip a molar distally if it can extrude at the
same time

 In

the absence of vertical growth the most
successful way to move first molar distally is
by extraction of 2nd molar



Extraction of 2nd molar can successfully
correct moderate class II ( not more than
4mm)

The ideal patient for distallization is
one who has less than a full cusp
class II molar relation

•

Main drawback of extra-oral approach is
patient compliance.

•

This pit fall has been overcome by the
intra-oral appliances but are not effective
as extra-oral appliances.


Various appliances used for Molar
Distalization :










Headgears
Wilson Bimetric arch design
ACCO
Crozat appliance
Crickett appliance
Modified Nance Lingual appliance
Non-extraction treatment
Schmuth and muller double plates
Molar distalization with magnets

Various appliances used for Molar
Distalization
Use of Super elastic NiTi
 Jones Jig
 The Pendulum appliance
 Clasp ring
 Removable molar distalization splint
 Fixed piston appliance
 The K-loop appliance
 The distal jet
 Using Implants
 Fixed functional appliances



3) Retraction of maxillary
incisors into a premolar
extraction space


A

straight forward way to correct excessive
over jet is to retract the protruding incisors
into the space created by extracting the
maxillary first premolar (more than 4mm)

 With

out lower extractions , class II elastic
use would have to be minimal, and extra oral
force might be needed ( or lingual arch with
button)

Class I


Class II

4) Extraction of
maxillary and
mandibular premolars


Class II Problems in
Adults (more than 16yrs)


Two possibilities of treatment
 Camouflage

 Surgery


TVL (True vertical line)
drawn through subnasale with
natural head posture

0
57

Color codes used with
the Arnett soft tissue
cephalometric analysis

4

2
64
-5

-3


Black
Green
Blue
Red =

= within 1 SD
= within 2 SD
= within 3 SD
more than 3 SD

TVL

TVL

0
57

64

4

-5

TVL

0
57

64

4

-1

0
57

64

4

2

-12

-8

-5

-11

-6

-3


TVL

TVL

0
57
64

3

63

0
3

-1

59

1

-8

-6

-6

-5


TVL

57

64

TVL

-2

0
71

3

53

-5

-1

-3

-12

-9

-11

-9


TVL

57

64

0
3

-5

TVL

0
57

64

4

2

-12

-5

-11

-3


Camouflage


The

objective of the treatment is to correct the
malocclusion while masking the underlying skeletal
problem less apparent
Skeletal

class II problems can be camouflaged
rather well (mild to moderate)
Camouflage

works better in late adolescents

( extrusive nature of orthodontic mechanics )
Camouflage

is not successful treatment for
vertical max excess

Orthognathic Surgery


Development of orthognathic Surgery
 Surgical

treatment for mandibular prognathism
began early in the twentieth century
 Trauner and Obwegeser’s introduction of the
sagittal split osteotomy in 1959 marked the
beginning of the modern era in orthognathic
surgery
 In 1960 Lefort I down fracture was introduced
by Epker and Bell
 Progress in orthognathic surgery has occurred
quite recently (1980s and 1990s)

CLASS II DENTOFACIAL
DEFORMITIES
1.

Mandibular deficiency

2.

Vertical maxillary excess

3.

Combination
The decision to operate on the mandible ,maxilla
or both jaws is based primarily on the vertical and
antero-posterior position of the maxillary incisor

Early vs later surgery
Orthognathic

surgery should be delayed
until growth is essentially completed in
patients who have problems of excessive
growth
For

patients with growth deficiency, surgery
can be considered earlier ,but rarely before
adolescent growth spurt


Class II Dentofacial
deformity secondary to
Mandibular deficiency


Mandibular
advancement (BSSO)




Pre-surgical orthodontic
treatment
Extraction of 5 5
4 4

Reduce upper and
lower incisor
proclination and
maintain class II molar
relation

Immediate pre surgical
planning
 Surgical

 Model

cephalometric prediction tracing

surgery

 Occlusal

splint construction


Surgical cephalometric prediction
tracing

Horizontal
osteotomy of
BSSO
Vertical
osteotomy of
BSSO
To properly
position
proximal
segments

Genioplasy


Model surgery and Occlusal
splint construction


BSSO


Mandibular advancement
with advancement
genioplasty


Immediate pre surgical
planning


Mandibular advancement
with reduction genioplasty


Class II Dentofacial
deformities secondary
to vertical maxillary
excess




Majority of individuals with class II vertical
max excess can be treated with or with out
advancement genioplasty
Two

basic techniques for superior
repositioning of the maxilla
Le Fort I max osteotomy
Total max sub apical osteotomy

Le Fort I max
osteotomy


Conclusion


There

is no one ideal method for treating ClassII
malocclusion.

Following

clinical examination ,a precise analysis of
cephalometric radiographs and dental casts should be
undertaken to identify the components of the malocclusion
that deviate from “normal”
Then

clinician can select the appropriate treatment
regimen from among a no. of options.

Class 2 malocclusion /certified fixed orthodontic courses by Indian dental academy

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