‫ حيدر الزرجياوي‬.‫د‬
16/4/2015
CL.III malocclusion
Definition
A CL. III malocclusion is rare as compared to
other type of malocclusions, with an
incidence of possibly less than 5 %.
Individual CL. III cases are characterized as
having a retruded maxilla or a prognathic
mandible and in some cases by a combination
of both. It is of special interest to the
orthodontist because it offers a therapeutic
challenge.
CL.III malocclusion can be defined according
to:

Angle's classification: the mesiobuccal
cusps of the maxillary 1st molars
occluding at least 1/2 cusp distal the
buccal grooves of the mandibular 1st
molars, and the canines relationship, it
described as upper canine is either 1/2
cusp or complete posterior to lower
canine.
In other words, the lower teeth occlude
mesial to their normal relationship with
the upper.
In CL. III cases, the lower incisors and
canines are inclined lingually because of the
pressure of the lower lip in its effort to close
the mouth.
The disharmony between maxilla and
mandible may be of lesser degree with a
normal occlusion on one side of the arches
and a CL. III occlusion on the other, so it is
called CL. III subdivision malocclusion.
Clinical Features of skeletal CL.III
Extra-Oral Features



British standards classification: the lower
incisors edges lie anterior to the cingulum
plateau of the upper incisors.


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A concave facial profile.
Anteriorly
divergent
profile.
Long face (increased
lower face height),
which may be pointed
at the chin.
Mandible appears to be
well developed (with an
obtuse gonial angle).
Orthodontics……….…………………………………………….....……..…............... Cl. III Malocclusion
Intra-Oral Features




that distinct characteristics of a CL.III
malocclusion due to prognathic mandible
were related to genetic inheritance.
A CL.III molar relationship.
A CL.III canine relationship.
A reverse overjet with possibly labially
inclined lower incisors and lingually
inclined upper incisions.
A posterior cross-bite unilateral or
bilateral (or functional) due to a
constricted maxillary arch or a more
forward positioned mandibular arch.
Soft tissue and habits
The soft tissues have minor influences on the
CL. III malocclusion pattern. In fact, the
reverse is often the case, with the soft tissues
tending to tilt the upper and lower incisors
towards each other so that the incisor
relationship is often less severe than the
underlying skeletal pattern.
Macroglossia, or anteriorly tongue posture,
which lies low in the oral cavity, are to be a
local factors in CL.III development.
Dental factor
Occlusal forces created by the abnormal
eruption may produce unfavorable incisal
guidance and promote a CL.III incisors
relationship. This may present initially as a
pseudo CL. III but if unattended can lead to a
true CL.III malocclusion. Premature loss of
second primary molars can lead to forward
drifting of permanent molars; the mandibular
first permanent molar assumes a more mesial
position, resulting in a dental CL.III
permanent molar relationship.
Classification
In evaluating the CL.III relationship, it is
important to consider whether the problem is
dentoalveolar or skeletal in origin. In the
diagnosis of CL.III malocclusions, patients
may present with CL.III symptoms such as
multiple teeth in anterior crossbite, minimal
overjet, or lingually inclined lower incisors.
In summary, anterior crossbites may be
caused by the improper inclination of the
maxillary
and
mandibular
incisors
(dentoalveolar),
occlusal
interferences
(functional), or skeletal discrepancies of the
maxilla and/or the mandible.
Etiology
Skeletal factor
Skeletal relationship is the most important
factor in the etiology of most CL.III
malocclusion, and the majority of CL.III
incisor relationships are associated with an
underlying CL.III skeletal relationship. The
growth pattern and the size of the jaws are
affected by heredity. Many studies showed
Premature loss of deciduous molars may also
cause anterior mandibular displacement. If the
mandible loses it's posterior proprioceptive
and functional support in habitual occlusion it
is often positioned anteriorly in an attempt to
establish full occlusal contact during chewing.
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Orthodontics……….…………………………………………….....……..…............... Cl. III Malocclusion
Congenital Abnormalities
3. To simplify phase II comprehensive
treatment. In mild and moderate Class III
patients, early treatment may eliminate the
necessity for orthognathic surgery
treatment.
4. To improve occlusal function, especially
if it is accompanied by a functional shift.
5. To provide more pleasing facial esthetics,
thus
improving
the
psychosocial
development of a child.
A transverse as well as anteroposterior
restriction of the mid-face growth can occur
in cases of cleft lip and palate with a normal
mandible, markedly when the patient has
undergone the surgical repair. This can be
attributed to restraining effect of scar tissue
following surgical intervention. Limitation in
vertical growth of the maxilla can also be
seen.
Treatment of Dentoalveolar
Functional CL.III Malocclusion
&
Early treatment should be considered in these
cases, in order to avoid potential adverse
growth influences in the maxilla and
mandible, and to improve upper lip posture
and facial appearance. Correction of multiple
teeth in anterior crossbite has been
accomplished by using a fixed or removable
appliance. During mixed dentition stage, the
removable appliance with springs can be used
successfully to tip one or more of upper
incisors labially. In addition, a mandibular
Hawley appliance with an anterior labial bow
can be used to tip the lower incisors lingually.
Correction of CL. III malocclusion using
removable appliance to change the upper
and/or lower incisors inclination can be
considered in cases with following features:
Management
CL.III malocclusion can be classified as
Dentoalveolar, Functional, or Skeletal, which
will determine the treatment approach and
prognosis. It is known that Class III
malocclusion exacerbates during growth,
mainly starting at adolescence.
There are three main treatment options for
skeletal class III malocclusion: growth
modification, dentoalveolar compensation
(orthodontic camouflage), and orthognathic
surgery. Growth modification should be
commenced before the pubertal growth spurt,
after this spurt, only the latter two options are
possible. The goals of early interceptive
treatment of CL. III malocclusion may
include the following:




1. To improve skeletal discrepancies and
provide a more favorable environment for
future growth.
2. To prevent progressive irreversible soft
tissue or bony changes. Anterior crossbite
is often accompanied with Class III
malocclusion can lead to thinning of the
labial alveolar plate and/or gingival
recession.
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A CL.I and mild CL.III skeletal pattern.
The upper incisors are not already
proclined and the lower not already
retroclined.
Well aligned teeth.
Sufficient overbite should be present at
the end of treatment, to retain the
corrected incisors position.
Orthodontics……….…………………………………………….....……..…............... Cl. III Malocclusion
of the pressure of the appliance on the lower
lip and dentition. The lower anterior facial
height tends to increase so it is
contraindicated for a child who has excessive
lower face height.
Treatment of
Malocclusion
Skeletal
CL.
III
Treatment of Growing Patient
The
developing
skeletal
Class
III
malocclusion is one of the most challenging
problems confronting the orthodontists.
Differentiate between midface deficient Class
III patients that would benefit from early
treatment
vs.
a
true
mandibular
prognathism that may require surgical
correction later. Class III malocclusions are
growth related problems that often become
severe if left untreated, so the treatment could
be beneficial if initiated early.
For a mild to moderate skeletal CL.III
malocclusion, among the approaches for
treatment is the growth modification by
using of orthopedic appliances, such as chincup, facial masks, and functional appliances.
On the other hands, for the cases with severe
skeletal prognathism, no treatment until
orthognathic surgery can be done at the end of
the growth period may be the best treatment.
Functional Appliance Therapy
The Frankel III appliance is used in treatment
of cases with mild maxillary deficiency, and
can be effective if the case is diagnosed early.
The biggest problem is of patient cooperation.
The Frankel III appliance possible action is
made with labial (vestibular) pads to stretch
the upper lip in addition to the periosteum
forward, in a way that stimulates forward
growth of the maxilla. At the same time, it
does not allow the mandible to advance
forward. Actually, most of the improvement
is from dental changes. The appliance allows
the maxillary molars to erupt and move
mesially while holding the lower molars in
place vertically and anteroposteriorly tips the
Chin Cup Therapy
CL.III malocclusion with a relatively normal
maxilla and a moderately protrusive mandible
may be treated with the use of chin-cup. Chin
cup is used to apply forces (450 gm per side),
which are directed along the direction of
growth of the condyle. Therefore it's action
are accomplished to lesser extent by
restraining the forward growth of the
mandible, and to larger extent by change in
the direction of mandibular growth, rotating
the chin down and back. In addition, lingual
tipping of the lower incisors occurs as a result
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Orthodontics……….…………………………………………….....……..…............... Cl. III Malocclusion
maxillary anterior teeth facially and retracts
the mandibular anterior teeth. Vertical
movement of maxillary molar will help in
rotating the chin down, back, and improve
facial appearance.
canine-primary molar area above the occlusal
plane. Approximately 350-450 grams of force
per side is applied via the elastics for 12-14
hours per day.
Treatment of adolescent
growing patients
and
non-
Treatment in the adolescent age is limited to
Orthodontic Camouflage or orthodontic
decompensation in an effort to prepare the
patient for surgery. Camouflage can be
achieved by proclining the maxillary incisors
and tipping the mandibular incisors lingually.
Single arch extractions, 1st premolars
extraction only in the mandibular arch, are
frequently done to create space for the
retraction of the mandibular anterior segment.
CL.III elastics in combination with fixed
appliance are frequently used in an effort to
tip/retract the mandibular incisors.
Facemask (Delaire Mask) Therapy
The facemask can be used in growing patients
with Class III malocclusions due to both
anteroposterior and vertical maxillary
deficiency, to help provide the impetus for the
maxilla to grow anteriorly and/or rotate
downwards. This causes a reciprocal
downward and backward rotation of the
mandible. It. is a very effective appliance if
the patient is cooperative.
The facemask obtains anchorage from the
forehead and chin. The forward force on the
maxilla is generated via elastics that attach to
an intra-oral maxillary appliance (either fixed
or removable). The removable appliance if
used, it is preferred to be as splint to make the
upper arch a single unit for maxillary
protraction. The maxillary appliance must
have hooks for attachment located in the
In a more severe cases and after the growth is
ceased, Orthognathic Surgery is indicated. It
is suggested for patients with an ANB angle
of greater than -4°. The most commonly used
surgical procedures are the bilateral sagittal
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Orthodontics……….…………………………………………….....……..…............... Cl. III Malocclusion
split osteotomy with retraction of the
mandible in cases of mandibular prognathism,
in cases of maxillary deficiency a Le-Fort I
down positioning may be attempted.
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