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CASE REPORT
Treatment of Skeletal Class III Malocclusion
with the Biofunctional System
RODRIGO HERMONT CANÇADO, DDS, MSc, PhD
KARINA MARIA SALVATORE DE FREITAS, DDS, MSc, PhD
FABRÍCIO PINELLI VALARELLI, DDS, MSc, PhD
BRUNO DA SILVA VIEIRA, DDS, MSc
LENIANA SANTOS NEVES, DDS, MSc, PhD
W
hen a skeletal Class III malocclusion is diagnosed early enough, the preferred treatment
is orthopedic, involving maxillary traction with facemasks—often combined with rapid maxillary expansion—followed by
orthodontic correction using
Class III elastics.1,2 If the problem
is not diagnosed until the permanent dentition, however, the treatment options are limited to com-
Dr. Cançado
pensatory or surgical-orthodontic
therapy.3 Surgical treatment may
produce the most esthetic results,
but is less commonly performed
because of its risks and expense.4
The success of compensatory orthodontic treatment depends on the severity of the anteroposterior discrepancy, the
facial and muscular balance, and
the influence of heredity on the
malocclusion.5-11 Class III patients
Dr. Freitas
Dr. Valarelli
typically present with a dental
compensation guided by the facial musculature, which further
complicates treatment planning
due to the limitations of orthodontic mechanics in the lower
arch.5,12,13
This article describes the
use of the Biofunctional* appliance system in compensatory
*Morelli Ortodontia, Sorocaba, São Paulo,
Brazil; www.morelli.com.br.
Dr. Vieira
Dr. Neves
Drs. Cançado, Freitas, and Valarelli are Professors, and Dr. Vieira is an orthodontic graduate student, Department of Orthodontics, Ingá Faculty,
Rodovia PR 317, no. 6114, Maringá 87035-510, Paraná, Brazil. Dr. Neves is a Professor, Department of Orthodontics, Federal University of Minas
Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. E-mail Dr. Cançado at [email protected].
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© 2015 JCO, Inc.
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Treatment of Skeletal Class III Malocclusion with the Biofunctional System
Fig. 1 12-year-old Class III female patient with impacted upper left canine and anterior crossbite before
treatment.
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Cançado, Freitas, Valarelli, Vieira, and Neves
TABLE 1
CEPHALOMETRIC ANALYSIS
Pre-
Post-
26 Months
treatment TreatmentPost-Treatment
SNA
Co-A
SNB
Co-Gn
ANB
Wits appraisal
FMA (MP-FH)
SN-GoGn
Occlusal plane-SN
Lower facial height (ANS-Me)
U1-NA
U1-NA
U1-PP
U6-PT vertical
U6-PP UMKC
L1-NB
L1-NB
L6 apex-Symphysis
L6 crown-Symphysis
L6-PP UMKC
Molar relationship
Overjet
Overbite
Nasolabial angle (Col-Sn-UL)
Upper lip-S line
Lower lip-S line
treatment of a skeletal Class III
malocclusion.
Diagnosis and Treatment
Planning
A 12-year-old female presented with the chief complaint
of an impacted upper left canine
and anterior crossbite. Clinical
examination showed moderate
mandibular protrusion, mild
VOLUME XLIX NUMBER 11
81.4°83.5° 82.9°
75.6mm79.4mm 80.2mm
82.6°81.0° 81.8°
100.9mm102.7mm 103.6mm
0.8°3.6° 4.1°
−3.3mm
+0.5mm
+1.9mm
23.7°
26.5°
26.0°
31.3°34.3° 33.6°
15.7°
13.8°
14.2°
57.5mm
58.3mm
59.3mm
32.1°32.7° 32.6°
3.0mm5.4mm 5.0mm
21.6mm21.8mm 22.1mm
19.2mm
20.5mm
20.2mm
14.8mm
16.6mm
17.2mm
33.6°32.2° 32.1°
8.3mm7.8mm 7.8mm
16.4mm
15.7mm
14.9mm
17.3mm
18.7mm
17.6mm
23.5mm
22.4mm
22.5mm
−3.9mm
−1.3mm
−1.5mm
−4.1mm2.2mm 2.5mm
1.2mm0.7mm 1.3mm
132.7°
106.8°
107.4°
−4.3mm
0.2mm
−0.4mm
2.2mm
2.0mm
2.4mm
maxillary retrusion, an excessive
nasolabial angle, a protrusive
lower lip, a retrusive upper lip,
and a concave profile (Fig. 1).
The patient had a bilateral Class
III molar relationship associated
with an anterior crossbite in centric occlusion, a 1.5mm discrepancy between the dental midlines, and a mild curve of Spee.
The panoramic radiograph confirmed that all permanent teeth
were present, including the third
molars, but the upper left canine
was impacted with a mesial angulation. Cephalometric analysis
indicated a moderate discrepancy
between the bony bases, a long
mandibular arch (Co-Gn), slightly excessive lower facial height,
and a counterclockwise rotation
of the palatal plane (Table 1). The
periapical radiographs revealed
normal upper and lower incisor
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Treatment of Skeletal Class III Malocclusion with the Biofunctional System
roots. The upper incisors were
protrusive, with a marked labial
inclination compensating for the
anteroposterior discrepancy between the bony bases; the lower
incisors were well positioned.
Treatment goals were to reduce the concave profile, improve
facial esthetics, and obtain Class
I molar and canine relationships
after moving the impacted upper
left canine into the arch. Although orthognathic surgery
could have improved the patient’s
esthetic appearance and occlusion, it was not deemed suitable
in this case because the skeletal
Class III malocclusion was mild
(ANB = .8º) and the patient and
parents were reluctant to authorize surgery.4,14,15 Due to the lack
of crowding in the mandibular
arch, extraction treatment could
actually have worsened the profile, with retraction of the incisors resulting in accentuated retraction of the upper and lower
lips and, consequently, an increased nasolabial angle.16,17
Therefore, we recommended a
nonextraction approach involving
traction of the impacted canine
and compensatory orthodontic
treatment with Class III intermaxillary elastics. Considering
the extreme labial tipping of the
upper incisors and the absence of
space for traction of the upper left
canine, the use of a Roth-prescription appliance for Class III
mechanics and space opening
could have worsened the incisor
tipping and further compromised
facial esthetics; it also would
have required significant torque
control of the upper incisors. Instead, a Biofunctional prescrip-
716
tion was chosen to simplify the
mechanics, especially the torque
control. The patient and her parents were advised that a good result would depend on the patient’s
compliance with elastic wear.
Treatment Progress
Leveling and alignment began with .016" round nickel titanium archwires in an .022" ×
.030" preadjusted Biofunctional
appliance. We prescribed ⅛" intermaxillary elastics to be attached from palatal buttons on the
upper incisors to Kobayashi
hooks on the lower lateral-incisor
brackets, crossing anteriorly. The
patient was instructed to wear the
elastics 24 hours a day, removing
them only to eat and play sports.
The Biofunctional Class III
bracket system applies lingual
crown torque on the upper incisors (0°) and buccal crown torque
on the lower incisors (10°) to
counteract the effects of Class III
elastics. In this case, because of
the significant dentoalveolar
compensation, the upper canine
slots were angulated 13°; this
would improve the anteroposterior occlusal discrepancy, facilitating protrusion of the upper incisors to increase the maxillary
arch length. The lower canine
slots were angulated 0° to enhance retrusion of the lower incisors, reducing mandibular arch
length and allowing compensatory correction of the skeletal
Class III discrepancy.12,18
With excellent patient compliance, the negative overjet was
corrected in two months. Leveling and alignment took another
six months, progressing to .016"
× .022" and .019 × .025" nickel
titanium and .019" × .025" stainless steel archwires. A nickel titanium open-coil spring was used
for 12 months between the upper
lateral left incisor and first premolar for space opening and posterior traction of the impacted
canine. Next, 3⁄16" intermaxillary
Class III elastics were worn for
six months to obtain skeletal
Class III dentoalveolar compensation. For the last two months of
finishing and detailing, ⅛" intermaxillary elastics were worn with
a braided archwire (Fig. 2).
Treatment Results
After 28 months of treatment, a significant improvement
in the patient’s profile could be
seen (Fig. 3). Class I molar and
ca n i ne r elat ion sh ip s we r e
achieved, the overjet and overbite
were improved, and the anterior
crossbite was corrected. The
Class III elastics promoted extrusion and mesial angulation of the
upper molars and mild extrusion
and distal angulation of the lower
molars. This generated a clockwise mandibular rotation that
helped alleviate the facial concavity.2,19 The upper incisors displayed protrusion without labial
tipping, while the lower incisors
showed retrusion with minimal
lingual tipping or extrusion (Table 1). There was a marked improvement in the relationship between the bony bases, due to the
reduced mandibular protrusion
and better positioning of the
maxilla relative to the cranial
base. The nasolabial angle and
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Cançado, Freitas, Valarelli, Vieira, and Neves
upper-lip protrusion were reduced without altering the lowerlip position.
A maxillary wraparound
plate and a mandibular 3-3 Bonda-Braid** lingual wire were prescribed for retention. Twenty-six
months later, the results remained
stable, with no change in apical
root morphology evident in the
periapical radiographs (Fig. 4).
Discussion
The anteroposterior position
of the upper and lower incisors
**Reliance Orthodontics, Inc., Itasca, IL;
www.relianceorthodontics.com.
has an important relationship to
facial harmony and smile esthetics. Although compensatory treatment of a skeletal Class III malocclusion inevitably produces some
labial inclination of the upper incisors and lingual inclination of
the lower incisors, excessive tipping can easily compromise a
pleasant smile, especially in a
young patient. Moreover, inordinate labiolingual compensation of
the incisors can generate bone dehiscences that may lead to gingival recession.20
According to Lin and Gu,
compensatory treatment of skeletal Class III malocclusions produced an average upper-incisor
proclination of 6° and protrusion
of 3mm relative to SN, along with
an average lower-incisor retroclination of 6.6° and retrusion of
2mm relative to the mandibular
plane.2 Sperry and colleagues
found that the upper incisors were
tipped 5° labially and the lower
incisors retroclined by 3.5°. 21
Similarly, Troy and colleagues
observed that the upper incisors
were more labially tipped and
compensated, while the lower incisors were more retroclined.22
Sperry and colleagues noted that Class III patients with
excessive dental inclinations
were about three times more
likely than Class I or II patients
Fig. 2 After 26 months of treatment, short intermaxillary elastics used with braided archwire for finishing
and detailing.
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Treatment of Skeletal Class III Malocclusion with the Biofunctional System
A
A
B
Fig. 3 A. Patient after 28 months of treatment. B. Superimposition of pre- and post-treatment cephalometric tracings.
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JCO/NOVEMBER 2015
Cançado, Freitas, Valarelli, Vieira, and Neves
A
A
Fig. 4 A. Patient 26 months after completion of treatment (continued on next page).
VOLUME XLIX NUMBER 11
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Treatment of Skeletal Class III Malocclusion with the Biofunctional System
B
C
Fig. 4 (cont.) B. Superimposition of post-treatment and 26-month-post-treatment cephalometric tracings. C. Superimposition of pretreatment (black), post-treatment (green), and 26-month-post-treatment
(red) cephalometric tracings.
to exhibit gingival recession after orthodontic treatment.21 Vasconcelos and colleagues also
found an association between
lingual inclination of the lower
incisors and the severity of gingival recession.16 In the case
shown here, the periodontal support and protection appeared
normal at the end of treatment,
based on photographs and periapical radiographs.
720
Conclusion
As an alternative for the
treatment of skeletal Class III
malocclusion, the Biofunctional
system can produce a satisfactory
and stable occlusion and acceptable facial esthetics without any
smile or profile impairment due
to excessive dental compensation.
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VOLUME XLIX NUMBER 11
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