Download ORTHODONTIC COMPENSATION IN SKELETAL CLASS III

Figueiredo
11/5/07
3:10 PM
Page 385
Márcio Antonio de
Figueiredo, MSc1
Danilo Furquim Siqueira,
PhD2
Silvana Bommarito, PhD3
ORTHODONTIC COMPENSATION IN
SKELETAL CLASS III MALOCCLUSION:
A CASE REPORT
Aim: To describe the dentoskeletal changes occurring during treatment of a patient with a skeletal Class III malocclusion treated for
orthodontic compensation at 10 years 4 months of age. Methods:
Rapid maxillary expansion was performed with a Hyrax appliance,
Petit orthopedic face mask, high-pull chin cap, and bioprogressive
fixed mechanics. Results: The mechanics employed yielded downward and backward mandibular rotation (3 degrees of opening of the
facial axis), advancement of the maxillary incisors, and retraction of
the mandibular incisors. The result was satisfactory from both
esthetic and functional standpoints, providing adequate overjet and
overbite, and with stability at 5 years posttreatment. Conclusion: The
option for compensatory treatment of the skeletal Class III malocclusion without extractions and without orthognathic surgery might be a
good option for young patients with good compliance, convergent
facial pattern (brachyfacial), and with deep bite, since such occlusal
characteristics allow the downward and backward mandibular rotation that is necessary for correction of this problem. World J Orthod
2007;8:385–396.
Marco Antonio Scanavini,
PhD4
1Resident,
Department of Orthodontics, Methodist University of São
Paulo, Brazil.
2Professor, Postgraduate Program in
Dentistry, Department of Orthodontics, Methodist University of São
Paulo; Professor, Discipline of Child
Clinic, Dental School, Methodist
University of São Paulo, Brazil.
3Professor, Human Communication
Disturbances, University Federal of
São Paulo (UNIFESP); Chair and
Professor, Postgraduate Program in
Dentistry, Department of Orthodontics, Methodist University of São
Paulo, Brazil.
4Coordinator, Postgraduate Program
in Dentistry, Department of Orthodontics, Methodist University of São
Paulo, Brazil.
CORRESPONDENCE
Dr Márcio Antonio de Figueiredo
Rua Capitão Nascimento Filho,
131–Vergueiro
Cep.18030-123
Sorocaba, SP
Brazil
E-mail:
[email protected]
lass III malocclusions may be classified into 2 types: pseudo Class III
and true Class III. According to Gianelly
et al,1 pseudo Class III involves anterior
crossbite in maximum intercuspation;
however, in centric relation, there is
Class I malocclusion with an orthognathic facial profile. According to Bench
et al,2 pseudo Class III may be caused
by inadequate positioning of the maxillary incisors (crowding, ectopic eruption,
trauma, early loss of primary or permanent teeth), which inter feres with
mandibular closure, displacing it anteriorly; in general, the problem is solved
after removal of the interference. The
true Class III involves a skeletal Class III
pattern in centric relation. 1 As mentioned by Bench et al,2 the true Class III
shows a genetic trend toward extreme
upward and backward condylar growth,
C
anterior crossbite, null overbite or open
bite, and dolichofacial pattern, which
contraindicates its correction by downward and backward mandibular rotation.
The clinician should determine if there is
another family member with the same
malocclusion to help in the diagnosis.
According to Bench et al2 and Fränkel
and Fränkel, 3 the anterior crossbite
caused by interferences (pseudo Class
III) may lead to upward and backward
condylar growth with downward and forward mandibular displacement, giving
rise to a true Class III because of inadequate growth stimulus. Gianelly et al1
stated that even though this relationship
may not be clear, it is advisable to adopt
the idea that prevention would be the
best option and thus perform early correction of the crossbite.
385
Figueiredo
11/5/07
3:10 PM
Page 386
WORLD JOURNAL OF ORTHODONTICS
Figueiredo et al
Fig 1 Initial photographs taken on
December 1992. (a,b) Frontal and lateral views of the face. (c to e) Posterior
and anterior crossbite.
a
c
The true Class III malocclusion may
also be called skeletal due to the involvement of skeletal structures; it may be
caused by maxillary retrusion, mandibular protrusion, or a combination of
both.1,4–6 Frequently, there is also maxillary constriction,1,2 represented by posterior crossbite.
There are 3 options for the treatment
of skeletal Class III malocclusion: orthopedic, compensatory, or surgical. Selection of treatment type is based on the
diagnosis, especially the indication of
heredity, facial pattern, age, gender,
severity of the problem, and patient compliance.
Turpin7 and Campbell8 mentioned positive and negative factors for the interceptive treatment of Class III malocclusion.
Positive factors are convergent facial pattern (brachyfacial), anterior functional
deviation (difference between centric
relation and maximum intercuspation),
symmetric condylar growth, growing status, ANB angle less than or equal to –2
degrees, expectation of good compli386
b
d
e
ance, absence of hereditary involvement,
and good facial esthetics. Negative factors include divergent facial type
(dolichofacial), absence of anterior functional deviation, asymmetric growth, nongrowing status, ANB angle larger than –2
degrees, expectation of poor compliance,
familial history, and unpleasant facial
esthetics.
According to Langlade,9 during normal
growth, the amount of growth of the cranial base is nearly equivalent to that of
the mandibular body; in the surgical
Class III syndrome there is hypodevelopment of the cranial base, exaggerated
mandibular growth (3.5 mm per year, as
analyzed by the facial axis). In addition to
this growth, the patient with a Class III
malocclusion may be in a growth period
for up to 16 years for females and 20
years for males.
As mentioned by Gianelly et al,1 orthopedic treatment of Class III malocclusion
in the permanent dentition is more difficult. Thus, treatment should be performed early whenever possible.
Figueiredo
11/5/07
3:10 PM
Page 387
VOLUME 8, NUMBER 4, 2007
Figueiredo
Fig 2
Initial dental casts.
Fig 3
Initial cephalometric radiograph.
Fig 4 Initial cephalometric analysis,
using Ricketts method.
CASE REPORT
Patient LRJ, a male 13 years of age,
requested treatment at the authors’
clinic, with referral to facial orthopedic
treatment. He and his parents brought
records taken 2.5 years earlier (cephalometric radiograph, panoramic radiograph, dental casts, extraoral and intraoral photographs). Anamnesis revealed
that the patient was being treated with a
Fränkel appliance (FR-3) 3 ; the initial
records of the patient showed a skeletal
Class III malocclusion, as observed on
the extraoral and intraoral photographs,
dental casts (Figs 1 and 2), and the
cephalometric analysis (Figs 3 and 4,
Table 1).
The patient was asked to interrupt use
of the Fränkel appliance and obtain new
records for reevaluation of the case.
These records revealed lack of space for
the maxillary right canine, which was
unerupted and impacted (Fig 5), and the
presence of a skeletal Class III malocclusion with an anterior edge-to-edge relationship and posterior open bite (Fig 6).
387
Figueiredo
11/5/07
3:10 PM
Page 388
WORLD JOURNAL OF ORTHODONTICS
Figueiredo et al
Table 1
Cephalometric analysis
Patient Normative value
SNA (degrees)
SNB (degrees)
ANB (degrees)
Cranial deflection (degrees)
Anterior cranial base (mm)
Posterior cranial length (mm)
Mandibular body length (mm)
Facial depth (degrees)
Convexity (mm)
Facial axis (degrees)
Growth pattern
85
101
5
31
54
27
72
100
5
96
Brachyfacial
82
80
2
27
55
41
64.2
86.7
0.1
93
Fig 5 Panoramic radiograph confirming presence of the maxillary
right canine, unerupted and impacted.
a
b
c
d
e
f
Fig 6 Photographs taken in October 1995, when treatment was initiated with fixed orthodontics. (a to c) Frontal, smiling, and
lateral views of the face. (d to f) Anterior edge-to-edge bite and posterior open bite.
388
Figueiredo
11/5/07
3:10 PM
Page 389
VOLUME 8, NUMBER 4, 2007
Figueiredo et al
Fig 7 Cephalometric radiograph
taken in August 1995.
Fig 8 Cephalometric analysis, by
Ricketts method, done before
onset of treatment with fixed
orthodontics.
The lateral cephalogram (Figs 7 and 8)
was taken with the patient in the edge-toedge position, which masked some
cephalometric measurements (SNB, 86
degrees; ANB, 1 degree; facial depth, 96
degrees; convexity, 1 mm; facial axis, 90
degrees) because of the downward and
backward mandibular rotation; however,
the internal structures revealed signs of a
Class III malocclusion, according to
Langlade, 9 including increased cranial
deflection (32 degrees), reduced posterior cranial length (30 mm), and
increased mandibular body length (81
mm). This information confirmed the
presence of a skeletal Class III malocclusion and the brachyfacial growth pattern.
Evaluation of the linear measurements, using the McNamara10 analysis,
revealed the presence of a Class III malocclusion with mild maxillary retrognathism and mandibular prognathism.
Analysis of the mandibular dental
casts was done according to Ricketts.11
Even though the measurements were
increased when compared to normative
values, they were considered normal, due
to the patient’s large tooth size.
Treatment plan
There were 2 treatment options for the
skeletal problem: (1) orthodontic treatment with orthognathic surgery and (2)
compensatory orthodontic treatment.
Orthodontic compensation was selected
by consensus between parents and orthodontist, especially due to the patient’s
age, which contraindicated surgery.
According to Gianelly et al,1 an orthopedic
approach is the first option until puberty
is reached. Pinho et al12 mentioned cost
reduction and potential risk associated
with orthognathic surgery as advantages
to the orthopedic approach, and the
involvement of esthetic appearance and
potential of occlusal instability as disadvantages. McNamara and Brudon5 highlighted that early correction of the Class III
malocclusion might lead to the need for
surgical correction later, and that a careful specialist should never guarantee the
Class III correction, since the individual
long-term result of such treatment is difficult to forecast.
The lack of space for eruption of the
maxillary right canine led to 3 treatment
options: (1) extraction of the impacted
canine; (2) extraction of 1 premolar on
the same side, to achieve space for
orthodontic extrusion of the canine; or
(3) orthodontic space opening. The third
option was selected because the skeletal
Class III malocclusion may be worsened
by the extraction of a maxillary tooth.
389
Figueiredo
11/5/07
3:10 PM
Page 390
WORLD JOURNAL OF ORTHODONTICS
Figueiredo et al
a
b
c
Fig 9 (a,b) Occlusal view of the maxilla before and soon after rapid expansion. (c) Intraoral frontal view after rapid maxillary
expansion; maxillary left central and lateral incisors connected to the Hyrax with a ligature wire 0.25 inches, so that the transeptal fibers would allow closure of the anterior diastemas for correction of the midline and space opening for the maxillary right
canine.
a
b
c
Fig 10 (a to c) Right, frontal, and left intraoral view of the patient with the doubleT segmented arch for leveling and expansion of mandibular premolars. (d) Triple-T
segmented arch for leveling of the maxillary right first and second premolars and
first molar and extrusion of the maxillary right canine.
d
Treatment
Treatment was performed within the principles of Ricketts’ bioprogressive therapy,
with use of the following appliances:
Hyrax rapid maxillary expander (Fig 9),
Petit face mask, mandibular bite block to
release the occlusion, chin cap, utility
arches, segmented arches (Fig 10), and
ideal arches.
The expander was activated 40 turns
(nearly 1 cm). The face mask was placed
immediately after finalization of rapid maxillary expansion, delivering nearly 900 kgf with
2 elastics 5/16-inch (8 oz) placed on each
side of the mask.
390
The chin cap was worn by the patient
during sleep, throughout the treatment
and follow-up years until he reached 20
years of age, with a force of 250 kgf. Use
of the chin cap may have helped in the
mandibular posterior positioning in the
temporal fossa, followed by downward
and backward rotation. According to
Gianelly et al, 1 mandibular posterior
repositioning and rotation are important
components of the response to Class III
treatment, and a successful treatment is
rarely achieved if such repositioning does
not occur. The final result is shown in
Figs 11 and 12.
Figueiredo
11/5/07
3:10 PM
Page 391
VOLUME 8, NUMBER 4, 2007
Figueiredo et al
Fig 11 Final intraoral and extraoral
photographs following removal of the
appliances on December 18, 1998
(patient was 16 years 3 months of age).
Fig 12 Final panoramic radiograph reveals normality (mandibular third molars
were extracted during the treatment).
391
Figueiredo
11/5/07
3:11 PM
Page 392
WORLD JOURNAL OF ORTHODONTICS
Figueiredo et al
Fig 13
graph.
Final cephalometric radio-
Fig 14 Final cephalometric analysis,
using Ricketts method.
b
a
Fig 15 (a to c)
T3, green).
c
Cephalometric superimposition using the basion-nasion plane with center in point Cc (T1, yellow; T2, orange;
a
b
c
Fig 16 (a to c) Basion-nasion-point A superimposition with center in nasion.
DISCUSSION
Analysis of the results through cephalometric analysis (Figs 13 and 14) reveal
392
skeletal and dentoalveolar alterations
that can be described by the superimposition method of Ricketts.13
Figueiredo
11/5/07
3:11 PM
Page 393
VOLUME 8, NUMBER 4, 2007
a
Fig 17 (a to c) Superimposition on the palatal plane (ENAENP) with center in the anterior nasal spine.
Figueiredo et al
b
Evaluation of skeletal and
dentoalveolar changes
The skeletal and dentoalveolar changes
discussed below occurred between
December 1992 (T1, treatment with
Fränkel FR-3), July 1995 (T2, treatment
onset), and January 1999 (T3, treatment
completion).
Basion-nasion plane with center in
point Cc (Fig 15). The facial axis was
opened 6 degrees (downward and backward mandibular rotation) between T1
and T2, and was closed 3 degrees
between T2 and T3, yielding an opening
of 3 degrees in the period between T1
and T3. Analysis of these data reveals
that the Fränkel FR-3 appliance yielded
downward and backward mandibular
rotation; after interruption of the FR-3
use, the mandible showed upward and
forward rotation, despite the use of extrusion mechanics (Hyrax, Petit face mask).
This effect, to a large extent, may be due
to the brachyfacial pattern.
Finally, this result (opening of the
facial axis) helped in the correction of the
Class III malocclusion, yielding downward
and backward mandibular rotation.
According to Gianelly et al,1 when there is
a deep bite, the occlusal complex may
show the effect of bite opening resulting
from mandibular rotation. Therefore,
these mechanics may be successfully
employed in brachyfacial patients with
Class III malocclusion since, when the
mandible is rotated in a downward and
backward direction and the anterior open
bite is corrected, a favorable overbite is
achieved, increasing the outcome stability. On the other hand, dolichofacial
patients do not have a favorable
response, since this downward and backward mandibular rotation gives rise to
anterior open bite, which is not ideal for
the esthetics and function of the patient.1
c
Basion-nasion-point A with center in
nasion (Fig 16). During the period from
T1 to T2 and T1 to T3, there was only
mild anterior maxillary displacement,
which may have occurred due to the stimulation of maxillary development provided by the Fränkel FR-3 appliance3 or
by normal growth itself since, as shown
by Baik et al,14 the orthopedic effects in
the maxilla with use of the Fränkel FR-3
appliance are mild.
Between T2 and T3, there was no
alteration in horizontal maxillary positioning, even though the Petit face mask was
applied with orthopedic force. This may
be explained by the bone maturation of
the patient, which reduced the skeletal
outcomes.
The rhythm of maxillary vertical growth
was more remarkable in the period during
which the patient was treated with the
Fränkel appliance (T1 and T2). This was
reduced when treatment was performed
with fixed appliances (T2 and T3), thus
keeping normal values (1.16 mm per year),
as shown in the period between T1 and T3.
Palatal plane with center in anterior
nasal spine (Fig 17). Between T1 and
T2, the maxillary incisors were retruded
(1 mm) and extruded (0.5 mm). This
alteration in positioning of the incisors
was not favorable for the Class III treatment, since it worsened the overjet.
Between T2 and T3, the incisors were
advanced 4 mm and intruded 1 mm.
Analysis of this period reveals that this
advancement had a favorable effect of
compensatory treatment of the skeletal
Class III malocclusion. In the period
between T1 and T3, there was 3 mm of
advancement and 0.5 mm of intrusion.
The maxillary molars were extruded 4
mm between T1 and T2 and did not show
mesial movement, which are both unfavorable treatment sequelae for the correction of the Class III malocclusion.
393
Figueiredo
11/5/07
3:11 PM
Page 394
WORLD JOURNAL OF ORTHODONTICS
Figueiredo et al
b
a
Fig 18 (a to c)
Superimposition on Plane Xi–Pm (suprapogonion) with center in point Pm.
a
Fig 19 (a to c)
b
c
Superimposition on intersection of the esthetic plane with the functional occlusal plane.
Between T2 and T3, the maxillary molars
showed 1 mm of mesial movement and 1
mm of extrusion. Between T1 and T3, the
maxillary first molars did not show mesial
movement; since this is a Class III malocclusion, this is not a good result, yet it
should be highlighted that at treatment
onset there was lack of space for eruption
of the right maxillary canine, which required
blockage of the maxillary first molars for
achievement of space for eruption. The
maxillary first molars also erupted 5 mm.
Plane Xi-Pm (point Xi, geometric center of mandibular ramus; point Pm
[suprapogonion], where chin curvature
changes from convex to concave) with
394
c
center in Pm (Fig 18). During the period
from T1 to T2, the mandibular first
molars had 4 mm of extrusion and 1.5
mm of uprighting, a favorable alteration
for Class III treatment. Between T2 and
T3, the molars had nearly no movement,
as observed in Fig 18b. This blockage
occurred due to the mechanics employed
(utility arches), since in normal conditions
these teeth erupt 0.5 mm per year. Investigation of the changes occurring
between T1 and T3 reveal 4 mm of extrusion, a normal amount for the 6-year
period. The same first molars presented
2 mm of uprighting, which was beneficial
for the treatment.
Figueiredo
11/5/07
3:11 PM
Page 395
VOLUME 8, NUMBER 4, 2007
Figueiredo et al
Fig 20 Final intraoral and extraoral
photographs 5 years posttreatment.
The mandibular incisors were
extruded 3 mm and advanced 1 mm in
the period between T1 and T2, which
was not favorable, since it worsens the
overjet and overbite. Between T2 and T3,
the incisors were retracted 1 mm and
blocked in vertically. Between T1 and T3,
the incisors moved distally 2 mm and 3
mm vertically. This movement was probably related to the effect of the compensatory treatment performed.
Esthetic plane (E) in intersection
with the occlusal plane (Fig 19). During
the period T1 to T2, the lower lip was lowered and there was mild posterior repositioning due to the downward and back-
ward mandibular rotation; the upper lip
was advanced, probably due to the effect
of the Fränkel FR-3 appliance. These mild
changes favored an improvement in the
soft-tissue profile.
Between T2 and T3, the lower lip was
mildly displaced backward and downward
because of retraction of the mandibular
incisors, whereas the upper lip showed
only downward movement. These mild
changes improved the soft-tissue profile,
as can be seen in Fig 19b.
Between T1 and T3, the changes are
more evident: The upper and lower lips
show downward displacement because
of opening of the facial axis (downward
395
Figueiredo
11/5/07
3:11 PM
Page 396
WORLD JOURNAL OF ORTHODONTICS
Figueiredo et al
and backward mandibular rotation). The
upper lip was advanced and the lower lip
was retruded, following the movement of
the incisors, resulting in an improved
soft-tissue profile.
The stability of the compensatory
treatment, as well as the adequate
esthetics from both facial and dental
viewpoints, can be seen in Fig 20, taken
5 years after treatment completion.
CONCLUSION
This article investigated the dentoskeletal and soft-tissue alterations occurring
during compensatory treatment of Class
III malocclusion, by the superimposition
method of Ricketts.13 These alterations
included downward and backward
mandibular rotation (opening of facial
axis, 3 degrees), mild maxillary advancement (1.5-degree increase in the angle
Ba-Na- A), advancement of maxillary
incisors, retraction of mandibular
incisors, and uprighting of the mandibular first molars.
Selection of the compensatory treatment (orthodontic camouflage) was satisfactory based on the final outcome, from
both functional and esthetic standpoints,
and the treatment stability at 5 years
posttreatment.
396
REFERENCES
1. Gianelly AA, Bednar J, Cociani S, Giancotti F,
Maino G, Richter O. Bidimensional technique:
Theory and practice. Islandia, NY: GAC International, 2000:128–141.
2. Bench RW, Gugino CF, Hilgers JJ. Bioprogressive
therapy part 8: Bioprogressive mixed dentition
treatment. J Clin Orthod 1978;12:279–298.
3. Fränkel R, Fränkel C. Orofacial orthopedics with
the function regulator. Basel: Karger, 1989:
36–38, 190–211.
4. Guyer EC, Ellis EW, McNamara JA Jr, Behrents
RG. Components of Class III malocclusion in
juveniles and adolescents. Angle Orthod 1986;
56:7–31.
5. McNamara JA Jr, Brudon WL. Tratamiento
ortodóncico y ortopédico en la dentición. Ann
Arbor: Needham, 1995:121–133.
6. Seher GA, Jalan DK, Sedat B. Correction of a
severe Class III malocclusion. Am J Orthod
Dentofacial Orthop 2004;126:237–244.
7. Turpin DL. Early Class III treatment. [unpublished thesis]. Presented at 81st session of the
American Association of Orthodontists, San
Francisco, 1981.
8. Campbell PM. The dilemma of Class III treatment. Angle Orthod 1983;53:175–191.
9. Langlade M. Diagnostic orthodontique. Paris:
Maloine, 1981:245–301, 696–714.
10. McNamara JA Jr. A method of cephalometric
evaluation. Am J Orthod 1984;86:449–469.
11. Ricketts RM. Provocations and perceptions in
craniofacial orthopedics. Glendora, CA: RMO,
1989:735, 817–818.
12. Pinho TMC, Torrent JMU, Pinto JGRC. Orthodontic camouflage in the case of a skeletal Class III
malocclusion. World J Orthod 2004;5:213–223.
13. Ricketts RM. A four-step method to distinguish
orthodontic changes from natural growth. J Clin
Orthod 1975;9:208–228.
14. Baik HS, Jee SH, Lee KJ, Oh TK. Treatment
effects of Fränkel functional regulator III in children with Class III malocclusions. Am J Orthod
Dentofacial Orthop 2004;125:294–301.