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American Journal of Orthodontics and Dentofacial Orthopedics
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Fig 1. Pretreatment facial photographs.
Fig 2. Pretreatment intraoral photographs.
TREATMENT ALTERNATIVES
This adult patient had no clinically significant
maxillomandibular growth potential to assist in establishing our treatment goals with orthodontics alone.
Orthognathic surgery to protract the maxilla with the
possibility of mandibular setback, combined with fixed
orthodontic treatment, was discussed with him. Maximum esthetics, ideal occlusion, and skeletal discrepancy correction would be possible with this approach.
Orthodontics alone would help camouflage some skeletal and dental aspects of the malocclusion, improving
esthetics and function. The orthodontic options included (1) maxillary expansion to correct the crossbite
and create arch space to derotate and align the teeth
and, if necessary, mandibular incisor extraction to
correct the overjet and the anterior crossbite; (2) 2
mandibular premolar extractions to upright the mandibular incisors and correct the mild crowding and the
crossbite; (3) a single mandibular right premolar extraction to upright the incisors, correct the crossbite,
and establish Class I canine occlusion; and (4) extraction of both mandibular second molars to establish a
Class I buccal and canine occlusion and upright the
mandibular incisors. The latter option would most
likely require the longest treatment time to retract the
premolars and the anterior segment.
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Fig 3. Pretreatment dental models.
Fig 4. Pretreatment panoramic and periapical radiographs.
Fig 5. Pretreatment cephalometric tracing.
TREATMENT PROGRESS
The patient refused surgical procedures and opted for
orthodontic treatment and camouflage, accepting maxillary dental expansion as the first stage of treatment.
Treatment began with the placement of a removable
expansion appliance (Fig 6) in the maxillary arch, and
the patient was instructed to activate it twice a week.
Subsequently, edgewise brackets were placed on all
maxillary and mandibular teeth, with coil springs be-
4. 246 Daher, Caron, and Wechsler
Table.
American Journal of Orthodontics and Dentofacial Orthopedics
August 2007
Cephalometric measurements
Measurement
SNA angle (°)
SNB angle (°)
ANB angle (°)
Wits (mm)
SN-Go Gn (°)
MP to FH (°)
U1 to NA (°)
U1 to NA (mm)
U1 to FH (°)
L1 to NB (°)
L1 to NB (mm)
L1 to MP (°)
U1 to L1 (°)
Pog to NB (mm)
Standard
Initial
Final
82
80
2
1
32
25
22
4
111
25
4
90
123
1
83
85
–2
–8
22
23
30
6
112
24
6
97
128
1
83
82
1
–3
26
23
25
6
111
13
1.5
85
141
0.3
improvement in the profile; the position of the upper lip
is closer to the esthetic plane. Separate superimpositions of the maxilla and the mandible show that the
maxillary teeth appear to have been advanced, whereas
the mandibular anteriors were retroclined. Because no
cephalometric radiograph was taken immediately after
facemask wear, the orthodontic and orthopedic effect of
the facemask could not be determined precisely. The
forward position of the maxillary base at the end of
treatment was most likely due to the combined effect of
the facemask and the Class III elastics.
Clinical examination of the mandibular position did
not show that the mandible shifted backwards, and
there was no evidence of a centric relation-centric
occlusion shift.
DISCUSSION
tween the maxillary first molars and canines to advance
the anterior teeth.
Because there was little progress in correcting the
anterior crossbite, it was decided to extract the mandibular right central incisor. The patient wore Class III
elastics full time and a protraction facemask (Fig 7) at
night to aid in the advancement of the maxillary arch.
Treatment time was approximately 2 years. Retention
consisted of a bonded lingual wire on the maxillary
anterior teeth, including the canines. A spring aligner
was used on the mandibular teeth.
TREATMENT RESULTS
At the end of treatment, the crossbites were corrected, and acceptable overjet and overbite were established (Figs 8-12). The posttreatment intraoral photographs show a good Class I occlusion on the left side,
with a slight Class III canine relationship on the right.
Normal overbite and overjet were achieved, and gingival heights on the maxillary anterior teeth were levelled. The occlusal views show good forms in both
arches. The extraoral frontal view shows a mesofacial
appearance, but the profile appears more orthognathic.
Posttreatment periapical radiographs show that the
level of interradicular bone remained relatively stable.
The roots of the mandibular anterior teeth remained
parallel despite the extraction of the mandibular central
incisor. The posttreatment panoramic radiograph shows
that bone levels were maintained. The maxillary teeth
were advanced slightly, and the mandibular incisors
were retracted. The maxillary skeletal base remained
relatively stable (SNA angle, 83°), whereas the mandibular base was reduced (SNB angle, 82°), giving a
positive ANB angle (1°). The maxilla advanced
slightly. Comparison of the soft-tissue profile in the
before and after cephalometric tracings (Fig 13) shows
In treating patients with Class III malocclusions, it
is essential to diagnose the components of the malocclusion correctly. In dealing with a dentoalveolar Class
III, it might be possible to achieve an ideal occlusion
with orthodontic tooth movement alone. However, if
the etiology of the malocclusion is skeletal, or a
combination of skeletal and dental factors, then treatment combining orthognathic surgery with conventional orthodontics is frequently necessary to obtain a
result closer to the ideal. The timing of treatment is also
important. In a case of early diagnosis of Class III
malocclusion with maxillary deficiency in the late
deciduous or early mixed dentition—ie, during the
period of growth—a rapid palatal expansion appliance
combined with a protraction facemask might be a
useful treatment option.5 However, if the skeletal discrepancy is caused by excessive growth of the mandible, there seems to be little that can be done because
“inhibiting mandibular growth has proven to be almost
impossible,”6 and orthognathic surgery to set back the
mandible at the end of adolescent growth seems to be
the only viable option. For adults, fewer methods of
treatment are available: either a combination of orthodontics and surgery or camouflage orthodontic treatment with various extraction combinations, depending
on the severity of the malocclusion. It is important to
listen to the patient’s main concerns in order to respond
adequately to his or her needs.
The most effective and efficient timing for such
treatment has been suggested to be the early mixed
dentition,7 before the patient is 8 years of age,8 before
age 10,6 until the age of 12,9 or even throughout
puberty.10 However, to our knowledge, no published
data in the literature advocate the use of protraction
force combined with maxillary expansion in nongrowing adults. For this patient, the expansion appliance and
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American Journal of Orthodontics and Dentofacial Orthopedics
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Fig 6. Intraoral photographs during treatment, showing maxillary removable expansion appliance
with posterior occlusal coverage.
Fig 7. Facemask worn at night.
the facemask therapy provided enough dentoalveolar
compensation to correct the crossbite and camouflage
the underlying Class III malocclusion. Although this
treatment modality is somewhat unorthodox in an adult,
the beneficial results were purely dental and were made
possible by a cooperative and motivated patient.
The effects of mandibular incisor extraction on
the occlusion depend on several factors: amount of
crowding in both arches, tooth mass relationship
between the 2 arches (Bolton analysis), type of
malocclusion, amounts of overbite and overjet, and
long-term stability.
The extraction of a mandibular incisor might cause
increases in overjet and overbite11; this effect is usually
desirable in Class III patients and detrimental in Class
I and Class II patients.12,13 The tooth-mass discrepancy
created by the extraction can be evaluated with a Bolton
analysis, but a diagnostic wax setup is probably the
better alternative for treatment-planning purposes. A
concomitant maxillary anterior interproximal enamel
reduction is sometimes indicated to compensate for the
tooth-mass difference created by the extraction.12 Careful planning and clear treatment objectives make this
treatment option viable.
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American Journal of Orthodontics and Dentofacial Orthopedics
August 2007
Fig 8. Posttreatment facial photographs.
Fig 9. Posttreatment intraoral photographs.
The rationale for using a fixed retainer in the
maxillary arch (and a removable retainer in the mandibular arch) was that it would counter the possibility of
mandibular incisor proclination, which might lead to
spacing between the maxillary anterior teeth, thus
compromising esthetics in the most conspicuous area of
the mouth. Riedel et al14 suggested that, in patients with
crowded mandibular arches, the removal of a mandibular incisor can allow for increased stability in the
mandibular anterior region even with no permanent
retention. In our patient, the 3-year posttreatment
records (not shown) demonstrated that the mandibular
anterior segment remained stable with the removable
retainer. In retrospect, an occlusal splint in the maxillary arch to prevent further incisor wear would also
have been an excellent preventive measure.
Owen15 described 2 patients who had only a few
signs and symptoms of temporomandibular dysfunction—ie, sore muscles of mastication and limited mandibular opening. One mandibular incisor was extracted
in each patient. After treatment, muscle tenderness was
eliminated, and maximum opening improved. In our
case, the patient had no symptoms of temporomandibular dysfunction either before or after orthodontic treatment, and we expect him to have normal temporomandibular joint function in the future. The Class III occlusion
7. Daher, Caron, and Wechsler 249
American Journal of Orthodontics and Dentofacial Orthopedics
Volume 132, Number 2
Fig 10. Posttreatment dental casts.
Fig 11. Posttreatment panoramic and periapical
radiographs.
on the right side does not appear to have negatively
affected the functional occlusion of the teeth on that side.
The mandibular incisor extraction helped to align
the mandibular anterior segment and provided the space
Fig 12. Posttreatment cephalometric tracing.
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American Journal of Orthodontics and Dentofacial Orthopedics
August 2007
Fig 13. Comparison of profile before and after treatment.
necessary to upright the incisors, thus facilitating crossbite correction. Positive overbite and overjet should
help maintain the results. Light forces were used
throughout the treatment to prevent or minimize apical
root resorption on the mandibular incisors. The posttreatment radiographs (Fig 11) show satisfactory root
alignment of the mandibular incisors with no evident
root resorption.
This was a compromise treatment, with an excellent
final result that has admirably met the patient’s needs.
The occlusion is functional and stable, and he has a
pleasing smile. His quality of life has been greatly
improved, and surgery was avoided.
CONCLUSIONS
The choice of treatment for any malocclusion must
be tailored to each patient. All treatment possibilities,
including those that are ideal and those that are a
compromise, should be considered and explained to the
patient, so that he or she can choose the most acceptable one. All problems perceived by a clinician might
not be problems in the patient’s eyes. The treatment
that this patient received satisfied his needs, despite its
limitations. Both the patient and the orthodontist were
satisfied with the results. The patient’s chief concern
was addressed and treated to his satisfaction, an esthetic
smile was established, and the malocclusion was
treated to a satisfactory and stable result.
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