Full text of DOI:10.1016/S0889-5406(00)70249-6

ABO CASE REPORT
Treatment of a Class I bimaxillary protrusive
malocclusion with a high mandibular plane angle:
An American Board of Orthodontics case report
a
b
J. Mark Griffies, DDS, and Charles E. Meyers, DDS, MS
El Paso, Tex., and Dublin, Ga.
A case report of the orthodontic treatment of a male adolescent with a Class I bimaxillary protrusive
malocclusion, complicated by a vertical growth pattern and high mandibular plane angle. Treatment
consisted of extraction of maxillary second premolars, mandibular first premolars, use of a transpalatal bar,
occipital pull headgear, and light wire mechanics. An acceptable result was achieved, with a decrease in the
facial axis, decrease in lip strain, and an attractive full smile. This case report was presented to the
American Board of Orthodontics in partial fulfillment of the requirements for the certification process
conducted by the Board. (Am J Orthod Dentofacial Orthop 2000;117:60-7)
T
he patient is a normally developing 11-
year 10-month-old male of Panamanian descent who
desires “straight teeth.” He is presently taking Ritalin to
control his hyperactivity and lengthen his attention
span. His dental health has been maintained through
routine annual dental visits, and he presently maintains
fair plaque control. He does not admit to any oral habits.
However, tongue thrust/posturing is suspected. Heredi-
tary influence is probable because his mother presents
with a similar malocclusion (Figs 1, 2, 3, and 4).
DIAGNOSIS
The patient presents with facial symmetry, a convex
profile, acute nasolabial angle, 4 mm of maxillary
incisor display on repose, and pronounced mentalis
strain on lip closure. The dental casts show a Class III
molar relationship with partially erupted maxillary
canines. There is 2.5 mm of overjet, 1 mm of overbite,
a level curve of Spee, and slight maxillary midline shift
to the left of the facial midline. The maxillary right and
left primary second molars are present. A moderate
mandibular arch length discrepancy and slight asym-
metry are noted in the canine region. Bolton analysis of
tooth size discrepancies reveals an estimated excess of
2
mm in the maxillary arch. Articulated models reveal
a left lateral shift of 0.3 mm and a distraction of 0.25
mm anterior and 0.75 mm inferior at the level of the
Fig 1. Pretreatment facial photographs.
The views and opinions of the authors expressed herein do not necessarily
reflect those of the U.S. government or the U.S. Army.
a
Lieutenant Colonel, U.S. Army.
In private practice in Dublin, Ga.
condyles. Temporomandibular joint (TMJ) sounds and
symptoms cannot be detected clinically and are
reported absent by the patient. Numerous wear facets
are noted on the maxillary and mandibular posterior
b
Reprint requests to: J. Mark Griffies, DDS, 217 Sheridan Rd., El Paso, TX 79906
Copyright © 2000 by the American Association of Orthodontists.
0
889-5406/2000/$12.00 + 0 8/5/89749
60

American Journal of Orthodontics and Dentofacial Orthopedics
Griffies and Meyers 61
Volume 117, Number 1
Fig 2. Pretreatment intraoral photographs.
Fig 3. Pretreatment cephalometric and panoramic radiographs.
occlusal surfaces. Panoramic radiographic analysis
show all teeth present. All unerupted third molar teeth
are forming normally with no root formation at present.
The maxillary second premolars are erupting normally
at about 85° to the occlusal plane. Anterior-superior
flattening of both the right and left condyles is noted.
Cephalometric analysis reveals a skeletal Class II rela-
tionship. This skeletal relationship appears to be due to
a slightly protrusive maxilla and the clockwise rotation
of the mandible. The high mandibular plane angle

62 Griffies and Meyers
American Journal of Orthodontics and Dentofacial Orthopedics
January 2000
Fig 4. Pretreatment cephalometric tracing.
(FMA, SNGoGn), decreased facial axis, and low ante-
rior to posterior face height ratio indicate a vertical
growth pattern and open bite tendency prior to ortho-
dontic treatment.
TREATMENT OBJECTIVES
1
2
. Correct to Class I molar and canine relationship.
. Maintain or reduce current anterior vertical dimen-
sion.
Fig 5. Posttreatment facial photographs.
3
4
5
. Correct mandibular crowding and gain mandibular
and maxillary dental symmetry.
relationship and allow maximum retraction of the
lower anteriors.
. Placement of maxillary and mandibular orthodontic
appliances and use light wires to level and align
both arches.
. Reproximate maxillary anteriors during finishing to
equalize the maxillary and mandibular mesial-distal
tooth sizes.
. After appliance removal, place a gnathologic posi-
tioner for final finishing (3 weeks) then maxillary
and mandibular removable retainers. Plan full-time
retainer wear for 1 year then nightly for 6 months.
. Reevaluate third molars for extraction.
. Establish ideal overjet and overbite with a canine
guided mutually protected occlusal scheme.
. Establish good facial balance with lips competent in
repose and upper incisor display of approximately 3
mm. Reduce protrusive lips and mentalis strain on
closure.
3
4
5
TREATMENT PLAN
The patient and parents are counseled to the possi-
ble need for surgical intervention, should his open bite
increase during treatment. All treatment mechanics will
be designed for maximum control of the vertical
dimension.
6
TREATMENT PROGRESS
1
. Placement of a transpalatal bar to the maxillary first
molars and start occipital pull headgear to maintain
vertical control during leveling and alignment.
The mandibular first premolars and maxillary pri-
mary second molars were removed with subsequent
placement of maxillary and mandibular orthodontic
appliances. The maxillary canines and second premo-
2. Extract maxillary second premolars and mandibular
first premolars to aid in the correction of the molar

American Journal of Orthodontics and Dentofacial Orthopedics
Griffies and Meyers 63
Volume 117, Number 1
Fig 6. Posttreatment intraoral photographs.
Fig 7. Posttreatment cephalometric and panoramic radiographs.
lars were bypassed on the initial bonding. Occipital
pull headgear and a transpalatal bar were started on this
initial appointment and continued during the first 6
months of leveling and alignment. During initial align-
ment, the mandibular incisors were uprighted slightly
to deepen the overbite and the maxillary canines were
brought into the arch using a 0.0175 twisted stainless
steel overlay wire to these teeth. The maxillary second
premolars were removed 5 months into treatment and
maxillary/mandibular 0.019 × 0.025 double keyhole

64 Griffies and Meyers
American Journal of Orthodontics and Dentofacial Orthopedics
January 2000
Fig 8. Pretreatment and posttreatment cephalometric superimpositions.
closing loops placed. The occipital pull headgear and
transpalatal bar were discontinued at this time to allow
mesial movement of the maxillary posterior teeth.
Space closure was completed on the lower arch after 4
months, and the closing loop arch wire was replaced
with a 0.018 stainless steel to relevel the arch. Space
closure was completed in the upper arch after 6 months
and a 0.017 × 0.025 stainless steel arch wire placed.
One year into treatment, progress records were
assessed and indicated further arch coordination was
required with the need to reposition several brackets.
During the next 6 months, finishing procedures
included the reproximation of maxillary anterior teeth
and vertical adjustment of canines to improve occlu-
sion. The final occlusion was established with the use
of short posterior Class III elastics (1/8 inch, 4 oz) for
3
weeks and then debonding both arches and placing a
gnathologic positioner for 3 weeks. A maxillary cir-
cumferential retainer and mandibular removable
retainer were subsequently placed. Total treatment time
was 18 months (Figs 5, 6, 7, and 8). Appointments
were at 4 to 6 week intervals, with good cooperation
and oral hygiene by the patient.
RESULTS ACHIEVED
Esthetically, the patient completed treatment with
an attractive full smile, teeth aligned, midlines correct,
and less than 1 mm of gingiva showing above the cen-
tral incisors when smiling. The final convex profile has
had a favorable improvement, with the retraction of the
protrusive maxillary incisors; the lips are full, compe-
tent, no longer strained, and in good balance.
Fig 9. Two-year posttreatment facial photographs.

American Journal of Orthodontics and Dentofacial Orthopedics
Griffies and Meyers 65
Volume 117, Number 1
Fig 10. Two-year posttreatment intraoral photographs.
Fig 11. Two-year posttreatment cephalometric and panoramic radiographs.
Functionally, the Class III molar relationship was
corrected to a Class I position, and the canines and
premolars are in a solid Class I relationship. The over-
jet was maintained at 2.5 mm and the overbite
increased to 2.5 mm. The midlines are coincident, with
a canine-guided occlusion and well-seated posterior
occlusion.
Probably the most dramatic change seen on the
cephalometric radiograph is the large amount of
condylar growth (Table I, Figs 7 and 8). The

66 Griffies and Meyers
American Journal of Orthodontics and Dentofacial Orthopedics
January 2000
Fig 12. Pretreatment and 2-year posttreatment superimpositions.
Table I. Cephalometric summary
Area of study
Measurement
Norms
(A)
(B)
(C)
Cranial base
N-S-Ar
S-N
123°
71 mm
112
64
114
66
116
67
Maxilla to cranial base
Mandible to cranial base
Maxillo-mandibular relations
Vertical height
SNA
A perpendicular
82°
0 mm
88
1
87
1
85
0
SNB
NPO-FH
80°
88°
78
82
80
84
79
84
ANB
Wits
2°
0 mm
10
1
7
1
6
–1
LFH
FMA
SN-GoGn
S-Go:N-Me
47°
25°
32°
62°
52
37
41
58
52
37
41
58
54
34
40
59
Maxillary and mandibular incisor position
U1-Na(mm)
U1-Na(deg)
U1-Max Pl
U1 to SN
L1-NB(mm)
L1-NB(deg)
IMPA
4 mm
22°
110°
103°
4 mm
25°
90°
2 mm
135°
7
24
120
112
15
40
100
9
5
7
17
113
104
11
31
90
5
23
115
107
12
37
96
7
L1-A pog
U1-L1(deg)
107
124
115
Soft tissue
S-line
Upper lip
Lower lip
Nasolabial angle
0 mm
0 mm
100°
9
15
87
7
13
91
6
10
96

American Journal of Orthodontics and Dentofacial Orthopedics
Griffies and Meyers 67
Volume 117, Number 1
patient’s growth pattern was predicted to be primar-
ily vertical, down the facial axis of 81°. The com-
posite superimposition shows growth primarily
down the facial axis but almost twice the amount
predicted with approximately 5 mm of horizontal
growth achieved. It appears that the facial axis did
close approximately 1°, which was desirable in this
open bite tendency case. The open bite did not
express itself, partly due to the use of a transpalatal
bar, and occipital headgear during the first 6 months
of treatment, light wire mechanics, and the large
amount of ramal growth achieved. The upper and
lower molars erupted slightly, but the ramal growth
was great enough to compensate for their eruption
and keep the bite closed.
The 2-year posttreatment records show continued
vertical and horizontal growth with a slight increase in
mandibular incisor irregularity and return of the maxil-
lary midline diastema. Overall the occlusion remained
stable (Figs 9, 10, 11, and 12).