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The
Tweed Profile
Published by
The Charles H. Tweed
International Foundation For
Orthodontic Research
and Education
Volume XI
2012
Contents
2
A Look At A Particular Type of Class II Malocclusion — Herb Klontz and Jim Vaden
Oklahoma City, Oklahoma and Cookeville, Tennessee
14
A New Twist on 3rd Order — Bob Stoner
Indianapolis, Indiana
18
The Human Face…Our Past…Present…Future? — Dennis Ward
Avon Lake, Ohio
21
Why the Single Bracket? — Elie Amm
Jbeil (Byblos), Lebanon
23
Class III Correction and Surgical Orthontics: the Good, the Bad,
Ugly — Mike Behnan
Clinton Township, Michigan
27
Cephalometrics Revisited — Hiroshi Maruo, Claudio Vinícius Sabatoski,
Orlando Tanaka, Armando Yukio Saga, Ivan Toshio Maruo
Brazil
36
Case Report: A Full Step Class II Patient Revisisted 27 Years
Posttreatment — Vance Dykhouse
Blue Springs, Missouri
40
Case Report: Vertical Control in a High Angle Patient Who Needed
Rapid Maxillary Expansion (RME) — Mauricio Escanola
Tepic, Nayarit / Mexico
43
Case Report: Treatment of a High Angle Adolescent Patient — Kortne Frederick Hou
Tukwila, Washington
45
Case Report: Correction of a Severe Class II Division I Malocclusion in
an Adolescent Patient — Jack Hou
Tukwila, Washington
and the
A Look At A Particular Type of Class II Malocclusion
Herb Klontz
Oklahoma City, Oklahoma
Jim Vaden
Cookeville, Tennessee
There are many variations of the Class II malocclusion. It
has been studied; its treatment protocols have been debated;
and the ramifications of its various treatment solutions have
been referenced in our literature for many, many years. The
purpose of this short paper is to offer a brief discussion of
the types of Class II malocclusions that are generally best
treatment planned for the removal of maxillary first premolars
and mandibular second premolars. What we will attempt with
this short article is to give the reader an overview of some
of the things to consider when treatment planning a Class II
malocclusion that would be well treated with the removal
of maxillary first/mandibular second premolars. Three case
reports will be used to illustrate our thoughts on the Class II
that is best corrected with this extraction pattern.
The Face
When the treatment plan is devised, the first area which must
be studied is the face. Is the face a consideration when an
extraction pattern is considered? Absolutely! Most patients
who are treatment planned for this extraction protocol have
a facial pattern that almost has balance, or the face may
well exhibit balance and harmony. The Z-angle of most of
these patients will range from the mid 70’s to the high 50’s
– low 60’s. A patient with a Z-angle of 45 should probably
not be treatment planned for maxillary first premolars and
mandibular second premolars because this patient needs
significant mandibular incisor uprighting.
The face plays a critical part in the diagnosis and in the
treatment plan. But the extraction pattern cannot be
based solely upon facial esthetics. Other areas must be
considered.
The Skeletal Pattern
Many patients who have a moderate to low vertical dimension
along with a Class II dentition can be well managed when
maxillary first/mandibular second premolars are removed. It
would be very difficult to remove these teeth and successfully
correct the malocclusion for a patient who has a very high
mandibular plane angle because this patient generally needs
more mandibular incisor uprighting than the clinician is going
to achieve with mandibular second premolar extractions.
Conversely, if the FMA is very low, mandibular incisors
should be left in their pretreatment positions and mandibular
second premolar extractions are a good choice if the Class
II dentition is to be corrected. Therefore, most patients who
are treated with the extraction of maxillary first/mandibular
seconds premolars have a moderate to low mandibular plane
angle.
The Dentition
If the mandibular incisors in the Class II patient are in good
position over basal bone, and if there is not a lot of crowding
of these teeth, maxillary first/mandibular second premolar
extractions should always be considered. This extraction
pattern will allow the clinician to maintain mandibular incisor
position and protract the mandibular posterior teeth for
molar correction. If there is significant mandibular anterior
crowding, the patient is generally not a candidate for this
extraction pattern. The patient should present with moderate
to minor crowding and a Class II dental relationship for this
extraction sequence to be considered.
In summary, there is no single factor that can be used
to unequivocally place a patient into the maxillary first
premolar/mandibular second premolar extraction category.
Yet, when the interrelationships of the face, the skeletal
pattern, and the dentition are considered, it becomes pretty
evident as to which teeth should be extracted. The records
of the three patients that follow will, hopefully, give a very
good picture of the types of patients who are most amenable
to treatment with this extraction pattern. The authors have
carefully selected these patients because each one had a
different set of problems that were sucessfully corrected.
2
Case #1 – Henry Griffey
Up until a few years ago, the records of this patient were shown at every Tweed Study Course. Henry is a classic maxillary
first premolar and mandibular second premolar extraction patient. His records are being presented in this article because his
malocclusion exemplifies all of the characteristics of a malocclusion that needs this type of treatment plan.
His face is reasonably balanced and harmonious. If he had no dental problems, the orthodontist would not treat him.
Facial esthetics and the desire to change facial esthetics is not the reason for treating Henry Griffey. Henry’s casts slow a
marked Class II relationship of the teeth with minor mandibular anterior crowding and moderate maxillary crowding. The
overbite is not significant. Overjet, because of the maxillary crowding, is not significant. The cephalometric radiograph
and its tracing exhibit a mandibular dentition that is upright with an IMPA of 86°. FMIA is 65° and the Z-angle is 71°. The
craniofacial difficulty is only 20. Total difficulty is 54. A low difficulty like this is relatively normal for patients who are
treatment planned with the removal of maxillary first premolars/mandibular second premolars.
3
The posttreatment face, when compared to the pretreatment face, shows a bit more softness, minor upper lip retraction, and
a small amount of mandibular projection when the overall face is viewed. The pretreatment/posttreatment casts exhibit
correction of the Class II dental occlusion, anchorage preparation in the mandibular arch, and a curve of occlusion in the
maxillary arch. Note that there is spacing between the maxillary first molars and second molars which is characteristic
of bulbous loop treatment. The pretreatment/posttreatment cephalograms exhibit control of the mandibular incisors,
anchorage preparation, and third molars that will need to be extracted. (Normally, third molar position is not a treatment
problem with these patients because the mandibular first and second molars are protracted.) The pretreatment/posttreatment
cephalometric tracings and values exhibit maintenance of mandibular incisor position, control of the vertical dimension, and
a Z-angle increase from 71° to 77°. Again, many of these patients do not need much of a facial change. The pretreatment/
posttreatment superimpostions exhibit downward and forward mandibular change when compared to the maxilla, more chin
projection, and control of the dentition as the patient was being treated.
4
5
Case #2 – Dara Smith
The facial esthetics of this patient, like the esthetics of Henry Griffey, would not warrant treatment unless the patient had a
malocclusion. The chin is a bit recessive, but this small amount of imbalance is not unsightly. The casts exhibit a Class II
dental relationship on the patient’s right side and a mesially inclined mandibular first molar on the patient’s left side. There
is a slight amount of maxillary anterior crowding. Overbite and overjet are not excessive. When one looks at the panoramic
radiograph, it is evident that the mandibular left second premolar has no space. The cephalogram and its tracing reflect a
very low mandibular plane angle of 13°, an ANB of 5°, a Z-angle of 78° and an IMPA of 104°. The total difficulty is 85.
Craniofacial difficulty is 60. This difficulty is a bit more than one normally sees on these patients and it is entirely due to
the low Frankfort mandibular plane angle. Treatment choices were to expand the dentition or to remove teeth. In many
instances, the treatment plan is based upon how to preserve the position of the mandibular anterior teeth. Dara’s mandibular
incisors are inclined to 104° and it is not prudent to increase that inclination. Extraction was the only choice. Maxillary first
premolars and mandibular second premolars were extracted.
6
The pretreatment/posttreatment facial photographs illustrate control of the upper lip and its relationship to the nose. There
is some projection of the mandible when it is compared to the rest of the face. The pretreatment/posttreatment casts exhibit
correction of the Class II dental problem and preservation of arch form and arch width. The pretreatment/posttreatment
cephalograms illustrate control of mandibular incisor position even though mandibular teeth were removed. When one
compares the pretreatment/posttreatment tracings, it is evident that the anterior part of the dentition did not change appreciably.
The FMIA increased to 69° while mandibular incisors uprighted only 3°. Extraction of the mandibular second premolars
allowed maintenance of mandibular incisor position and protraction of mandibular molars for this low angle patient. The
Z-angle increased from 78° to 84°. Superimpositions reflect control of the anterior part of the dentition and protraction of
the mandibular molars. There was a significant amount of mandibular growth as is evidenced by the chin projection.
7
Records were made seven years after the cessation of active retention. Note the pleasing balance and harmony of the lower
face. The casts reflect aligned teeth and a well interdigitated occlusion. There has been very little change in the position of
the mandibular anterior teeth. Third molars are in the process of erupting. The recall cephalogram and its tracing exhibit
very minor changes in the dentition. The superimpositions confirm continued mandibular change, but this change has
merely enhanced the harmony of the lower face. The pretreatment/posttreatment/recall smiling photographs confirm a very
balanced face as well as a broad and esthetic smile.
8
9
Case #3 – Ryleigh Day
Unlike the two patients whose records have been shown, facial photographs of this 11 year old female show facial imbalance.
The mandible is retruded in relation to the maxilla. The casts exhibit an end to end Class II dental relationship, minor
crowding, and a 3 mm curve of Spee. The panoramic radiograph illustrates a healthy dentition and the absence of, or poor
development of, third molars. The cephalogram and its tracing confirm the retrusion of the mandible in relation to the
maxilla with an ANB of 5°. The FMA is a normal 23°. Mandibular incisors are protruded at 99°. There is minor crowding
and a need to upright mandibular incisors as well as to protract the mandibular molars. The craniofacial difficulty is only
19. Total difficulty is 53.5, due to the Class II dental relationship.
10
The maxillary first premolars and mandibular second premolars were extracted. Maxillary premolars were extracted because
maxillary incisors needed to have proper third order inclination and intrusion as well as retraction because the mandibular
incisors had to be uprighted.
The pretreatment/posttreatment facial photographs exhibit a pleasing and more balanced face than the pretreatment face. The
chin projection is much better at posttreatment. Pretreatment/posttreatment casts exhibit the interdigitated Class I occlusion
with maintenance of arch form and arch width. The posttreatment panoramic radiograph reveals a healthy dentition and
the developing third molars in the mandibular left and in the maxillary right and left quadrants. The third molars are not a
factor. The pretreatment/posttreatment cephalograms confirm the fact that the maxillary incisors were retracted and their
axial inclination was improved. Pretreatment/posttreatment tracings illustrate mandibular incisor uprighting from 99° to
89° while vertical control was maintained. The pretreatement/posttreatment superimpositions confirm vertical control,
downward and forward mandibular change, and uprighting of mandibular incisors as well as intrusion and retraction of
maxillary incisors. These carefully controlled movements without vertical expansion were important and essential for
favorable mandibular change. Pretreatment/posttreatment smiling photographs confirm an improved smile arc and proper
placement of the maxillary and mandibular anterior teeth in the face.
11
12
Though these three patients had different problems, their treatment plan of maxillary first premolar/mandibular second
premolar extractions was appropriate. Each received benefit from his/her treatment. This extraction sequence is a very
versatile treatment plan decision. Many types of malocclusions can be successfully treated with this extraction pattern. It
is important to remember that it should probably not be considered when the vertical dimension of the patient is high and/
or if the patient has excessive mandibular crowding. This extraction pattern should be seriously considered, however, for
patients who present with combinations of a significant Class II malocclusion, a deep curve of Spee, minor to moderate
mandibular anterior crowding, and normal or below normal vertical dimension.
13
A New Twist on 3rd Order
Bob Stoner
Indianapolis, Indiana
The purpose of this discussion is to elucidate some variables that affect 3rd order control. (Fig. 1)
Fig. 1
Numerous “experts” have devised bracket systems that are based on “ideals” for the third order of each individual tooth.
These bracket systems claim to require little third order adjustment in “most cases” and ideals for each bracket are based
on the average 3rd order needed to achieve the ideal position. One can see from the chart of the seven bracket types sold by
Ormco that there is great variability in the 3rd order for each tooth between bracket systems.
3rd Order Prescriptions in Ormco Catalog
Rx
Max 5
Max 4
Max 3
Max 2
Max 1
Mand
Mand 2
Mand 3
Mand 4
Mand 5
I
-7°
-7°
0°
7°
14°
-1°
-1°
-7°
-11°
-17°
II
0°
0°
7°
14°
22°
0°
0°
7°
0°
0°
III
-7°
-7°
3°
7°
14°
-5°
-5°
-7°
-11°
-17°
IV
-8°
-6°
3°
9°
15°
-5°
-5°
-6°
-7°
-9°
V
-7°
-7°
7°
10°
17°
-6°
-6°
7°
-17°
-17°
VI
-8°
-6°
7°
14°
22°
-10°
-10°
-6°
-7°
-17°
VII
-3°
-2°
0°
9°
11°
3°
3°
-2°
-8°
-8°
VIII
-11°
-11°
-7°
0°
7°
-6°
-6°
-11°
-17°
-22°
11°
11°
14°
14°
15°
10°
10°
9°
17°
22°
Range
Fig. 2
In 1957 Stifter received a patent for the first preadjusted “straight-wire” appliance that was supposed to eliminate the
need for wire bending. However, the specialty was focused on individual treatment at that time rather than on practice
14
management. Thus, the appliance was never accepted. Have
these technological advancements in bracket manufacturing
really improved the control of the edgewise appliance? Can
we rely on “magic” appliances to replace the development
of the skills required to manipulate the edgewise appliance
in harmony with treatment? Or do we still need to develop
the hand/eye coordination and finesse that has always been a
requirement for quintessential orthodontic treatment.
Fig. 5: Variation in the occluso/
incisal-gingival position of the
bracket on the tooth
Fig. 6: Variation in adhesive thickness
Fig. 3
Evaluate the validity of standardization of 3rd order relative
to:
1. Variability of a crown’s labial morphology for a given
tooth type (Fig. 3 and 4)
2. Variability due to occluso/inciso-gingival position of the
bracket (Fig. 5)
3. Inconsistent bracket adhesive thickness (Fig. 6)
4. Variability of the long-axis of the crown relative to the
long axis of the tooth (Fig. 7)
5. Differences in the slot size to wire size (“wire / bracket
slop”) (Fig. 8)
Fig. 7: Variation in crown root anglulation
Fig. 8: Deviation angle
Fig. 4: Variation in labial morphology
15
Also, there are times during treatment when the 3rd order
needs to be routinely changed in order to maintain or change
the moment to force ratio. In the following example of
uprighting the mandibular incisors, it is apparent that the
3rd order needs to be increased with successive adjustments
to maintain the position of the incisor apex as the tooth is
uprighted. (Fig. 9)
Fig. 11: Long axis of tooth and crown
Fig. 9: Uprighting lower incisors
around the apex requires sequentially increasing anterior 3rd order
in the closing arch
In order to determine the degree of variability in the 3rd order
requirement due to differences in the labial morphology
of the crowns, differences in the crown to root angulation,
and differences in the occluso/gingival bracket position, 25
extracted teeth of each tooth type were measured. Mandibular
central and lateral incisors were grouped together as they
were considered to be very similar. Also, 3rd molars were
not measured.
Each tooth was placed on an opaque overhead light projector
and their shadows were magnified and projected onto paper.
The outlines of each tooth were traced and were measured. A
line was drawn relative to the long axis of the crown (LAC)
and the long axis of the tooth (LAT). Perpendiculars were
drawn from LAC to the labial surface of the crowns at the
middle and at the incisal or occlusal third to represent two
different bracket positions. From these two points, tangents
were drawn and the angles were measured. (Fig. 10 and 11)
ɑ1 is the angle formed by the tangent at the incisal 1/3 and
the long axis of the tooth (LAT). ɑ2 is the angle formed by
the tangent at the middle of the crown relative to the longaxis of the tooth.
ɑ1 - ɑ2 = the difference in 3rd order inherent in the change
in bracket position between the incisal 1/3 and the middle
of the crown for an individual tooth. The results are shown
below. (Fig. 12)
Maxillary Central Incisor
Maxillary Lateral Incisor
Maxillary Canine
Maxillary 1st premolar
Maxillary 2nd premolar
Maxillary 1st molar
(mesio-buccal cusp)
Maxillary 1st molar
(disto-buccal cusp)
Maxillary 2nd molar
Mandibular incisor
Mandibular canine
Mandibular 1st premolar
Mandibular 2nd premolar
Mandibular 1st molar
Mandibular 2nd molar
Min
1°
3°
0°
0°
2°
-13°
Max
13°
13°
11°
14°
18°
17°
Mean
6°
7°
6°
9°
8°
6°
SD
±3°
±2°
±3°
±3°
±4°
±5°
0°
20°
9°
±5°
-10°
-4°
2°
2°
7°
2°
1°
20°
8°
11°
20°
21°
20°
23°
5°
3°
7°
9°
11°
10°
11°
±6°
±3°
±3°
±5°
±4°
±6°
±5°
Fig. 12: Variability in 3rd order due to change in
bracket position for each tooth type
Fig. 10: Long axis of tooth and crown
The range of 3rd order was quite severe for some of the teeth.
And each tooth type has at least one out of the 25 samples
that varied more than 10̊ (except the mandibular incisors)
and some varied even more thant 20̊.
16
ɑ2 is the angle formed from the center of the crown to the longaxis of the tooth (LAT). The variability of ɑ2 between the 25
samples within each tooth type constitutes the difference in
the degree of 3rd order required for each of the tooth types in
order to maintain the long axis in the same direction. The
variability is shown in figure 13 below.
Maxillary Central Incisor
Maxillary Lateral Incisor
Maxillary Canine
Maxillary 1st premolar
Maxillary 2nd premolar
Maxillary 1st molar (mesio-buccal cusp)
10°
15°
16°
22°
26°
st
Maxillary 1 molar (disto-buccal cusp)
24°
nd
Maxillary 2 molar
30°
Mandibular incisor
12°
Mandibular canine
16°
Mandibular 1st premolar
25°
22°
nd
34°
st
Mandibular 1 molar
30°
Mandibular 2nd molar
21°
Mandibular 2 premolar
rd
Fig. 13: Range of 3 order variation at the middle
of the crown
Even if one were to accurately position the bracket in the
exact center of the crown of each tooth, the variation in 3rd
order would vary between the 25 patients the amount shown
in figure 14. One could expect that if these 25 patients were
to walk into your office, you would need to vary the 3rd order
by 16̊ for the maxillary canines and 34̊ for the mandibular
2nd premolars.
Sometimes root position supersedes crown position when the
root begins to approximate the cortical bone or an adjacent
root. Therefore, variation in the crown to root angulation
can be a factor in the 3rd order requirement for a tooth. The
variability in the labiolingual direction of the crown to root
can be inferred from the angle LAC to LAT. (Long-axis of the
crown to the long-axis of the tooth). The variability within
each given tooth type is shown in figure 14. It is also quite
apparent that significant adjustment will need to be made to
prevent root impingement in some cases.
Maxillary Central Incisor
Maxillary Lateral Incisor
Maxillary Canine
Maxillary 1st premolar
Maxillary 2nd premolar
Maxillary 1st molar
Maxillary 2nd molar
8°
14°
8°
14°
12°
15°
19°
Mandibular incisor
Mandibular canine
Mandibular 1st premolar
Mandibular 2nd premolar
Mandibular 1st molar
Mandibular 2nd molar
14°
8°
14°
19°
14°
21°
Fig. 14: Difference in long-axis of the
tooth (LAT) to the long-axis of the crown
(LAC)
Summary and Conclusions:
1. The variability of the labial convexity of the crowns is
statistically and clinically significant. This variability will
necessitate significant adjustments to the appliance relative
to any pre-adjusted 3rd order bracket or pre-set standard to
achieve the desired 3rd order positioning.
2. The variability produced from differences in the bracket
position is statistically and clinically significant. This
variability will necessitate significant adjustments to the
appliance relative to pre-adjusted 3rd order bracket or pre-set
standard to achieve the desired 3rd order positioning.
3. The variability in the crown to root angulation is statistically
and clinically significant.
4. Differences in the adhesive thickness, bracket “slop”,
moment to force ratio changes and maintenance will all add
to the necessity for significant adjustments to the appliance
relative to pre-adjusted 3rd order bracket or standard bracket
to achieve the desired 3rd order positioning.
Therefore, this study shows that one cannot depend on the
preadjusted bracket nor on a specific standard bracket to
achieve ideal tooth positioning. WE MUST BEND THE
WIRE!
* Statistical tables and analyses were omitted but are
available from Dr. Stoner
17
The Human Face…Our Past…Present…Future?
Dennis Ward
Avon Lake, Ohio
The study of human evolution is the study of the human
face, in particular, the mouth. Our first sensory organ was
the mouth; then the teeth. The story of how our faces have
evolved through millions of years of adaptation is essentially
a story about the mouth. From early bags of cells that
organized and combined to form a primitive hole to better
assimilate food, to the complex skeleto-facial structure
of modern Homo sapiens; our mouth has been foremost
in determining the structure, esthetics and function of the
human face. Survival of any species is dependent upon two
basic functions: procreation and sustenance. Our faces and
in particular, the anatomic position of our teeth, has been at
the forefront of our evolutionary development.
For millions of years of evolution and countless environmental
adaptations, our early hominid ancestors were designed for
survival and efficiency. As our brain capacity increased and
our ability to reason and logically solve problems expanded,
our faces continually receded below the cranial vault
(Figure 1).
Figure 1
Approximately 50,000 years ago Homo sapiens appeared.
With a brain capacity of 1500cc, which nearly tripled the
capacity of their early cousins, new abilities were in reach.
Fire, tools and communication were all being employed to
further expand the growing population (Figure 2).
There are two prevailing theories on why our faces receded
to present day dimensions. One is that as our size increased
(the early hominids were 4 feet tall), our brain cavities also
increased. This increase in size expanded our ability to
think and develop more efficient ways to obtain and prepare
food. The masticatory system became less dependent on
mechanical efficiency, thus it moved under the face as the
brain expanded.
Figure 2
18
The second theory is much more interesting. Human beings
are “hard wired” for symmetry. When given choices between
beauty and ugliness, symmetry or asymmetry, we will always
choose symmetry. Symmetry is biologically relevant to the
survival of the species! The human face is the equivalent
of the peacock’s tail. The more attractive a face, the more
likely to mate. So the second theory of why the lower face
receded beneath the upper face is it was more symmetric,
thus a more attractive face.
In 1946, Dr. Tweed published “The Frankfort-Mandibular
Plane Angle in Orthodontic Diagnosis, Classification,
Treatment Planning and Prognosis” in The American Journal
of Orthodontics and Oral Surgery. In his review of the article
Dr. Herb Margolis praised Dr. Tweed for recognizing that
“uprighting incisors was in direct harmony with evolutionary
trends in the development of man and tipping these teeth
forward by the orthodontist is, in my opinion, ‘evolution in
reverse’”.
Figure 4
The following patient (Figures 3 to 12) is an example of
expansion treatment, or as Margolis would say, “evolution
in reverse”. Jody Turner is a 53 year old woman who had
orthodontic treatment twice. The treatment plans involved
a non premolar extraction protocol. The protrusion of her
mandibular incisors was marked. Retreatment with a proper
treatment plan gave her a balanced face.
Figure 5
Figure 3
FMIA
FMA
IMPA
SNA
SNB
ANB
AO/BO
44
20
116
82
77
5
6.6mm
OP
Z
UL
TC
PFH
AFH
MI
0
65
6.3mm
16mm
52.1
71.7
0.73
Figure 6
19
Total Space Analysis
T/A disc.
0
Headfilm
19.2
Total
19.2
Mid:
T/A disc.
0
COS
2.1
Total
2.1
Ant:
Occ. Disharmony
Post:
Total:
0
2.8
18.5
Pretreatment
Figure 7
FMIA
FMA
IMPA
SNA
SNB
ANB
AO/BO
OP
Z
UL
TC
PFH
AFH
MI
44
20
116
82
77
5
6.6
0
65
6.3
16
52.1
71.7
0.73
Posttreatment
71
18
91
82
79
3
2.5
-1
84
9.7
13.9
54.3
69.4
0.78
Figure 11
Figure 8
Figure 12
Figure 9
The philosophy of “expand the dental arch at all costs” is not
new. It is in direct contrast to symmetry and balance. How it
ends is up to us. This trend can only be fought with proper
diagnosis. It is the significant contribution we can make to
our specialty.
Figure 10
20
Why the Single Bracket?
Elie Amm
Jbeil (Byblos), Lebanon
There are many types of brackets available. This fact
makes the choice of brackets difficult for the experienced
clinician and even more difficult for the newly graduated
orthodontist. Are there advantages with the single bracket
that the twin bracket does not have?
Current orthodontic practice trends are highly influenced by
the marketing skills of supply companies and the folks who
lecture for them. Most of the time, commercial interests
go in a divergent direction than scientific values. Nonevidenced based data can mislead the clinician into a poor
treatment plan that results in poor treatment for the patient.
Good treatment (Figures 1, 2 and 3) requires a proper
treatment plan and force system.
A newly graduated orthodontist is considered an easy
target for the “gurus” of the market. I did an in-depth
study to find the system that would keep me independent
and true to scientific principles. Everybody wants a system
that is simple, affordable, good for all circumstances, and
efficient. Orthodontists are always obliged to individualize
the 1st, 2nd, and 3rd order bends for each patient during a
particular phase of treatment. To face the huge variety of
brackets available in the market and the company’s ads can
cause a lot of confusion. I went “back to basics” and chose
the standard edgewise single bracket! Call this technique
Tweed + 5 Minutes – an illusion to the five minutes that is
spent to bend a wire. In fact, these five minutes are very
useful and could be considered a marketing tool. During
this 5 minutes, patients can brush their teeth without
wasting time, and/or the doctor can socialize with the
patient and/or the patients’ family.
The single bracket allows the orthodontist to have one
bracket for all the teeth. The only difference between
premolar and anterior brackets is the pad design that fits
the labial surface. There is one bracket for maxillary and
mandibular incisors, and one for maxillary and mandibular
cuspids and bicuspids. When only one bracket is used for
all the teeth, the true variable is the archwire.
Figure 1
Figure 2
21
Figure 3
Is this bracket system efficient? Interbracket width answers
this question. Interbracket width depends on the size of
the teeth and the size of the bracket; it is obvious that to
increase the interbracket width one has to decrease the size
of the bracket. With sequential bonding (Figure 4) it is very
important to increase the interbracket width as much as
possible in order to decrease the “stiffness” of the system.
Stiffness is inversely proportional to the interbracket width.
Creekmore stated that: “Surprisingly, light forces depend
more on interbracket width than archwire size.”
With the single bracket one has: 1) patient comfort 2)
exactness of posterior loops and hooks 3) a decrease in
the number of round archwires required 4) an increase in
the first rectangular archwire’s dimensions 5) a decrease
in the total number of archwires 6) early leveling 7) early
torque control 8) arch form control and 9) a decrease in the
treatment time. (Figures 6 and 7)
The twin bracket proponents consider rotational control
easier because only one wing of the bracket is tied to the
archwire and the rotation is corrected quickly. This fact
is true but there are sometimes problems. For example,
during the correction of a severe rotation, the clinician is
obliged to bond the wider twin bracket off the center of
the tooth and rebond it in the right position after partial
rotation correction. This problem is less likely with the
single bracket because it is narrower and the chance to
bond it in the right position at the outset is better (Figure 8).
With a single bracket the clinician can use some rotational
auxiliaries like a Steiner wedge. An easy and simple way to
correct the rotations is to use a power chain!
Another “marketing” tool the single bracket presents is that
it is considered by many patients to be the most esthetic
metal bracket (Figure 9). There is no study to prove this
idea, but our practice has patients who seek this kind
of bracket. It is our “trademark” in our small town in
Lebanon.
Figure 5
Figure 6
Figure 7
Figure 8
Try staying single (with brackets)! You will like it.
Consider Tweed + 5 minutes (Figure 10).
Figure 9
Figure 4
Figure 10
22
Class III Correction and Surgical Orthontics:
the Good, the Bad, and the Ugly
Mike Behnan
Clinton Township, Michigan
Introduction
Tweed-Merrifield orthodontists have placed great emphasis
on the facial profile. When a patient is best treated in
conjunction with orthognathic surgery, our oral-maxillofacial
surgeon colleagues have largely determined the surgical
procedure. By doing so they greatly influence the final
result. Occasionally, our treatment objectives are out of sync
with those sought by the surgeon, particularly with Class III
malocclusions.
There seems to be a trend to prefer Le Fort I maxillary
advancements over mandibular setbacks – even for patients
with mandibular prognathism. Concern over airway space
is often cited as the rationale for avoiding mandibular
setbacks. While the airway certainly has its place in the
diagnostic process, advocating maxillary advancements only
could compromise esthetics when a mandibular setback is
warranted. This paper seeks to demonstrate the importance
of the diagnostic process and its impact on the treatment
result. The patient records presented show some good, some
bad, and some ugly esthetic finishes.
Case #1: The Good
Our first patient represents what we will classify as a “good”
result. The Class III female patient presented with an obvious
mandibular prognathism along with dental compensations
for the skeletal discrepancy (Figure 1). The task at hand
was to remove dental compensations in preparation for a
mandibular setback surgery. Thus, a Class II extraction
pattern of maxillary first premolars and mandibular second
premolars was selected. Post-surgical treatment records
demonstrate a pleasing facial profile and an excellent
orthodontic result (Figure 2).
23
Figure 1: Pretreatment records for case #1.
A, extraoral photos. B, intraoral photos. C,
panorex. D, lateral cephalogram.
Figure 2: Post-treatment records for case #1.
A, extraoral photos. B, intraoral photo.
Case #2: The Bad
Our second patient falls into what can be called a “bad”
result. This adult male presented with a severe Class III
malocclusion (Figure 3). The surgical cephalometric
analysis often used by Bilodeau1 features the measurements
of Tweed2, McNamara3, Delaire4, and Legan5. The
pretreatment SNB of 90º and Delaire’s FM point-clivusmenton angle of 104º (ideally between 85º and 90º) indicate
mandibular prognathism.
Additionally, McNamara’s
nasion Frankfort perpendicular to Point A indicates that
the maxilla’s anteroposterior position is ideal. Despite our
diagnosis of mandibular prognathism, the maxillofacial
surgeon insisted on a Le Fort I maxillary advancement. This
significant repositioning of a single jaw corrected the Class
III malocclusion, but resulted in what many would deem
an unsatisfactory facial result (Figure 4). The mother of the
patient was particularly dissatisfied with the result.
Figure 4: Posttreatment records for case #2.
A, extraoral photos. B, intraoral photos.
Figure 3: Pretreatment records for case #2.
A, extraoral photos. B, intraoral photos. C,
panorex. D, lateral cephalogram.
24
Case #3: The Ugly
Our final case report falls under the category of “ugly” in
the opinion of the author. This adult male presented with
a severe Class III malocclusion (Figure 5). The significant
anteroposterior dental discrepancy suggested orthodontic
treatment be done in conjunction with orthognathic surgery.
Despite the dental discrepancy, the facial profile seems rather
pleasant for an adult male. The cephalometric analysis
points to both moderate maxillary prognathism and severe
mandibular prognathism. While the author anticipated a
mandibular setback surgery only, the maxillofacial surgeon
insisted on some degree of maxillary advancement. This
decision raised concern, especially since the patient already
had some degree of maxillary prognathism. In any event, the
surgery proceeded, and a post-surgical lateral cephalogram
indicates that an unplanned advancement genioplasty was
performed as well. It is possible that the genioplasty was
included to offset the controversial maxillary advancement.
Either way, the post-surgical extraoral photos (Figures 6 and
7) demonstrate an unpleasant facial profile. In comparison to
the initial profile, the posttreatment profile seems unbalanced,
aged, and less masculine. Despite an otherwise excellent
orthodontic result, the ill-advised surgical treatment may
have spoiled the treatment.
Figure 5: Pretreatment records for case #3.
A, extraoral photos. B, intraoral photos. C,
panorex. D, lateral cephalogram.
25
Figure 6: Posttreatment records for case #3.
A, extraoral photos. B, intraoral photos.
Figure 7: Cephalometric analysis for Case #3.
Conclusions
A complex treatment plan that requires orthognathic
surgery demands a careful diagnosis and treatment plan.
Attempting to treat otherwise or to simply “straighten the
teeth” before surgery may produce “bad” or “ugly” results.
Perhaps the time has come for the orthodontist to get more
directly involved with the surgical treatment planning
before our patients walk into the operating room.
References
1. Bilodeau JE. Correction of a severe Class III malocclusion that required orthognathic surgery: a case report.
Semin Orthod 1996;2(4):279-88.
2. Tweed CH. A philosophy of orthodontic treatment. Am
J Orthod Oral Surg 1945;31:74-103.
3. McNamara JA. A method of cephalometric evaluation.
Am J Orthod. 1984;86:449-469.
4. Delaire J, Schendel SA, Tulasne JF. An architectural
and structural craniofacial analysis: A new lateral cephalometric analysis. J Oral Surg 1981;52:226-238.
5. Legan HL, Burstone CJ. Soft tissue cephalometric analysis for orthognathic surgery. J Oral Surg 1980;38:744751.
26
Cephalometrics Revised
Hiroshi Maruo
Claudio Vinícius Sabatoski
Orlando Tanaka
Armando Yukio Saga
Ivan Toshio Maruo
Introduction
As technological advances become more available to our
specialty, the professional needs to use his/her good sense
and judgment. Are we ready to leave cephalometrics and
cephalometric analyses behind for CBCT or MRI imaging?1
Kragskov et al.2 stated that conventional cephalometry is
an inexpensive and well-established method for evaluating
patients with dentofacial deformities, and that there is no
evidence that CB CT is more reliable. The benefit of 3D CT
cephalometrics could be for severe asymmetric craniofacial
syndromic patients.
But we must ask if the specialty has learned everything about
two-dimensional imaging. For example, discussion about
the use of either Nasion or Occlusal Plane as landmarks is
well-know but still controversial.3 Although cephalometrics
has been extensively studied, little attention has been paid
to how an inexperienced orthodontist can integrate apparent
cephalometric discrepancies with clinical findings in order
to reach a proper treatment plan for the patient.
Methods
Since the first cephalometric analysis4, all cephalometric
analyses – including 3D cephalometric analyses5 – follow
the same step: the patient’s values are compared with average
standard values which were obtained from attractive faces
of people with normal occlusions. However, orthodontic
patients have a malocclusion and usually show a lack of
facial balance and harmony6. So, more than to standardize,
the goal of every orthodontist should be to individualize the
cephalometric analysis to the patient.
The Tweed-Merrifield cephalometric analysis was chosen for
this study because it, like other analyses, uses measurements
that indicate the skeletal, dental and esthetic patterns of
patients. The standard values for the Tweed Merrifield
analysis are shown in Fig. 1.
Before orthodontists totally embrace 3D imaging, it would be
wise to look back to what we know and what we do not know
about cephalometrics. The purpose of this article is to discuss
tracing or measurement errors, to show the more frequent
disparities and incongruencies in a cephalometric analysis
and to assess and explain them with individual case reports.
By becoming familiar with all these issues, cephalometrics
can be more fully understood and the specialty will be able
to apply the same reasoning to interpretation of 3D imaging
in a way that will provide quality service to our patients.
Fig. 1: Tweed-Merrifield Cephalometric Analysis
27
Case #1
A male, 15 years-old, with a dolichofacial, convex profile and
lack of lip seal had a Class II division 1 malocclusion with an
overjet of 9.0 mm (Figs. 2, 3). How can this Class II division
1, patient have an ANB of 1.0º, and AO-BO of –9.0 mm?
If the SNA and SNB angles show, respectively, the anterior
or posterior position of the maxilla and the mandible, aren’t
the decreased measurements of this patient an indication that
they are retracted? How can a convex profile and a Z angle
of 65.0º be explained if the SNA measures 72.0º and SNB
measures 71.0º?
If the cephalogram is studied, the reasons are not so very
difficult to explain. ANB is 1.0º because the patient’s face is
“vertical” and his anterior cranial base is inclined downward
— S point is lower than point N. The anterior cranial base is
longer as a result of Nasion being more forward. The more
forward point N, the more ANB decreases. So, the more
forward point N is located and the more inferior S is located
to cause of a more inclined anterior cranial base, the more
the SNA, SNB and ANB angles decrease.
Fig. 2: Case #1 Pretreatment Photographs
AO-BO is -9.0 mm because of the vertical facial type and
because of the inclined occlusal plane. As the occlusal plane
incline increases, the projection of A and B points tends to
decrease progressively.
If the anterior cranial base and occlusal plane are excessively
inclined, the SNA, SNB and ANB are decreased. This boy’s
face should be much more vertical than the FMA indicates.
If the AO-BO of -9.0 mm is due to the occlusal plane’s
accentuated inclination, which is compatible with extremely
vertical faces, it is confirmed by the following values: PFH
of 42.0 mm, AFH of 78.0 mm and FHI of 0.53. Although
FMA is 34°, it does correspond to these other measurements,
which leads to the possibility of a Frankfort plane tracing
error. And assuming that this interpretation is true7,8, it
is possible to understand why occlusal plane and Z angle
are not as inclined as they would be expected to be with
AO-BO of -9.0 mm and FHI of 0.53. These discrepancies
could somewhat compromise the cephalometric discrepancy
calculation, which in this case would be even greater if SNA,
SNB and ANB were more reflective of the skeletal problem.
Several studies7-10 confirm this possibility for this patient.
Fig. 3: Case #1 Cephalometric Tracing and Analysis
Case # 2
This male patient, treated fifteen years ago, was 18 yearsold, brachifacial and had a straight and harmonious profile
with good lip seal. The Class II division 2 malocclusion has
normal overjet and overbite and coincident midlines (Figs.
4 and 5). His frontal and profile photographs (Fig. 4) show
a well balanced and harmonious face which does not reflect
the malocclusion that is exhibited by the casts.
Cephalometrically (Fig. 5), an ANB of 5.0º indicates a
skeletal Class II while an FMIA of 53.0º and an IMPA of
105.0º confirm protruded mandibular incisors. The Z angle
of 80.0º reflects a straight and balanced profile. If one uses
28
it must be understood that the low mandibular plane angle
dictates the mandibular incisors’ labial inclination. This is
nature’s compensation to disguise the Class II so that the
profile is balanced. If a cephalometric correction had been
done and the mandibular incisors uprighted, the maxillary
incisors, which are normal, would have an unesthetic lingual
inclination.
The patient was treated without extractions. The results are
shown in Figs. 6 and 7. The frontal and profile photographs
(Fig. 6) show good lip seal, proportional and symmetrical
facial thirds and a straight and balanced profile. Maintenance
of the balanced and harmonious face was a pretreatment
goal.
Fig. 4: Case #2 Pretreatment Photographs
Fig. 6: Case #2 Posttreatment Photographs
Fig. 5: Case #2 Cephalometric Tracing and Analysis
a cephalometric discrepancy calculation, IMPA should
be 68.0º. To reach this value would require mandibular
extraction to upright the mandibular incisors. Is it possible
to upright the mandibular incisors this much? What about
maxillary incisor position? Why are the mandibular incisors
so buccally inclined and the maxillary incisors so well
positioned? Ordinarily, aren’t the incisors balanced by lips
and by tongue?
For this patient we cannot think in the manner just described.
The Z angle is 80.0º and the profile is straight. The IMPA is
105° to compensate the Class II skeletal pattern, as the ANB
and AO-BO show. And ANB and AO-BO are not significantly
large because the gonial angle is closed. The FMA is low. So,
29
Fig. 7: Case #2 Cephalometric Tracing and Analysis
The frontal and lateral views of the casts (Fig. 6) show the
corrected dentition with good interdigitation of the teeth.
Thus, it was possible to treat the patient and respect nature’s
compensation while correcting the Class II dental problem.
There is no doubt about the fact that it was “hard” treatment.
The patient’s five year recall photographs (Fig. 8) show
that the profile became more “flat”. Imagine what would
have happened to the profile with extraction treatment. It is
important to understand that the issue here is not to repudiate
or to discredited an analysis, but to interpret it correctly.
Case # 3
The patient is 15 years, 6 months old with a Class III
dentition. He has a balanced and harmonious face with good
proportions that does not reflect a malocclusion (Fig. 10).
This worsening of the patient’s profile with age cannot be
attributed to the orthodontic treatment. As the cephalometric
analysis shows (Fig. 9), the profile change was due to total
chin growth from the beginning to the end of the period
studied. However, if this patient had been treated with
extractions to upright mandibular incisors, the facial result
would have been disastrous and a reason for a lot of criticism
of the treatment.
The frontal view of the casts (Fig. 10) shows edge-to-edge
incisors, maxillary spacing and 7mm of mandibular anterior
crowding. The lateral views (Fig. 10) show teeth in a Class III
relationship and molars and premolars with sharp vestibular
inclinations. This occlusion was probably due to previous
orthodontic treatment which attempted to excessively
expand the dental arches. The cephalometric analysis (Fig.
11) shows increased SNA and SNB values in relation to the
average standard values. FMA is 23.0º; FMIA should be of
68.0º. The patient’s FMIA is 71.5º. These numbers indicate
mandibular incisor uprighting is not necessary. But the
discrepancy is based on people with normal occlusion with
ANBs close to 2.0º. Whereas, in this patient the malocclusion
is Class III with ANB of -2.0º and the AO-BO is -7.5 mm.
Fig. 8: Case #2 Recall Treatment Photographs
Fig. 10: Case #3 Pretreatment Photographs
Fig. 9: Case #2 Cephalometric Tracing and Analysis
Fig. 11: Case #3 Cephalometric Tracing and Analysis
30
There is no doubt that there must be some sort of dental
compensation.
So, for this patient, what would be the compensation or
cephalometric discrepancy? One of the most important
aspects is the patient’s profile which, despite a Z angle of
85.5º, is very well balanced and harmonious — not concave.
This is due to head anatomy with the increased PFH and,
consequently, with an increased FHI as well.
Maxillary incisor position must be considered and left as it is
pretreatment. So, it should be reasoned that the mandibular
incisor position must compensate for the negative ANB
with a much more lingual inclination than it would be with
an ANB of 2.0º. Because the maxillary incisor is not only
well positioned but is stable, and the lower facial profile is
both harmonious and balanced, the mandibular incisor must
be changed as much as is necessary in order to establish
normal overjet and overbite as well as to maintain the
balanced and harmonious profile. So going counter to the
traditional cephalometric discrepancy calculation rule, the
mandibular incisor must be inclined 3.5 mm lingual – which
is equivalent to 7.0 mm of cephalometric discrepancy.
Considering this discrepancy, the malocclusion type and the
maxillary third molar agenesis, treatment was planned with
mandibular first molar extractions. In order to evaluate this
type of reasoning, there is nothing better than this patient’s
treatment result (Figs. 12 and 13).
Fig. 13: Case #3 Cephalometric Tracing and Analysis
lingual, the same profile was maintained, that is, the Z angle
remained exactly the same.
Conclusions
With critical evaluation and rational interpretation of these
patients’ cephalometric analyses, there is no motive for the
statement that one analysis dictates extraction of more or less
teeth than another. It becomes clear that differences between
cephalometric analysis methods, the extraction or lack of
extraction of teeth and facial profile management depend
In the frontal and profile photographs (Fig. 12) there is good exclusively on the professional’s interpretation.
lip seal with a straight profile. Facial balance and harmony
were maintained. The frontal and lateral views of the The following conclusions can be reached:
casts (Fig. 12) show good interdigitation of the teeth, with
mandibular second and third molars occupying, respectively, 1. In the utilization of the Tweed-Merrifield cephalometric
analysis it is possible to detect tracing errors through
the first and second molar positions (Fig. 13). There was
measurement interpretation as a whole.
maintenance of ANB and improvement in AO-BO to 1.5
2.
ANB and AO-BO do not always reflect a skeletal anteriormm. Although the mandibular incisors were inclined to the
posterior discrepancy.
3. SNA and SNB do not always accurately confirm the
anterior or posterior position of the jaws. Their increase
or decrease in relation to the average standard value could
be caused by a shorter or longer cranial base as well as its
inclination.
4. The cephalometric discrepancy is misinterpreted some
times and should not be a definitive application of a simple
mathematical rule.
5. The position of the maxillary incisor as well as ANB,
AO-BO, FHI and Z angle helps to interpret and clarify a
cephalometric discrepancy.
Fig. 12: Case #3 Posttreatment Photographs
31
References
1. Halazonetis DJ. From 2-dimensional cephalograms to 3-dimensional computed tomography scans. Am J Orthod
Dentofacial Orthop 2005;127:627-637.
2. Kragskov J, Bosh C, Gyldensted C, Sindet-Pedersen S. Comparison of the reliability of craniofacial anatomic landmarks
based on cephalometric radiographs and three-dimensional CT Scans. Cleft Palate-Craniofacial J 1997;34(2):111116,.
3. Jacobson A. The “Wits” appraisal of jaw disharmony. Am J Orthod Dentofacial Orthop 2003;124(5):470-479.
4. Downs WB. Variations in facial relationships: their significance in treatment and prognosis. Am J Orthod 1948;34:812–
840.
5. Park SH, Yu HS, Kim KD, Lee KJ, Baike HS. A proposal for a new analysis of craniofacial morphology by 3-dimensional
computed tomography. Am J Orthod Dentofacial Orthop 2006;129(5):600.e23-600.e34.
6. Tweed CH. Clinical Orthodontics: volume one. St. Louis (MO): Mosby Company; 1966.
7. Sandler P. Reproducibility of Cephalometric Measurements. Br J Orthod 1988;15:105-10.
8. Cooke M, Wei S. Cephalometric errors: a comparison between repeat measurements and retaken radiographs. Aust Dent
J 1991;36:38-43.
9. Gravely J, Benzies P. The clinical significance of tracing error in cephalometry. Br J Orthod 1974;1:95-101.
10. Staburn A, Danielson K. Precision in cephalometric landmark identification. Eur J Orthod 1982;4:185-96.
32
Case
Reports
A Case Report: A Full Step Class II Patient Revisisted 27 Years
Posttreatment
Vance Dykhouse
Blue Springs, Missouri
Tammy Sage had comprehensive orthodontic treatment
in the mid 1970’s. She returned to our office to have
her son treated in 2005. We made a set of records in
2005, almost twenty-eight years after her treatment was
finished in 1977.
Tammy’s case was originally presented with three sets
of records at a Central Section Tweed meeting in 1979.
A two-year post-treatment set of records was almost a
necessity for case presentations at that time.
Tammy presented a bilateral full step Class II, Division
I malocclusion without crowding. Her overbite was
extremely deep. She was a non-grower, 14 years, 2
months in age at the beginning of orthodontic treatment.
The decision was made to treat Tammy non-extraction
despite a higher than desired IMPA. Good headgear
wear and anchorage preparation would be a necessity
for successful treatment. (Please pardon the glasses in
the extra oral photographs.)
36
Tammy’s treatment began in 1975. She had a high
mandibular frenum and a Stillman’s cleft on tooth
#25 that is not visible on the beginning intraoral
photographs. She had a graft in late 1975 that was
successful.
Tammy was an excellent patient. After initial leveling,
she wore a straight pull J-hook headgear and Class III
elastics to set mandibular anchorage. Mechanics were
then reversed to a high pull J-hook and vertical elastics
during sleeping hours with full-time Class II elastics.
The bite was opened and a solid Class I occlusion was
attained. Maxillary second molars were tipped out of
occlusion, a la Tweed mechanics in use at that time.
Active treatment time was 26 months. Tammy was 16
years, 5 months in age when appliances were removed
and retention began.
A third set of records was taken twenty-six months
after appliance removal. Tammy was 18 years, 7
months of age. The Class I buccal occlusion had
been maintained and the overbite had not returned.
The maxillary molars settled into excellent occlusion.
Third molars were gone. Spaces remained closed. A
maxillary Hawley retainer and a lower fixed retainer
were worn until this time.
In 2005, Tammy returned to our office with her son
who had a similar malocclusion, and was ready for
37
orthodontic treatment. A fourth set of records was
made. Tammy was 44 years, 4 months of age. The
records were taken 1 month shy of twenty-eight years
post appliance removal. Tammy’s Class II correction
has held well. Her overbite correction has also remained
stable. The thirty year old gingival cleft has remained
non pathological. She has had to have quite a bit of
dental work over the past twenty five years.
38
Cephalometric measurements from the four sets of record are presented in summary form.
Cephalometric Summary
FMA
IMPA
FMIA
SnGoGn
SNA
SNB
ANB
T to NB
Pog to NB
Int-Inc angle
Occ-PL
Ao-Bo
Z angle
39
12/74
22
99
59
27
84.5
78
6.5
5
4
117
17
7
74
4/77
22
98
60
27
82
78.5
3.5
6
4
133
14
2.5
76
6/79
20
101
59
26
83
80
3
6
4
130
12
4
83
3/05
18
101
62
30
82.5
80.5
2
5
3
132
18
4
88
Case Report: Vertical Control in a High Angle Patient Who Needed
R apid Maxillary Expansion (RME)
Mauricio Escanola
Tepic, Nayarit / Mexico
In our professional life we are faced with patients whose
malocclusions challenge us as orthodontists to test the
concepts we have learned and to use our clinical judgment
to apply the biomechanical resources that allow us to
offer the patient facial esthetics, occlusal harmony and
stability.
Patients who combine a vertical hyperdivergent skeletal
pattern with maxillary collapse are difficult to treat because
the treatment of a patient with maxillary collapse requires
maxillary expansion. The literature clearly demostrates
that, immediately after expansion, there is downward
maxillary displacement and extrusion of the supporting
teeth which leads to downward and backward mandibular
rotation2,4-6,8–10,14-17. The opening rotation of the mandible
induces cephalometric changes such as increases in
inclination of the mandibular plane, increases in lower
anterior facial height and facial convexity bite opening in
the anterior region.
clinically related to insufficient width of the palatal
vault, a deep palate and outward inclined dentoalveolar
processes. All these factors indicate a skeletal maxillary
constriction. Dentally, the patient has an edge to edge
bite and severe crowding with ectopic maxillary canines
(Fig. 1, 2). Cephalometric values show an FMA of 30°,
an occlusal plane of 13°, a facial index of 61%, an IMPA
of 87° and a Z angle of 76° (Fig. 3).
Figure 1. Pretreatment photographs.
In this context, some orthodontists have advised against
performing RME in patients who have predominantly
vertical growth patterns and convex facial profiles1,3 in
order to prevent worsening of the malocclusion. However,
a proper diagnosis, understanding of the functional forces
and implementation of an appropriate force system that
favors vertical and horizontal control during treatment
are able to minimize the undesirable anteroposterior and
vertical effects of RME7, 11-13, 20-23.
Case Report
Karen C., is a 16 year old young lady who presents
a straight profile and a Class I malocclusion with a
hyperdivergent skeletal pattern that is complicated by
maxillary constriction and posterior crossbite due to the
mouth breathing habit. According to Staley´s intermolar
analysis24 the deficit of 8mm in the maxillary arch is
Figure 2. Pretreatment dental casts.
40
Figure 3. Pretreatment cephalogram, cephalometric values and
tracing.
Figure 6. Posttreatment dental casts.
The main factors associated with the treatment of this
patient are:
1. High mandibular plane angle (hyperdivergent
skeletal pattern)
2. Maxillary constriction
3. Dental crowding
4. Good facial profile
Merrifield’s guidelines suggested that four first premolars
should be extracted in order to solve the space problem .
This patient was treated with rapid maxillary expansion
(REM) before extractions and fixed appliances (Fig. 4) so
that anchorage loss during the closure of the spaces would
not affect facial balance.
Posttreatment cephalometric values (Fig. 7) show that
there was good vertical control since the FMA, the
occlusal plane and facial index were not altered despite
maxillary expansion. Z angle was increased to 79°.
The superimpositions (Fig. 8) show that space closure
was achieved with mesial movement of the molars and
minimal anterior retraction so that facial balance would
not be harmed. There was no posterior extrusion and
therefore no clockwise mandibular rotation due to lack of
vertical control.
For a patient with a normal vertical dimension, and
even more for a patient with a hyperdivergent skeletal
pattern, to not have control of the vertical dimension
predisposes to failure. On the other hand, good control of
vertical dimension during treatment allows a predictable
outcome.
Figure 4. a) Post maxillary expansion; b) After 6 months of
contention.
The posttreatment records (Fig. 5, 6) illustrate that facial
harmony was maintained. There was an improvement in
the esthetics of the smile. Posttreatment casts confirm the
improvement of the transverse dimension and shape of
the maxillary arch as well as good arch coordination and
occlusal interdigitation.
Figure 5. Posttreatment photographs.
41
Figure 7. Posttreatment cephalogram, cephalometric values and
tracing.
Figure 8. Superimpositions.
References
1. Alpern MC, Yurosko JJ. Rapid palatal expansion in adults with and without surgery. Angle Orthod.
1987;57(3):245–263.
2. Asanza S, Cisneros GJ, Nieberg LG. Comparison of Hyrax and bonded expansion appliances. Angle Orthod.
1997; 67(1):15–22.
3. Bishara SE, Staley RN. Maxillary expansion: clinical implications. Am J Orthod Dentofacial Orthop.
1987;91(1):3–14.
4. Byrum AG Jr. Evaluation of anterior-posterior and vertical skeletal change vs. dental change in rapid palatal
expansion cases as studied by lateral cephalograms. Am J Orthod. 1971;60(4):419.
5. Chung CH, Font B. Skeletal and dental changes in the sagittal, vertical, and transverse dimensions after rapid
palatal expansion. Am J Orthod Dentofacial Orthop. 2004;126(5): 569–575.
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Case Report: Treatment of a High Angle Adolescent Patient
Kortne Frederick hou
Tukwila, Washington
This is the case report of an Angle’s Class I crowded,
high mandibular plane angle malocclusion. The
patient’s medical history was negative. Etiology of the
malocclusion was heredity.
Pretreatment Records
The facial photographs (Fig. 1) exhibit a convex
facial profile, lower lip eversion, and a retrognathic
appearance of the mandible. The casts (Fig. 2) exhibit
a deep overbite, an Angle’s Class I occlusion, a deep
curve of Spee, and mandibular anterior crowding. The
panoramic radiograph (Fig. 3) confirms that all teeth
are present, the periodontium is healthy, and there is
no pathology. The cephalogram and its tracing (Fig.
4a, b) confirm a high mandibular plane angle of 36°.
Mandibular retrognathia is confirmed by the SNB
of 74°. The Z angle is a poor 58° and both maxillary
and mandibular lips are in front of the E plane. The
craniofacial analysis difficulty value for this patient
Fig. 1. Pretreatment photographs.
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Fig. 2. Pretreatment dental casts.
Fig. 3. Pretreatment panoramic radiograph.
Fig. 4a. Pretreatment cephalogram and 4b) tracing.
is 98. The total space analysis difficulty is 22.9. The
patient’s total dentition difficulty was 120.9.
Treatment Plan
Due to the bialveolar protrusion and the 7 mm of
mandibular anterior crowding, maxillary and mandibular
first premolars were removed. The removal of these
teeth was done in order to facilitate elimination of the
crowding and reduction of the bialveolar protrusion.
Posttreatment Records
The pretreatment / posttreatment facial photographs
(Fig. 5) confirm a more pleasing face with less protrusion
of the lips. The smile line is vastly improved. The
posttreatment casts (Fig. 6) exhibit correction of the
crowding, a reduction in the overbite, and an excellent
Class I interdigitation of the teeth. Arch width and arch
form were preserved during the course of treatment. The
the mandible due to vertical control during treatment
and a nice downward and forward chin projection. The
pretreatment/posttreatment smiles (Fig. 10) confirm
the intrusion and retraction of the maxillary anterior
teeth which resulted in much less gingival display upon
smiling.
Fig. 7. Posttreatment panoramic radiograph.
Fig. 8a. Posttreatment cephalogram 8b.tracing.
Fig. 5. Posttreatment photographs.
Fig. 9. Superimpositions.
Fig. 6. Posttreatment dental casts.
posttreatment panoramic radiograph (Fig. 7) reveals
that the teeth remain healthy and that all extraction
spaces have been closed by adequate uprighting of
teeth into the extraction spaces. The posttreatment
cephalogram and its tracing (Fig. 8a, b) confirms
retraction of teeth, control of the vertical dimension,
and a marked reduction in the dental protrusion. The
superimpositions (Fig. 9) illustrate an autorotation of
Fig. 10. Pretreatment and Posttreatment smiles.
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Case Report: Correction of a Severe Class II Division I
Malocclusion in an Adolescent Patient
Jack Hou
Tukwila, Washington
This is a case report of a young female who has an
extreme protrusion of the teeth which causes a significant
facial imbalance. The etiology of the malocclusion was
heredity. There were no medical complications.
Pretreatment Records
The facial photographs (Fig. 1) exhibit a very convex
face with quite a bit of mandibular lip eversion. The
nasolabial angle is acute. The pretreatment casts (Fig.
2) exhibit a deep curve of Spee, an Angle’s Class II
dental relationship, and flared maxillary and mandibular
incisors. The pretreatment panoramic radiograph (Fig. 3)
confirms that all teeth are present and the periodontium
is healthy. The pretreatment cephalogram and its
tracing (Fig. 4a, b) confirm very protruded maxillary
and mandibular incisors, a Class II skeletal relationship,
and a very low Z angle. The craniofacial difficulty for
the patient was only 34 because the skeletal pattern was
reasonable. The tooth arch discrepancy for this patient
was 22 mm because of the excessive mandibular incisor
flaring.
Treatment Plan
Due to the severity of the protrusion, maxillary and
mandibular first premolars were extracted. The patient
was banded with an 022 edgewise appliance. After
one year of treatment, the mandibular third molars and
maxillary first molars were extracted so that the Angle’s
Class II dental relationship could be corrected without
proclining mandibular incisors. The patient was treated,
all spaces were closed, and the patient was placed in
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Fig. 1. Pretreatment photographs.
Fig. 2. Pretreatment casts.
Fig. 3. Pretreatment panoramic radiograph.
Hawley retainers at the cessation of
treatment.
Fig. 4a. Pretreatment cephalogram and 4b) tracing.
Fig. 5. Pretreatment/posttreatment photographs.
Fig. 6. Posttreatment casts.
Fig. 7. Posttreatment panoramic radiograph.
Posttreatment Records
The pretreatment/posttreatment photographs (Fig. 5) confirm marked reduction
in the bialveolar protrusion, lip strain has
been eliminated, and the patient has a
much more balanced and pleasing facial
profile. The posttreatment casts (Fig. 6)
exhibit correction of the dentition to a
Class I dental relationship and a reduction in the protrusion. Maxillary third
molars will erupt and take the place of
the maxillary second molars which have
been moved mesially. The posttreatment
panoramic radiograph (Fig. 7) exhibits
roots that are parallel in the extraction
sites and the erupting maxillary third
molars. The posttreatment cephalogram
and its tracing (Fig. 8a, b) confirm maintenance of the vertical dimension, quite
a bit of mandibular incisor uprighting,
and an improved Z angle. The superimpostions (Fig. 9) illustrate intrusion and
retraction of the maxillary anterior teeth
and uprighting of the mandibular anterior teeth. The pretreatment/posttreatment smiles (Fig. 10) are testament to
the treatment plan and to the treatment
which was delivered. The patient was
seen on recall and new casts were made.
These casts (Fig. 11) confirm eruption
of the maxillary third molars and a very
functional dentition. The presentation
of this case report exhibits the use of
Tweed-Merrifield mechanics and what
can be done for a patient who has a severe malocclusion - if the treatment plan
is proper and if the force systems are delivered in a proper manner.
Fig. 8a. Pretreatment cephalogram and 8b) tracing.
46
“Addendum”
This patient had been treated twice prior to these records. The facial photographs (Fig. 12) show protrusion
and lip strain. The pretreatment dental photographs exhibit an excellent Class I dental relationship, a very
small amount of crowding, and a rather protruded smile.
The cephalogram with IMPA and FMIA highlighted
(Fig. 13) exhibits mandibular incisors that are at 100°
to mandibular plane and a low FMIA. The protrusion
is evident
Fig. 9. Pretreatment/posttreatment superimpostions.
The patient wanted retreatment. Maxillary and mandibular second premolars were removed. The posttreatment facial photographs and photographs of the teeth
(Fig. 14)
illustrate reduction of the protrusion and
a nice Class I interdigitation of the teeth. The posttreatment cephalogram (not shown) confirmed that mandibular incisors were uprighted from 100° to 86° and the
Fig. 10. Pretreatment/posttreatment smiles.
Fig. 12. Pretreatment photographs.
Fig. 11. Recall casts.
Fig. 13. Pretreatment cephalogram.
47
FMIA improved from 58° to 69°. The final comparison of the facial profile (Fig. 15) is graphic evidence
of what should be done when patients with bialveolar
protrustions are properly treatment planned. The final
recall photographs of teeth and face (Fig. 16) say a lot
of things about where orthodontics should be going and
what kind of service we can render to our patients if the
treatment plan and the force systems are proper.
Fig. 14. Posttreatment photographs.
Fig. 15. Pretreatment/posttreatment/recall profile photographs.
Fig. 16. Recall photographs.
48