case report - The Charles H. Tweed International Foundation
case report - The Charles H. Tweed International Foundation
case report - The Charles H. Tweed International Foundation
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Th e<br />
Tw e e d Pr o f i l e<br />
Pu b l i s h e d b y<br />
Th e Ch a r l e s h. Tw e e d<br />
in T e r n aT i o n a l fo u n d aT i o n fo r<br />
orT h o d o n T i C re s e a r C h<br />
a n d ed u C aT i o n<br />
Vo l u m e Xi<br />
2012
Co n t e n t s<br />
2 A Lo o k At A PA rt i c u L A r ty P e o f cL A s s ii MA L o c c L u s i o n — he r b Kl o n T z a n d Jim Va d e n<br />
oK l a h o m a Ci T y, oK l a h o m a a n d Co o K e V i l l e, Te n n e s s e e<br />
14 A ne w tw i s t o n 3 r d or d e r — bo b sT o n e r<br />
in d i a n a P o l i s, in d i a n a<br />
18 th e hu M A n fA c e…ou r PA s t…Pr e s e n t…fu t u r e? — de n n i s wa r d<br />
aV o n la K e, oh i o<br />
21 wh y t h e si n g L e Br A c k e t? — el i e am m<br />
Jb e i l (by b l o s), le b a n o n<br />
23 cL A s s iii co r r e c t i o n A n d su r g i c A L or t h o n t i c s: t h e go o d, t h e BA d, A n d t h e<br />
ug Ly — mi K e be h n a n<br />
Cl i n T o n To w n s h i P, mi C h i g a n<br />
27 ce P h A L o M e t r i c s re v i s i t e d — hi r o s h i ma r u o, Cl a u d i o ViníCius sa b aT o s K i,<br />
or l a n d o Ta n a K a, ar m a n d o yu K i o sa g a, iVa n To s h i o ma r u o<br />
br a z i l<br />
36 cA s e re P o r t: A fu L L st e P cL A s s ii PAt i e n t re v i s i s t e d 27 ye A r s<br />
Po s t t r e At M e n t — Va n C e dy K h o u s e<br />
bl u e sP r i n g s, mi s s o u r i<br />
40 cA s e re P o r t: ve rt i c A L co n t r o L in A hi g h An g L e PAt i e n t wh o ne e d e d<br />
rA P i d MA x i L L A ry ex PA n s i o n (rMe) — ma u r i C i o es C a n o l a<br />
Te P i C, naya r iT / me X i C o<br />
43 cA s e re P o r t: tr e At M e n t o f A hi g h An g L e Ad o L e s c e n t PAt i e n t — Ko rT n e fr e d e r i C K ho u<br />
Tu K w i l a, wa s h i n g T o n<br />
45 cA s e re P o r t: co r r e c t i o n o f A se v e r e cL A s s ii division i MA L o c c L u s i o n in<br />
A n Ad o L e s c e n t PAt i e n t — Ja C K ho u<br />
Tu K w i l a, wa s h i n g T o n
he r b Kl o n T z<br />
oK l a h o m a Ci T y, oK l a h o m a<br />
Jim Va d e n<br />
Co o K e V i l l e, Te n n e s s e e<br />
A Lo o k At A PA rt i c u L A r ty P e o f cL A s s ii MA L o c c L u s i o n<br />
<strong>The</strong>re are many variations of the Class II malocclusion. It<br />
has been studied; its treatment protocols have been debated;<br />
and the ramifications of its various treatment solutions have<br />
been referenced in our literature for many, many years. <strong>The</strong><br />
purpose of this short paper is to offer a brief discussion of<br />
the types of Class II malocclusions that are generally best<br />
treatment planned for the removal of maxillary first premolars<br />
and mandibular second premolars. What we will attempt with<br />
this short article is to give the reader an overview of some<br />
of the things to consider when treatment planning a Class II<br />
malocclusion that would be well treated with the removal<br />
of maxillary first/mandibular second premolars. Three <strong>case</strong><br />
<strong>report</strong>s will be used to illustrate our thoughts on the Class II<br />
that is best corrected with this extraction pattern.<br />
th e fA c e<br />
When the treatment plan is devised, the first area which must<br />
be studied is the face. Is the face a consideration when an<br />
extraction pattern is considered? Absolutely! Most patients<br />
who are treatment planned for this extraction protocol have<br />
a facial pattern that almost has balance, or the face may<br />
well exhibit balance and harmony. <strong>The</strong> Z-angle of most of<br />
these patients will range from the mid 70’s to the high 50’s<br />
– low 60’s. A patient with a Z-angle of 45 should probably<br />
not be treatment planned for maxillary first premolars and<br />
mandibular second premolars because this patient needs<br />
significant mandibular incisor uprighting.<br />
<strong>The</strong> face plays a critical part in the diagnosis and in the<br />
treatment plan. But the extraction pattern cannot be<br />
based solely upon facial esthetics. Other areas must be<br />
considered.<br />
th e sk e L e tA L PAt t e r n<br />
Many patients who have a moderate to low vertical dimension<br />
along with a Class II dentition can be well managed when<br />
maxillary first/mandibular second premolars are removed. It<br />
would be very difficult to remove these teeth and successfully<br />
correct the malocclusion for a patient who has a very high<br />
mandibular plane angle because this patient generally needs<br />
more mandibular incisor uprighting than the clinician is going<br />
to achieve with mandibular second premolar extractions.<br />
Conversely, if the FMA is very low, mandibular incisors<br />
should be left in their pretreatment positions and mandibular<br />
second premolar extractions are a good choice if the Class<br />
II dentition is to be corrected. <strong>The</strong>refore, most patients who<br />
are treated with the extraction of maxillary first/mandibular<br />
seconds premolars have a moderate to low mandibular plane<br />
angle.<br />
th e de n t i t i o n<br />
If the mandibular incisors in the Class II patient are in good<br />
position over basal bone, and if there is not a lot of crowding<br />
of these teeth, maxillary first/mandibular second premolar<br />
extractions should always be considered. This extraction<br />
pattern will allow the clinician to maintain mandibular incisor<br />
position and protract the mandibular posterior teeth for<br />
molar correction. If there is significant mandibular anterior<br />
crowding, the patient is generally not a candidate for this<br />
extraction pattern. <strong>The</strong> patient should present with moderate<br />
to minor crowding and a Class II dental relationship for this<br />
extraction sequence to be considered.<br />
In summary, there is no single factor that can be used<br />
to unequivocally place a patient into the maxillary first<br />
premolar/mandibular second premolar extraction category.<br />
Yet, when the interrelationships of the face, the skeletal<br />
pattern, and the dentition are considered, it becomes pretty<br />
evident as to which teeth should be extracted. <strong>The</strong> records<br />
of the three patients that follow will, hopefully, give a very<br />
good picture of the types of patients who are most amenable<br />
to treatment with this extraction pattern. <strong>The</strong> authors have<br />
carefully selected these patients because each one had a<br />
different set of problems that were sucessfully corrected.<br />
2
cA s e #1 – he n r y gr i f f e y<br />
Up until a few years ago, the records of this patient were shown at every <strong>Tweed</strong> Study Course. Henry is a classic maxillary<br />
first premolar and mandibular second premolar extraction patient. His records are being presented in this article because his<br />
malocclusion exemplifies all of the characteristics of a malocclusion that needs this type of treatment plan.<br />
His face is reasonably balanced and harmonious. If he had no dental problems, the orthodontist would not treat him.<br />
Facial esthetics and the desire to change facial esthetics is not the reason for treating Henry Griffey. Henry’s casts slow a<br />
marked Class II relationship of the teeth with minor mandibular anterior crowding and moderate maxillary crowding. <strong>The</strong><br />
overbite is not significant. Overjet, because of the maxillary crowding, is not significant. <strong>The</strong> cephalometric radiograph<br />
and its tracing exhibit a mandibular dentition that is upright with an IMPA of 86°. FMIA is 65° and the Z-angle is 71°. <strong>The</strong><br />
craniofacial difficulty is only 20. Total difficulty is 54. A low difficulty like this is relatively normal for patients who are<br />
treatment planned with the removal of maxillary first premolars/mandibular second premolars.<br />
3
<strong>The</strong> posttreatment face, when compared to the pretreatment face, shows a bit more softness, minor upper lip retraction, and<br />
a small amount of mandibular projection when the overall face is viewed. <strong>The</strong> pretreatment/posttreatment casts exhibit<br />
correction of the Class II dental occlusion, anchorage preparation in the mandibular arch, and a curve of occlusion in the<br />
maxillary arch. Note that there is spacing between the maxillary first molars and second molars which is characteristic<br />
of bulbous loop treatment. <strong>The</strong> pretreatment/posttreatment cephalograms exhibit control of the mandibular incisors,<br />
anchorage preparation, and third molars that will need to be extracted. (Normally, third molar position is not a treatment<br />
problem with these patients because the mandibular first and second molars are protracted.) <strong>The</strong> pretreatment/posttreatment<br />
cephalometric tracings and values exhibit maintenance of mandibular incisor position, control of the vertical dimension, and<br />
a Z-angle increase from 71° to 77°. Again, many of these patients do not need much of a facial change. <strong>The</strong> pretreatment/<br />
posttreatment superimpostions exhibit downward and forward mandibular change when compared to the maxilla, more chin<br />
projection, and control of the dentition as the patient was being treated.<br />
4
cA s e #2 – dA r A sM i t h<br />
<strong>The</strong> facial esthetics of this patient, like the esthetics of Henry Griffey, would not warrant treatment unless the patient had a<br />
malocclusion. <strong>The</strong> chin is a bit recessive, but this small amount of imbalance is not unsightly. <strong>The</strong> casts exhibit a Class II<br />
dental relationship on the patient’s right side and a mesially inclined mandibular first molar on the patient’s left side. <strong>The</strong>re<br />
is a slight amount of maxillary anterior crowding. Overbite and overjet are not excessive. When one looks at the panoramic<br />
radiograph, it is evident that the mandibular left second premolar has no space. <strong>The</strong> cephalogram and its tracing reflect a<br />
very low mandibular plane angle of 13°, an ANB of 5°, a Z-angle of 78° and an IMPA of 104°. <strong>The</strong> total difficulty is 85.<br />
Craniofacial difficulty is 60. This difficulty is a bit more than one normally sees on these patients and it is entirely due to<br />
the low Frankfort mandibular plane angle. Treatment choices were to expand the dentition or to remove teeth. In many<br />
instances, the treatment plan is based upon how to preserve the position of the mandibular anterior teeth. Dara’s mandibular<br />
incisors are inclined to 104° and it is not prudent to increase that inclination. Extraction was the only choice. Maxillary first<br />
premolars and mandibular second premolars were extracted.<br />
6
<strong>The</strong> pretreatment/posttreatment facial photographs illustrate control of the upper lip and its relationship to the nose. <strong>The</strong>re<br />
is some projection of the mandible when it is compared to the rest of the face. <strong>The</strong> pretreatment/posttreatment casts exhibit<br />
correction of the Class II dental problem and preservation of arch form and arch width. <strong>The</strong> pretreatment/posttreatment<br />
cephalograms illustrate control of mandibular incisor position even though mandibular teeth were removed. When one<br />
compares the pretreatment/posttreatment tracings, it is evident that the anterior part of the dentition did not change appreciably.<br />
<strong>The</strong> FMIA increased to 69° while mandibular incisors uprighted only 3°. Extraction of the mandibular second premolars<br />
allowed maintenance of mandibular incisor position and protraction of mandibular molars for this low angle patient. <strong>The</strong><br />
Z-angle increased from 78° to 84°. Superimpositions reflect control of the anterior part of the dentition and protraction of<br />
the mandibular molars. <strong>The</strong>re was a significant amount of mandibular growth as is evidenced by the chin projection.<br />
7
Records were made seven years after the cessation of active retention. Note the pleasing balance and harmony of the lower<br />
face. <strong>The</strong> casts reflect aligned teeth and a well interdigitated occlusion. <strong>The</strong>re has been very little change in the position of<br />
the mandibular anterior teeth. Third molars are in the process of erupting. <strong>The</strong> recall cephalogram and its tracing exhibit<br />
very minor changes in the dentition. <strong>The</strong> superimpositions confirm continued mandibular change, but this change has<br />
merely enhanced the harmony of the lower face. <strong>The</strong> pretreatment/posttreatment/recall smiling photographs confirm a very<br />
balanced face as well as a broad and esthetic smile.<br />
8
cA s e #3 – ry L e i g h dAy<br />
Unlike the two patients whose records have been shown, facial photographs of this 11 year old female show facial imbalance.<br />
<strong>The</strong> mandible is retruded in relation to the maxilla. <strong>The</strong> casts exhibit an end to end Class II dental relationship, minor<br />
crowding, and a 3 mm curve of Spee. <strong>The</strong> panoramic radiograph illustrates a healthy dentition and the absence of, or poor<br />
development of, third molars. <strong>The</strong> cephalogram and its tracing confirm the retrusion of the mandible in relation to the<br />
maxilla with an ANB of 5°. <strong>The</strong> FMA is a normal 23°. Mandibular incisors are protruded at 99°. <strong>The</strong>re is minor crowding<br />
and a need to upright mandibular incisors as well as to protract the mandibular molars. <strong>The</strong> craniofacial difficulty is only<br />
19. Total difficulty is 53.5, due to the Class II dental relationship.<br />
10
<strong>The</strong> maxillary first premolars and mandibular second premolars were extracted. Maxillary premolars were extracted because<br />
maxillary incisors needed to have proper third order inclination and intrusion as well as retraction because the mandibular<br />
incisors had to be uprighted.<br />
<strong>The</strong> pretreatment/posttreatment facial photographs exhibit a pleasing and more balanced face than the pretreatment face. <strong>The</strong><br />
chin projection is much better at posttreatment. Pretreatment/posttreatment casts exhibit the interdigitated Class I occlusion<br />
with maintenance of arch form and arch width. <strong>The</strong> posttreatment panoramic radiograph reveals a healthy dentition and<br />
the developing third molars in the mandibular left and in the maxillary right and left quadrants. <strong>The</strong> third molars are not a<br />
factor. <strong>The</strong> pretreatment/posttreatment cephalograms confirm the fact that the maxillary incisors were retracted and their<br />
axial inclination was improved. Pretreatment/posttreatment tracings illustrate mandibular incisor uprighting from 99° to<br />
89° while vertical control was maintained. <strong>The</strong> pretreatement/posttreatment superimpositions confirm vertical control,<br />
downward and forward mandibular change, and uprighting of mandibular incisors as well as intrusion and retraction of<br />
maxillary incisors. <strong>The</strong>se carefully controlled movements without vertical expansion were important and essential for<br />
favorable mandibular change. Pretreatment/posttreatment smiling photographs confirm an improved smile arc and proper<br />
placement of the maxillary and mandibular anterior teeth in the face.<br />
11
Though these three patients had different problems, their treatment plan of maxillary first premolar/mandibular second<br />
premolar extractions was appropriate. Each received benefit from his/her treatment. This extraction sequence is a very<br />
versatile treatment plan decision. Many types of malocclusions can be successfully treated with this extraction pattern. It<br />
is important to remember that it should probably not be considered when the vertical dimension of the patient is high and/<br />
or if the patient has excessive mandibular crowding. This extraction pattern should be seriously considered, however, for<br />
patients who present with combinations of a significant Class II malocclusion, a deep curve of Spee, minor to moderate<br />
mandibular anterior crowding, and normal or below normal vertical dimension.<br />
13
o b sT o n e r<br />
in d i a n a P o l i s, in d i a n a<br />
A ne w tw i s t o n 3r d or d e r<br />
<strong>The</strong> purpose of this discussion is to elucidate some variables that affect 3 rd order control. (Fig. 1)<br />
Fig. 1<br />
Numerous “experts” have devised bracket systems that are based on “ideals” for the third order of each individual tooth.<br />
<strong>The</strong>se bracket systems claim to require little third order adjustment in “most <strong>case</strong>s” and ideals for each bracket are based<br />
on the average 3 rd order needed to achieve the ideal position. One can see from the chart of the seven bracket types sold by<br />
Ormco that there is great variability in the 3 rd order for each tooth between bracket systems.<br />
3 rd Order Prescriptions in Ormco Catalog<br />
Rx Max 5 Max 4 Max 3 Max 2 Max 1 Mand Mand 2 Mand 3 Mand 4 Mand 5<br />
I -7° -7° 0° 7° 14° -1° -1° -7° -11° -17°<br />
II 0° 0° 7° 14° 22° 0° 0° 7° 0° 0°<br />
III -7° -7° 3° 7° 14° -5° -5° -7° -11° -17°<br />
IV -8° -6° 3° 9° 15° -5° -5° -6° -7° -9°<br />
V -7° -7° 7° 10° 17° -6° -6° 7° -17° -17°<br />
VI -8° -6° 7° 14° 22° -10° -10° -6° -7° -17°<br />
VII -3° -2° 0° 9° 11° 3° 3° -2° -8° -8°<br />
VIII -11° -11° -7° 0° 7° -6° -6° -11° -17° -22°<br />
Range 11° 11° 14° 14° 15° 10° 10° 9° 17° 22°<br />
Fig. 2<br />
In 1957 Stifter received a patent for the first preadjusted “straight-wire” appliance that was supposed to eliminate the<br />
need for wire bending. However, the specialty was focused on individual treatment at that time rather than on practice<br />
14
management. Thus, the appliance was never accepted. Have<br />
these technological advancements in bracket manufacturing<br />
really improved the control of the edgewise appliance? Can<br />
we rely on “magic” appliances to replace the development<br />
of the skills required to manipulate the edgewise appliance<br />
in harmony with treatment? Or do we still need to develop<br />
the hand/eye coordination and finesse that has always been a<br />
requirement for quintessential orthodontic treatment.<br />
Fig. 3<br />
Evaluate the validity of standardization of 3 rd order relative<br />
to:<br />
1.<br />
2.<br />
3.<br />
4.<br />
5.<br />
15<br />
Variability of a crown’s labial morphology for a given<br />
tooth type (Fig. 3 and 4)<br />
Variability due to occluso/inciso-gingival position of the<br />
bracket (Fig. 5)<br />
Inconsistent bracket adhesive thickness (Fig. 6)<br />
Variability of the long-axis of the crown relative to the<br />
long axis of the tooth (Fig. 7)<br />
Differences in the slot size to wire size (“wire / bracket<br />
slop”) (Fig. 8)<br />
Fig. 4: Variation in labial morphology<br />
Fig. 5: Variation in the occluso/<br />
incisal-gingival position of the<br />
bracket on the tooth<br />
Fig. 6: Variation in adhesive thickness<br />
Fig. 7: Variation in crown root anglulation<br />
Fig. 8: Deviation angle
Also, there are times during treatment when the 3 rd order<br />
needs to be routinely changed in order to maintain or change<br />
the moment to force ratio. In the following example of<br />
uprighting the mandibular incisors, it is apparent that the<br />
3 rd order needs to be increased with successive adjustments<br />
to maintain the position of the incisor apex as the tooth is<br />
uprighted. (Fig. 9)<br />
Fig. 9: Uprighting lower incisors<br />
around the apex requires sequentially<br />
increasing anterior 3 rd order<br />
in the closing arch<br />
In order to determine the degree of variability in the 3 rd order<br />
requirement due to differences in the labial morphology<br />
of the crowns, differences in the crown to root angulation,<br />
and differences in the occluso/gingival bracket position, 25<br />
extracted teeth of each tooth type were measured. Mandibular<br />
central and lateral incisors were grouped together as they<br />
were considered to be very similar. Also, 3 rd molars were<br />
not measured.<br />
Each tooth was placed on an opaque overhead light projector<br />
and their shadows were magnified and projected onto paper.<br />
<strong>The</strong> outlines of each tooth were traced and were measured. A<br />
line was drawn relative to the long axis of the crown (LAC)<br />
and the long axis of the tooth (LAT). Perpendiculars were<br />
drawn from LAC to the labial surface of the crowns at the<br />
middle and at the incisal or occlusal third to represent two<br />
different bracket positions. From these two points, tangents<br />
were drawn and the angles were measured. (Fig. 10 and 11)<br />
Fig. 10: Long axis of tooth and crown<br />
Fig. 11: Long axis of tooth and crown<br />
ɑ 1 is the angle formed by the tangent at the incisal 1/3 and<br />
the long axis of the tooth (LAT). ɑ 2 is the angle formed by<br />
the tangent at the middle of the crown relative to the longaxis<br />
of the tooth.<br />
ɑ 1 - ɑ 2 = the difference in 3 rd order inherent in the change<br />
in bracket position between the incisal 1/3 and the middle<br />
of the crown for an individual tooth. <strong>The</strong> results are shown<br />
below. (Fig. 12)<br />
Min Max Mean SD<br />
Maxillary Central Incisor 1° 13° 6° ±3°<br />
Maxillary Lateral Incisor 3° 13° 7° ±2°<br />
Maxillary Canine 0° 11° 6° ±3°<br />
Maxillary 1 st premolar 0° 14° 9° ±3°<br />
Maxillary 2 nd premolar 2° 18° 8° ±4°<br />
Maxillary 1 st molar<br />
(mesio-buccal cusp)<br />
Maxillary 1 st molar<br />
(disto-buccal cusp)<br />
-13° 17° 6° ±5°<br />
0° 20° 9° ±5°<br />
Maxillary 2 nd molar -10° 20° 5° ±6°<br />
Mandibular incisor -4° 8° 3° ±3°<br />
Mandibular canine 2° 11° 7° ±3°<br />
Mandibular 1 st premolar 2° 20° 9° ±5°<br />
Mandibular 2 nd premolar 7° 21° 11° ±4°<br />
Mandibular 1st molar 2° 20° 10° ±6°<br />
Mandibular 2nd molar 1° 23° 11° ±5°<br />
Fig. 12: Variability in 3rd order due to change in<br />
bracket position for each tooth type<br />
<strong>The</strong> range of 3 rd order was quite severe for some of the teeth.<br />
And each tooth type has at least one out of the 25 samples<br />
that varied more than 10̊ (except the mandibular incisors)<br />
and some varied even more thant 20̊.<br />
16
ɑ is the angle formed from the center of the crown to the long-<br />
2<br />
axis of the tooth (LAT). <strong>The</strong> variability of ɑ between the 25<br />
2<br />
samples within each tooth type constitutes the difference in<br />
the degree of 3rd order required for each of the tooth types in<br />
order to maintain the long axis in the same direction. <strong>The</strong><br />
variability is shown in figure 13 below.<br />
Fig. 13: Range of 3rd Maxillary Central Incisor 10°<br />
Maxillary Lateral Incisor 15°<br />
Maxillary Canine 16°<br />
Maxillary 1<br />
order variation at the middle<br />
of the crown<br />
st premolar 22°<br />
Maxillary 2nd premolar 26°<br />
Maxillary 1st molar (mesio-buccal cusp) 22°<br />
Maxillary 1st molar (disto-buccal cusp) 24°<br />
Maxillary 2nd molar 30°<br />
Mandibular incisor 12°<br />
Mandibular canine 16°<br />
Mandibular 1st premolar 25°<br />
Mandibular 2nd premolar 34°<br />
Mandibular 1st molar 30°<br />
Mandibular 2nd molar 21°<br />
Even if one were to accurately position the bracket in the<br />
exact center of the crown of each tooth, the variation in 3 rd<br />
order would vary between the 25 patients the amount shown<br />
in figure 14. One could expect that if these 25 patients were<br />
to walk into your office, you would need to vary the 3 rd order<br />
by 16̊ for the maxillary canines and 34̊ for the mandibular<br />
2nd premolars.<br />
Sometimes root position supersedes crown position when the<br />
root begins to approximate the cortical bone or an adjacent<br />
root. <strong>The</strong>refore, variation in the crown to root angulation<br />
can be a factor in the 3 rd order requirement for a tooth. <strong>The</strong><br />
variability in the labiolingual direction of the crown to root<br />
can be inferred from the angle LAC to LAT. (Long-axis of the<br />
crown to the long-axis of the tooth). <strong>The</strong> variability within<br />
each given tooth type is shown in figure 14. It is also quite<br />
apparent that significant adjustment will need to be made to<br />
prevent root impingement in some <strong>case</strong>s.<br />
17<br />
Maxillary Central Incisor 8°<br />
Maxillary Lateral Incisor 14°<br />
Maxillary Canine 8°<br />
Maxillary 1 st premolar 14°<br />
Maxillary 2 nd premolar 12°<br />
Maxillary 1 st molar 15°<br />
Maxillary 2 nd molar 19°<br />
Mandibular incisor 14°<br />
Mandibular canine 8°<br />
Mandibular 1 st premolar 14°<br />
Mandibular 2 nd premolar 19°<br />
Mandibular 1st molar 14°<br />
Mandibular 2nd molar 21°<br />
Fig. 14: Difference in long-axis of the<br />
tooth (LAT) to the long-axis of the crown<br />
(LAC)<br />
su M M A r y A n d co n c L u s i o n s:<br />
1. <strong>The</strong> variability of the labial convexity of the crowns is<br />
statistically and clinically significant. This variability will<br />
necessitate significant adjustments to the appliance relative<br />
to any pre-adjusted 3 rd order bracket or pre-set standard to<br />
achieve the desired 3 rd order positioning.<br />
2. <strong>The</strong> variability produced from differences in the bracket<br />
position is statistically and clinically significant. This<br />
variability will necessitate significant adjustments to the<br />
appliance relative to pre-adjusted 3 rd order bracket or pre-set<br />
standard to achieve the desired 3 rd order positioning.<br />
3. <strong>The</strong> variability in the crown to root angulation is statistically<br />
and clinically significant.<br />
4. Differences in the adhesive thickness, bracket “slop”,<br />
moment to force ratio changes and maintenance will all add<br />
to the necessity for significant adjustments to the appliance<br />
relative to pre-adjusted 3 rd order bracket or standard bracket<br />
to achieve the desired 3 rd order positioning.<br />
<strong>The</strong>refore, this study shows that one cannot depend on the<br />
preadjusted bracket nor on a specific standard bracket to<br />
achieve ideal tooth positioning. WE MUST BEND THE<br />
WIRE!<br />
* Statistical tables and analyses were omitted but are<br />
available from Dr. Stoner
de n n i s wa r d<br />
aV o n la K e, oh i o<br />
th e hu M A n fA c e…ou r PA s t…Pr e s e n t…fu t u r e?<br />
<strong>The</strong> study of human evolution is the study of the human<br />
face, in particular, the mouth. Our first sensory organ was<br />
the mouth; then the teeth. <strong>The</strong> story of how our faces have<br />
evolved through millions of years of adaptation is essentially<br />
a story about the mouth. From early bags of cells that<br />
organized and combined to form a primitive hole to better<br />
assimilate food, to the complex skeleto-facial structure<br />
of modern Homo sapiens; our mouth has been foremost<br />
in determining the structure, esthetics and function of the<br />
human face. Survival of any species is dependent upon two<br />
basic functions: procreation and sustenance. Our faces and<br />
in particular, the anatomic position of our teeth, has been at<br />
the forefront of our evolutionary development.<br />
For millions of years of evolution and countless environmental<br />
adaptations, our early hominid ancestors were designed for<br />
survival and efficiency. As our brain capacity increased and<br />
our ability to reason and logically solve problems expanded,<br />
our faces continually receded below the cranial vault<br />
(Figure 1).<br />
Approximately 50,000 years ago Homo sapiens appeared.<br />
With a brain capacity of 1500cc, which nearly tripled the<br />
capacity of their early cousins, new abilities were in reach.<br />
Fire, tools and communication were all being employed to<br />
further expand the growing population (Figure 2).<br />
<strong>The</strong>re are two prevailing theories on why our faces receded<br />
to present day dimensions. One is that as our size increased<br />
(the early hominids were 4 feet tall), our brain cavities also<br />
increased. This increase in size expanded our ability to<br />
think and develop more efficient ways to obtain and prepare<br />
food. <strong>The</strong> masticatory system became less dependent on<br />
mechanical efficiency, thus it moved under the face as the<br />
brain expanded.<br />
Figure 2<br />
Figure 1<br />
18
<strong>The</strong> second theory is much more interesting. Human beings<br />
are “hard wired” for symmetry. When given choices between<br />
beauty and ugliness, symmetry or asymmetry, we will always<br />
choose symmetry. Symmetry is biologically relevant to the<br />
survival of the species! <strong>The</strong> human face is the equivalent<br />
of the peacock’s tail. <strong>The</strong> more attractive a face, the more<br />
likely to mate. So the second theory of why the lower face<br />
receded beneath the upper face is it was more symmetric,<br />
thus a more attractive face.<br />
In 1946, Dr. <strong>Tweed</strong> published “<strong>The</strong> Frankfort-Mandibular<br />
Plane Angle in Orthodontic Diagnosis, Classification,<br />
Treatment Planning and Prognosis” in <strong>The</strong> American Journal<br />
of Orthodontics and Oral Surgery. In his review of the article<br />
Dr. Herb Margolis praised Dr. <strong>Tweed</strong> for recognizing that<br />
“uprighting incisors was in direct harmony with evolutionary<br />
trends in the development of man and tipping these teeth<br />
forward by the orthodontist is, in my opinion, ‘evolution in<br />
reverse’”.<br />
<strong>The</strong> following patient (Figures 3 to 12) is an example of<br />
expansion treatment, or as Margolis would say, “evolution<br />
in reverse”. Jody Turner is a 53 year old woman who had<br />
orthodontic treatment twice. <strong>The</strong> treatment plans involved<br />
a non premolar extraction protocol. <strong>The</strong> protrusion of her<br />
mandibular incisors was marked. Retreatment with a proper<br />
treatment plan gave her a balanced face.<br />
19<br />
Figure 3<br />
Figure 4<br />
Figure 5<br />
FMIA 44 Total Space Analysis<br />
FMA 20 Ant: T/A disc. 0<br />
IMPA 116 Headfilm 19.2<br />
SNA 82 Total 19.2<br />
SNB 77 Mid: T/A disc. 0<br />
ANB 5 COS 2.1<br />
AO/BO 6.6mm Total 2.1<br />
OP 0<br />
Z 65 Occ. Disharmony 0<br />
UL 6.3mm Post: 2.8<br />
TC 16mm Total: 18.5<br />
PFH 52.1<br />
AFH 71.7<br />
MI 0.73<br />
Figure 6
Figure 7<br />
Figure 8<br />
Figure 9<br />
Figure 10<br />
Pretreatment Posttreatment<br />
FMIA 44 71<br />
FMA 20 18<br />
IMPA 116 91<br />
SNA 82 82<br />
SNB 77 79<br />
ANB 5 3<br />
AO/BO 6.6 2.5<br />
OP 0 -1<br />
Z 65 84<br />
UL 6.3 9.7<br />
TC 16 13.9<br />
PFH 52.1 54.3<br />
AFH 71.7 69.4<br />
MI 0.73 0.78<br />
Figure 11<br />
Figure 12<br />
<strong>The</strong> philosophy of “expand the dental arch at all costs” is not<br />
new. It is in direct contrast to symmetry and balance. How it<br />
ends is up to us. This trend can only be fought with proper<br />
diagnosis. It is the significant contribution we can make to<br />
our specialty.<br />
20
el i e am m<br />
Jb e i l (by b l o s), le b a n o n<br />
<strong>The</strong>re are many types of brackets available. This fact<br />
makes the choice of brackets difficult for the experienced<br />
clinician and even more difficult for the newly graduated<br />
orthodontist. Are there advantages with the single bracket<br />
that the twin bracket does not have?<br />
Current orthodontic practice trends are highly influenced by<br />
the marketing skills of supply companies and the folks who<br />
lecture for them. Most of the time, commercial interests<br />
go in a divergent direction than scientific values. Nonevidenced<br />
based data can mislead the clinician into a poor<br />
treatment plan that results in poor treatment for the patient.<br />
Good treatment (Figures 1, 2 and 3) requires a proper<br />
treatment plan and force system.<br />
21<br />
Figure 1<br />
Figure 2<br />
wh y t h e si n g L e Br A c k e t?<br />
A newly graduated orthodontist is considered an easy<br />
target for the “gurus” of the market. I did an in-depth<br />
study to find the system that would keep me independent<br />
and true to scientific principles. Everybody wants a system<br />
that is simple, affordable, good for all circumstances, and<br />
efficient. Orthodontists are always obliged to individualize<br />
the 1st, 2nd, and 3rd order bends for each patient during a<br />
particular phase of treatment. To face the huge variety of<br />
brackets available in the market and the company’s ads can<br />
cause a lot of confusion. I went “back to basics” and chose<br />
the standard edgewise single bracket! Call this technique<br />
<strong>Tweed</strong> + 5 Minutes – an illusion to the five minutes that is<br />
spent to bend a wire. In fact, these five minutes are very<br />
useful and could be considered a marketing tool. During<br />
this 5 minutes, patients can brush their teeth without<br />
wasting time, and/or the doctor can socialize with the<br />
patient and/or the patients’ family.<br />
<strong>The</strong> single bracket allows the orthodontist to have one<br />
bracket for all the teeth. <strong>The</strong> only difference between<br />
premolar and anterior brackets is the pad design that fits<br />
the labial surface. <strong>The</strong>re is one bracket for maxillary and<br />
mandibular incisors, and one for maxillary and mandibular<br />
cuspids and bicuspids. When only one bracket is used for<br />
all the teeth, the true variable is the archwire.<br />
Figure 3
Is this bracket system efficient? Interbracket width answers<br />
this question. Interbracket width depends on the size of<br />
the teeth and the size of the bracket; it is obvious that to<br />
increase the interbracket width one has to decrease the size<br />
of the bracket. With sequential bonding (Figure 4) it is very<br />
important to increase the interbracket width as much as<br />
possible in order to decrease the “stiffness” of the system.<br />
Stiffness is inversely proportional to the interbracket width.<br />
Creekmore stated that: “Surprisingly, light forces depend<br />
more on interbracket width than archwire size.”<br />
With the single bracket one has: 1) patient comfort 2)<br />
exactness of posterior loops and hooks 3) a decrease in<br />
the number of round archwires required 4) an increase in<br />
the first rectangular archwire’s dimensions 5) a decrease<br />
in the total number of archwires 6) early leveling 7) early<br />
torque control 8) arch form control and 9) a decrease in the<br />
treatment time. (Figures 6 and 7)<br />
<strong>The</strong> twin bracket proponents consider rotational control<br />
easier because only one wing of the bracket is tied to the<br />
archwire and the rotation is corrected quickly. This fact<br />
is true but there are sometimes problems. For example,<br />
during the correction of a severe rotation, the clinician is<br />
obliged to bond the wider twin bracket off the center of<br />
the tooth and rebond it in the right position after partial<br />
rotation correction. This problem is less likely with the<br />
single bracket because it is narrower and the chance to<br />
bond it in the right position at the outset is better (Figure 8).<br />
With a single bracket the clinician can use some rotational<br />
auxiliaries like a Steiner wedge. An easy and simple way to<br />
correct the rotations is to use a power chain!<br />
Another “marketing” tool the single bracket presents is that<br />
it is considered by many patients to be the most esthetic<br />
metal bracket (Figure 9). <strong>The</strong>re is no study to prove this<br />
idea, but our practice has patients who seek this kind<br />
of bracket. It is our “trademark” in our small town in<br />
Lebanon.<br />
Try staying single (with brackets)! You will like it.<br />
Consider <strong>Tweed</strong> + 5 minutes (Figure 10).<br />
Figure 4<br />
Figure 9<br />
Figure 5<br />
Figure 6<br />
Figure 7<br />
Figure 8<br />
Figure 10<br />
22
in t r o d u c t i o n<br />
23<br />
cL A s s iii co r r e c t i o n A n d su r g i c A L or t h o n t i c s:<br />
t h e go o d, t h e BA d, A n d t h e ug Ly<br />
<strong>Tweed</strong>-Merrifield orthodontists have placed great emphasis<br />
on the facial profile. When a patient is best treated in<br />
conjunction with orthognathic surgery, our oral-maxillofacial<br />
surgeon colleagues have largely determined the surgical<br />
procedure. By doing so they greatly influence the final<br />
result. Occasionally, our treatment objectives are out of sync<br />
with those sought by the surgeon, particularly with Class III<br />
malocclusions.<br />
<strong>The</strong>re seems to be a trend to prefer Le Fort I maxillary<br />
advancements over mandibular setbacks – even for patients<br />
with mandibular prognathism. Concern over airway space<br />
is often cited as the rationale for avoiding mandibular<br />
setbacks. While the airway certainly has its place in the<br />
diagnostic process, advocating maxillary advancements only<br />
could compromise esthetics when a mandibular setback is<br />
warranted. This paper seeks to demonstrate the importance<br />
of the diagnostic process and its impact on the treatment<br />
result. <strong>The</strong> patient records presented show some good, some<br />
bad, and some ugly esthetic finishes.<br />
cA s e #1: th e go o d<br />
Our first patient represents what we will classify as a “good”<br />
result. <strong>The</strong> Class III female patient presented with an obvious<br />
mandibular prognathism along with dental compensations<br />
for the skeletal discrepancy (Figure 1). <strong>The</strong> task at hand<br />
was to remove dental compensations in preparation for a<br />
mandibular setback surgery. Thus, a Class II extraction<br />
pattern of maxillary first premolars and mandibular second<br />
premolars was selected. Post-surgical treatment records<br />
demonstrate a pleasing facial profile and an excellent<br />
orthodontic result (Figure 2).<br />
mi K e be h n a n<br />
Cl i n T on To w n s h i P, mi C h i g a n<br />
Figure 1: Pretreatment records for <strong>case</strong> #1.<br />
A, extraoral photos. B, intraoral photos. C,<br />
panorex. D, lateral cephalogram.
Figure 2: Post-treatment records for <strong>case</strong> #1.<br />
A, extraoral photos. B, intraoral photo.<br />
cA s e #2: th e BA d<br />
Our second patient falls into what can be called a “bad”<br />
result. This adult male presented with a severe Class III<br />
malocclusion (Figure 3). <strong>The</strong> surgical cephalometric<br />
analysis often used by Bilodeau1 features the measurements<br />
of <strong>Tweed</strong>2, McNamara3, Delaire4, and Legan5. <strong>The</strong><br />
pretreatment SNB of 90º and Delaire’s FM point-clivusmenton<br />
angle of 104º (ideally between 85º and 90º) indicate<br />
mandibular prognathism. Additionally, McNamara’s<br />
nasion Frankfort perpendicular to Point A indicates that<br />
the maxilla’s anteroposterior position is ideal. Despite our<br />
diagnosis of mandibular prognathism, the maxillofacial<br />
surgeon insisted on a Le Fort I maxillary advancement. This<br />
significant repositioning of a single jaw corrected the Class<br />
III malocclusion, but resulted in what many would deem<br />
an unsatisfactory facial result (Figure 4). <strong>The</strong> mother of the<br />
patient was particularly dissatisfied with the result.<br />
Figure 3: Pretreatment records for <strong>case</strong> #2.<br />
A, extraoral photos. B, intraoral photos. C,<br />
panorex. D, lateral cephalogram.<br />
Figure 4: Posttreatment records for <strong>case</strong> #2.<br />
A, extraoral photos. B, intraoral photos.<br />
24
cA s e #3: th e ug Ly<br />
Our final <strong>case</strong> <strong>report</strong> falls under the category of “ugly” in<br />
the opinion of the author. This adult male presented with<br />
a severe Class III malocclusion (Figure 5). <strong>The</strong> significant<br />
anteroposterior dental discrepancy suggested orthodontic<br />
treatment be done in conjunction with orthognathic surgery.<br />
Despite the dental discrepancy, the facial profile seems rather<br />
pleasant for an adult male. <strong>The</strong> cephalometric analysis<br />
points to both moderate maxillary prognathism and severe<br />
mandibular prognathism. While the author anticipated a<br />
mandibular setback surgery only, the maxillofacial surgeon<br />
insisted on some degree of maxillary advancement. This<br />
decision raised concern, especially since the patient already<br />
had some degree of maxillary prognathism. In any event, the<br />
surgery proceeded, and a post-surgical lateral cephalogram<br />
indicates that an unplanned advancement genioplasty was<br />
performed as well. It is possible that the genioplasty was<br />
included to offset the controversial maxillary advancement.<br />
Either way, the post-surgical extraoral photos (Figures 6 and<br />
7) demonstrate an unpleasant facial profile. In comparison to<br />
the initial profile, the posttreatment profile seems unbalanced,<br />
aged, and less masculine. Despite an otherwise excellent<br />
orthodontic result, the ill-advised surgical treatment may<br />
have spoiled the treatment.<br />
25<br />
Figure 5: Pretreatment records for <strong>case</strong> #3.<br />
A, extraoral photos. B, intraoral photos. C,<br />
panorex. D, lateral cephalogram.<br />
Figure 6: Posttreatment records for <strong>case</strong> #3.<br />
A, extraoral photos. B, intraoral photos.
Figure 7: Cephalometric analysis for Case #3.<br />
co n c L u s i o n s<br />
A complex treatment plan that requires orthognathic<br />
surgery demands a careful diagnosis and treatment plan.<br />
Attempting to treat otherwise or to simply “straighten the<br />
teeth” before surgery may produce “bad” or “ugly” results.<br />
Perhaps the time has come for the orthodontist to get more<br />
directly involved with the surgical treatment planning<br />
before our patients walk into the operating room.<br />
re f e r e n c e s<br />
1.<br />
2.<br />
3.<br />
4.<br />
5.<br />
Bilodeau JE. Correction of a severe Class III malocclusion<br />
that required orthognathic surgery: a <strong>case</strong> <strong>report</strong>.<br />
Semin Orthod 1996;2(4):279-88.<br />
<strong>Tweed</strong> CH. A philosophy of orthodontic treatment. Am<br />
J Orthod Oral Surg 1945;31:74-103.<br />
McNamara JA. A method of cephalometric evaluation.<br />
Am J Orthod. 1984;86:449-469.<br />
Delaire J, Schendel SA, Tulasne JF. An architectural<br />
and structural craniofacial analysis: A new lateral cephalometric<br />
analysis. J Oral Surg 1981;52:226-238.<br />
Legan HL, Burstone CJ. Soft tissue cephalometric analysis<br />
for orthognathic surgery. J Oral Surg 1980;38:744-<br />
751.<br />
26
hi ro s h i ma ru o<br />
Cl a u d i o Vi n í C i us sa b a T o s K i<br />
or l a n d o Ta n a K a<br />
ar m a n d o yu K io sa g a<br />
iVa n To s h i o ma ru o<br />
in t r o d u c t i o n<br />
As technological advances become more available to our<br />
specialty, the professional needs to use his/her good sense<br />
and judgment. Are we ready to leave cephalometrics and<br />
cephalometric analyses behind for CBCT or MRI imaging? 1<br />
Kragskov et al. 2 stated that conventional cephalometry is<br />
an inexpensive and well-established method for evaluating<br />
patients with dentofacial deformities, and that there is no<br />
evidence that CB CT is more reliable. <strong>The</strong> benefit of 3D CT<br />
cephalometrics could be for severe asymmetric craniofacial<br />
syndromic patients.<br />
But we must ask if the specialty has learned everything about<br />
two-dimensional imaging. For example, discussion about<br />
the use of either Nasion or Occlusal Plane as landmarks is<br />
well-know but still controversial. 3 Although cephalometrics<br />
has been extensively studied, little attention has been paid<br />
to how an inexperienced orthodontist can integrate apparent<br />
cephalometric discrepancies with clinical findings in order<br />
to reach a proper treatment plan for the patient.<br />
Before orthodontists totally embrace 3D imaging, it would be<br />
wise to look back to what we know and what we do not know<br />
about cephalometrics. <strong>The</strong> purpose of this article is to discuss<br />
tracing or measurement errors, to show the more frequent<br />
disparities and incongruencies in a cephalometric analysis<br />
and to assess and explain them with individual <strong>case</strong> <strong>report</strong>s.<br />
By becoming familiar with all these issues, cephalometrics<br />
can be more fully understood and the specialty will be able<br />
to apply the same reasoning to interpretation of 3D imaging<br />
in a way that will provide quality service to our patients.<br />
27<br />
ce P h A L o M e t r i c s re v i s e d<br />
Me t h o d s<br />
Since the first cephalometric analysis 4 , all cephalometric<br />
analyses – including 3D cephalometric analyses 5 – follow<br />
the same step: the patient’s values are compared with average<br />
standard values which were obtained from attractive faces<br />
of people with normal occlusions. However, orthodontic<br />
patients have a malocclusion and usually show a lack of<br />
facial balance and harmony 6 . So, more than to standardize,<br />
the goal of every orthodontist should be to individualize the<br />
cephalometric analysis to the patient.<br />
<strong>The</strong> <strong>Tweed</strong>-Merrifield cephalometric analysis was chosen for<br />
this study because it, like other analyses, uses measurements<br />
that indicate the skeletal, dental and esthetic patterns of<br />
patients. <strong>The</strong> standard values for the <strong>Tweed</strong> Merrifield<br />
analysis are shown in Fig. 1.<br />
Fig. 1: <strong>Tweed</strong>-Merrifield Cephalometric Analysis
cA s e #1<br />
A male, 15 years-old, with a dolichofacial, convex profile and<br />
lack of lip seal had a Class II division 1 malocclusion with an<br />
overjet of 9.0 mm (Figs. 2, 3). How can this Class II division<br />
1, patient have an ANB of 1.0º, and AO-BO of –9.0 mm?<br />
If the SNA and SNB angles show, respectively, the anterior<br />
or posterior position of the maxilla and the mandible, aren’t<br />
the decreased measurements of this patient an indication that<br />
they are retracted? How can a convex profile and a Z angle<br />
of 65.0º be explained if the SNA measures 72.0º and SNB<br />
measures 71.0º?<br />
If the cephalogram is studied, the reasons are not so very<br />
difficult to explain. ANB is 1.0º because the patient’s face is<br />
“vertical” and his anterior cranial base is inclined downward<br />
— S point is lower than point N. <strong>The</strong> anterior cranial base is<br />
longer as a result of Nasion being more forward. <strong>The</strong> more<br />
forward point N, the more ANB decreases. So, the more<br />
forward point N is located and the more inferior S is located<br />
to cause of a more inclined anterior cranial base, the more<br />
the SNA, SNB and ANB angles decrease.<br />
AO-BO is -9.0 mm because of the vertical facial type and<br />
because of the inclined occlusal plane. As the occlusal plane<br />
incline increases, the projection of A and B points tends to<br />
decrease progressively.<br />
If the anterior cranial base and occlusal plane are excessively<br />
inclined, the SNA, SNB and ANB are decreased. This boy’s<br />
face should be much more vertical than the FMA indicates.<br />
If the AO-BO of -9.0 mm is due to the occlusal plane’s<br />
accentuated inclination, which is compatible with extremely<br />
vertical faces, it is confirmed by the following values: PFH<br />
of 42.0 mm, AFH of 78.0 mm and FHI of 0.53. Although<br />
FMA is 34°, it does correspond to these other measurements,<br />
which leads to the possibility of a Frankfort plane tracing<br />
error. And assuming that this interpretation is true 7,8 , it<br />
is possible to understand why occlusal plane and Z angle<br />
are not as inclined as they would be expected to be with<br />
AO-BO of -9.0 mm and FHI of 0.53. <strong>The</strong>se discrepancies<br />
could somewhat compromise the cephalometric discrepancy<br />
calculation, which in this <strong>case</strong> would be even greater if SNA,<br />
SNB and ANB were more reflective of the skeletal problem.<br />
Several studies 7-10 confirm this possibility for this patient.<br />
Fig. 2: Case #1 Pretreatment Photographs<br />
Fig. 3: Case #1 Cephalometric Tracing and Analysis<br />
cA s e # 2<br />
This male patient, treated fifteen years ago, was 18 yearsold,<br />
brachifacial and had a straight and harmonious profile<br />
with good lip seal. <strong>The</strong> Class II division 2 malocclusion has<br />
normal overjet and overbite and coincident midlines (Figs.<br />
4 and 5). His frontal and profile photographs (Fig. 4) show<br />
a well balanced and harmonious face which does not reflect<br />
the malocclusion that is exhibited by the casts.<br />
Cephalometrically (Fig. 5), an ANB of 5.0º indicates a<br />
skeletal Class II while an FMIA of 53.0º and an IMPA of<br />
105.0º confirm protruded mandibular incisors. <strong>The</strong> Z angle<br />
of 80.0º reflects a straight and balanced profile. If one uses<br />
28
Fig. 4: Case #2 Pretreatment Photographs<br />
Fig. 5: Case #2 Cephalometric Tracing and Analysis<br />
a cephalometric discrepancy calculation, IMPA should<br />
be 68.0º. To reach this value would require mandibular<br />
extraction to upright the mandibular incisors. Is it possible<br />
to upright the mandibular incisors this much? What about<br />
maxillary incisor position? Why are the mandibular incisors<br />
so buccally inclined and the maxillary incisors so well<br />
positioned? Ordinarily, aren’t the incisors balanced by lips<br />
and by tongue?<br />
For this patient we cannot think in the manner just described.<br />
<strong>The</strong> Z angle is 80.0º and the profile is straight. <strong>The</strong> IMPA is<br />
105° to compensate the Class II skeletal pattern, as the ANB<br />
and AO-BO show. And ANB and AO-BO are not significantly<br />
large because the gonial angle is closed. <strong>The</strong> FMA is low. So,<br />
29<br />
it must be understood that the low mandibular plane angle<br />
dictates the mandibular incisors’ labial inclination. This is<br />
nature’s compensation to disguise the Class II so that the<br />
profile is balanced. If a cephalometric correction had been<br />
done and the mandibular incisors uprighted, the maxillary<br />
incisors, which are normal, would have an unesthetic lingual<br />
inclination.<br />
<strong>The</strong> patient was treated without extractions. <strong>The</strong> results are<br />
shown in Figs. 6 and 7. <strong>The</strong> frontal and profile photographs<br />
(Fig. 6) show good lip seal, proportional and symmetrical<br />
facial thirds and a straight and balanced profile. Maintenance<br />
of the balanced and harmonious face was a pretreatment<br />
goal.<br />
Fig. 6: Case #2 Posttreatment Photographs<br />
Fig. 7: Case #2 Cephalometric Tracing and Analysis
<strong>The</strong> frontal and lateral views of the casts (Fig. 6) show the<br />
corrected dentition with good interdigitation of the teeth.<br />
Thus, it was possible to treat the patient and respect nature’s<br />
compensation while correcting the Class II dental problem.<br />
<strong>The</strong>re is no doubt about the fact that it was “hard” treatment.<br />
<strong>The</strong> patient’s five year recall photographs (Fig. 8) show<br />
that the profile became more “flat”. Imagine what would<br />
have happened to the profile with extraction treatment. It is<br />
important to understand that the issue here is not to repudiate<br />
or to discredited an analysis, but to interpret it correctly.<br />
This worsening of the patient’s profile with age cannot be<br />
attributed to the orthodontic treatment. As the cephalometric<br />
analysis shows (Fig. 9), the profile change was due to total<br />
chin growth from the beginning to the end of the period<br />
studied. However, if this patient had been treated with<br />
extractions to upright mandibular incisors, the facial result<br />
would have been disastrous and a reason for a lot of criticism<br />
of the treatment.<br />
Fig. 8: Case #2 Recall Treatment Photographs<br />
Fig. 9: Case #2 Cephalometric Tracing and Analysis<br />
cA s e # 3<br />
<strong>The</strong> patient is 15 years, 6 months old with a Class III<br />
dentition. He has a balanced and harmonious face with good<br />
proportions that does not reflect a malocclusion (Fig. 10).<br />
<strong>The</strong> frontal view of the casts (Fig. 10) shows edge-to-edge<br />
incisors, maxillary spacing and 7mm of mandibular anterior<br />
crowding. <strong>The</strong> lateral views (Fig. 10) show teeth in a Class III<br />
relationship and molars and premolars with sharp vestibular<br />
inclinations. This occlusion was probably due to previous<br />
orthodontic treatment which attempted to excessively<br />
expand the dental arches. <strong>The</strong> cephalometric analysis (Fig.<br />
11) shows increased SNA and SNB values in relation to the<br />
average standard values. FMA is 23.0º; FMIA should be of<br />
68.0º. <strong>The</strong> patient’s FMIA is 71.5º. <strong>The</strong>se numbers indicate<br />
mandibular incisor uprighting is not necessary. But the<br />
discrepancy is based on people with normal occlusion with<br />
ANBs close to 2.0º. Whereas, in this patient the malocclusion<br />
is Class III with ANB of -2.0º and the AO-BO is -7.5 mm.<br />
Fig. 10: Case #3 Pretreatment Photographs<br />
Fig. 11: Case #3 Cephalometric Tracing and Analysis<br />
30
<strong>The</strong>re is no doubt that there must be some sort of dental<br />
compensation.<br />
So, for this patient, what would be the compensation or<br />
cephalometric discrepancy? One of the most important<br />
aspects is the patient’s profile which, despite a Z angle of<br />
85.5º, is very well balanced and harmonious — not concave.<br />
This is due to head anatomy with the increased PFH and,<br />
consequently, with an increased FHI as well.<br />
Maxillary incisor position must be considered and left as it is<br />
pretreatment. So, it should be reasoned that the mandibular<br />
incisor position must compensate for the negative ANB<br />
with a much more lingual inclination than it would be with<br />
an ANB of 2.0º. Because the maxillary incisor is not only<br />
well positioned but is stable, and the lower facial profile is<br />
both harmonious and balanced, the mandibular incisor must<br />
be changed as much as is necessary in order to establish<br />
normal overjet and overbite as well as to maintain the<br />
balanced and harmonious profile. So going counter to the<br />
traditional cephalometric discrepancy calculation rule, the<br />
mandibular incisor must be inclined 3.5 mm lingual – which<br />
is equivalent to 7.0 mm of cephalometric discrepancy.<br />
Considering this discrepancy, the malocclusion type and the<br />
maxillary third molar agenesis, treatment was planned with<br />
mandibular first molar extractions. In order to evaluate this<br />
type of reasoning, there is nothing better than this patient’s<br />
treatment result (Figs. 12 and 13).<br />
In the frontal and profile photographs (Fig. 12) there is good<br />
lip seal with a straight profile. Facial balance and harmony<br />
were maintained. <strong>The</strong> frontal and lateral views of the<br />
casts (Fig. 12) show good interdigitation of the teeth, with<br />
mandibular second and third molars occupying, respectively,<br />
the first and second molar positions (Fig. 13). <strong>The</strong>re was<br />
maintenance of ANB and improvement in AO-BO to 1.5<br />
mm. Although the mandibular incisors were inclined to the<br />
31<br />
Fig. 12: Case #3 Posttreatment Photographs<br />
Fig. 13: Case #3 Cephalometric Tracing and Analysis<br />
lingual, the same profile was maintained, that is, the Z angle<br />
remained exactly the same.<br />
co n c L u s i o n s<br />
With critical evaluation and rational interpretation of these<br />
patients’ cephalometric analyses, there is no motive for the<br />
statement that one analysis dictates extraction of more or less<br />
teeth than another. It becomes clear that differences between<br />
cephalometric analysis methods, the extraction or lack of<br />
extraction of teeth and facial profile management depend<br />
exclusively on the professional’s interpretation.<br />
<strong>The</strong> following conclusions can be reached:<br />
1.<br />
2.<br />
3.<br />
4.<br />
5.<br />
In the utilization of the <strong>Tweed</strong>-Merrifield cephalometric<br />
analysis it is possible to detect tracing errors through<br />
measurement interpretation as a whole.<br />
ANB and AO-BO do not always reflect a skeletal anteriorposterior<br />
discrepancy.<br />
SNA and SNB do not always accurately confirm the<br />
anterior or posterior position of the jaws. <strong>The</strong>ir increase<br />
or decrease in relation to the average standard value could<br />
be caused by a shorter or longer cranial base as well as its<br />
inclination.<br />
<strong>The</strong> cephalometric discrepancy is misinterpreted some<br />
times and should not be a definitive application of a simple<br />
mathematical rule.<br />
<strong>The</strong> position of the maxillary incisor as well as ANB,<br />
AO-BO, FHI and Z angle helps to interpret and clarify a<br />
cephalometric discrepancy.
e f e r e n c e s<br />
1. Halazonetis DJ. From 2-dimensional cephalograms to 3-dimensional computed tomography scans. Am J Orthod<br />
Dentofacial Orthop 2005;127:627-637.<br />
2. Kragskov J, Bosh C, Gyldensted C, Sindet-Pedersen S. Comparison of the reliability of craniofacial anatomic landmarks<br />
based on cephalometric radiographs and three-dimensional CT Scans. Cleft Palate-Craniofacial J 1997;34(2):111-<br />
116,.<br />
3. Jacobson A. <strong>The</strong> “Wits” appraisal of jaw disharmony. Am J Orthod Dentofacial Orthop 2003;124(5):470-479.<br />
4. Downs WB. Variations in facial relationships: their significance in treatment and prognosis. Am J Orthod 1948;34:812–<br />
840.<br />
5. Park SH, Yu HS, Kim KD, Lee KJ, Baike HS. A proposal for a new analysis of craniofacial morphology by 3-dimensional<br />
computed tomography. Am J Orthod Dentofacial Orthop 2006;129(5):600.e23-600.e34.<br />
6. <strong>Tweed</strong> CH. Clinical Orthodontics: volume one. St. Louis (MO): Mosby Company; 1966.<br />
7. Sandler P. Reproducibility of Cephalometric Measurements. Br J Orthod 1988;15:105-10.<br />
8. Cooke M, Wei S. Cephalometric errors: a comparison between repeat measurements and retaken radiographs. Aust Dent<br />
J 1991;36:38-43.<br />
9. Gravely J, Benzies P. <strong>The</strong> clinical significance of tracing error in cephalometry. Br J Orthod 1974;1:95-101.<br />
10.<br />
Staburn A, Danielson K. Precision in cephalometric landmark identification. Eur J Orthod 1982;4:185-96.<br />
32
cA s e<br />
re P o r t s
Va nC e dy K h o u s e<br />
blu e sP r i n g s, missou r i<br />
A cA s e re P o r t: A fu L L st e P cL A s s ii PAt i e n t revisisted 27 ye A r s<br />
Tammy Sage had comprehensive orthodontic treatment<br />
in the mid 1970’s. She returned to our office to have<br />
her son treated in 2005. We made a set of records in<br />
2005, almost twenty-eight years after her treatment was<br />
finished in 1977.<br />
Tammy’s <strong>case</strong> was originally presented with three sets<br />
of records at a Central Section <strong>Tweed</strong> meeting in 1979.<br />
A two-year post-treatment set of records was almost a<br />
necessity for <strong>case</strong> presentations at that time.<br />
Tammy presented a bilateral full step Class II, Division<br />
I malocclusion without crowding. Her overbite was<br />
extremely deep. She was a non-grower, 14 years, 2<br />
months in age at the beginning of orthodontic treatment.<br />
<strong>The</strong> decision was made to treat Tammy non-extraction<br />
despite a higher than desired IMPA. Good headgear<br />
wear and anchorage preparation would be a necessity<br />
for successful treatment. (Please pardon the glasses in<br />
the extra oral photographs.)<br />
Po st t r e At M e n t<br />
36
Tammy’s treatment began in 1975. She had a high<br />
mandibular frenum and a Stillman’s cleft on tooth<br />
#25 that is not visible on the beginning intraoral<br />
photographs. She had a graft in late 1975 that was<br />
successful.<br />
Tammy was an excellent patient. After initial leveling,<br />
she wore a straight pull J-hook headgear and Class III<br />
elastics to set mandibular anchorage. Mechanics were<br />
then reversed to a high pull J-hook and vertical elastics<br />
during sleeping hours with full-time Class II elastics.<br />
<strong>The</strong> bite was opened and a solid Class I occlusion was<br />
attained. Maxillary second molars were tipped out of<br />
occlusion, a la <strong>Tweed</strong> mechanics in use at that time.<br />
Active treatment time was 26 months. Tammy was 16<br />
years, 5 months in age when appliances were removed<br />
and retention began.<br />
A third set of records was taken twenty-six months<br />
after appliance removal. Tammy was 18 years, 7<br />
37<br />
months of age. <strong>The</strong> Class I buccal occlusion had<br />
been maintained and the overbite had not returned.<br />
<strong>The</strong> maxillary molars settled into excellent occlusion.<br />
Third molars were gone. Spaces remained closed. A<br />
maxillary Hawley retainer and a lower fixed retainer<br />
were worn until this time.<br />
In 2005, Tammy returned to our office with her son<br />
who had a similar malocclusion, and was ready for
orthodontic treatment. A fourth set of records was<br />
made. Tammy was 44 years, 4 months of age. <strong>The</strong><br />
records were taken 1 month shy of twenty-eight years<br />
post appliance removal. Tammy’s Class II correction<br />
has held well. Her overbite correction has also remained<br />
stable. <strong>The</strong> thirty year old gingival cleft has remained<br />
non pathological. She has had to have quite a bit of<br />
dental work over the past twenty five years.<br />
38
Cephalometric measurements from the four sets of record are presented in summary form.<br />
39<br />
Cephalometric Summary<br />
12/74 4/77 6/79 3/05<br />
FMA 22 22 20 18<br />
IMPA 99 98 101 101<br />
FMIA 59 60 59 62<br />
SnGoGn 27 27 26 30<br />
SNA 84.5 82 83 82.5<br />
SNB 78 78.5 80 80.5<br />
ANB 6.5 3.5 3 2<br />
T to NB 5 6 6 5<br />
Pog to NB 4 4 4 3<br />
Int-Inc angle 117 133 130 132<br />
Occ-PL 17 14 12 18<br />
Ao-Bo 7 2.5 4 4<br />
Z angle 74 76 83 88
cA s e re P o r t: ve r t i c A L co n t r o L in A hi g h An g L e PA t i e n t wh o ne e de d<br />
rA Pi d MAx i L L A ry ex PA n s i o n (rMe)<br />
ma u r iC i o es C a n o l a<br />
Te PiC, naya r iT / me X iC o<br />
In our professional life we are faced with patients whose<br />
malocclusions challenge us as orthodontists to test the<br />
concepts we have learned and to use our clinical judgment<br />
to apply the biomechanical resources that allow us to<br />
offer the patient facial esthetics, occlusal harmony and<br />
stability.<br />
Patients who combine a vertical hyperdivergent skeletal<br />
pattern with maxillary collapse are difficult to treat because<br />
the treatment of a patient with maxillary collapse requires<br />
maxillary expansion. <strong>The</strong> literature clearly demostrates<br />
that, immediately after expansion, there is downward<br />
maxillary displacement and extrusion of the supporting<br />
teeth which leads to downward and backward mandibular<br />
rotation 2,4-6,8–10,14-17 . <strong>The</strong> opening rotation of the mandible<br />
induces cephalometric changes such as increases in<br />
inclination of the mandibular plane, increases in lower<br />
anterior facial height and facial convexity bite opening in<br />
the anterior region.<br />
In this context, some orthodontists have advised against<br />
performing RME in patients who have predominantly<br />
vertical growth patterns and convex facial profiles 1,3 in<br />
order to prevent worsening of the malocclusion. However,<br />
a proper diagnosis, understanding of the functional forces<br />
and implementation of an appropriate force system that<br />
favors vertical and horizontal control during treatment<br />
are able to minimize the undesirable anteroposterior and<br />
vertical effects of RME 7, 11-13, 20-23 .<br />
cA s e re P o r t<br />
Karen C., is a 16 year old young lady who presents<br />
a straight profile and a Class I malocclusion with a<br />
hyperdivergent skeletal pattern that is complicated by<br />
maxillary constriction and posterior crossbite due to the<br />
mouth breathing habit. According to Staley´s intermolar<br />
analysis 24 the deficit of 8mm in the maxillary arch is<br />
clinically related to insufficient width of the palatal<br />
vault, a deep palate and outward inclined dentoalveolar<br />
processes. All these factors indicate a skeletal maxillary<br />
constriction. Dentally, the patient has an edge to edge<br />
bite and severe crowding with ectopic maxillary canines<br />
(Fig. 1, 2). Cephalometric values show an FMA of 30°,<br />
an occlusal plane of 13°, a facial index of 61%, an IMPA<br />
of 87° and a Z angle of 76° (Fig. 3).<br />
Figure 1. Pretreatment photographs.<br />
Figure 2. Pretreatment dental casts.<br />
40
Figure 3. Pretreatment cephalogram, cephalometric values and<br />
tracing.<br />
<strong>The</strong> main factors associated with the treatment of this<br />
patient are:<br />
41<br />
1.<br />
2.<br />
3.<br />
4.<br />
High mandibular plane angle (hyperdivergent<br />
skeletal pattern)<br />
Maxillary constriction<br />
Dental crowding<br />
Good facial profile<br />
Merrifield’s guidelines suggested that four first premolars<br />
should be extracted in order to solve the space problem .<br />
This patient was treated with rapid maxillary expansion<br />
(REM) before extractions and fixed appliances (Fig. 4) so<br />
that anchorage loss during the closure of the spaces would<br />
not affect facial balance.<br />
Figure 4. a) Post maxillary expansion; b) After 6 months of<br />
contention.<br />
<strong>The</strong> posttreatment records (Fig. 5, 6) illustrate that facial<br />
harmony was maintained. <strong>The</strong>re was an improvement in<br />
the esthetics of the smile. Posttreatment casts confirm the<br />
improvement of the transverse dimension and shape of<br />
the maxillary arch as well as good arch coordination and<br />
occlusal interdigitation.<br />
Figure 5. Posttreatment photographs.<br />
Figure 6. Posttreatment dental casts.<br />
Posttreatment cephalometric values (Fig. 7) show that<br />
there was good vertical control since the FMA, the<br />
occlusal plane and facial index were not altered despite<br />
maxillary expansion. Z angle was increased to 79°.<br />
<strong>The</strong> superimpositions (Fig. 8) show that space closure<br />
was achieved with mesial movement of the molars and<br />
minimal anterior retraction so that facial balance would<br />
not be harmed. <strong>The</strong>re was no posterior extrusion and<br />
therefore no clockwise mandibular rotation due to lack of<br />
vertical control.<br />
For a patient with a normal vertical dimension, and<br />
even more for a patient with a hyperdivergent skeletal<br />
pattern, to not have control of the vertical dimension<br />
predisposes to failure. On the other hand, good control of<br />
vertical dimension during treatment allows a predictable<br />
outcome.<br />
Figure 7. Posttreatment cephalogram, cephalometric values and<br />
tracing.<br />
Figure 8. Superimpositions.
e f e r e n c e s<br />
1. Alpern MC, Yurosko JJ. Rapid palatal expansion in adults with and without surgery. Angle Orthod.<br />
1987;57(3):245–263.<br />
2. Asanza S, Cisneros GJ, Nieberg LG. Comparison of Hyrax and bonded expansion appliances. Angle Orthod.<br />
1997; 67(1):15–22.<br />
3. Bishara SE, Staley RN. Maxillary expansion: clinical implications. Am J Orthod Dentofacial Orthop.<br />
1987;91(1):3–14.<br />
4. Byrum AG Jr. Evaluation of anterior-posterior and vertical skeletal change vs. dental change in rapid palatal<br />
expansion <strong>case</strong>s as studied by lateral cephalograms. Am J Orthod. 1971;60(4):419.<br />
5. Chung CH, Font B. Skeletal and dental changes in the sagittal, vertical, and transverse dimensions after rapid<br />
palatal expansion. Am J Orthod Dentofacial Orthop. 2004;126(5): 569–575.<br />
6. Davis WM, Kronman JH. Anatomical changes induced by splitting of the midpalatal suture. Angle Orthod.<br />
1969;39(2): 126–132.<br />
7. Garib DG, Henriques JF, Janson G, Freitas MR, Coelho RA. Rapid maxillary expansion--tooth tissue-borne<br />
versus tooth-borne expanders: a computed tomography evaluation of dentoskeletal effects. Angle Orthod.<br />
2005;75(4):548-57.<br />
8. Haas AJ. <strong>The</strong> treatment of maxillary deficiency by opening the midpalatal suture. Angle Orthod. 1965;35:200–<br />
217.<br />
9. Haas AJ. Rapid expansion of the maxillary dental arch and nasal cavity by opening the midpalatal suture. Angle<br />
Orthod. 1961;31(2):73–90.<br />
10. Heflin BM. A three-dimensional cephalometric study of the influence of expansion of the midpalatal suture on<br />
the bones of the face. Am J Orthod. 1970;57(2):194–195.<br />
11. Merrifield, L.L.: <strong>The</strong> profile line as an aid to critical evaluation of facial esthetics. Am J Orthod: 804-822, 1966.<br />
12. Merrifield, L.L., Cross, J.; A study on directional forces. Am J Orthod., 1970.<br />
13. Merrifield L.L.: Differential diagnosis with total space analysis. J <strong>Tweed</strong> 6: 10-15, 1978.<br />
14. Sandikcioglu M, Hazar S. Skeletal and dental changes after maxillary expansion in the mixed dentition. Am J<br />
Orthod Dentofacial Orthop. 1997;111(3):321–327.<br />
15. Silva Filho OG, Boas MC, Capelozza Filho L. Rapid maxillary expansion in the primary and mixed dentitions: a<br />
cephalometric evaluation. Am J Orthod Dentofacial Orthop 1991; 100(2):171–179.<br />
16. Wertz R, Dreskin M. Midpalatal suture opening: a normative study. Am J Orthod. 1977;71(4):367–381.<br />
17. Wertz RA. Skeletal and dental changes accompanying rapid midpalatal suture opening. Am J Orthod.<br />
1970;58(1):41–66.<br />
18. Reed N, Ghosh J, Nanda RS. Comparison of treatment outcomes with banded and bonded RPE appliances. Am J<br />
Orthod Dentofacial Orthop. 1999;116(1):31–40.<br />
19. Sarver DM, Johnston MW. Skeletal changes in vertical and anterior displacement of the maxilla with bonded<br />
rapid palatal expansion appliances. Am J Orthod Dentofacial Orthop. 1989;95(6):462–466.<br />
20. Wendling LK, McNamara JA Jr, Franchi L, Baccetti T. A prospective study of the short-term treatment effects<br />
of the acrylic-splint rapid maxillary expander combined with the lower Schwarz appliance. Angle Orthod.<br />
2005;75(1):7–14.<br />
21. Schulz SO, McNamara JA Jr, Baccetti T, Franchi L. Treatment effects of bonded RME and vertical-pull chin<br />
cup followed by fixed appliance in patients with increased vertical dimension. Am J Orthod Dentofacial Orthop.<br />
2005;128(3): 326–336.<br />
22. Chang JY, McNamara JA Jr, Herberger TA. A longitudinal study of skeletal side effects induced by rapid<br />
maxillary expansion. Am J Orthod Dentofacial Orthop. 1997;112(3): 330–337.<br />
23. Velazquez P, Benito E, Bravo LA. Rapid maxillary expansion. A study of the long-term effects. Am J Orthod<br />
Dentofacial Orthop. 1996;109(4):361–367.<br />
24. Robert N. Staley, Wendell R. Stuntz, Lawrence C. Peterson. A comparison of arch widths in adults with normal<br />
occlusion and adults with Class II, Division 1 malocclusion. American Journal of Orthodontics. August 1985<br />
(Vol. 88, Issue 2, Pages 163-169)<br />
42
43<br />
cA s e re P o r t: tr e At M e n t o f A hi g h An g L e Ad o L e s c e n t PAt i e n t<br />
This is the <strong>case</strong> <strong>report</strong> of an Angle’s Class I crowded,<br />
high mandibular plane angle malocclusion. <strong>The</strong><br />
patient’s medical history was negative. Etiology of the<br />
malocclusion was heredity.<br />
Pr e t r e At M e n t re c o r d s<br />
<strong>The</strong> facial photographs (Fig. 1) exhibit a convex<br />
facial profile, lower lip eversion, and a retrognathic<br />
appearance of the mandible. <strong>The</strong> casts (Fig. 2) exhibit<br />
a deep overbite, an Angle’s Class I occlusion, a deep<br />
curve of Spee, and mandibular anterior crowding. <strong>The</strong><br />
panoramic radiograph (Fig. 3) confirms that all teeth<br />
are present, the periodontium is healthy, and there is<br />
no pathology. <strong>The</strong> cephalogram and its tracing (Fig.<br />
4a, b) confirm a high mandibular plane angle of 36°.<br />
Mandibular retrognathia is confirmed by the SNB<br />
of 74°. <strong>The</strong> Z angle is a poor 58° and both maxillary<br />
and mandibular lips are in front of the E plane. <strong>The</strong><br />
craniofacial analysis difficulty value for this patient<br />
Fig. 1. Pretreatment photographs.<br />
Fig. 2. Pretreatment dental casts.<br />
Fig. 3. Pretreatment panoramic radiograph.<br />
Fig. 4a. Pretreatment cephalogram and 4b) tracing.<br />
Ko rT n e fr e de r iC K h o u<br />
Tu K w i l a, wa s h i n g T o n
is 98. <strong>The</strong> total space analysis difficulty is 22.9. <strong>The</strong><br />
patient’s total dentition difficulty was 120.9.<br />
Tr e aT m e n T Pl a n<br />
Due to the bialveolar protrusion and the 7 mm of<br />
mandibular anterior crowding, maxillary and mandibular<br />
first premolars were removed. <strong>The</strong> removal of these<br />
teeth was done in order to facilitate elimination of the<br />
crowding and reduction of the bialveolar protrusion.<br />
Po s t t r e At M e n t re c o r d s<br />
<strong>The</strong> pretreatment / posttreatment facial photographs<br />
(Fig. 5) confirm a more pleasing face with less protrusion<br />
of the lips. <strong>The</strong> smile line is vastly improved. <strong>The</strong><br />
posttreatment casts (Fig. 6) exhibit correction of the<br />
crowding, a reduction in the overbite, and an excellent<br />
Class I interdigitation of the teeth. Arch width and arch<br />
form were preserved during the course of treatment. <strong>The</strong><br />
Fig. 5. Posttreatment photographs.<br />
Fig. 6. Posttreatment dental casts.<br />
posttreatment panoramic radiograph (Fig. 7) reveals<br />
that the teeth remain healthy and that all extraction<br />
spaces have been closed by adequate uprighting of<br />
teeth into the extraction spaces. <strong>The</strong> posttreatment<br />
cephalogram and its tracing (Fig. 8a, b) confirms<br />
retraction of teeth, control of the vertical dimension,<br />
and a marked reduction in the dental protrusion. <strong>The</strong><br />
superimpositions (Fig. 9) illustrate an autorotation of<br />
the mandible due to vertical control during treatment<br />
and a nice downward and forward chin projection. <strong>The</strong><br />
pretreatment/posttreatment smiles (Fig. 10) confirm<br />
the intrusion and retraction of the maxillary anterior<br />
teeth which resulted in much less gingival display upon<br />
smiling.<br />
Fig. 7. Posttreatment panoramic radiograph.<br />
Fig. 8a. Posttreatment cephalogram 8b.tracing.<br />
Fig. 9. Superimpositions.<br />
Fig. 10. Pretreatment and Posttreatment smiles.<br />
44
Ja C K ho u<br />
Tu K w i l a, wa s h i n g T o n<br />
This is a <strong>case</strong> <strong>report</strong> of a young female who has an<br />
extreme protrusion of the teeth which causes a significant<br />
facial imbalance. <strong>The</strong> etiology of the malocclusion was<br />
heredity. <strong>The</strong>re were no medical complications.<br />
Pr e t r e At M e n t re c o r d s<br />
<strong>The</strong> facial photographs (Fig. 1) exhibit a very convex<br />
face with quite a bit of mandibular lip eversion. <strong>The</strong><br />
nasolabial angle is acute. <strong>The</strong> pretreatment casts (Fig.<br />
2) exhibit a deep curve of Spee, an Angle’s Class II<br />
dental relationship, and flared maxillary and mandibular<br />
incisors. <strong>The</strong> pretreatment panoramic radiograph (Fig. 3)<br />
confirms that all teeth are present and the periodontium<br />
is healthy. <strong>The</strong> pretreatment cephalogram and its<br />
tracing (Fig. 4a, b) confirm very protruded maxillary<br />
and mandibular incisors, a Class II skeletal relationship,<br />
and a very low Z angle. <strong>The</strong> craniofacial difficulty for<br />
the patient was only 34 because the skeletal pattern was<br />
reasonable. <strong>The</strong> tooth arch discrepancy for this patient<br />
was 22 mm because of the excessive mandibular incisor<br />
flaring.<br />
tr e At M e n t PL A n<br />
Due to the severity of the protrusion, maxillary and<br />
mandibular first premolars were extracted. <strong>The</strong> patient<br />
was banded with an 022 edgewise appliance. After<br />
one year of treatment, the mandibular third molars and<br />
maxillary first molars were extracted so that the Angle’s<br />
Class II dental relationship could be corrected without<br />
proclining mandibular incisors. <strong>The</strong> patient was treated,<br />
all spaces were closed, and the patient was placed in<br />
45<br />
cA s e re P o r t: cor r e c t ion o f A se v e r e cL A s s ii di v i s i o n i<br />
MA L o c c L u s i o n in A n Ad o L e s c e n t PA t i e n t<br />
Fig. 1. Pretreatment photographs.<br />
Fig. 2. Pretreatment casts.<br />
Fig. 3. Pretreatment panoramic radiograph.
Fig. 4a. Pretreatment cephalogram and 4b) tracing.<br />
Fig. 5. Pretreatment/posttreatment photographs.<br />
Fig. 6. Posttreatment casts.<br />
Fig. 7. Posttreatment panoramic radiograph.<br />
Fig. 8a. Pretreatment cephalogram and 8b) tracing.<br />
Hawley retainers at the cessation of<br />
treatment.<br />
Po s t t r e At M e n t re c o r d s<br />
<strong>The</strong> pretreatment/posttreatment photographs<br />
(Fig. 5) confirm marked reduction<br />
in the bialveolar protrusion, lip strain has<br />
been eliminated, and the patient has a<br />
much more balanced and pleasing facial<br />
profile. <strong>The</strong> posttreatment casts (Fig. 6)<br />
exhibit correction of the dentition to a<br />
Class I dental relationship and a reduction<br />
in the protrusion. Maxillary third<br />
molars will erupt and take the place of<br />
the maxillary second molars which have<br />
been moved mesially. <strong>The</strong> posttreatment<br />
panoramic radiograph (Fig. 7) exhibits<br />
roots that are parallel in the extraction<br />
sites and the erupting maxillary third<br />
molars. <strong>The</strong> posttreatment cephalogram<br />
and its tracing (Fig. 8a, b) confirm maintenance<br />
of the vertical dimension, quite<br />
a bit of mandibular incisor uprighting,<br />
and an improved Z angle. <strong>The</strong> superimpostions<br />
(Fig. 9) illustrate intrusion and<br />
retraction of the maxillary anterior teeth<br />
and uprighting of the mandibular anterior<br />
teeth. <strong>The</strong> pretreatment/posttreatment<br />
smiles (Fig. 10) are testament to<br />
the treatment plan and to the treatment<br />
which was delivered. <strong>The</strong> patient was<br />
seen on recall and new casts were made.<br />
<strong>The</strong>se casts (Fig. 11) confirm eruption<br />
of the maxillary third molars and a very<br />
functional dentition. <strong>The</strong> presentation<br />
of this <strong>case</strong> <strong>report</strong> exhibits the use of<br />
<strong>Tweed</strong>-Merrifield mechanics and what<br />
can be done for a patient who has a severe<br />
malocclusion - if the treatment plan<br />
is proper and if the force systems are delivered<br />
in a proper manner.<br />
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Fig. 9. Pretreatment/posttreatment superimpostions.<br />
47<br />
Fig. 10. Pretreatment/posttreatment smiles.<br />
Fig. 11. Recall casts.<br />
“Ad d e n d u M”<br />
This patient had been treated twice prior to these records.<br />
<strong>The</strong> facial photographs (Fig. 12) show protrusion<br />
and lip strain. <strong>The</strong> pretreatment dental photographs exhibit<br />
an excellent Class I dental relationship, a very<br />
small amount of crowding, and a rather protruded smile.<br />
<strong>The</strong> cephalogram with IMPA and FMIA highlighted<br />
(Fig. 13) exhibits mandibular incisors that are at 100°<br />
to mandibular plane and a low FMIA. <strong>The</strong> protrusion<br />
is evident<br />
<strong>The</strong> patient wanted retreatment. Maxillary and mandibular<br />
second premolars were removed. <strong>The</strong> posttreatment<br />
facial photographs and photographs of the teeth<br />
(Fig. 14) illustrate reduction of the protrusion and<br />
a nice Class I interdigitation of the teeth. <strong>The</strong> posttreatment<br />
cephalogram (not shown) confirmed that mandibular<br />
incisors were uprighted from 100° to 86° and the<br />
Fig. 12. Pretreatment photographs.<br />
Fig. 13. Pretreatment cephalogram.
Fig. 14. Posttreatment photographs.<br />
Fig. 15. Pretreatment/posttreatment/recall profile photographs.<br />
FMIA improved from 58° to 69°. <strong>The</strong> final comparison<br />
of the facial profile (Fig. 15) is graphic evidence<br />
of what should be done when patients with bialveolar<br />
protrustions are properly treatment planned. <strong>The</strong> final<br />
recall photographs of teeth and face (Fig. 16) say a lot<br />
of things about where orthodontics should be going and<br />
what kind of service we can render to our patients if the<br />
treatment plan and the force systems are proper.<br />
Fig. 16. Recall photographs.<br />
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