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A philosophy of combined orthopedic-orthodontic treatment
A ph,ilosoph,y of combined o&opedic-orthrodontic treatment J.-P. Pfeiffer,
Dr.med.dent.,
D.M.D., and D. GrobBty,
Dr. Pfeiffer
Dr.med.dent.
Lausunne and Vevey,Switzerland Treatment of many Class II malocclusions should be started in the late mixed dentition with removable orthopedic appliances, such as activator and extraoral forces. These appliances are used simultaneously, successively, or separately, depending on the differential diagnosis. Once the orthopedic problem is solved, the teeth are moved to an ideal occlusion, both anatomically and functionally, by means of sophisticated fixed appliances, such as the straight wire type of mechanism.
Key words: Orthopedics,
activator, extraoral forces, headgear, reverse headgear, Class II
I
n 1972l and 1975” we published in the AMERICAN JOURNAL OF ORTHODONTICStwo articles describing our orthopedic approach to the Class II malocclusion treatment prior to fixed orthodontic mechanotherapy. Subsequently, this approach has been refined by the incorporation of selected ideas from leaders in the field in order to fulfill any clinical demand required by the differential diagnosis. TREATMENT-PHILOSOPHY, ANDSEQUENCES
OBJECTIVES,
In this discussion, we shall limit ourselves to the Class II malocclusions. In 1926, W. B. Cannon used for the first time the term homeostusis. He indicates that there is a regulating adaptation attempting to maintain a state of equilibrium between an organism and its surroundings. If, for instance, we consider the two different dental relationships (Fig. I)-one a Class II dental protrusion and the other a Class l-we see that both are in a state of equilibrium. The upper one, before treatment, is in a perverted state of equilibrium, the teeth being in equilibrium with the lip but not with the face. The lower one, after treatment, corresponds to a true physiologic neuromuscular equilibrium, the teeth being in harmony with the lips and the face. In both cases, the lower lip is the determining factor located once in front and once behind the upper incisors. Bass” said that in most cases a malocclusion is the result of a breakdown
in homeostasis
between
This article is dedicated to Dr. Ronald Roth for his outstanding functmnal occlusion. 0002.9416/82/03018S+
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the dif-
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1982 The C. V. Mosby Co
to
ferent structures, the position of the teeth being merely a symptom of the whole phenomenon. If we conduct our orthodontic treatment within the frame of the original malocclusion, teeth are simply moved in their respective alveolar bases. However, they cannot reach a true state of equilibrium since perverting forces, owing to basal bone disharmony and muscle dysfunction, are exerting their influence on them. Thus, it is important to correct the skeletal discrepancy$rst, changing bone form and position and creating a new possibly more balanced environment to which the matrix can progressively readapt. Our treatment objectives are to restore a good anatomic occlusion with healthy periodontal tissue, establish a protectingfunctional articulation, and create a well-balanced soft-tissue equilibrium leading to pleasant facial esthetics. Considering these rather demanding treatment objectives, it would seem irrational to try to move teeth prior to correction of the skeletal and soft-tissue imbalances. Therefore, we follow the sequence of remodeling bones, harmonizing muscles, and moving teeth. The documents and criteria on which our diagnosis is based are the history, clinical examination, orthodontic models, fifteen intraoral x-ray films taken with the 16-inch long-cone technique, a lateral and frontal headplate, hand and wrist x-ray films, and six photographs. The lateral head film remains our key diagnostic tool. During the last 15 years we have used successively or simultaneously the analyses of Steiner, Bjork, Jarabak, and Ricketts. Today, we use elements of all four of them. These are SNA, SNB, ANB; palatal, occlusal, and mandibular plane angles; Steiner’s acceptable arrangements for the incisors; Bjork’s poly185
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Fig. 1. A and B, Before treatment, the teeth are in equilibrium with the lip but not with the face. C and D, After treatment and out of retention, the teeth are in equilibrium with the lip and with the face.
gon; Jarabak’s facial height proportion and gonial angle halves; nasopharyngeal airway permeability (distance to the nearest adenoid tissue from a point on a parallel of the pterigoid vertical, 5 mm. above PNS); convexity of the upper jaw (distance from point A to the facial plane, used for esthetic appraisal); maxillary depth (angle formed by Frankfort plane and the plane N-A, indicates the sagittal position of maxilla, clinical norm + 90 degrees); upper first molar to Ptv; lower first molar to Xi (gives indication for lower third molars, personal adaptation of the R.M.D.S. third molar probability evaluation); anterior lower facial height (angle formed by points ANS-Xi-PO); Ricketts’ esthetic line (E plane) Sagittal and vertical mechanics in the orthopedic and orthodontic correction of a skeletal Class II malocclusion must be considered, but first let us define both terms: Dentofacial orthopedics-Treatment directed toward altering the relationship of the bony elements of the jaws and the pattern of activity of the oro-facial musculature. Dentofacial orthodontics-Treatment directed toward altering the relationship of the teeth to each other and the face.
Am. J. Orthud. Much 1982
There are several possibilities available in the sagittal plane. One (Fig. 2, A) is to procline the lower teeth and to retrude the upper ones without any orthopedic treatment or bodily tooth movement. The resulting skeletal and dental imbalance is typical of the use of unimaxillary removable appliances. Bodily orthodontic movement alone (Fig. 2, B) also has limitations, such as the cortical plates of the palate and the symphysis. Our concept of ideal treatment must therefore be complemented by orthopedics. Extraction of two dental units in the maxilla and retraction of the upper anterior segment (Fig. 2, C) may also be a compromise in the correction of a skeletal Class II malocclusion, since the cortical plate of the palate limits the amount of bodily movement and ideal inclination. The last two approaches mentioned are at times the only possibilities, other than surgery, in adult Class II treatment. In the growing child, however, we have a wider spectrum of therapeutic possibilities. In cases in which the maxilla is well situated and the lower jaw is retruded (Fig. 3,A), growth of the mandible should be enhanced. At times, even the lower teeth should be moved forward bodily if the symphysis is well developed. In the cases (perhaps fewer than thought) in which the mandible is in good relation to the cranium (Fig. 3, B), only the maxillary structures should be relocated posteriorly by orthopedic means. In cases in which the sagittal problem is complicated by a skeletal open-bite (Fig. 3,C), expression of mandibular growth can be enhanced by restraining vertical growth of the maxillary bone and teeth and thereby bringing the mandible up and forward. There are several possibilities available in the vertical plane. In a dental and skeletal deep-bite situation (Fig. 4,A), the vertical development of the molar and the premolar should be stimulated as much as possible, if needed, even through active extrusion. In dental deepbite cases with normal skeletal structures (Fig. 4, B), an adequate removable appliance will handle the situation by interrupting growth in the incisor region and promoting it in the molar/premolar region. For a dental deep-bite with skeletal open-bite (Fig. 4,C), it is advisable to maintain the vertical dimension in the molar region or even decrease it by intrusion of these teeth and resort to incisor intrusion only to correct the deepbite. Much depends on the compensating mechanisms at the ramus level (Fig. 5). If ramus length and orientation are good, the posterior teeth can be elongated without any fear, and this will open the bite very effectively. The mandibular plane angle can be opened by molar extrusion induced either by a cervical traction or
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Fig. 2. A, Moving dental arches on their bases and tipping front teeth does not eliminate the skeletal discrepancy of the Class II malocclusion and places the teeth in improper axial inclinations. B, Bodily movement of the incisors is limited by the cortical plates and therefore cannot always resolve the overjet problem because of the basal discrepancy. C, Extraction of two dental units in the upper jaw also may not permit bodily movement of upper incisors so as to compensate for the skeletal imbalance. The cortical plate of the palate limits such a movement.
Fig. 3. A, In cases in which the mandible is underdeveloped or posteriorly displaced, every effort should be made to orthopedically influence condylar growth enhancement. 8, If the maxilla is at fault, it should be relocated posteriorly by orthopedic means. C, In skeletal open-bite cases, the sagittal discrepancy can, to a certain extent, be decreased by interrupting vertical growth of the maxilla and by intruding the upper molars. The mandible can thus swing forward and close.
Fig. 4. A, In dental and skeletal deep-bite cases, the posterior teeth should have complete freedom to erupt freely, whereas alveolar growth of the front teeth is completely interrupted. To further this natural bite-opening effect (dashed line), the posterior teeth should even be actively extruded (gray line). 8, In those cases in which the deep-bite is of dental origin, a simple orthopedic appliance can correct the problem by selectively interrupting or promoting tooth eruption. C, In dental deep-bite and skeletal open-bite cases, the excessive overbite should be corrected by means of incisor intrusion only. In these cases we would even recommend interrupting simultaneously alveolar growth of the upper molars and premolars.
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Fig. 5. Three drawings based on the work of Schudy and Jarabak. They are essential for the underor harmonious vertical growth. The descent of the standing of the vertical dimension. A, “Normal” palate and the alveolar growth of the upper and lower molars are compensated by quantitatively equal growth of the ramus; occlusal and mandibular planes remain parallel. B, A case in which the vertical growth at the level of the ramus, which is oversized, is much more important than in the palate and molar areas. The mandible performs an anterior closing rotation around a fulcrum situated at the molar level. In this case, the molars can and should be elongated to correct the deep-bite since the ramus overcompensates for this vertical increment in the molar region. C, The reverse situation in which the descent of the palate and alveolar growth at the molar level cannot be neutralized by growth of the ramus, which is undersized and poorly orientated. The mandible performs a posterior opening rotation whose fulcrum is situated at the condylar level. In this case, the vertical growth of the molars should be interrupted and the deep-bite corrected by incisor intrusion.
by Class II, Class III, or vertical elastics. If ramus length and angulation are unfuvoruble, all the abovementioned mechanics should be avoided and the deepbite should be corrected at the incisor level. The same considerations should be given to esthetics. In skeletal deep-bite, the lower half of the anterior facial height can be increased by molar extrusion. In skeletal open-bite, the lower half of the anterior facial height can be decreused by molar intrusion (Fig. 6). Incisor intrusion or extrusion does not in any way modify the lower anterior facial height or change esthetics. Our orthopedic therapeutic tools are the activator, anteroposterior extraoral forces anchored on bands cemented on the upper first molars, anteroposterior extraoral forces anchored on the activator, at either the premolar or incisor level, posteroanterior extraoral forces anchored on a facial mask and a palatal splitting device as described by Derrichsweiler and reintroduced by Haas. APPLIANCES The activator
Fig. 6. A, The anterior
lower facial height of this boy with an anterior-closing mandibular growth tendency should be increased for the sake of good facial esthetics; this same dimension should be decreased in the case of the girl shown in B.
The activator we use has little in common with the appliances created by Andresen4 and developed by Hiupl and Petrik. These authors have constructed moderately activated appliances, working through isotonic muscle contractions which produce intermittent forces transmitted to the teeth by small inclined planes. Our appliance (Fig. 7) produces a rnussive anterior displace-
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Fig. 7. A, The wax bite registers
the vertical and sagittal positions of the “activated” mandible. There must be an important anterior displacement of the mandible. B, C, and D show the activator with the expansion screw, the labial bow, the two Adams’ cribs, and the two long lower wings.
ment of the mandible and puts the muscles under heavy stress, which is isometric in nature. The elongated mandibular retractors are restraining maxillary growth. The mandibular protractors are contracted and are thought to induce cellular activity in the condyle through the interplay of the lateral pterygoid muscle as has been suggested by Petrovicsm8 and McNamara.g-ll The net effect on the basal bone is a moderate orthopedic correction of the sagittal skeletal discrepancy. a reduction of the Our own results (Fig. 8) suggest ANB angle of 1.74 degrees over an l&month period, mainly owing to an increase in the SNB angle and a decrease in the SNA angle. In addition to these basic orthopedic changes, the activator permits a selective influence on the eruption pattern of the teeth. It has been very clearly shown by Harvold12 how this can affect the final sagittal and vertical position of the teeth. Finally, the activator can contribute to the correction of different muscle dysfunctions, inappropriate respiration, and pernicious habits. The design and handling of the appliance vary to a great extent, depending on the differential diagnosis, but the construction bite for a Class II malocclusion is made essentially according to the same basic principles in all cases. The sagittal activation is 2 to 3 mm. short of muximum propulsion and the vertical activation should be at least 3 to 4 mm. beyond the freeway space. In deep-bite
cases there should be sufficient vertical activation to leave a 3 mm. thick wedge between the incisors (Fig. 9). The basic design shows an upper labial arch, an expansion screw, and two long lower wings. Depending on the presence of bands on the upper first molars, the retention of the appliance is secured either by Adams’ cribs, Dominique clasps, eyelets, or the extraoral forces themselves. The exact outline and shape of the appliance vary greatly, depending on the differential diagnosis in both sagittal and vertical dimension. As far as the sagittal dimension is concerned, either the lower teeth have to be moved mesially or not, and the acrylic will be shaped and ground accordingly. If the lower teeth are not to be moved anteriorly, the wings should be in close contact with the alveolar process but in no contact at all with the lingual aspect of the incisors which are, however, completely covered with acrylic on their labial aspects. If, on the other hand, the lower teeth should be moved mesially on their bases and the incisors tipped labially, the wings should not touch the alveolar process but only the lingual aspects of the incisors which are not covered with acrylic. Concerning vertical dimension, where eruption has to be interrupted the acrylic should not be relieved, and where alveolar growth has to be stimulated the teeth should be freed from all acrylic contact. If we wish to influence more substantially vertical growth of the
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Fig. 8. The dashed lines represent our own treatment result superimposed on graphs of normal growth as published in Riolo et al.: At/as of Craniofacial Growth (Ann Arbor, 1974, University of Michigan). The dots found on the lines of the atlas represent the male values, the crosses represent the female values. A, The SNA angle in our sampling of twenty-seven patients appears slightly decreased by the activator treatment. 8, The SNB angle appears slightly increased from the average. C, The ANB angle is reduced 1.74 degrees over an l&month period.
maxilla, we hook the extraoral forces directly onto the activator, in either the premolar or the incisor region. This method implies an adjunction of tubes in the premolar region or of looped torquing devices in the incisor region. Extraoral forces anchored the upper first molars
on bands
cemented
on
When we originally designed the combination of activator and extraoral forces 15 years ago’, * the ex-
Fig. 9. A, The sagittal activation of the activator should be very important. Maximum: propulsion is represented by the crosshatched teeth. The correct activation is illustrated by the darkshaded teeth. In other words, the activated position goes well beyond the Class I relationship. B, The vertical &Ovation in a moderate deep-bite, 2 to 3 mm. beyond rest position. C, The vertical activation in a severe deep-bite, 4 to 5 mm. beyond rest position. As a matter of fact, we need, in both examples B and C, a ledge of 2 to 3 mm. of acrylic to interrupt vertical growth of the incisors.
traoral forces were always inserted into the molar tubes (Fig. 10). Today’ we use this approach in about 70 percent of our cases. Depending on skeletal configuration, we use the cervical traction to promote deliberate molar extrusion (as, for example, in hypodivergent growth tendencies) and the occipital traction to promote more horizontal or even vertical or intrusive forces. Whenever facial morphology permits it, we use cervical forces since they produce a relative shearing effect at the sutural level, in opposition to occipital forces which produce a relative compression of the suture. In 198 1 Kragt, I3 in an unpublished thesis, showed in his holographic study of a macerated skull that the over-all maximum displacement of the maxillofacial complex was much greater with the cervical traction than with the occipital headgear.
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Fig. 10. In 70 percent of our Class II cases, the extraoral forces are transmitted to the teeth and the maxilla by means of the two molar bands. A shows the Kloehn headgear used in all cases in which vertical growth of the ramus compensates for the desired molar extrusion. B illustrates the strong eyelet loop placed just mesial to the tube openings to transmit the posteriorly directed forces to the entire activator. The face-bow’s U-loop bend leans against the eyelet and permits direction of the extraoral forces to the maxilla itself. C shows the Dominique clasp which holds the activator in place. It passes gingival to the mesial hook of the molar band; if fitted snugly distal to the band, it may reduce the distal driving of the molars.
Extraoral forces anchored either in the premolar in the incisor region of the activator
or
In 1978 Teuscher14 proposed a modification of our original design when he advocated anchoring the extraoral forces directly on the activator (Fig. 11). Two tubes are polymerized together with the activator, and a face-bow is inserted semipermanently into the tubes. The outer bows must be very short in order to allow the extraoral forces to pass as close as possible to the center of resistance of the maxilla. The extraoral forces are intended to redirect the vertical growth of the maxilla, eliminate the anteroinferior tipping of palatal and occlusal planes, and maintain the activator in place. We use this combination in hyperdivergent cases with open-bite tendency. In our opinion, it should not be used in hypodivergent cases where the downward growth of the maxilla will be beneficial to the correction of the deep-bite and the improvement of facial esthetics. In 1975 Bass15described an upper plate showing a looped torquing device for the upper incisors. He used this plate in conjunction with extraoral forces hooked directly to the loops of the torquing device to restrain growth of the maxilla in the anterior region. We have added this looped torquing device to all activators which need torque for the upper incisors (Fig. 12), The Class II, Division 2 cases offer an ideal indication for this device. The extraoral forces coming from a helmet are hooked by means of two swivel hooks onto the loops of the torquing device. Reverse
headgear
Dietrich,16 McNamara,” and we have suggested that more Class II cases than originally thought may illustrate a retracted or underdeveloped mandible
Fig. 11. In the hyperdivergent
cases with open-bite tendency, the extraoral forces are directly hooked onto the activator, as described by Teuscher. A shows the variable-pull helmet headgear developed by Merrifield. We have used this appliance during the last 15 years. It permits numerous force applications, depending on the position and the number of buttons used. B and C, We have changed Teuscher’s original design; we have added two Adams’ cribs and have replaced the delicate original torquing spurs by the sturdy coiled device designed by Bass. The acrylic covers the whole palate and the activation is very important, as described in Fig. 9.
alone. We therefore make extensive use of the activator and reverse headgear (Fig. 13). We prefer the mask with the occipitofrontal fixation strap which holds the appliance in place. It can be used easily in the mixed dentition on a full-size arch, 0.018 or 0.022 inch, de-
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Fig. 12. In the hypodivergent deep-bite cases growing in an anterior mandibular closing manner, vertical growth in the incisor region should be completely interrupted, while the posterior teeth are given entire freedom to continue their elongation. A, The extraoral forces used are transmitted directly to the activator by two swivel hooks. 8, The swivel hooks are anchored in the coiled loops of the torquing device, as described by Bass. C, The vertical activation in the molar area was, in this severe deep-bite case, 6 mm. beyond the rest position. Of course, this illustration shows the activator before the acrylic in the molar region had been entirely relieved, leaving just a ledge in between the upper and lower incisors.
Fig. 13. In the Class II cases calling for a protraction of the mandible and the lower arch on the lower jaw, we resort to the activator and a reverse headgear anchored on a partial fixed appliance. A shows the reverse headgear type that we use. B and C illustrate the activator used in combination with the lower fixed appliance during the mixed-dentition period. The lower rectangular arch shows two bent hooks in the canine region for the elastics coming from the reverse headgear.
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Legend: ------
Cervical Occipital
Hg.= Kloehn headgear Hg.Variable pull medium high
Reverse Hg. - Delaire Teuscher Hg.- Headgear x = displaced structure
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Fig. 14. Schematic representation of the different types of dental and skeletal Class II cases and their respective treatments. Every situation is illustrated by four superposed rectangles. The uppermost and the lowermost ones represent the basal bones; the middle ones represent the alveolar bones and dental arches. The misplaced structures are marked by an X, showing each time if the Class II is because of a dental or skeletal problem and if it is located in the upper or the lower jaw. Thus, the upper part of the figures shows mainly dental Class II and the lower part shows skeletal ones. The left row illustrates rather horizontal growers, the right one rather vertical growers. The dashed lines permit to compare each situation to the “normal” at the top of the row. For each type of Class II malocclusion, the most suitable appliance(s) is(are) indicated.
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Fig. 15. Treatment is started in the late mixed dentition around 10.5 years for girls and 11.5 years for boys. orthopedic and orthodontic phases properly, but should the first year of puberty.
pending on the bracket slot fixed on two molar and four incisor bands. Generally, the arch shows a utility design and bypasses the deciduous teeth. A reversed curve of Spee and a buccal root torque are incorporated into the heat-treated arch. This type of mechanics can, of course, be applied only if the differential diagnosis and the form of the symphysis call for it. INDICATIONS
FOR THE DIFFERENT
APPLIANCES
The indications for the different appliances as used separately, simultaneously, or successively depend on
when the growth rate is at its lowest, that is, It should include enough time to handle the ideally be finished in ifs major phases during
the differential diagnosis established according to the characteristics revealed by the records (Fig. 14). The indications for use of the activator alone during the orthopedic phase of treatment can be listed as follows: skeletal and dental Class I malocclusions with deep-bite in which the correction of the vertical problem and the skeletal morphology call for eruption or even overeruption of the buccal segment; skeletal Class I and dental Class II malocclusions in which upper teeth have to be moved posteriorly and lower teeth anteriorly, be they in deep; normal, or open-bite position;
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Fig. 16. Because
of a protracted maxilla and a retruded mandible, combined with a severe deep-bite, the treatment of this Class II case has taken 30 months (1 year of orthopedic treatment and 18 months of orthodontic treatment). The appliances used were a Kloehn headgear, an activator, and complete fixed appliances. A to C, Profile views 2 years before treatment, at the end of the orthopedic phase, and 2 years out of retention. D to F, Front views. G to I, Models, right view.
minor skeletal Class II cases, particularly those with a retracted mandible; minor skeletal Class I or Class II malocclusions, combined with muscle dysfunction, such as thumb- or lip-sucking, tongue-thrusting, or mouth breathing; space maintenance; active upper expansion in cases of cross-bite; minor tooth movement. The indications for anteroposterior extraoral forces anchored on the upper permanent$rst molars, as used alone during the orthopedic phase are treatment of moderate skeletal Class II malocclusion owing to a protracted maxilla; treatment of skeletal Class I with space shortage in the upper jaw; anchorage reinforcement during fixed mechanbtherapy. Indications for the combined approach, using both appliances, include severe skeletal Class II malocclu-
sion, combined or not with a deep-bite or open-bite, in which the maxilla is protracted; severe skeletal Class II malocclusion combined or not with a deep-bite or open-bite, with a retracted mandible (in this case, the growth of the maxilla is interrupted sagittally, vertically, or both while growth of the mandible is enhanced); severe skeletal Class II malocclusion with space shortage in the upper jaw; severe skeletal Class II malocclusion combined with muscle dysfunction; all skeletal Class II malocclusion calling at one time or another for the simultaneous or successive use of the two appliances. TREATMENT
TIMING
AND TIME
The effectiveness of the simultaneous use of both appliances, which we described in 1972,l permits us to
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Fig. 16 (Cont’d). J-L, Models, left view. M to 0, Intraoral views. P to R, Cephalometric tracings. The orthopedic appliances, activator and Kloehn headgear, have solved all major problems. The fixed appliances have corrected the remaining deep-bite and the faulty axial inclinations (tip and torque). The Class II elastics have been used over only a short period of time. The deep-bite has been corrected by molar extrusion, which favorably influenced the short lower anterior facial height. The SNA has decreased by 4.5 degrees and the SNB has increased by 0.5 degree in 8 years of observation.
ignore to a large extent the pubertal growth spurt.” We do not wait, as proposed by Bj6rk,ls for puberty to give us a maximum growth increment to start treatment. We finish all our cases with complete fixed appliances in order to achieve the best anatomic occlusion and functional articulation. Our treatment, therefore, consists of 12 to 18 months of orthopedics and 12 to 18 months of orthodontics, for a total of 24 to 36 months, and should ideally be finished at or before puberty (Fig. 15). Waiting for maximum growth velocity is inappropriate for the following reasons: It postpones the beginning of treatment to a period when the adaptability of the soft tissue is decreasing rapidly; it places the patient in an age period where he has to face many psychological problems conflicting with adequate cooperation; it complicates the therapeutic ap-
proach since most of the permanent teeth have erupted and cannot be guided into place; the space-management problem would be difficult to solve and could imply more extraction cases, particularly if dental eruption and chronologic age are ahead of skeletal age (very often, especially in boys, the second molars are fully grown and hamper any distal movement of the first molars); it may compromise long-term stability because the tissues do not get a chance to adapt themselves to the new environment. RESULTSANDSUBSEQUENTTREATMENT
At the end of the orthopedic phase of treatment with simultaneous, successive, or separate use of activator and/or extraoral forces the neuromuscular balance should be restored as well as the skeletal disharmony
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Fig. 17. The treatment of this severe Class If case, combined with a skeletal and dental open-bite, has taken 3 years but may have been started too early. Today, we would have started when the patient was 10 years of ‘age. The appliances used were an occipital headgear, an activator with an expansion screw for the maxilla only, an upper complete fixed appliance, and a lower lingual arch. A to C, Profile views, 1 year before treatment, during the orthopedic phase, and 6 months after end of retention. D to E, Front views. G to I, Models, right view.
being corrected sagittally , vertically, and transversally. Also, the dental Class II malocclusion should be corrected or overcorrected and the dental deep-bite or open-bite significantly improved. As a result, the remaining treatment with fixed appliances can be limited to the correction or overcorrection of the remaining deep-bite or open-bite, the correction of the angulation, inclination, and rotation of individual teeth, and the creation of a functional occlusion according, in our opinion, to a mutually protected occlusion with a canine guidance concept. Three years ago we changed from the standard 0.018 inch edgewise technique which we had been using for the last 15 years to the 0.022 inch straightwire setup.‘, ** 22-25
ADVANTAGES ORTHOPEDIC
OF THE PRELIMINARY PHASE
The preliminary orthopedic phase should take away the need for major tooth movement since we attempted to move the dental units with their respective bony support. Retention is performed with a positioner, preferably of the gnathologic type,24 an upper Hawley retainer, and a fixed lower canine-to-canine retainer. If there is any doubt about the space available for the correct eruption of the third molars, they are extracted. CASE
REPORTS
Figs. 16 to 18 illustrate three cases that have been treated according to the principles outlined in this article, combining orthopedic and orthodontic methods.
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Fig. 17 (Cont’d). J to L, Models,
front view. M too, Intraoral views. P to R, Cephalometric tracings. The orthopedic phase has considerably remodeled the skeletal pattern. The ANB angle has been reduced by 5 degrees within 15 months. The skeletal and dental open-bite has been closed. During the orthodontic phase, the ANB angle was further reduced, almost too much. Altogether, ANB has been reduced from 5.5 degrees to 1 degree andthe angle formed by palatal and mandibular planes from 34 degrees to 27 degrees. The SNA has decreased by 7 degrees and the SNB has increased by 0.5 degree in 5% years of observation.
CONCLUSION
In summary, we believe that this approach is attractive because it may reduce the stress imposed on the patient as well as on the orthodontist. It may also bypass the iatrogenic side effects that an extensive and prolonged use of mechanotherapy might entail. REFERENCES 1. Pfeiffer, J.-P., and Grob&y, D.: Simultaneous use of cervical appliance and activator: An orthopedic approach to fixed appliance therapy, A#. J. ORTHOD. 61: 353-373, 1972. 2. Pfeiffer, J.-P., and Grobety, D.: The Class II malocclusion: Differential diagnosis and clinical application of activators, extraoral tractions and fixed appliances, AM. J. ORTHOD. 68: 499-544, 1975.
3. Bass, N. M.: Oral communication, Orthopedic Symposium, Munich, 1980. 4. Andresen, V., Haupl, K., and Petrik, L.: Funktionskieferorthopldie, Munchen, 1957, J. A. Barth. 5. Petrovic, A. G., Stutzmann, J. J., and Oudet, C. L.: Control processes in the post-natal growth of the conylar cartilage of the mandible, Monograph No. 4, pg. lOI- 153, Craniofacial Growth and Development, McNamara, J. A., ed. The University of Michigan, Ann Arbor, 1975. 6. Petrovic, A. G.: L’ajustement occlusal: son role dans les processus physiologiques de controle de la croissance du cartilage condylien, Orthod. Fr. 48:23-76, 1977. 7. Petrovic, A. G., and Oudet , C L. : Variations in the number of sarcomeres produced by the postural hyperpropulsor, Monograph No. 8, Ann Arbor, 1978, Center of Human Growth and Development, The University of Michigan, pp. 233-245. 8. Petrovic, A. G., and Stutzmann, J.: Controle de la croissance
Volume 81 Number
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Fig. 18. This extremely severe Class II case, mainly owing to a retruded mandible and a retruded lower arch on the lower basal bone, has been treated for 3 years. First, the activator has been used alone and later combined with a reverse headgear hooked onto the lower fixed appliance. Finally, the upper fixed appliance has contributed to improvement of axial inclination of the teeth. A to C, Profile views 1 year before treatment, after the end of the orthopedic phase, and 1 year after the end of the orthodontic phase. D to F, Front views. G to I, Models, right view.
treatment
199
200
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and
Am. J. Orthod. March 1982
Grobtty
Fig. 18 (Co&d). J to L, Models, front view. M to 0, Intraoral views. P to R, Cephalometric tracings. orthopedic phase has permitted a considerable improvement in the skeletal disharmony. The angle has been reduced from 12.5 degrees to 7 degrees, mainly by a E°ree increase in the angle, which is a rare occurrence. Furthermore, the reverse headgear has pulled the entire lower anteriorly on the basal bone. There has been bone remodeling at point B which relatively reduced value of pogonion. During the orthodontic phase,‘the ANB angle was further reduced to 4 degrees. mandibular plane angle has been reduced and facial esthetics satisfactorily restored. SNA has creased by 2.5 degrees and SNB has increased by 6 degrees over the 5 years of observation.
9.
~10.
11.
12. 13.
post-natale du squelette facial, donntes experimentales et modBle cybemitique, Actual. Odontostomatol. 128: 81 l-841, 1979. McNamara, J. A.: Neuromuscular and skeletal adaptations to altered functions in the orofacial regions, AM. J. ORTHOD. 64: 578-606, 1973. McNamara, J. A., Connelly, T. G., and McBride, M. C.: Histological studies of temporomandibular joint adaptations, Mohograph No. 4, Craniofacial Growth and Development, Ann Arbor, 1975, Center for Human Growth and Development, The University of Michigan, pp. 209-277. McNamara, J. A., and Carlson, D. S.: Quantitative analysis of temporomandibular joint adaptations to protrusive function, AM. . J. ORTHOD. 76: 593-611, 1979. Harvold, E. P.: The activator in interceptive orthodontics, St. Louis, 1974, The C.V. Mosby Company. Kragt, G.: Initial deiito-ficial orthopedic reactions; a holographic study, Thesis, University of Groningen, 1981.
The ANB SNB arch the The de-
14. Teuscher, U.: A growth-related concept for skeletal Class II treatment, AM. J. ORTHOD. 74: 258-275, 1978. 15. Bass, N. M.: Innovation in skeletal Class II treatment including effective incisor root torque in a preliminary removable appliance phase, Br. J. Orthod. 3: 223-230, 1976. 16. Dietrich, U. C.: Aktivator - mandibuliire Reaktion, Schweiz. Monatsschr. Zahnheilkd. 83: 1093- 1104, 1973. 17. McNamara, J. A.: Oral communication, Orthopedic Symposium, Munich, 1980. 18. Pfeiffer, J.-P.: Should orthopedic treatment of severe Class II malocclusions be related to growth, Eur. J. Orthod. 2:249-256, 1980. 19. Bjark, A.: Timing of interceptive orthodontic measures based on stages of maturation, Trans. Eur. Orthod. Sot., pp. 61-74, 1972. 20. Andrews, L.: The keys to normal occlusion, AM. J. ORTHOD. 62: 296-309, 1972.
Volume 81 Number 3 21. Andrew%, L.: The straight-wire appliance, Syllabus of Philosophy and Technique, 1975, published by Lawrence Andrew%. 22. Roth, R. H.: Gnathological concepts and orthodontic treatment goals. In Jarabak, J. R., and Fizzel, J. A.: Technique and treatment with the light-wire appliances, ed. 2, St. Louis, 1972, The C. V.. Mosby Company. 23. Roth, R. H.: Temporomandibular pain-dysfunction and occlusal relationship, Angle Orthod. 43: 136-153, 1973. 24. Roth, R. H.: Five year clinical evaluation of the Andrews straight wire appliance, J. Clin. Orthod. 10: 836-850, 1976. 25. Roth, R. H.: Functional occlusion for the orthodontist, J. Clin. Orthod. 15: 32-51, 100-123, 174-198, 246-264, 1981.
Combined orthopedic-orthodontic
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26.
201
Herren, P.: Die Wirkungsweise des Aktivators, Schweiz: Monatsschr. Zahnheilkd. 63: 829-879, 1953. 27. Herren, P.: The activator’s mode of action, AM. J. ORTHOD. 45: 512-527, 1959. 28. Schudy, F.: The association of anatomical entities as applied to clinical orthodontics, Angle &hod. 36: 190-203, 1966. 29. Schudy, F.: The control of vertical overbite in clinical orthodontics, Angle Orthod. 38: 19-39, 1968.
32, Ave. du L&an, 1005 Lmsanne, Switzerland (J. P. PfeifSer) 58, Rue d’ltalie, 1800 Vevey, Switzerland ?D. Grob$y)
Dr.med.dent.,
D.M.D., and D. GrobBty,
Dr. Pfeiffer
Dr.med.dent.
Lausunne and Vevey,Switzerland Treatment of many Class II malocclusions should be started in the late mixed dentition with removable orthopedic appliances, such as activator and extraoral forces. These appliances are used simultaneously, successively, or separately, depending on the differential diagnosis. Once the orthopedic problem is solved, the teeth are moved to an ideal occlusion, both anatomically and functionally, by means of sophisticated fixed appliances, such as the straight wire type of mechanism.
Key words: Orthopedics,
activator, extraoral forces, headgear, reverse headgear, Class II
I
n 1972l and 1975” we published in the AMERICAN JOURNAL OF ORTHODONTICStwo articles describing our orthopedic approach to the Class II malocclusion treatment prior to fixed orthodontic mechanotherapy. Subsequently, this approach has been refined by the incorporation of selected ideas from leaders in the field in order to fulfill any clinical demand required by the differential diagnosis. TREATMENT-PHILOSOPHY, ANDSEQUENCES
OBJECTIVES,
In this discussion, we shall limit ourselves to the Class II malocclusions. In 1926, W. B. Cannon used for the first time the term homeostusis. He indicates that there is a regulating adaptation attempting to maintain a state of equilibrium between an organism and its surroundings. If, for instance, we consider the two different dental relationships (Fig. I)-one a Class II dental protrusion and the other a Class l-we see that both are in a state of equilibrium. The upper one, before treatment, is in a perverted state of equilibrium, the teeth being in equilibrium with the lip but not with the face. The lower one, after treatment, corresponds to a true physiologic neuromuscular equilibrium, the teeth being in harmony with the lips and the face. In both cases, the lower lip is the determining factor located once in front and once behind the upper incisors. Bass” said that in most cases a malocclusion is the result of a breakdown
in homeostasis
between
This article is dedicated to Dr. Ronald Roth for his outstanding functmnal occlusion. 0002.9416/82/03018S+
17$01,70/O 0
the dif-
contribution
1982 The C. V. Mosby Co
to
ferent structures, the position of the teeth being merely a symptom of the whole phenomenon. If we conduct our orthodontic treatment within the frame of the original malocclusion, teeth are simply moved in their respective alveolar bases. However, they cannot reach a true state of equilibrium since perverting forces, owing to basal bone disharmony and muscle dysfunction, are exerting their influence on them. Thus, it is important to correct the skeletal discrepancy$rst, changing bone form and position and creating a new possibly more balanced environment to which the matrix can progressively readapt. Our treatment objectives are to restore a good anatomic occlusion with healthy periodontal tissue, establish a protectingfunctional articulation, and create a well-balanced soft-tissue equilibrium leading to pleasant facial esthetics. Considering these rather demanding treatment objectives, it would seem irrational to try to move teeth prior to correction of the skeletal and soft-tissue imbalances. Therefore, we follow the sequence of remodeling bones, harmonizing muscles, and moving teeth. The documents and criteria on which our diagnosis is based are the history, clinical examination, orthodontic models, fifteen intraoral x-ray films taken with the 16-inch long-cone technique, a lateral and frontal headplate, hand and wrist x-ray films, and six photographs. The lateral head film remains our key diagnostic tool. During the last 15 years we have used successively or simultaneously the analyses of Steiner, Bjork, Jarabak, and Ricketts. Today, we use elements of all four of them. These are SNA, SNB, ANB; palatal, occlusal, and mandibular plane angles; Steiner’s acceptable arrangements for the incisors; Bjork’s poly185
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Fig. 1. A and B, Before treatment, the teeth are in equilibrium with the lip but not with the face. C and D, After treatment and out of retention, the teeth are in equilibrium with the lip and with the face.
gon; Jarabak’s facial height proportion and gonial angle halves; nasopharyngeal airway permeability (distance to the nearest adenoid tissue from a point on a parallel of the pterigoid vertical, 5 mm. above PNS); convexity of the upper jaw (distance from point A to the facial plane, used for esthetic appraisal); maxillary depth (angle formed by Frankfort plane and the plane N-A, indicates the sagittal position of maxilla, clinical norm + 90 degrees); upper first molar to Ptv; lower first molar to Xi (gives indication for lower third molars, personal adaptation of the R.M.D.S. third molar probability evaluation); anterior lower facial height (angle formed by points ANS-Xi-PO); Ricketts’ esthetic line (E plane) Sagittal and vertical mechanics in the orthopedic and orthodontic correction of a skeletal Class II malocclusion must be considered, but first let us define both terms: Dentofacial orthopedics-Treatment directed toward altering the relationship of the bony elements of the jaws and the pattern of activity of the oro-facial musculature. Dentofacial orthodontics-Treatment directed toward altering the relationship of the teeth to each other and the face.
Am. J. Orthud. Much 1982
There are several possibilities available in the sagittal plane. One (Fig. 2, A) is to procline the lower teeth and to retrude the upper ones without any orthopedic treatment or bodily tooth movement. The resulting skeletal and dental imbalance is typical of the use of unimaxillary removable appliances. Bodily orthodontic movement alone (Fig. 2, B) also has limitations, such as the cortical plates of the palate and the symphysis. Our concept of ideal treatment must therefore be complemented by orthopedics. Extraction of two dental units in the maxilla and retraction of the upper anterior segment (Fig. 2, C) may also be a compromise in the correction of a skeletal Class II malocclusion, since the cortical plate of the palate limits the amount of bodily movement and ideal inclination. The last two approaches mentioned are at times the only possibilities, other than surgery, in adult Class II treatment. In the growing child, however, we have a wider spectrum of therapeutic possibilities. In cases in which the maxilla is well situated and the lower jaw is retruded (Fig. 3,A), growth of the mandible should be enhanced. At times, even the lower teeth should be moved forward bodily if the symphysis is well developed. In the cases (perhaps fewer than thought) in which the mandible is in good relation to the cranium (Fig. 3, B), only the maxillary structures should be relocated posteriorly by orthopedic means. In cases in which the sagittal problem is complicated by a skeletal open-bite (Fig. 3,C), expression of mandibular growth can be enhanced by restraining vertical growth of the maxillary bone and teeth and thereby bringing the mandible up and forward. There are several possibilities available in the vertical plane. In a dental and skeletal deep-bite situation (Fig. 4,A), the vertical development of the molar and the premolar should be stimulated as much as possible, if needed, even through active extrusion. In dental deepbite cases with normal skeletal structures (Fig. 4, B), an adequate removable appliance will handle the situation by interrupting growth in the incisor region and promoting it in the molar/premolar region. For a dental deep-bite with skeletal open-bite (Fig. 4,C), it is advisable to maintain the vertical dimension in the molar region or even decrease it by intrusion of these teeth and resort to incisor intrusion only to correct the deepbite. Much depends on the compensating mechanisms at the ramus level (Fig. 5). If ramus length and orientation are good, the posterior teeth can be elongated without any fear, and this will open the bite very effectively. The mandibular plane angle can be opened by molar extrusion induced either by a cervical traction or
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Fig. 2. A, Moving dental arches on their bases and tipping front teeth does not eliminate the skeletal discrepancy of the Class II malocclusion and places the teeth in improper axial inclinations. B, Bodily movement of the incisors is limited by the cortical plates and therefore cannot always resolve the overjet problem because of the basal discrepancy. C, Extraction of two dental units in the upper jaw also may not permit bodily movement of upper incisors so as to compensate for the skeletal imbalance. The cortical plate of the palate limits such a movement.
Fig. 3. A, In cases in which the mandible is underdeveloped or posteriorly displaced, every effort should be made to orthopedically influence condylar growth enhancement. 8, If the maxilla is at fault, it should be relocated posteriorly by orthopedic means. C, In skeletal open-bite cases, the sagittal discrepancy can, to a certain extent, be decreased by interrupting vertical growth of the maxilla and by intruding the upper molars. The mandible can thus swing forward and close.
Fig. 4. A, In dental and skeletal deep-bite cases, the posterior teeth should have complete freedom to erupt freely, whereas alveolar growth of the front teeth is completely interrupted. To further this natural bite-opening effect (dashed line), the posterior teeth should even be actively extruded (gray line). 8, In those cases in which the deep-bite is of dental origin, a simple orthopedic appliance can correct the problem by selectively interrupting or promoting tooth eruption. C, In dental deep-bite and skeletal open-bite cases, the excessive overbite should be corrected by means of incisor intrusion only. In these cases we would even recommend interrupting simultaneously alveolar growth of the upper molars and premolars.
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GrobiQ
Fig. 5. Three drawings based on the work of Schudy and Jarabak. They are essential for the underor harmonious vertical growth. The descent of the standing of the vertical dimension. A, “Normal” palate and the alveolar growth of the upper and lower molars are compensated by quantitatively equal growth of the ramus; occlusal and mandibular planes remain parallel. B, A case in which the vertical growth at the level of the ramus, which is oversized, is much more important than in the palate and molar areas. The mandible performs an anterior closing rotation around a fulcrum situated at the molar level. In this case, the molars can and should be elongated to correct the deep-bite since the ramus overcompensates for this vertical increment in the molar region. C, The reverse situation in which the descent of the palate and alveolar growth at the molar level cannot be neutralized by growth of the ramus, which is undersized and poorly orientated. The mandible performs a posterior opening rotation whose fulcrum is situated at the condylar level. In this case, the vertical growth of the molars should be interrupted and the deep-bite corrected by incisor intrusion.
by Class II, Class III, or vertical elastics. If ramus length and angulation are unfuvoruble, all the abovementioned mechanics should be avoided and the deepbite should be corrected at the incisor level. The same considerations should be given to esthetics. In skeletal deep-bite, the lower half of the anterior facial height can be increased by molar extrusion. In skeletal open-bite, the lower half of the anterior facial height can be decreused by molar intrusion (Fig. 6). Incisor intrusion or extrusion does not in any way modify the lower anterior facial height or change esthetics. Our orthopedic therapeutic tools are the activator, anteroposterior extraoral forces anchored on bands cemented on the upper first molars, anteroposterior extraoral forces anchored on the activator, at either the premolar or incisor level, posteroanterior extraoral forces anchored on a facial mask and a palatal splitting device as described by Derrichsweiler and reintroduced by Haas. APPLIANCES The activator
Fig. 6. A, The anterior
lower facial height of this boy with an anterior-closing mandibular growth tendency should be increased for the sake of good facial esthetics; this same dimension should be decreased in the case of the girl shown in B.
The activator we use has little in common with the appliances created by Andresen4 and developed by Hiupl and Petrik. These authors have constructed moderately activated appliances, working through isotonic muscle contractions which produce intermittent forces transmitted to the teeth by small inclined planes. Our appliance (Fig. 7) produces a rnussive anterior displace-
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Fig. 7. A, The wax bite registers
the vertical and sagittal positions of the “activated” mandible. There must be an important anterior displacement of the mandible. B, C, and D show the activator with the expansion screw, the labial bow, the two Adams’ cribs, and the two long lower wings.
ment of the mandible and puts the muscles under heavy stress, which is isometric in nature. The elongated mandibular retractors are restraining maxillary growth. The mandibular protractors are contracted and are thought to induce cellular activity in the condyle through the interplay of the lateral pterygoid muscle as has been suggested by Petrovicsm8 and McNamara.g-ll The net effect on the basal bone is a moderate orthopedic correction of the sagittal skeletal discrepancy. a reduction of the Our own results (Fig. 8) suggest ANB angle of 1.74 degrees over an l&month period, mainly owing to an increase in the SNB angle and a decrease in the SNA angle. In addition to these basic orthopedic changes, the activator permits a selective influence on the eruption pattern of the teeth. It has been very clearly shown by Harvold12 how this can affect the final sagittal and vertical position of the teeth. Finally, the activator can contribute to the correction of different muscle dysfunctions, inappropriate respiration, and pernicious habits. The design and handling of the appliance vary to a great extent, depending on the differential diagnosis, but the construction bite for a Class II malocclusion is made essentially according to the same basic principles in all cases. The sagittal activation is 2 to 3 mm. short of muximum propulsion and the vertical activation should be at least 3 to 4 mm. beyond the freeway space. In deep-bite
cases there should be sufficient vertical activation to leave a 3 mm. thick wedge between the incisors (Fig. 9). The basic design shows an upper labial arch, an expansion screw, and two long lower wings. Depending on the presence of bands on the upper first molars, the retention of the appliance is secured either by Adams’ cribs, Dominique clasps, eyelets, or the extraoral forces themselves. The exact outline and shape of the appliance vary greatly, depending on the differential diagnosis in both sagittal and vertical dimension. As far as the sagittal dimension is concerned, either the lower teeth have to be moved mesially or not, and the acrylic will be shaped and ground accordingly. If the lower teeth are not to be moved anteriorly, the wings should be in close contact with the alveolar process but in no contact at all with the lingual aspect of the incisors which are, however, completely covered with acrylic on their labial aspects. If, on the other hand, the lower teeth should be moved mesially on their bases and the incisors tipped labially, the wings should not touch the alveolar process but only the lingual aspects of the incisors which are not covered with acrylic. Concerning vertical dimension, where eruption has to be interrupted the acrylic should not be relieved, and where alveolar growth has to be stimulated the teeth should be freed from all acrylic contact. If we wish to influence more substantially vertical growth of the
190
Am. J. Orrlxui March 19X2
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Fig. 8. The dashed lines represent our own treatment result superimposed on graphs of normal growth as published in Riolo et al.: At/as of Craniofacial Growth (Ann Arbor, 1974, University of Michigan). The dots found on the lines of the atlas represent the male values, the crosses represent the female values. A, The SNA angle in our sampling of twenty-seven patients appears slightly decreased by the activator treatment. 8, The SNB angle appears slightly increased from the average. C, The ANB angle is reduced 1.74 degrees over an l&month period.
maxilla, we hook the extraoral forces directly onto the activator, in either the premolar or the incisor region. This method implies an adjunction of tubes in the premolar region or of looped torquing devices in the incisor region. Extraoral forces anchored the upper first molars
on bands
cemented
on
When we originally designed the combination of activator and extraoral forces 15 years ago’, * the ex-
Fig. 9. A, The sagittal activation of the activator should be very important. Maximum: propulsion is represented by the crosshatched teeth. The correct activation is illustrated by the darkshaded teeth. In other words, the activated position goes well beyond the Class I relationship. B, The vertical &Ovation in a moderate deep-bite, 2 to 3 mm. beyond rest position. C, The vertical activation in a severe deep-bite, 4 to 5 mm. beyond rest position. As a matter of fact, we need, in both examples B and C, a ledge of 2 to 3 mm. of acrylic to interrupt vertical growth of the incisors.
traoral forces were always inserted into the molar tubes (Fig. 10). Today’ we use this approach in about 70 percent of our cases. Depending on skeletal configuration, we use the cervical traction to promote deliberate molar extrusion (as, for example, in hypodivergent growth tendencies) and the occipital traction to promote more horizontal or even vertical or intrusive forces. Whenever facial morphology permits it, we use cervical forces since they produce a relative shearing effect at the sutural level, in opposition to occipital forces which produce a relative compression of the suture. In 198 1 Kragt, I3 in an unpublished thesis, showed in his holographic study of a macerated skull that the over-all maximum displacement of the maxillofacial complex was much greater with the cervical traction than with the occipital headgear.
Volume 81 Number 3
Combined orthopedic-orthodontic
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191
Fig. 10. In 70 percent of our Class II cases, the extraoral forces are transmitted to the teeth and the maxilla by means of the two molar bands. A shows the Kloehn headgear used in all cases in which vertical growth of the ramus compensates for the desired molar extrusion. B illustrates the strong eyelet loop placed just mesial to the tube openings to transmit the posteriorly directed forces to the entire activator. The face-bow’s U-loop bend leans against the eyelet and permits direction of the extraoral forces to the maxilla itself. C shows the Dominique clasp which holds the activator in place. It passes gingival to the mesial hook of the molar band; if fitted snugly distal to the band, it may reduce the distal driving of the molars.
Extraoral forces anchored either in the premolar in the incisor region of the activator
or
In 1978 Teuscher14 proposed a modification of our original design when he advocated anchoring the extraoral forces directly on the activator (Fig. 11). Two tubes are polymerized together with the activator, and a face-bow is inserted semipermanently into the tubes. The outer bows must be very short in order to allow the extraoral forces to pass as close as possible to the center of resistance of the maxilla. The extraoral forces are intended to redirect the vertical growth of the maxilla, eliminate the anteroinferior tipping of palatal and occlusal planes, and maintain the activator in place. We use this combination in hyperdivergent cases with open-bite tendency. In our opinion, it should not be used in hypodivergent cases where the downward growth of the maxilla will be beneficial to the correction of the deep-bite and the improvement of facial esthetics. In 1975 Bass15described an upper plate showing a looped torquing device for the upper incisors. He used this plate in conjunction with extraoral forces hooked directly to the loops of the torquing device to restrain growth of the maxilla in the anterior region. We have added this looped torquing device to all activators which need torque for the upper incisors (Fig. 12), The Class II, Division 2 cases offer an ideal indication for this device. The extraoral forces coming from a helmet are hooked by means of two swivel hooks onto the loops of the torquing device. Reverse
headgear
Dietrich,16 McNamara,” and we have suggested that more Class II cases than originally thought may illustrate a retracted or underdeveloped mandible
Fig. 11. In the hyperdivergent
cases with open-bite tendency, the extraoral forces are directly hooked onto the activator, as described by Teuscher. A shows the variable-pull helmet headgear developed by Merrifield. We have used this appliance during the last 15 years. It permits numerous force applications, depending on the position and the number of buttons used. B and C, We have changed Teuscher’s original design; we have added two Adams’ cribs and have replaced the delicate original torquing spurs by the sturdy coiled device designed by Bass. The acrylic covers the whole palate and the activation is very important, as described in Fig. 9.
alone. We therefore make extensive use of the activator and reverse headgear (Fig. 13). We prefer the mask with the occipitofrontal fixation strap which holds the appliance in place. It can be used easily in the mixed dentition on a full-size arch, 0.018 or 0.022 inch, de-
192
Pfeiffer and Grobity
Fig. 12. In the hypodivergent deep-bite cases growing in an anterior mandibular closing manner, vertical growth in the incisor region should be completely interrupted, while the posterior teeth are given entire freedom to continue their elongation. A, The extraoral forces used are transmitted directly to the activator by two swivel hooks. 8, The swivel hooks are anchored in the coiled loops of the torquing device, as described by Bass. C, The vertical activation in the molar area was, in this severe deep-bite case, 6 mm. beyond the rest position. Of course, this illustration shows the activator before the acrylic in the molar region had been entirely relieved, leaving just a ledge in between the upper and lower incisors.
Fig. 13. In the Class II cases calling for a protraction of the mandible and the lower arch on the lower jaw, we resort to the activator and a reverse headgear anchored on a partial fixed appliance. A shows the reverse headgear type that we use. B and C illustrate the activator used in combination with the lower fixed appliance during the mixed-dentition period. The lower rectangular arch shows two bent hooks in the canine region for the elastics coming from the reverse headgear.
Am. J. Orrhod. March 1982
Combined orthopedic-orthodontic
Volume 81 Number 3
Legend: ------
Cervical Occipital
Hg.= Kloehn headgear Hg.Variable pull medium high
Reverse Hg. - Delaire Teuscher Hg.- Headgear x = displaced structure
mask fixed
treatment
on activator
Normal
Activator
+
(occipital
Activator
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alone
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Fig. 14. Schematic representation of the different types of dental and skeletal Class II cases and their respective treatments. Every situation is illustrated by four superposed rectangles. The uppermost and the lowermost ones represent the basal bones; the middle ones represent the alveolar bones and dental arches. The misplaced structures are marked by an X, showing each time if the Class II is because of a dental or skeletal problem and if it is located in the upper or the lower jaw. Thus, the upper part of the figures shows mainly dental Class II and the lower part shows skeletal ones. The left row illustrates rather horizontal growers, the right one rather vertical growers. The dashed lines permit to compare each situation to the “normal” at the top of the row. For each type of Class II malocclusion, the most suitable appliance(s) is(are) indicated.
193
194
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Am. .I. Orrhod. March 1982
Fig. 15. Treatment is started in the late mixed dentition around 10.5 years for girls and 11.5 years for boys. orthopedic and orthodontic phases properly, but should the first year of puberty.
pending on the bracket slot fixed on two molar and four incisor bands. Generally, the arch shows a utility design and bypasses the deciduous teeth. A reversed curve of Spee and a buccal root torque are incorporated into the heat-treated arch. This type of mechanics can, of course, be applied only if the differential diagnosis and the form of the symphysis call for it. INDICATIONS
FOR THE DIFFERENT
APPLIANCES
The indications for the different appliances as used separately, simultaneously, or successively depend on
when the growth rate is at its lowest, that is, It should include enough time to handle the ideally be finished in ifs major phases during
the differential diagnosis established according to the characteristics revealed by the records (Fig. 14). The indications for use of the activator alone during the orthopedic phase of treatment can be listed as follows: skeletal and dental Class I malocclusions with deep-bite in which the correction of the vertical problem and the skeletal morphology call for eruption or even overeruption of the buccal segment; skeletal Class I and dental Class II malocclusions in which upper teeth have to be moved posteriorly and lower teeth anteriorly, be they in deep; normal, or open-bite position;
Volume 8 I Number 3
Combined orthopedic-orthodontic treatment 195
Fig. 16. Because
of a protracted maxilla and a retruded mandible, combined with a severe deep-bite, the treatment of this Class II case has taken 30 months (1 year of orthopedic treatment and 18 months of orthodontic treatment). The appliances used were a Kloehn headgear, an activator, and complete fixed appliances. A to C, Profile views 2 years before treatment, at the end of the orthopedic phase, and 2 years out of retention. D to F, Front views. G to I, Models, right view.
minor skeletal Class II cases, particularly those with a retracted mandible; minor skeletal Class I or Class II malocclusions, combined with muscle dysfunction, such as thumb- or lip-sucking, tongue-thrusting, or mouth breathing; space maintenance; active upper expansion in cases of cross-bite; minor tooth movement. The indications for anteroposterior extraoral forces anchored on the upper permanent$rst molars, as used alone during the orthopedic phase are treatment of moderate skeletal Class II malocclusion owing to a protracted maxilla; treatment of skeletal Class I with space shortage in the upper jaw; anchorage reinforcement during fixed mechanbtherapy. Indications for the combined approach, using both appliances, include severe skeletal Class II malocclu-
sion, combined or not with a deep-bite or open-bite, in which the maxilla is protracted; severe skeletal Class II malocclusion combined or not with a deep-bite or open-bite, with a retracted mandible (in this case, the growth of the maxilla is interrupted sagittally, vertically, or both while growth of the mandible is enhanced); severe skeletal Class II malocclusion with space shortage in the upper jaw; severe skeletal Class II malocclusion combined with muscle dysfunction; all skeletal Class II malocclusion calling at one time or another for the simultaneous or successive use of the two appliances. TREATMENT
TIMING
AND TIME
The effectiveness of the simultaneous use of both appliances, which we described in 1972,l permits us to
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Fig. 16 (Cont’d). J-L, Models, left view. M to 0, Intraoral views. P to R, Cephalometric tracings. The orthopedic appliances, activator and Kloehn headgear, have solved all major problems. The fixed appliances have corrected the remaining deep-bite and the faulty axial inclinations (tip and torque). The Class II elastics have been used over only a short period of time. The deep-bite has been corrected by molar extrusion, which favorably influenced the short lower anterior facial height. The SNA has decreased by 4.5 degrees and the SNB has increased by 0.5 degree in 8 years of observation.
ignore to a large extent the pubertal growth spurt.” We do not wait, as proposed by Bj6rk,ls for puberty to give us a maximum growth increment to start treatment. We finish all our cases with complete fixed appliances in order to achieve the best anatomic occlusion and functional articulation. Our treatment, therefore, consists of 12 to 18 months of orthopedics and 12 to 18 months of orthodontics, for a total of 24 to 36 months, and should ideally be finished at or before puberty (Fig. 15). Waiting for maximum growth velocity is inappropriate for the following reasons: It postpones the beginning of treatment to a period when the adaptability of the soft tissue is decreasing rapidly; it places the patient in an age period where he has to face many psychological problems conflicting with adequate cooperation; it complicates the therapeutic ap-
proach since most of the permanent teeth have erupted and cannot be guided into place; the space-management problem would be difficult to solve and could imply more extraction cases, particularly if dental eruption and chronologic age are ahead of skeletal age (very often, especially in boys, the second molars are fully grown and hamper any distal movement of the first molars); it may compromise long-term stability because the tissues do not get a chance to adapt themselves to the new environment. RESULTSANDSUBSEQUENTTREATMENT
At the end of the orthopedic phase of treatment with simultaneous, successive, or separate use of activator and/or extraoral forces the neuromuscular balance should be restored as well as the skeletal disharmony
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Fig. 17. The treatment of this severe Class If case, combined with a skeletal and dental open-bite, has taken 3 years but may have been started too early. Today, we would have started when the patient was 10 years of ‘age. The appliances used were an occipital headgear, an activator with an expansion screw for the maxilla only, an upper complete fixed appliance, and a lower lingual arch. A to C, Profile views, 1 year before treatment, during the orthopedic phase, and 6 months after end of retention. D to E, Front views. G to I, Models, right view.
being corrected sagittally , vertically, and transversally. Also, the dental Class II malocclusion should be corrected or overcorrected and the dental deep-bite or open-bite significantly improved. As a result, the remaining treatment with fixed appliances can be limited to the correction or overcorrection of the remaining deep-bite or open-bite, the correction of the angulation, inclination, and rotation of individual teeth, and the creation of a functional occlusion according, in our opinion, to a mutually protected occlusion with a canine guidance concept. Three years ago we changed from the standard 0.018 inch edgewise technique which we had been using for the last 15 years to the 0.022 inch straightwire setup.‘, ** 22-25
ADVANTAGES ORTHOPEDIC
OF THE PRELIMINARY PHASE
The preliminary orthopedic phase should take away the need for major tooth movement since we attempted to move the dental units with their respective bony support. Retention is performed with a positioner, preferably of the gnathologic type,24 an upper Hawley retainer, and a fixed lower canine-to-canine retainer. If there is any doubt about the space available for the correct eruption of the third molars, they are extracted. CASE
REPORTS
Figs. 16 to 18 illustrate three cases that have been treated according to the principles outlined in this article, combining orthopedic and orthodontic methods.
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Fig. 17 (Cont’d). J to L, Models,
front view. M too, Intraoral views. P to R, Cephalometric tracings. The orthopedic phase has considerably remodeled the skeletal pattern. The ANB angle has been reduced by 5 degrees within 15 months. The skeletal and dental open-bite has been closed. During the orthodontic phase, the ANB angle was further reduced, almost too much. Altogether, ANB has been reduced from 5.5 degrees to 1 degree andthe angle formed by palatal and mandibular planes from 34 degrees to 27 degrees. The SNA has decreased by 7 degrees and the SNB has increased by 0.5 degree in 5% years of observation.
CONCLUSION
In summary, we believe that this approach is attractive because it may reduce the stress imposed on the patient as well as on the orthodontist. It may also bypass the iatrogenic side effects that an extensive and prolonged use of mechanotherapy might entail. REFERENCES 1. Pfeiffer, J.-P., and Grob&y, D.: Simultaneous use of cervical appliance and activator: An orthopedic approach to fixed appliance therapy, A#. J. ORTHOD. 61: 353-373, 1972. 2. Pfeiffer, J.-P., and Grobety, D.: The Class II malocclusion: Differential diagnosis and clinical application of activators, extraoral tractions and fixed appliances, AM. J. ORTHOD. 68: 499-544, 1975.
3. Bass, N. M.: Oral communication, Orthopedic Symposium, Munich, 1980. 4. Andresen, V., Haupl, K., and Petrik, L.: Funktionskieferorthopldie, Munchen, 1957, J. A. Barth. 5. Petrovic, A. G., Stutzmann, J. J., and Oudet, C. L.: Control processes in the post-natal growth of the conylar cartilage of the mandible, Monograph No. 4, pg. lOI- 153, Craniofacial Growth and Development, McNamara, J. A., ed. The University of Michigan, Ann Arbor, 1975. 6. Petrovic, A. G.: L’ajustement occlusal: son role dans les processus physiologiques de controle de la croissance du cartilage condylien, Orthod. Fr. 48:23-76, 1977. 7. Petrovic, A. G., and Oudet , C L. : Variations in the number of sarcomeres produced by the postural hyperpropulsor, Monograph No. 8, Ann Arbor, 1978, Center of Human Growth and Development, The University of Michigan, pp. 233-245. 8. Petrovic, A. G., and Stutzmann, J.: Controle de la croissance
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Fig. 18. This extremely severe Class II case, mainly owing to a retruded mandible and a retruded lower arch on the lower basal bone, has been treated for 3 years. First, the activator has been used alone and later combined with a reverse headgear hooked onto the lower fixed appliance. Finally, the upper fixed appliance has contributed to improvement of axial inclination of the teeth. A to C, Profile views 1 year before treatment, after the end of the orthopedic phase, and 1 year after the end of the orthodontic phase. D to F, Front views. G to I, Models, right view.
treatment
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Fig. 18 (Co&d). J to L, Models, front view. M to 0, Intraoral views. P to R, Cephalometric tracings. orthopedic phase has permitted a considerable improvement in the skeletal disharmony. The angle has been reduced from 12.5 degrees to 7 degrees, mainly by a E°ree increase in the angle, which is a rare occurrence. Furthermore, the reverse headgear has pulled the entire lower anteriorly on the basal bone. There has been bone remodeling at point B which relatively reduced value of pogonion. During the orthodontic phase,‘the ANB angle was further reduced to 4 degrees. mandibular plane angle has been reduced and facial esthetics satisfactorily restored. SNA has creased by 2.5 degrees and SNB has increased by 6 degrees over the 5 years of observation.
9.
~10.
11.
12. 13.
post-natale du squelette facial, donntes experimentales et modBle cybemitique, Actual. Odontostomatol. 128: 81 l-841, 1979. McNamara, J. A.: Neuromuscular and skeletal adaptations to altered functions in the orofacial regions, AM. J. ORTHOD. 64: 578-606, 1973. McNamara, J. A., Connelly, T. G., and McBride, M. C.: Histological studies of temporomandibular joint adaptations, Mohograph No. 4, Craniofacial Growth and Development, Ann Arbor, 1975, Center for Human Growth and Development, The University of Michigan, pp. 209-277. McNamara, J. A., and Carlson, D. S.: Quantitative analysis of temporomandibular joint adaptations to protrusive function, AM. . J. ORTHOD. 76: 593-611, 1979. Harvold, E. P.: The activator in interceptive orthodontics, St. Louis, 1974, The C.V. Mosby Company. Kragt, G.: Initial deiito-ficial orthopedic reactions; a holographic study, Thesis, University of Groningen, 1981.
The ANB SNB arch the The de-
14. Teuscher, U.: A growth-related concept for skeletal Class II treatment, AM. J. ORTHOD. 74: 258-275, 1978. 15. Bass, N. M.: Innovation in skeletal Class II treatment including effective incisor root torque in a preliminary removable appliance phase, Br. J. Orthod. 3: 223-230, 1976. 16. Dietrich, U. C.: Aktivator - mandibuliire Reaktion, Schweiz. Monatsschr. Zahnheilkd. 83: 1093- 1104, 1973. 17. McNamara, J. A.: Oral communication, Orthopedic Symposium, Munich, 1980. 18. Pfeiffer, J.-P.: Should orthopedic treatment of severe Class II malocclusions be related to growth, Eur. J. Orthod. 2:249-256, 1980. 19. Bjark, A.: Timing of interceptive orthodontic measures based on stages of maturation, Trans. Eur. Orthod. Sot., pp. 61-74, 1972. 20. Andrews, L.: The keys to normal occlusion, AM. J. ORTHOD. 62: 296-309, 1972.
Volume 81 Number 3 21. Andrew%, L.: The straight-wire appliance, Syllabus of Philosophy and Technique, 1975, published by Lawrence Andrew%. 22. Roth, R. H.: Gnathological concepts and orthodontic treatment goals. In Jarabak, J. R., and Fizzel, J. A.: Technique and treatment with the light-wire appliances, ed. 2, St. Louis, 1972, The C. V.. Mosby Company. 23. Roth, R. H.: Temporomandibular pain-dysfunction and occlusal relationship, Angle Orthod. 43: 136-153, 1973. 24. Roth, R. H.: Five year clinical evaluation of the Andrews straight wire appliance, J. Clin. Orthod. 10: 836-850, 1976. 25. Roth, R. H.: Functional occlusion for the orthodontist, J. Clin. Orthod. 15: 32-51, 100-123, 174-198, 246-264, 1981.
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26.
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Herren, P.: Die Wirkungsweise des Aktivators, Schweiz: Monatsschr. Zahnheilkd. 63: 829-879, 1953. 27. Herren, P.: The activator’s mode of action, AM. J. ORTHOD. 45: 512-527, 1959. 28. Schudy, F.: The association of anatomical entities as applied to clinical orthodontics, Angle &hod. 36: 190-203, 1966. 29. Schudy, F.: The control of vertical overbite in clinical orthodontics, Angle Orthod. 38: 19-39, 1968.
32, Ave. du L&an, 1005 Lmsanne, Switzerland (J. P. PfeifSer) 58, Rue d’ltalie, 1800 Vevey, Switzerland ?D. Grob$y)