American Journal of ORTHODONTICS and DENTOFACIAL ORTHOPEDICS Volume 10l Number 2
Founded in 1915
Copyright © 1992 by the American Association of Orthodontists
Clinical application of the ACCO appliance. Part I David W. Warren, DDS Miami, Fl.
Difficult Class II, Division 1 malocclusions can be successfully treated with a combination of fixed and removable appliances. The clinical application of the Margolis ACCO appliance is demonstrated in a variety of malocclusions through the use of before-treatment progress, and posttreatment records. (AMJ ORTHOD DENTOFACORTHOP 1992;101:101-11 .)
I n the treatment of Class II, Division 1 malocclusions, it is often desirable to proceed without the extraction of teeth, and this can be done without sac814124623
rificing esthetics, stability, and function. The mechanisms used here are a combination of fixed and removable appliances to correct arch relationship and overbite, to gain space, and to align individual teeth. Since most Class II malocclusions are characterized
Fig. 1. Pretreatment facial photographs. 101
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Fig. 2. Initial intraoral views.
Fig. 3. Pretreatment cephalometdc tracing.
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Fig. 4. Progress vmw, ACCO phase.
Fig. 5. Posttreatment facial photographs.
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Fig. 6. Posttreatment intraoral photographs.
by a mesial rotation of the maxillary first permanent molars, a transpalatal arch is used initially to accomplish distobuccal rotation of these teeth around the large palatal roots. This phase of treatment gains approximately 2 mm of correction of molar relationship. After rotation and limited expansion of the first permanent molars, the transpalatal arch is discontinued, to be followed by a removable appliance. The removable appliance is the Margolis ACCO (an acronym for acrylic-cervical-occipital) defining a combination of a modified Hawley appliance reinforced with straight-pull headgear. The ACCO appliance aids in the correction of arch relationship and severe overjet, as well as in the removal of occlusal interferences that may be responsible for mandibular deflection. It has the following components, as shown in case 1 (Fig. 4). 1. Retainer portion A. Palatal acrylic B. Anterior bite plane C. Labial bow
D. Finger springs E. Clasps 2. Headgear portion A. Cervical-occipital headgear B. Cervical headgear The palatal acrylic aids retention and serves as the framework of the appliance to which the other components of the retainer are attached. The labial bow contacts the maxillary incisors, is covered with a ribbon of acrylic, and has loops incorporated into the wire between the central and lateral incisors. The labial bow serves to provide (1) a source of retention and (2) a place for the cervical-occipital headgear to be attached. The finger springs are made of 0.018 or 0.020-inch wire, and their function is to move maxillary posterior teeth distally. The springs can be placed wherever distal movement is needed, and they accomplish a gentle tipping action. To minimize the anterior component of force, it is recommended that activation be applied unilaterally. Clasps can be attached to the premolars to
C Fig. 7. Posttreatment cephalometric superimposition.
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Fig. 8. Pretreatment intraoral photographs.
Fig. 9. Initial intraoral views.
Fig. 10. Pretreatment cephalometric tracing.
provide additional anchorage when the appliance is initially placed. As soon as the patient accepts the appliance, these clasps should be removed to permit free movement of the premolars. The cervical-occipital headgear is attached to the labial bow of the retainer through the loops located between the maxillary central incisors and lateral incisors. The headgear is attached so that the hooks are placed in a downward direction. The cervical-occipital headgear serves to counteract the anterior component of force to the maxillary anterior teeth caused by the finger springs against the posterior teeth. A cervical headgear may be attached to the maxillary first molars to assist the action of the ACCO. If the treatment plan is to use both cervical and occipital headgear, as is usually done in severe Class II, Division 1 cases (not subdivision cases), the patient begins with a cervical headgear worn 14 to 16 hours per day and the acrylic portion of the ACCO. In 2 to 4 months, the
cervical-occipital headgear is added, to be worn at night during sleep. When the maxillary molars and premolars are in a Class I or a super Class I relationship, it is proper to discontinue the ACCO appliance. At this time, a fullbanded-bonded orthodontic appliance is placed with the appropriate arch wires. Routine orthodontic treatment is continued for detailed tooth movement. In the mandibular arch, the arch wire is tied back, and Class III elastics can be used with the headgear to prevent forward movement of the mandibular incisors (Fig. 12). Case 1
An l 1½-year-old boy was referred for treatment of a Class II, Division 1 malocclusion. The patient's chief complaint was "overbite--show gums when I smile." The patient had a symmetrical anterior facial appearance. There was a full profile with a mentatis muscle strain, and
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Fig. 11. Progress intraoral photographs, ACCO phase.
the lower lip cushioned the lingual aspect of the maxillary incisors during function (Fig. 1). Intraoral views show the nature of the malocclusions (Fig. 2). The cephalogram revealed a Class II malocclusion, with the maxillary and mandibular incisors well related to the NA and NB lines. The skeletal pattern was good (Fig. 3). The casts showed a severe Class 1I, Division 1 malocclusion with severe overbite, severe overjet, and a large max-
illary diastema. The molars and canines were in full Class 1I relationship. The periodontium and temporomandibular joints were healthy, and the Bolton analysis was within normal limits. The treatment plan called for no tooth extraction since the patient was entering his growth spurt and had a good mandibular dental arch. The nonextraction treatment plan had two continuous
Fig. 12. Progress intraoral photographs, full-banded phase.
I Fig. 13. Posttreatment facial photographs.
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Fig. 14. Posttreatment facial photographs. phases of treatment, an ACCO phase and a full-banded phase (Fig. 4). Treatment time for this case was 23 months. The patient achieved good facial balance and an attractive smile (Figs. 5 and 6). The occlusion was Class I, and the cephalometric analysis revealed the maxilla and the mandible were coordinated (Figs. 5 to 7).
Case 2 A 13V2-year-old boy was referred for treatment of a Class II, Division 1 malocclusion. The patient's chief complaint was "my teeth don't look good." The patient's face was symmetrical from the frontal view. The profile was full (Fig. 8). The casts showed a Class II, Division 1 malocclusion with severe overbite, moderate overjet, absence of the maxillary right central incisor, and mild mandibular crowding. The molars and canines were in a Class II relationship. The patient had gingival inflammation. The temporomandibular joints were healthy, and the Bolton analysis was within normal limits (Fig. 9). The cephatogram revealed a Class II malocclusion with maxillary and mandibular incisors upright in relation to NA and NB lines. The skeletal pattern was good (Fig. 10). The treatment plan called for no tooth extraction since continued growth was likely and the patient had a good mandibular dental arch.
The nonextraction treatment plan used three continuous phases of treatment, an initial maxillary anterior alignment phase, an ACCO phase, and a full-banded phase (Figs. I! and 12). Treatment time for this case was 30 months. The patient achieved good facial balance and an attractive smile. The occlusion was Class I, and space had been created for the proper replacement of the maxillary right central incisor. The cephalometric analysis indicated the maxilla and the mandible were well coordinated (Figs. 13 to 15).
CONCLUSION The A C C O appliance provides the orthodontist with the advantage of b e i n g able to treat a severe Class II, Division 1 malocclusion with an effective combination o f fixed and r e m o v a b l e appliances. Treatment of a representative group o f Class II, Division 1 malocclusions was presented to illustrate the appliances previously described.
REFERENCES 1. Bernstein L. The ACCO appliance. J Clin Orthod 1969;3:461-8. 2. Bemstein L. Treatment of Class II, Division 1 maximum anchorage cases with the ACCO appliance..I Clin Orthod 1970; 4:374-83. 3. Blafer J. Troubleshooting the ACCO. J Clin Orthod 1970;4:44061.
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Fig. 15. Cephalometric tracing superimposition, before, and after treatment.
4. Cetlin NM, Tenhoeve A. Nonextraction treatment. J Clin Orthod 1983;17:396-413. 5. Jacobson A, Caulfield PW. Introduction to radiographic cephalometry. Philadelphia: Lea & Febiger, 1985. 6. Merrifield L, Cross J. Directional forces. AM J OkTHOD DENTOrAC OR~IOP 1970;57:435-64.
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