Molar distalization with the acrylic cervical occipital appliance

Department o f Orthodontics, Boston University Goldman School of Dental Medicine, Boston, MA, USA
Seminars in Orthodontics 01/2000; DOI: 10.1053/od.2000.5896

ABSTRACT Symmetric or asymmetric molar distalization is readily accomplished using a removable appliance, the acrylic cervical occipital (ACCO) appliance. Movement occurs at the rate of approximately 1 mm per month with considerable individual variation. Molar movement is primarily tipping, requiring some overcorrection to allow for subsequent uprighting.

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    ABSTRACT: The aim of this study was to compare the effects of 2 distalization systems supported by intraosseous screws for maxillary molar distalization. Forty subjects with skeletal Class I dental Class II malocclusion were divided into group 1 (8 girls, 12 boys) and group 2 (11 girls, 9 boys). An anchorage unit was prepared by placing an intraosseous screw in the premaxillary area of each subject. To increase the anchorage in group 2, we used an acrylic plate resembling the Nance button around the screw. The screws were placed and immediately loaded to distalize the maxillary first molars or second molars when they were present. Skeletal and dental changes were measured on cephalograms, and dental casts were obtained before and after distalization. The average distalization times were 4.6 months for group 1 and 5.4 months for group 2. On the cephalograms, the maxillary first molars were tipped 9.05 degrees in group 1 and 0.75 degrees in group 2. The mean distal movements were 3.95 mm in group 1 and 3.88 mm in group 2. On the dental casts, the mean distalization amounts were 4.85 mm for group 1 and 3.70 mm for group 2. In group 1, the maxillary molars were rotated distopalatally to a moderate degree, but this was not significant in group 2. Mild protrusion of the maxillary central incisors was also recorded for group 1 but not for group 2. However, there were no changes in overjet, overbite, and mandibular plane angle measurements for either group. Immediately loaded intraosseous screw-supported anchorage units were successful for molar distalization in both groups. In group 2, side effects such as molar tipping and rotation were smaller, but distalization times were longer and hygiene was poorer.
    American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 03/2007; 131(2):161.e1-8. · 1.33 Impact Factor
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    ABSTRACT: The aim of this study was to present a temporary anchorage device with intraosseous screw for unilateral molar distalization to make a space for the impacted premolar and to found well balanced occlusion in a case. A 13-year-old male who have an impacted premolar is presented with skeletal Class I and dental Class 2 relationship. The screw was placed and immediately loaded to distalize the left upper first and second molar. The average distalization time to achieve an overcorrected Class I molar relationship was 3.6 months. There was no change in overjet, overbite, or mandibular plane angle measurements. Mild protrusion (0.5 mm) of the upper left central incisor was also recorded. Immediately loaded intraosseous screw-supported anchorage unit was successful in achieving sufficient unilateral molar distalization without anchorage loss. This treatment procedure was an alternative treatment to the extraction therapy.
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    Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie 06/2003; 64(3):201-13. · 0.69 Impact Factor