Orthopaedic correction of skeletal class II adult patients

Abstract

AIM: To determine the skeletal, dental and soft tissue profi le changes and the mechanism of Class II correction in a sample of mature individuals treated with the Herbst appliance. SUBJECTS AND METHOD: A prospective study of 15 consecutive (4 males, 11 females) mature individuals treated with the Herbst appliance followed by multibracket appliance therapy was conducted. All subjects had a hand-wrist stage of R-IJ or R-J. Their mean pre-treatment age was 22 years (16.6-39.3 years). A stepwise advancement protocol was used. Lateral cephalograms from before treatment and at the end of multibracket appliance therapy were examined using standard angular cephalometrics and the linear SO analysis of Pancherz. RESULTS: All patients were treated to an ideal Class I occlusion with normal overjet and overbite. The angular mandibular variables, SNB and SNPg, increased by 1.1 and 0.84 degrees, respectively. ANB reduction was 1.29 degrees. Soft tissue profi le convexity, excluding the nose, reduced by 2.90 degrees, while profi le convexity, including the nose, reduced by 1.43 degrees. The hard tissue convexity variable, NAPg, increased by 3.21 degrees. The correction of a Class II malocclusion involved skeletal and dental changes. Twenty-two per cent of the overjet correction was skeletal and 78 per cent dental. Twenty-six per cent of the molar relationship correction was skeletal and 74 per cent dental. CONCLUSION: The Herbst appliance is an effective method for correcting a skeletal Class II malocclusion in mature non-growing individuals. It provides a non-surgical modality of treatment that avoids the deleterious effects of camoufl age therapy by directly addressing mandibular retrognathism and improving facial convexity.