LAUSR

Abstract Aim This retrospective study was undertaken to assess the rotational effects of the Herbst appliance and fixed appliances in the treatment of Class II Division 1 subjects with different vertical facial patterns. Method Pretreatment, post-Herbst, and post-fixed appliance lateral cephalograms from 115 growing Class II Division 1 subjects were divided into three groups based on differences in the mandibular plane angle. Changes in dental and skeletal measurements were assessed within these vertical groups and in relation to pretreatment overbite, overjet, and stage of cervical maturity. Results During the overall treatment period, there were changes as expected in upper and lower incisor angulations, reductions in the incisal overjet, and increases in total mandibular length in all groups. A real increase in horizontal chin projection was, however, seen only in mesofacial and brachyfacial subjects. In general, rotational facial changes during treatment were minimal, so that dolichofacial patterns remained long and brachyfacial patterns remained short. Conclusion The results support previous reports that combined Herbst and fixed appliance treatment is likely to be associated with considerable Class II dental correction in many cases. Although there is likely to be a wide range of individual response to the use of the Herbst appliance, it is unlikely that such overall treatment will be associated with clinically significant forward mandibular rotation in dolichofacial subjects.