Dentofacial changes in Taiwanese children with Angle Class II division 1 malocclusion using headgear and bionator

Abstract

We investigated the dentofacial cephalometric changes of treatment with the headgear and bionator appliance on children with Class II division 1 malocclusion and mandibular retrusion. standardized lateral cephalograms were taken on 70 growing children before and after treatment. The control sample was obtained from the files of the Department of Orthodontics, Osaka Dental University. We compared the results with the data of a study on normal occlusion and evaluated the effectiveness of the appliances by comparing the experimental subjects before and after treatment with normal subjects during growth.
The results showed that there was little change in the SNB angle in the experimental group compared with the controls. However, the headgear and bionator treatment produced a significant decrease in the SNa angle, aNB angle, and the angle of convexity, as well as a significant increase in the a-B plane angle, and the length of the mandible. Changes in the lingual inclination of the maxillary and the mandibular incisors were also observed.
These results seem to indicate that the correction of a Class II division 1 malocclusion with the headgear and bionator appliance is achieved not only by a combination of maxillary and mandibular skeletal effects, but also by significant dental changes.