Class II correction in patients treated with Class II elastics and with fixed functional appliances: A comparative study

The aim of the present study was to evaluate quantitatively the skeletal an d dental changes contributing to Class II corrections in subjects treated w ith Class II elastics (Begg technique) compared with subjects treated with fixed functional appliances (Herbst appliance). Thirty-six male patients wi th Class II, Division 1 malocclusions whose treatment had not included extr action were investigated. Eighteen were treated with the Begg technique, an d eighteen were treated with Herbst appliance for an average period of 1.3 and 0.5 years, respectively. Lateral radiographs in habitual occlusion were taken at the start of treatment and 12 months afterwards. In the Begg grou p, the maxilla moved forward 1 mm more than in the Herbst group, and the ma ndible moved 1 mm more in the Herbst group than in the Begg group. The skel etal improvement in the Herbst group exceeded the changes in the Begg group by, on average, 2.0 mm (P < .01). The overjet reduction in the Begg group was larger (2.1 mm; P < .01) than in the Herbst group, mostly because of de ntal movements. The skeletal part of the overjet reduction was 4% in the Be gg group compared with 51% in the Herbst group. The molar correction was si milar in both groups, but in the Begg group, the skeletal improvement was 1 0%, compared with 66% in the Herbst group. The overbite correction and the increase in the anterior lower facial height and in the NSL/ML angle were l arger in the Begg group (P < .05). The conclusions of this study were that the changes contributing to the Class II corrections in Begg and Herbst the rapy were skeletal and dental. The skeletal changes were, however, larger i n the Herbst-treated group. On the other hand, favorable and unfavorable ve rtical changes were more pronounced in the group treated with Class II elas tics.