RESUMO
This study evaluated the changes in the skeletal profile of Class II subjects submitted to orthodontic treatment. The experimental group comprised the lateral cephalograms of 30 Brazilian subjects (17 female and 13 male subjects) obtained between the mean ages of 11.1 years (initial) and 15.1 years (final) and treated with cervical headgear and edgewise appliance. The control group comprised the lateral cephalograms of 30 Canadian individuals (13 females and 17 male individuals) at the ages of 6, 9, 12, 14, and 16 years from the Burlington Growth Study University of Toronto, Canada, who did not receive any kind of orthodontic treatment. The results demonstrated a reduction in the convexity of the skeletal profile of both groups. However, this change was only significant for the Canadian sample of 6- to 9-year olds (P < .01), whereas reduction was greater for the Brazilian group and was significant between the initial and final ages (P < .01). In the Canadian control group, the maxilla presented a tendency toward a forward displacement (P < .01), which was not observed in the experimental group (P < .01). The mandible presented a forward displacement in both groups; yet, only the Canadian group demonstrated a significant difference, which occurred between 9 and 16 years (P < or = .01).