During orthodontic treatment of 29 patients with a Class II malocclusion, the remaining overjet was corrected surgically by intraoral mandibular distraction osteogenesis. The patients were divided in two groups. Group A was treated orthodontically in a two-phase approach, using functional and fixed appliances. Group B was treated in a one-phase approach with only fixed appliances. Before treatment the differences in age, gender and severity of the malocclusion between the groups, were not statistically significant. After distraction-osteogenesis, all orthodontic treatments could be finished successfully. The mean treatment time was for group A 44.2 and for group B 28.6 months. The difference was statistically significant (p < 0,001). The mean orthodontic treatment time after distraction osteogenesis was 9.1 months. The mean cost for the orthodontic treatment was not statistically significant different between the groups.