Two patients with telescopic bites due to narrow mandibular arches were treated by mandibular widening and mandibular lengthening with intraoral distraction osteogenesis. Both patients underwent distraction osteogenesis surgery successfully, without any complications. The amount of widening in the 2 cases was 6 mm and 5 mm, and the intercanine distance increased by 2.1 mm and 4.9 mm, respectively. Nonextraction orthodontic treatment was performed after removal of the distraction devices in both cases. The postsurgical orthodontic treatment periods of the 2 cases were 13 months and 7 months, respectively. Eventually, functional occlusions and good profiles were obtained in both cases. Although both patients complained of temporomandibular joint symptoms at the first consultation, those symptoms were improved after treatment. At 3 years after debonding, dentofacial relapse was negligible. In conclusion, mandibular widening by intraoral distraction osteogenesis appeared to be an effective modality for correcting telescopic bites. World J Orthod 2007; 8:221–231.