Seven children with facial asymmetry, mean age 12 years (range 11-14.5) were treated by intraoral distraction osteogenesis to lengthen the hypoplastic ramus. We achieved a mean increase in length of the ramus of 13mm (range 10-16). In only one patient did we achieve a posterior open bite on the distraction side. All patients ended with a symmetrical chin. It was helpful to place an orthodontic bite block on the opposite side either preoperatively or postoperatively to cant the plane of occlusion. The duration of follow-up was too short to allow conclusions to be drawn about the future requirement for bimaxillary osteotomies.