Arch expansion: an integral part of surgical orthodontics

Two cases of mandibular prognathism have been presented. In both cases expansion of the dental arches was performed prior to surgery for the achievement of good and stable interarch relationships postoperatively. In the first case maxillary arch was expanded with a rapid-expansion technique; in the second, expansion of the mandibular arch was performed with a modified removable Coffine appliance. Results at 15 months and 2 years after retention showed the expansion to be stable.