Surgically assisted rapid maxillary expansion by opening the midpalatal suture.

The results of surgically assisted rapid maxillary expansion by opening of the midpalatal suture in 25 patients are reported. Osteotomy of the lateral wall of the maxilla combined with pterygomaxillary dysjunction and midpalatal suture separation allowed for successful rapid maxillary expansion in 23 patients. The two patients who did not respond to treatment were found to have unusually thick midpalatal sutures, which were successfully expanded after the midpalatal sutures were osteotomized.