Non-surgically assisted rapid maxillary expansion in adults.

This study was designed to investigate the effect of nonsurgical rapid maxillary expansion in adult patients diagnosed as having real or relative transverse maxillary deficiency. Thirty-eight patients were consecutively treated with a fixed rapid maxillary expansion appliance of the Haas design. Successful expansion, as judged by clinical evidence of the creation of a diastema at the central incisors, was possible in 81.5% of the patients. Morbidity ranged from mild discomfort to significant pain, edema, and palatal lesions, which, in most instances, did not compromise the expansion. Only moderate maxillary expansion was possible in most patients, but enough was obtained to facilitate the achievement of satisfactory final interocclusal relations.