Treatment of a severe arch-length deficiency with anteroposterior and transverse expansion: long-term stability.

This article describes the nonextraction treatment of a girl in the late mixed dentition with a severe arch-length deficiency. Rapid maxillary expansion and molar distalization were combined with a lip bumper in the mandible, followed by fixed appliances. Although the literature has reported a high rate of relapse with this method of treatment, excellent stability was achieved at 5 years 3 months posttreatment. The merits of extraction vs nonextraction treatment and stability are discussed.