A major challenge in orthodontics is to provide a treatment result that remains stable after appliances are removed. Orthodontic treatment can move teeth from their neutral positions, which increases potential for future relapse. The literature from the University of Washington, Seattle, shows that relapse is pervasive and of considerable magnitude (Little RM. Stability and relapse of mandibular anterior alignment: University of Washington studies. Semin Orthod 1999;5:191-204). The intent of this study was to quantify the posttreatment dental changes that occurred over approximately a quarter century in a cohort of women who had received comprehensive orthodontic treatment as teenagers.