Management of overbite with the Invisalign appliance

Introduction: Most of the published literature on the management of overbite with the Invisalign appliance (Align Technology, Santa Clara, Calif) consists of case reports and case series. Methods: In this retrospective study of 120 patients, we sought to assess the nature of overbite changes with the Invisalign appliance. Records were collected from 3 practitioners, all experienced with the Invisalign technique. The patients were consecutively treated adults (> 18 years old) who underwent orthodontic treatment only with the Invisalign appliance. Patients with major transverse or anteroposterior changes or extraction treatment plans were excluded. The study sample included 68 patients with normal overbites, 40 with deepbites, and 12 with open bites. Their median age was 33 years, and 70% of the patients were women. Results: Cephalometric analyses indicated that the deepbite patients had a median overbite opening of 1.5 mm, whereas the open bite patients had a median deepening of 1.5 mm. The median change for the normal overbite patients was 0.3 mm. Changes in incisor position were responsible for most of the improvements in the deepbite and open bite groups. Minimal changes in molar vertical position and mandibular plane angle were noted. Conclusions: The Invisalign appliance appears to manage the vertical dimension relatively well, and the primary mechanism is via incisor movements.