Anterior Open-bite Malocclusion: a Longitudinal 10-year Postretention Evaluation of Orthodontically Treated Patients

Long-term response of the anterior open-bite malocclusion was evaluated in forty-one white subjects who had undergone orthodontic treatment and were out of retention a minimum of 9 years 6 months. The purpose of the study was threefold: (1) to make cephalometric comparisons between a sample of open-bite patients and a sample with normal cephalometric standards, (2) to evaluate treatment and posttreatment changes that occurred in treated open-bite patients, and (3) to search for predictors and associations of value. Changes occurring across time in the open-bite patients were analyzed by computer means using pretreatment, posttreatment, and long-term cephalometric radiographs and dental casts. An analysis of subgroups was reviewed to compare dentoalveolar and skeletal relationships of both stable and relapse groups. More than 35% of the treated open-bite patients demonstrated a postretention open bite of 3 mm or more, with the relapse subgroup demonstrating across-time, less mandibular anterior dental height, less upper anterior facial height, greater lower anterior facial height, and less posterior facial height. Neither the magnitude of pretreatment open bite, mandibular plane angle, nor any other single parameter of dentofacial form proved to be a reliable predictor of posttreatment stability.