Skeletal open bite correction with rapid molar intruder appliance in growing individuals

Abstract

Objective: To determine the dentofacial effects of a fixed functional appliance, the rapid molar intruder (RMI). Materials and Methods: One control group (n = 10) and two study groups (n = 10 each) were formed. The first experimental group consisted of growing children in the mixed dentition period who received RMI therapy alone. The second experimental group consisted of growing children in the early permanent dentition period who received both RMI and fixed appliance (edgewise) therapy together. Mean changes for the measurements for each group were evaluated by the Wilcoxon signed rank test. Comparisons of the mean changes between the groups were made by the Kruskal-Wallis test. Results: Open bite correction was achieved by counterclockwise rotation of the mandible as a consequence of redirecting growth in both treatment groups. The ANB angle decreased significantly (P < .05). Significant decreases were also noted for vertical skeletal characteristics in both treatment groups (P < .05). Molar intrusion was statistically significant for both maxillary and mandibular first molars (P < .05) in both treatment groups. Conclusions: The RMI appliance provided effective bite closure and favorable dentofacial changes for nonsurgical open bite treatment in growing patients. It was concluded that this method could be regarded as a safe and noncompliance alternative for early intervention of skeletal open bite correction. © 2007 by The EH Angle Education and Research Foundation, Inc.