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INTRODUCTION: Orthopedic maxillary expansion, also commonly referred to as Rapid Maxillary Expansion (RME) is a widely used orthodontic technique for early treatment of skeletal transverse deficiencies1. Condylar changes in response to RME have been observed using a variety of imaging techniques such as tomograms2, magnetic resonance imaging3-4 and cone beam computerized tomography5. To this day, most of the studies have focused on changes in condylar position after RME but to best our knowledge, no study has examined the changes in condylar shape and volume in addition to position. OBJECTIVES: The aim of this retrospective cohort study is to determine the long term effect of Rapid Maxillary Expansion (RME) on condylar shape, volume and orientation as well as on mandibular rotation. METHOD: Pre- and post-expansion cone beam computerized tomography (CBCT) images of forty-four healthy subjects (mean age=11.8±2.06) who previously had undergone banded RME were selected from a CBCT repository. Due to extensive time range existing between the pre- and post-CBCTs (0.7-4.7y, average time = 2.4y ± 0.97), a stratified analysis was run to account for the subject’s growth. Two subgroups were created according to the Baccetti Cervical Maturation stage : a “growing” group (n=37, mean age=11.86y, diff CVM>1) and a “non-growing” group (n=7, mean age=11.73y, diff CVM |
