Accelerated Orthodontic Tooth Movement Following Le Fort I Osteotomy in a Rodent Model

Purpose In surgery-first accelerated orthognathic surgery, the clinical phenomenon of accelerated orthodontic tooth movement after osteotomy is a benefit compared with the conventional approach. However, because much of the literature on this phenomenon is based on empirical evidence and case reports, experimental animal-based studies are needed to verify and quantify this acceleration effect. The purpose of this prospective experimental study was to identify whether osteotomy procedures increase tooth movement. Material and Methods Le Fort I osteotomies were performed on the left maxillas in 15 male adult Sprague-Dawley rats. After surgery, a continuous force of 0.5 N was placed on the maxillary left first molar to move the tooth mesially. Another 15 rats had no surgery and served as controls. On days 1, 14, and 28, digital caliper measurements were taken to record tooth movement. Results In the experimental group, the maxillary left first molars moved significantly more rapidly on days 14 and 28 ( P < .05). Histologic findings showed more active alveolar bone remodeling. Conclusion Le Fort I osteotomy significantly accelerated the rate of orthodontic tooth movement. Histologically, more active and extensive bone remodeling was observed after osteotomy.