A skeletal Class III facial asymmetry case with a canted occlusal plane treated by LeFort I with unilateral horseshoe osteotomy

To treat facial asymmetry with severe inclination of the frontal occlusal plane, unilateral maxillary impaction in the molar region must be performed to reposition the maxilla. We herein report the successful surgical-orthodontic treatment of a patient with facial asymmetry and significant canted occlusal plane by LeFort I combined with unilateral horseshoe osteotomy and mandibular bilateral intraoral vertical ramus osteotomy (IVRO). A 20-year-old male patient had a chief complaint of mandibular protrusion and mandibular dental crowding. The total active treatment period was 31 months. After postsurgical orthodontic treatment, the right side of the maxilla was impacted by 4.0 mm, while the left side was maintained vertically. The facial asymmetry and canted occlusal plane had mostly improved and satisfactory occlusion, and a straight-type profile had been obtained. In addition, the condylar path length was increased during maximum reciprocal jaw movement, and the incisal path became stable during lateral excursion. Acceptable occlusion and a satisfactory facial profile were maintained after the two-year retention period. Our results suggest that the combination of LeFort I with unilateral horseshoe osteotomy is a useful technique for achieving reliable, superior repositioning of maxillae with a severe cant.