Mandibular autorotation revisited: Accuracy and stability of maxillary impaction in retrognathic patients with condylar osteoarthritis

The aim of this retrospective study was to evaluate the accuracy of maxillary positioning with mandibular autorotation using the straight locking miniplate (SLM) technique and computer-aided design/computer-aided manufacturing (CAD/CAM) wafers on postoperative stability in patients with skeletal class II malocclusion and condylar osteoarthritis. Cephalometric analysis of the maxillary position and MA center (ARC) before (T0), 3 days (T1), 3 months (T2), and 1 year (T3) after surgery was performed. Analysis of 21 patients revealed a mean movement of −2.0 ± 2.2 mm (x-axis) and 5.4 ± 2.4 mm (y-axis) at U1 and of −1.5 ± 2.4 mm (x-axis) and 4.9 ± 1.6 mm (y-axis) at U7. The SNA, SNB, ANB, and SN-MP angles and ramus inclination at T0 were significantly different from those at T1, T2, and T3. The distance from the ARC to the Co of T2 and T3 was significantly smaller than that of T1 on the x-axis, indicating that the ARC converged horizontally to Co. There was no significant difference in the amount of rotation at any time point. Accurate maxillary positioning with mandibular autorotation using SLM and CAD/CAM wafers may correct the unstable rotation axis of the mandible and prevent early postoperative relapse.