Hemimandibular Hyperplasia Correction by Simultaneous Orthognathic Surgery and Condylectomy Under Digital Guidance

Orthognathic surgery with simultaneous condylectomy under digital guidance has been proved to be a feasible method to treat hemimandibular hyperplasia (HH). The objective of this study was to evaluate the effects and precision of correction of HH by use of this method.This was a case-series study. Fourteen patients with HH who had undergone simultaneous bimaxillary orthognathic surgery and condylectomy from January 2016 to April 2017 were included in this study. Presurgical virtual treatment planning was performed, transferred to the operation room, and realized with the assistance of surgical navigation and 3-dimensionally printed occlusion splints. Postoperative computed tomography data were used to analyze improvement in facial symmetry and verify the accuracy of the surgical procedure.All patients exhibited satisfactory clinical effects; facial asymmetry was corrected as expected. Postoperative validation showed that the presurgical planning had been achieved more precisely on the unaffected side than on the affected side. Moreover, bilateral mandibular proximal segments showed a tendency for outward rotation compared with the presurgical planning model. Furthermore, when we assessed facial symmetry compared with the presurgical model, deviation of all midline landmarks was less than 2 mm, occlusal-plane inclination was less than 1 mm, and the asymmetry index of paired landmarks was remarkably decreased after surgery (P < .01).Orthognathic surgery with simultaneous condylectomy under digital guidance is a realistic and precise method for treatment of HH. Surgical results can be validated during surgery by virtual navigation. However, movement of each bone segment cannot be accurately controlled as planned before surgery.