Customized Three-Dimensional Printing Spacers for Bone Positioning in Orthognathic Surgery for Correction and Prevention of Facial Asymmetry.

Orthognathic surgery is a powerful tool for correction of facial asymmetry and malocclusion. The goal is to achieve good dental function and facial aesthetics. Three-dimensional simulation is used for surgical planning, and bone gaps could be created to achieve facial balance. In this study, customized "spacers" were made using computer-aided design and three-dimensional printing for guides for use during surgery. With the final three-dimensional plan, the skull images were exported to 3-Matic software, where spacers were designed according to the bone gaps. Three-dimensionally-printed spacers were made and used to facilitate positioning and fixation. Consecutive patients with facial asymmetry were recruited in this prospective study. The postoperative outcome was assessed using a visual analogue scale and the three-dimensional facial surface area discrepancy index for subjective and objective evaluation. There were 12 patients and a total of 19 spacers for the Le Fort I and mandibular ramus segments. The spacers worked nicely during the bone fixation process. Mean preoperative and postoperative visual analogue scale scores were 4.83 and 7.14, with a statistically significant improvement for facial symmetry (p = 0.018). Mean preoperative and postoperative facial surface area discrepancy index was 0.95 and 0.98, and the correction of asymmetry was significant (p = 0.009). There were no related surgical complications. All patients were satisfied with the correction of facial asymmetry and malocclusion. The custom-made, three-dimensionally-printed spacers help to achieve surgical precision to correct and prevent facial asymmetry in orthognathic surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.