Stability of lingual plate osteotomy in orthognathic surgery for patients with severe facial asymmetry: A retrospective analysis with 1-year follow-up

This study aimed to evaluate the stability of lingual plate osteotomy after sagittal split ramus osteotomy (SSRO) in patients with severe facial asymmetry. It included 20 patients undergoing lingual plate osteotomy between January 2011 and January 2017. Cephalometric X-ray imaging and three-dimensional computed tomography (3DCT) were performed before the operation and then 1 day and 1 year after the operation. The relapse rate and postoperative complications were assessed. The operation time was compared between lingual plate osteotomy and transoral angle osteotomy. Specific values measured on cephalometric X-ray and 3DCT images showed significant changes 1 day after the operation, with 47.9% correction occurring in the occlusal plane angle (mean ± SD = 1.74 ± 0.84°, p < 0.05). However, no significant differences were found between measurements taken 1 day and 1 year after the operation, with a 5% change seen in the occlusal plane angle (mean ± SD = 0.1 ± 0.24°, p = 0.61), suggesting that the surgical outcomes can be well maintained for at least 1 year after surgery. Three patients experienced numbness postoperatively but recovered within 1 year. The operation time for lingual plate osteotomy was shorter than that for transoral angle osteotomy. Our findings indicate that lingual plate osteotomy after SSRO is stable, effective, and safe in patients with severe facial asymmetry.