Reverse-engineering-based quantitative three-dimensional measurement of facial swelling after administration of Yunnan Baiyao following orthognathic surgery

Abstract

To evaluate the effects of perioperative oral administration of Yunan Baiyao on reduction of postoperative facial swelling following bimaxillary orthognathic surgery. Patients scheduled for Le Fort I osteotomies and bilateral sagittal split ramus osteotomies were enrolled in the prospective, randomized, double-blind, placebo-controlled clinical study. Patients were orally administrated with Yunnan Baiyao capsules or placebo capsules before 3 days of operation and 5 days post-operation. Three-dimensional face images were recorded with OKIO-SC-400 Scanning System in 40 patients at pre-operation, postoperatively 3 day, 1 week and 1 month. Facial scans from different time periods were registrated to same coordinates and overlaid onto the baseline facial scan. 3D and 2D model deviations were performed with reverse engineering software to compare the differences between each two models and to quantitatively determine the reductions in facial swelling. There were 18 patients in Yunnan Baiyao group and 22 patients in control group. The severe swelling region was in the cheek, followed by the upper and lower lip. The average reduction of swelling thickness in Yunnan Baiyao group and control group from 3 day to 1 week postoperative was 3.6 mm and 2.3 mm respectively; there was significant difference between the two groups. Significant differences were also found in percentage changes of facial morphology from 3 day to 1 week postoperative (49.0% and 38.3% respectively). There were no significant changes in facial volumes of swelling between the two groups. Perioperative oral administration of Yunnan Baiyao capsules can effectively reduce the magnitude of facial swelling in bimaxillary orthognathic surgery. Yunnan Biayao has efficacy of anti-inflammatory response.