Intravenous Dexamethasone Administration Before Orthognathic Surgery Reduces the Postoperative Edema of the Masseter Muscle: A Randomized Controlled Trial

Purpose: Dexamethasone seems to suppress postoperative swelling. However, the standard administration dose of dexamethasone for bilateral sagittal split osteotomy (BSSO) has not been reported. This study focused on clarifying the most effective dose of dexamethasone for BSSO. Materials and Methods: This research was planned as a prospective, randomized controlled, doubleblind study. Patients undergoing BSSO were randomly assigned to receive intravenous preoperative dexamethasone under 3 different dose conditions: 16 mg, 8 mg, and 0mg (control). The endpoints of this study were 1) postoperative changes in masseter muscle thickness and buccal soft tissue thickness; 2) postoperative changes in maximum incisal opening; 3) postoperative changes in sensation of the chin and lower lip region; 4) postoperative changes in blood examination findings (white blood cell count, neutrophil count, C-reactive protein level, and lymphocyte count); and 5) types of complications. Data were recorded at 2 to 4 time intervals: before surgery, postoperative day 1, postoperative day 2, and postoperative day 3. Average age, gender, average body mass index, average surgery time, and average blood loss also were examined. Data were analyzed by 1-way analysis of variance (Bonferroni multiple-comparisons test) after the Bartlett test. Results: We enrolled 24 patients, including 5 men and 19 women, in this study. The rate of increase in the thickness of the masseter muscle 24 hours after BSSO was 38.4% in the 16-mg group (n = 8), 57.7% in the 8-mg group (n = 8), and 56.1% in the 0-mg group (n = 8). The rate of increase in masseter muscle thickness in the 16-mg group was significantly lower than that in the 0-mg group (P < .05). Regarding the number of lymphocytes after surgery, the 16-mg and 8-mg groups maintained preoperative levels whereas there was a reduced number of lymphocytes in the control group. No statistically significant results were obtained for the following study endpoints: postoperative changes in maximum incisal opening and postoperative changes in sensation of the chin and lower lip region. Conclusions: This investigation showed that the most effective dose of dexamethasone for BSSO is 16 mg. (C) 2017 American Association of Oral and Maxillofacial Surgeons