Chang Chun-Shin, Lin Susie, Wallace Christopher Glenn, Hsiao Yen-Chang, Lin Che-Min, Kang Gavin Chun-Wui, Chen Zung-Chung, Chen Philip Kuo-Ting, Lo Lun-Jou, Chen Yu-Ray, Chen Jyh-Ping
Department of Oral and Maxillofacial Surgery, Vanderbilt University Medical Center, Nashville, TN.
Craniofacial Research Center, Departments of Medical Research, Plastic Surgery, and Craniofacial Orthodontics, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
Ann Plast Surg. 2019 Jan;82(1S Suppl 1):S29-S32. doi: 10.1097/SAP.0000000000001705.
Botulinum neurotoxin A (BoNT-A) is a minimally invasive and technically straightforward treatment of masseter muscle (MM) volume reduction and facial contouring, but the literature on its long-term effect on MM volume remains unclear.
This study aimed to assess quantitatively for progressive volume changes of lower facial contour after 3 BoNT-A injections in patients with bilateral MM hypertrophy causing square facial morphology using 3-dimensional computed tomographic scans.
Ten female patients with square facial morphology due to bilateral MM hypertrophy were recruited to, and 6 completed, this clinical study. Each received 24 U of BoNT-A into the inferior portion of each MM on both sides, repeated 6 monthly to complete 3 treatments. Masseter muscle volume changes were assessed using 3-dimensional computed tomography at pretreatment (before injections) and posttreatment (1 year after the third injection).
Mean MM volume significantly reduced from 26.39 ± 4.18 cm before treatment to 23.26 ± 4.31 cm 1 year after treatment (P = 0.002).
Three consecutive 6-monthly BoNT-A injections into the MMs reduced their volume by 12% when assessed 1 year after completion of treatment.
肉毒杆菌神经毒素A（BoNT-A）是一种用于减少咬肌（MM）体积和面部轮廓塑形的微创且技术操作简单的治疗方法，但关于其对MM体积长期影响的文献仍不明确。
本研究旨在使用三维计算机断层扫描，对双侧MM肥大导致方形面部形态的患者进行3次BoNT-A注射后，定量评估面部下轮廓的渐进性体积变化。
招募了10名因双侧MM肥大导致方形面部形态的女性患者参与本临床研究，其中6名完成了研究。每位患者双侧MM下部各注射24 U的BoNT-A，每6个月重复一次，共完成3次治疗。在治疗前（注射前）和治疗后（第三次注射后1年）使用三维计算机断层扫描评估咬肌体积变化。
治疗前平均MM体积为26.39±4.18 cm，治疗后1年为23.26±4.31 cm，平均MM体积显著减小（P = 0.002）。
在完成治疗1年后评估，连续3次每6个月向咬肌注射BoNT-A可使其体积减少12%。
