The Change of Facial Contouring after Unilateral Injection of Botulinum Toxin in Unilateral Masseter Hypertrophy Patients
구강회복응용과학지 , Vol.27(2) : 247~251, 2011
Botulinum toxin type A (BoNT-A) is used for treating bilateral masseter hypertrophy since 1994. Recently there have been more clinical studies in this area, with some authors reporting that BoNT-A can reduce the size of the masseter muscle, as documented by photography, ultrasonography, computed tomography, and 3D(three dimensional) laser scan. However, earlier studies were only for bilateral masseter hypertrophy cases, not for unilateral masseter hypertrophy cases. The aim of this study was to use 3D laser scanning to evaluate changes in the external facial contour induced by unilateral BoNT-A injection. BoNT-A was injected into hypertrophic masseter muscle unilaterally in 10 patients with asymmetric masseter hypertrophy. The clinical effects of unilaterally injected BoNT-A were evaluated before the injection and 4, 8, and 12weeks after the injection using 3D laser scan. And the mean values of both sides (injection and non-injection sides) were compared with. At injection side, mean values of the volume and the bulkiest height at each time point diminished significantly between pre-injection and 4, 8, and 12weeks post-injection. At non-injection side, in contrast, mean values of the volume and the bulkiest height diminished also but less than that of injected side, and there was no statistical significance. In this limited study, we concluded that the unilaterally BoNT-A injection side showed greater mean values of the reduction of muscle volume than non-injection side at 4, 8, and 12 weeks after the injection.