Purpose: This study assessed the effectiveness of incobotulinum toxin type A (IBTx) for chronic myofascial pain affecting the masseter and temporal muscles.

Methods: Twenty two patients who received a diagnosis of chronic masseter and temporalis myofascial pain were evaluated by using a visual analog pain scale (VAS), digital pressure algometry, and the SF-36 Health Survey at baseline (T0), before IBTx injection. Patients were again evaluated at 2 months (T1) and 7 months (T2) after IBTx injection.

Results: VAS scores for pain significantly differed (P = 0.029, Friedman test). Post-hoc tests showed a significant reduction in pain at 2 months (T0–T1) and 7 months (T0–T2) (P = 0.011 and P = 0.028, respectively; Wilcoxon test) but not between 2 and 7 months (P = 0.676; Wilcoxon test). There was no significant difference in pressure algometry values (P = 0.385, Friedman test). Quality of life (QOL) assessment showed a significant difference (P = 0.002, Friedman test). Post-hoc tests showed a significant improvement in QOLat 2 months, but no significant difference at 7 months (P = 0.004 and P = 0.260, Wilcoxon test).

Conclusion: IBTx injection resulted in safe, effective short-term pain relief for patients with chronic facial pain affecting the masseter and temporalis muscles.

目的：本研究评估了A型肉毒杆菌毒素（IBTx）对影响咬肌和颞肌的慢性肌筋膜疼痛的有效性。

方法：在IBTx注射之前，通过视觉模拟疼痛量表（VAS），数字压力法和基线时的SF-36健康检查（T0）对22例诊断为慢性咬肌和颞肌肌筋膜疼痛的患者进行了评估。在IBTx注射后2个月（T1）和7个月（T2）再次对患者进行评估。

结果：疼痛的VAS评分存在显着差异（P = 0.029，Friedman检验）。事后测试显示，在2个月（T0–T1）和7个月（T0–T2）时疼痛显着减轻（分别为P = 0.011和P = 0.028； Wilcoxon测试），但在2到7个月之间没有（P = 0.676； Wilcoxon测试）。压力法测量值无显着差异（P = 0.385，Friedman检验）。生活质量（QOL）评估显示出显着差异（P = 0.002，Friedman检验）。事后测试显示，在2个月时的生活质量显着改善，但在7个月时没有显着性差异（P = 0.004和P = 0.260，Wilcoxon检验）。

结论： IBTx注射剂可有效，有效地缓解慢性面部疼痛影响咬肌和颞肌的短期疼痛。