肉毒杆菌毒素对兔颞下颌关节骨关节病咀嚼肌肌电的影响

目的：研究肉毒杆菌毒素对颞下颌关节骨关节病咀嚼肌功能的影响,为应用肉毒杆菌毒素治疗该病提供依据.方法：30只兔作咀嚼肌肌电图检查,其结果作为肌电正常值,并应用胶原酶注射法制成颞下颌关节骨关节病动物模型,随机分为2组.实验组兔双侧嚼肌、颞肌注射肉毒杆菌毒素,对照组仅为骨关节病状态.分别于4、8、12周末对2组兔作咀嚼肌肌电图检查,分析对比2组兔肌电电位的变化.所得资料用SPSS11.0软件行团体t检验.结果：姿势位时,对照组各时间点肌电电位显著高于正常;实验组在4周、8周末低于正常,12周末与正常相比无显著差异（P＞0.05）.牙尖交错最大紧咬状态下,对照组各时间点肌电电位显著低于正常;实验组在4周、8周末略低于正常,12周末与正常相比无显著差异（P＞0.05）.结论：肉毒杆菌毒素能改变颞下颌关节骨关节病咀嚼肌的功能状态,促进肌功能恢复正常.

The influence of botulinum toxin on the masticatory muscles of the temporomandibular joint osteoarthritis in rabbit

PURPOSE: To study the influence of botulinum toxin on masticatory muscle activity in temporomandibular joint model osteoarthritis(TMJOA). METHODS: 30 adult rabbits were examined with EMG,and TMJOA was established by collagenase injection, then divided into experimental group and control group. EMG of masticatory muscles was recorded during postural position and clenching at the end of 4 weeks, 8 weeks and 12 weeks. Botulinum toxin was injected into the masseter muscle and temporal muscle in the experimental group. Those of the control group were only with TMJOA. All data were analyzed with group t test in SPSS 11.0. RESULTS: During postural position, EMG activity of masticatory muscles in the control group was significantly higher than that of the normal at each examination(P<0.05). EMG activity in th experimental group was lower than normal at the end of 4 weeks and 8 weeks(P<0.05), but at the end of 12 weeks, the two groups showed no difference(P>0.05). During clenching, EMG activity in the control group was lower than normal at each measurement(P<0.05),EMG activity in the experimental group was lower than normal at the end of 4 weeks and 8 weeks(P<0.05), but showed no difference at the end of 12 weeks. CONCLUSION: Botulinum toxin can change and improve masticatory muscle function of TMJOA in rabbit.