重复咬合干扰对大鼠咬肌痛觉敏感的易化作用

Repetitive Occlusal Interference Facilitates Masseter Hyperalgesia in Rats

目的:分析初次咬合干扰对再次咬合干扰致大鼠咀嚼肌痛觉敏感的影响。方法:于大鼠右上第一磨牙粘固0.4mm厚金属冠,建立咬合干扰;初次干扰2d后去除,再次干扰2d或4d后去除,测试2次干扰前后多个时间点双侧咬肌机械摆头阈值。结果:初次干扰2d去除后阈值需8d恢复至基线;初次干扰2d后再次干扰2d去除,阈值需10d恢复至基线;初次干扰2d后再次干扰4d去除,阈值需19d恢复至基线;初次假手术后再次干扰4d去除,阈值仅需12d恢复至基线。结论:初次咬合干扰2d对再次咬合干扰2d、4d致咬肌痛敏有易化作用,表现在延长了再次咬合干扰致咬肌痛敏的恢复时间。本研究成功建立了重复咬合干扰易化咀嚼肌痛敏的动物模型。

Objective：To investigate the influence of previous occlusal interference on masticatory muscle hyperalgesia induced by secondary occlusal interference in rats.Methods：Repetitive occlusal interferences were obtained by bonding a 0.4 mm thick metal crown on the upper first molar in rat and removing it after two or four days.The bilateral head withdrawal thresholds were measured at multiple time points.Results：Eight days were needed for the thresholds to recover to baseline after the removal of the first occlusal interference which lasted for two days,and 10 days were needed after two occlusal interferences which both lasted for two days.And it took respectively 19 days and 12 days for the thresholds to recover to baseline after the removal of the second occlusal interference which lasted for 4 days following the first occlusal interference which lasted for 2 days or following sham operation.Conclusion：The first occlusal interference which lasted for 2 days facilitated masseter hyperalgesia induced by the second occlusal interference which lasted for 2 or 4 days in postponing the recovery time without increasing the severity of masseter hyperalgesia.This study successfully established an animal model of repetitive occlusal interference-facilitated masticatory muscle pain.