下颌前突患者胸锁乳突肌和咀嚼肌的肌电研究

Electromyographic activity of sternocleidomastoid and masticatory muscle in patients with prognathism

目的探讨下颌前突患者在下颌运动和姿势位时,双侧颞肌前束(TA)、咬肌(MM)、二腹肌前腹(DA)和胸锁乳突肌(SCM)的肌电活动情况,为临床进行正颌手术提供参考数据。方法选取于中国医科大学口腔医院颌面外科就诊的下颌前突患者32名为研究对象,运用美国BioEMGⅡ八道表面肌电仪和BioFLEX带状双极表面电极记录患者在下颌不同功能运动时咀嚼肌的肌电幅值。同时选取口腔专业本科生36人,作为对照进行统计分析。结果下颌姿势位时,除MM外,其他咀嚼肌的肌电幅值均增高,与对照组间差异有统计学意义(P<0.01)。在牙尖交错位(最大紧咬)时,下颌前突患者TA、MM的肌电幅值均低于对照组(P<0.01)。在前伸位时,除DA外,下颌前突组咀嚼肌的肌电幅值较正常者高,差异有统计学意义(P<0.01)。在后退位时,除MM和DA外,TA、SCM的肌电幅值高于对照组(P<0.01)。结论下颌前突患者咀嚼肌的肌电活动发生变化,颅面骨骼形态影响颈部肌群。

Objective To investigate the electromyographic activities of anterior temporalis（TA）,masseter muscle（MM）,digastric anterior（DA）,sternocleidomastoid（SCM） at postural position（MPP） and various mandibular movements in prognathic patients.Methods Thirty-two patients with prognathism were selected from the clinic of oral and maxillofacial surgery of China Medical University.36 healthy college students with normal occlusion were selected as normal controls.A BioEMG Ⅱ diagnostic system with BioFLEX surface electrode was used to record the electromyo-graphic activities of the above muscles.Results Compared with the control group,the electromyographic activities of TA,SCM and DA in prognathic patients were higher in MPP.The electromyographic activities of TA,MM were sig-nificantly lower than the control group in clenching（P0.01）.In protrusion,the electromyographic activities of TA,MM and SCM in prognathic patients were higher than the control group（P0.01）.In retrusion,the electromyographic activities of TA,SCM in prognathic patients were higher than the control group（P0.01）.Conclusion The masticatory muscles electromyographic activity of prognathism is abnormal.