下颌偏突颌畸形患者双侧下颌骨升支矢状劈开术前后咀嚼肌功能变化探究

Exploration on Changes of Masseter Function in Patients with Asymmetric Mandibular Prognathism Before and After Bilateral Sagittal Split Ramus Osteotomy

目的:探究下颌偏突颌畸形患者双侧下颌骨升支矢状劈开术(BSSRO)前后咀嚼肌功能变化。方法:选取2016年6月-2018年6月笔者医院收治的31例下颌偏突颌畸形患者为观察组,另选取30例年龄相仿的正常志愿者为对照组。测定两组自由咀嚼状态下的半分钟咀嚼效能、吞咽反射前咀嚼效能。采用OXFORD双通道肌电诱发仪采集两组紧咬位、大张口运动的MML、MMR、TAL、TAR肌电值;计算相应部位的咀嚼肌活动量指数(AcI)。结果:术前,观察组患者的半分钟及吞咽反射前咀嚼效能,紧咬位、大张口运动时的MML、MMR、TAL、TAR及AcI指标均低于对照组,差异有统计学意义(P<0.05);术后3个月,观察组患者的咀嚼效能指标及各功能运动中的MML、MMR、TAL、TAR肌电值均明显小于对照组及术前(P<0.05),各功能运动中AcI指标明显大于术前(P<0.05);术后1年,观察组患者的咀嚼效能指标及各功能运动中的MML、MMR、TAL、TAR肌电值均明显高于术后3个月(P<0.05),但部分指标仍与对照组无差异(P>0.05)。结论:下颌偏突颌畸形患者术前的咀嚼肌功能弱于健康人群,行BSSRO后咀嚼肌功能得到了一定程度的改善。

Objective To explore changes of masseter function in patients with asymmetric mandibular prognathism before and after Bilateral Sagittal Split Ramus Osteotomy(BSSRO).Methods 31 patients with asymmetric mandibular prognathism who were admitted to the hospital from June 2016 to June 2018 were enrolled as observation group.Another 30 normal volunteers with similar age were enrolled as control group.The half-minute mastication efficiency in free-mastication status,and mastication efficiency before swallowing reflex in both groups were measured.MXL,MMR,TAL and TAR electromyogram(EMG)values of biting position and large mouth movement in both groups were collected by OXFORD dual channel EMG evocative instrument.The masseter activity indexes(AcI)of corresponding sites were calculated.Results Before surgery,halfminute mastication efficiency,mastication efficiency before swallowing reflex,MXL,MMR,TAL and TAR of biting position and large mouth movement,and AcI indexes in observation group were lower than those in control group(P<0.05).At 3 months after surgery,mastication efficiency indexes,MXL,MMR,TAL and TAR EMG values of each functional exercise in observation group were significantly lower than those in control group and those before surgery(P<0.05),and all AcI indexes were significantly higher than those before surgery(P<0.05).At 1 year after surgery,mastication efficiency indexes,MXL,MMR,TAL and TAR EMG values of each functional exercise in observation group were significantly higher than those at 3 months after surgery(P<0.05).However,there were still differences in some indexes compared with those in control group(P>0.05).Conclusion The preoperative masseter function in patients with asymmetric mandibular prognathism is weaker than that of healthy people.The masseter function is improved after BSSRO to some extent.