种植体型功能矫治器矫治过程中Beagle犬咬肌肌纤维类型的变化

Fibre-type differences in masseter muscle of Beagle dogs with implanted functional appliance therapy

目的 :观察种植体型功能矫治器引导Beagle犬下颌骨前移治疗过程中咬肌MyHC-I表达量的变化,探讨种植体型功能矫治器矫治过程中咀嚼肌的适应性改建,为矫形治疗提供理论依据。方法:8只7个月龄雄性Beagle犬分别在安装矫治器治疗后4、8、12周及拆除矫治器后4周(即16周)处死,取咬肌浅层中部组织做切片,用SABC法检测MyHC-I在Beagle犬咬肌中的表达,采用SPSS11.5软件包对数据进行统计学分析。结果 :MyHC-I在对照组咬肌中的阳性表达率为7.61%,在4周实验组咬肌中的阳性表达率为20.43%﹙P<0.01﹚,8周时达到最大,而后逐渐减少。拆除矫治器后,咬肌中MyHC-I的表达逐渐减少,直至与对照组水平接近。结论:种植体型功能矫治器前移下颌过程中咬肌MyHC-I的表达出现明显变化,种植体型功能矫治器能明显促进咀嚼肌的适应性改建。

PURPOSE： To observe the changes of MyHC-I expression in masseter muscle of Beagle dogs with implanted functional appliance therapy, and to investigate the adaptive remodeling of masticatory muscle. METHODS： Eight, seven- month-old, male Beagle dogs were randomly assigned to experimental group and control group and were killed at 4,8,12 weeks during treatment and 4 weeks after the appliance removed （16 weeks）. Serial cross-sections of superficial masseter muscle were cut and stained with MyHC-I antibodies.SPSSll.5 software package was used for statistical analysis. RESULTS： The positive expression rate of MyHC-I was 7.61% in the control group, and 20.43% in the experimental groups at 4 weeks （P〈0.01）. The amount of type I fibres reached to peak at 8 weeks. With increase of treatment time, the amount of type I fibres gradually reduced. At 16 weeks, the amount of type I fibres was similar to the control groups. CONCLUSIONS： The expression of MyHC-I is significantly changed in masseter muscles of Beagle dogs with implanted functional appliance therapy. Implanted functional appliance forward mandibular displacement therapy can obviously promote the adaptive remodeling of masticatory muscle.