中文摘要：

目的：探讨＂应力-生长（改建）＂在细胞水平上的体现,为功能矫形治疗和矫治效果的保持提供新思路和实验依据。方法：本实验选用20只4周龄,雄性SD大鼠随机分为8组。其中实验组大鼠经戊巴比妥麻醉后佩戴上颌斜面导板,对照组未佩用。依据时间不同又分为四组：1d,7d,14d,21d。采用RT-PCR技术分析各组大鼠翼外肌组织中肌分化相关基因MyoD、myogenin mRNA的表达变化。结果：未施加功能矫形力的大鼠翼外肌组织MyoD表达伴随其生长发育呈现递减趋势,实验组在第7 d出现表达上调。同时,力学刺激后实验组动物myogenin的表达与对照组相比较在14 d组出现明显上调。结论：功能矫形力作用于翼外肌组织可以诱导MyoD和myogenin的表达上调进而诱导成肌细胞的分化。

英文摘要：

Objective：To investigate the expression of ＂stress-growth（reconstruction） ＂ at the cellular level for provide new ideas and experimental evidence about functional orthopedic treatment and treatment effects remain.Methods：Twenty,28 days old,male Sprague-Dawley（SD） rats were chosen in this research.SD rats are randomly divided into eight groups：control 1 d,7 d,14 d,21 d and experimental 1 d,7 d,14 d,21 d.When rats were anaesthetized by intraperitoneal injections of pentobarbital,the inclined bite plate were put into its mouth.RT-PCR was taken at 1,7,14,21 days after appliance activation.The gene expression of lateral pterygoid MyoD and myogenin mRNA is determined by RT-PCR technology.Results：MyoD,myogenin mRNA decreased in all juvenile rats lateral pterygoid.And expression of MyoD in control group reduced,while myogenin enhanced in 7 d.With the removable functional appliance-inclined bite plate rats,both the expressions of MyoD and myogenin enhanced,especially in 7 d.Conclusions：Expression of MyoD and myogenin mRNA in juvenile rats lateral pterygoid after functional mandibular protrusion increased.