犬正畸牙移动过程中张力侧牙周膜肌成纤维细胞的表达研究

目的 初步探讨正畸牙移动过程中牙周膜肌成纤维细胞是否存在及其表达规律.方法 Beagls犬5只,采用自制的加力装置用镍钛螺旋拉簧加力100 g,远中移动犬第一前磨牙,主动加力4周, 4周后去除加力装置,分别于加力后1、2、3、4、8周各处死1只.测量实验牙移动距离;取正畸牙张力侧牙周膜,采用免疫组化检测α-平滑肌肌动蛋白(α-SMA)的表达;透射电镜观察α-SMA染色阳性区域细胞的超微结构.结果 实验牙移动距离第1周达到高峰,第2周开始牙齿移动速度减慢,到第3周降至最低,第4周又有所加快.免疫组化结果α-SMA的表达从加力开始至第2周达到最大值,到第4周基本恢复正常.透射电镜观察可见胞浆内有密体结构出现.结论 肌成纤维细胞存在于正畸牙牙周膜中,其表达改变可能是受到正畸力的刺激.肌成纤维可能起到对抗张力限制牙齿移动的作用.

Proliferation of Myofibroblast in Periodental Tension Side during Orthodontic Tooth Movement of Beagle Dogs

OBJECTIVE: To examine the proliferation of myofibroblast in periodental tension side of beagle dog during experimental tooth movement in orthodontics. METHODS: By the fixed orthodontic appliance, the five beagles were treated with 100 g forces that moved medially the maxillary first premolar, and the treatment lasted for four weeks. Using transmission electron microscope and immunohistochemistry, the proliferation of myofibroblast and expression of alpha-smooth muscle actin (alpha-SMA) were evaluated at week 1, 2, 3, 4 or 8 respectively after the orthodontic treatment. RESULTS: During the total of four weeks, the expression of a-SMA increased in week 1 and reached the maximum in week 2; in week 4, the expression of alpha-SMA went back to normal level. Transmission electron microscopy showed that the myofibroblast contained the dense body appearing in cytoplasm. CONCLUSION: The myofibroblast exists in periodontium and is concerned with the orthodontic tooth movement.