目的　观察应用微型种植支抗使犬牙齿移动过程中基质金属蛋白酶-2（MMP-2）的表达变化，探讨其在骨改建中的作用。  方法　建立应用微型种植支抗压低犬上颌右侧第二切牙的实验模型。对其施加100 g的牵引力后，分别于加力后6、12、24、36周处死。选择一侧第2切牙连同牙龈、牙槽骨完整切取，进行HE染色观察组织形态，免疫组织化学检测MMP-2表达变化及时间分布特点。左侧上颌第2切牙不予施加力作为对照组，并选取同名牙周围组织进行HE及免疫组化检测。  结果　HE显示对照组中犬牙齿根尖部有大量牙骨质，而被压低牙齿根尖可见牙骨质吸收。免疫组化显示牙周组织中MMP-2的表达在加力6周后开始增加，24周达最高峰，其后开始下降，结果提示差异有统计学意义（P<0.05）。  结论　在压低犬切牙过程中，MMP-2参与了牙周组织的改建。

Objective　To observe the expression of matrix metalloproteinase 2 in the periodontal tissues with implant anchorage for the anterior tooth in dogs and to explore its role in the bone remodeling.  Methods　The experimental model was established by pressing down the anterior tooth with implant anchorage. After imposing 100g  force, the dogs were executed sequentially  at  6，12，24，36 weeks.  The right second maxilla incisor with gum and the integral alveolar bone in the affected side were cut out for observation of general morphology by HE staining and detection of  the change of expression and time distribution characteristics of matrix metallopmteinase 2(MMP-2) by immunohistochemistry. The left side without force imposed is chosen as the control group, and the tissue surrounding the right second maxilla incisor was explored by immunohistochemicaI detection and HE staining.　 Results　It showed that there is a large number of bone in the tooth root apex of the control group by HE staining. However, it manifested bone absorption in the tooth root apex with force applied. The expression of MMP-2 in the periodontal tissue raised at 6 weeks, peaked at 24 weeks, and then began to decline afterwards. the result showed that difference was statistically significant after application of force by immunohistochemistry (P<0.05).　Conclusions　In the process of pressing down the incisor, MMP-2 plays the important role in the reconstruction of periodontal tissue.