The effects of MMP-2 and TIMP-2 on orthodontic tooth movement and root absorption: a study in rats
LIU Hong
LU Jun
ZHANG Zhen
WAN Zhe
ZHANG Qin
Abstract：AIM: To study the effects of MMP-2 and TIMP-2 on orthodontic root absorption in rats.METHODS: The root resorption model of 30 rats caused by orthodontic force was established.Samples were respectively collected on day 0, 1, 3, 5, 7,14 and 21 after treatment(n=5).Another 5 rats were used as the controls.The morphology of root absorption was observed by HE staining, MMP-2 and TIPM-2 expression was evaluated by immunohistochemical staining(IHCS).RESULTS: HE staining showed that root absorption started from day 3, with bone resorption lacunae formation confined to cementum, reached the peak at day 7,dentine was involved in the severe cases.After day 21 the root absorption degree reduced, osteoblasts gathered in the ares of root absorption.IHCS showed that MMP-2 and TIMP-2 positive expression mainly located in cytoplasm in root absorption area.Weak expression of MMP-2 was identified in control group.In treatment group, MMP-2 positive cells increased and reached the peak at day 7, gradually declined after day 14, and reduced more after day 21, but stronger than the controls.The expression of TIMP-2 was similar to that of MMP-2.CONCLUSION: MMP-2/TIMP-2 are involved in the metabolism of extracellular matrix in the process of root absorption.
Keywords：orthodontic tooth movementroot absorptionMMP-2TIMP-2
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 382-386 )