Abstract:

Objective　To observe the expression patterns of matrix metalloproteinase-3 and its inhibitor, tissue inhibitor metalloproteinases (TIMP)-1, in remodeling phase of mandibular distraction osteogenesis.Methods　Bilateral mandibular osteot- omies were performed in 8 mature rabbits. The mandibles were lengthened 6 mm using a custom-made distractor with a rate of 1 mm/d. All animals were killed in 4 weeks after completion of distraction. The distracted calluses were harvested and processed for histology and immunohistochemistry of MMP-3 and TIMP-1.Results　Elevated expression of both MMP-3 and TIMP-1 was found in the distracted calluses resulting frommandibular lengthening. Positive staining forMMP-3 was seen in the osteoblasts and osteocytes, and TIMP-1 was mainly localized in osteoblasts.Conclusion　MMP-3 and TIMP-1 appear to play important roles in the remodeling of new bone created by mandibular distraction osteogenesis.

Key words: mandibular osteodistraction, matrixmetalloproteinase-3, tissue inhibitormetalloproteinases-1, bone re- modeling