Effect of recombinant human tissue inhibitor of matrix metalloproteinase-1 in mandibular distraction osteogenesis in rabbits: A computed tomographic study

Matrix metalloproteinases (MMPs), together with their tissue inhibitors (TIMPs), are responsible for the controlled degradation of collagen in bone. We studied the long-term stability of the regenerated bone formed by distraction osteogenesis, and the effect of recombinant human TIMP-1 on the remodelling of bone formed by mandibular distraction osteogenesis in rabbits. Nine rabbits were subjected to distraction osteogenesis of the mandible and divided into three groups: a control group with no collagen implanted; a sham-control group with a collagen sheet implanted; and an experimental group with a collagen sheet impregnated with rhTIMP-1 implanted. Computed tomograms were taken at weeks 4, 12, and 24 after distraction, and micro-computed tomograms and histological examinations were made at week 24. There was no significant resorption of regenerated bone at the site of distraction in any group after 6 months of consolidation, suggesting that the regenerated bone formed by distraction osteogenesis is stable. We found no obvious influence of rhTIMP-1 in the collagen sheet on the bony regenerate after 6 months of consolidation.