Collagenases and gelatinases in bone healing. The focus on mandibular fractures

Due to high amount of collagen fibres in the structure of bone, the enzymes capable of collagen digestion play a key role in bone remodelling. Matrix metalloproteinases (MMPs), prevailing extracellular endopeptideses, can digest extracellularly located proteins, e.g. collagen, proteoglycans, elastin or fibronectin. Among MMPs, collagenases (MMP-1, MMP-8 and MMP-13) and gelatinases (MMP-2 and MMP-9) can cleave collagen particles to forms that are able to undergo further steps of catabolism intracellularly. In addition, activity of the gelatinases (as an activation of proinflammatory cytokines) facilitates spreading inflammation that is necessary during the first stage of bone healing. Further studies related to the role of various MMPs in mandibular fractures should precisely explain their function in the bone healing and evaluate the influence of MMPs inhibitors on that process. This review provides the basic information about two groups among MMPs family, collagenases and gelatinases, and their role in repairing processes after mandibular fractures.