Bone Formation by Distraction Clinical and Structural Studies

摘要

A positive bone-remodelling balance may be sustained by above-optimal strain application. Obviously, these strains are also self-regulating since, once bone mass has increased or adapted sufficiently to the high or inappropriate strain, the stimulus itself disappears But if osteogenic stimulation is not sufficient, under bone remodelling a progressive bone loss will occur This is the scenario that should be taken into consideration when evaluating the processes involved in bone distraction performed to augment bone mass if the bone must be prevented from becoming brittle (i.e. incapable of withstanding a normal functional load bearing). To evaluate the morphostructural stiffness of mandibular bone mass augmented under distraction, we carried out an ultrastructural study and compared the regeneration parameters of different control and gradually distracted bone samples. Osteogenesis in the distraction groups showed a prevalently stress-strain structural orientation and a structural complexity that was in line with clinical-mechanical observations. These data also open attractive prospects for the further improvement of mechanical tissue stiffness during distraction processes, locally favouring intramemebranous ossification through injection of BMP associated with polysaccharide and nanostructured HA particles, as already shown by our group in other bone-tissue-regenerating models.