On experimentally produced model of mandible fractures (on 18 rabbits) the efficacy of compression osteosynthesis was compared with fixation by usual plates (non-compression osteosynthesis). As was shown by histological study and morphometrical analysis of tissue structures from the region of experimentally isolated in rabbit mandible bone fragments fixed by microdevices for compression and non-compression osteosynthesis in cases of compression osteosynthesis if compared with non-compression osteosynthesis at the experimental terms of 2, 3 and 4 months more intensive new formation and secondary rebuilding of bone tissue with its compactification in the region of cortical layer happened. Histological study and morphometrical analysis of histological pictures showed that reparative osteosynthesis processes were activated in cases of compression osteogenesis not only in cortical but also in sponge layer that together with contact enforcing of the edge of experimentally isolated bone fragment with maternal bone and bone splinters fixation strengthening stipulated for integral positive effect in the form of bone integrity restoration acceleration. In case of non-compression osteosynthesis the processes of reparative bone formation were observed mainly in cortical layer region, in sponge layers they were expressed poorly.