Biomechanical grounding of the transalveolar osteosynthesis of еdentulous мandible fractures

The purpose of the work is improvement of the effectiveness of the mandibular fractures treatment in patients with partial or complete adentia by developing and experimentally testing transalveolar osteosynthesis technique. An experimental study was carried out by 3D computer simulation modeling by the final element analysis to assess the efficiency of mandibular fractures fixation at partial or complete adentia using the Ш-shaped plate, which we developed for the transalveolar osteosynthesis method. Calculations of the immobilized fractures for static (own weight) and dynamic (functional) loads were performed according to the author's method, taking into account pronounced resorptive processes in the bone from the beginning of the reparative reaction to assess the rigidity of fragments fixation during the entire period of the fractures healing. Under the conditions of the same three-dimensional model of the mandible, calculations were performed when the fracture was fixed with ordinary linear titanium osseous plates. It is proved that at functional load the new plate provides a compression effect in the fractures region, as evidenced by the negative displacements in the final elements of the mental region according to the results of design load combination 2- 3. The maximum efforts in the screws of the calculation model with a conventional bone plate were 136.955 N, which is almost ten times more than on the model with a Ш-shaped titanium retainer (12.656 N).