BIOMECHANICAL JUSTIFICATION OF THE CHOICE OF OPTIMAL FIXATION OF BONE FRAGMENTS OF THE LOWER JAW WHEN PLACING THE TOOTH IN THE FRACTURE LINE

Abstract

The presence of teeth on the lower jaw leads to a decrease in the volume of bone tissue of the jaw and, as a result, a decrease in the strength in the cross-sections of the jaw in the places where the dental holes are located. One of the main factors that affect the localization of fractures within the dentition is the presence of dental holes, through which, most often, fracture lines pass. In patients with a temporary dentition, factors that further “weaken” the lower jaw (reduce the volume of bone tissue in the jaw), without a doubt, can be attributed to the presence of rudiments of permanent teeth, through which fracture lines pass. The study of the stress-strain state of fixing plates, screws that hold them and directly hard tissues of the dentoalveolar series in the area of localization of traumatic fracture of the lower jaw is most expedient to perform using finite element analysis, the prospects of which in solving various biomechanical problems in modern dentistry have recently been increasingly confirmed in the works of both foreign and domestic authors. The purpose of our work. Justification of the choice of rational fixation for accurate anatomical reposition of fragments when placing a tooth in the line of a traumatic fracture of the lower jaw by conducting a biomechanical study. Materials and methods of research. We performed mathematical modeling using the well-known modeling package and finite element analysis FEMAP 10.2.0, designed for implementation in the Windows environment on a personal computer. Studies were performed on models of the lower jaw with overall cross-sectional dimensions corresponding to some average dimensions. Fixing of three-dimensional models of the lower jaw with different locations of fractures was carried out in the nodes of finite elements located at the sites of attachment of the masticatory muscles. Conclusions. One of the main factors that affect the localization of fractures within the dentition is the presence of holes of teeth and rudiments of permanent teeth, their topography, which significantly reduce the area of bone tissue in the crosssections of the jaw and through which, most often, the lines of fractures pass. For reliable fixation of fragments of the lower jaw with the possibility of perceiving functional loads that occur when chewing food, we can recommend fixing the fracture with two mini-plates.