Experimental Modelling of Non-Gunshot Fractures of the Mandible

The article summarizes the results of clinical and experimental studies of the formation of mandibular fractures of non-gunshot origin depending on the direction and angle of impact, the features of destruction of its surface during jaw clamping and unclamping. To conduct an experimental reproduction of mechanical blunt trauma of the mandible, to document the localization of fractures and to determine the potential relationship between the site of impact and the site of fracture to determine the nature of bone destruction depending on both the direction of impact and the state of functioning of the jaws. The study revealed a clear pattern. Namely, fractures were formed either in the area of impact to the lower jaw or in the area adjacent to the impact site. The number of fractures also varied depending on the impact site. In no case did a blow to the same area cause exactly the same type of fracture, and the location of fractures that occurred in areas other than the impact site also differed significantly in terms of the structural geometry of the mandible. The fractures occurred consistently in areas recognized as biomechanically weak, such as the necks of the articular and condylar processes, corners, and mental foramina. There was a difference between fractures in closed and open jaws. Thus, with closed jaws, fractures from direct compression are formed on the outer surface of the jaw, and on the inner surface - tension, where the primary fracture is formed, and a bone fracture zone is formed at the site of direct contact. On the contrary, when the jaws are open, indirect fractures are formed on the opposite side. That is, when diagnosing non-gunshot fractures of the mandible, it is necessary to take into account not only the force of impact, its direction, but also the condition of the masticatory muscles during the injury and the position of the victim's head.