Simulation And Biomechanical Evaluation On Gunshot Wound Of Human Mandible By Finite Element Method

Whether peacetime or wartime,the maxillofacial firearm wound is the important issue of maxillofacial trauma research. It's always difficult to analyze the dynamic injury procedure of gunshot wound and the biomechanical changes of injury tissues. Because the previous studies on gunshot wound is mostly based on cadaver, animal or artificial materials model, it was difficult to make an accurate analysis of dynamic injury process and relevant biomechanical changes.FEM (Finite Element Method) is the numerical methods most widely used today in engineering analysis. Because of its versatility and effectiveness, along with the rapid development of computer science and technology, it has become an important part of computer-aided design (CAD) and computer-aided manufacture (CAM).A three-dimensional (3D) mandibular finite element model was set up, its geometric shape was highly similar to the mandible. The Mimics,LS-DYNA softwares were used to make a simulation on the injury process of mandibular gunshot wound. The possibility of using finite element method to imitate the injury process of maxillofacial gunshot wound had been discussed.Method: The DICOM data obtained from CT scanning of Chinese digitized visible human female are remerged into a 3D FE model through Mimics and ANSA software, then a simulation of the 3D FE model penetrated by a 7.62mm bullet is carried out through LS-DYNA software from different angle and biomechanical parameter of mandible is analyzed.Results:1. A 3D FE model of human mandible was established with highly-identical geometric size and the dynamic process of 7.62mm bullet damage to the model was successfully simulated. The mandible model has 5927 tetrahedrons, 78 pentagons, 23480 hexagons and 164613 nodes; 2. The results of this work indicated exit wounds in model tend to be larger than the entrances resulting from the same shot.3.There was higher stress at the outside of contralateral angle under the impact to angle from 90,67.5 degree while at the side of angle from 45 degree;4. The stress changes may aggregate at the angle, body, chin and condyle of the mandible.Conclusions:The procedure of bullet damage to the mandible can be simulated by the finite element. The stress changes caused by stress wave may aggregate at the angle, body, chin and condyle of the mandible, result in change or destruction of conduction and form strong stress gradient.