The Analysis Of Maxillofacial Bio-mechanics Under Various Load With Three-dimensional Finite Element Method

Object:To understand the changes of stress distribution of maxillofacial bone in different load conditions and further explore their bio-mechanical characteristics and the possible mechanism of maxillofacial fracture occurrence and the theoretical basis of rigid internal fixation and provide guidence for the diagnosis and treatment of maxillofacial fractures.Methods:l.To analyse the principal stress and stress distribution of mandible when the force act on the mandibular angle area in different direction,size and part with three-dimensional finite element method.2, To analyse the stress distribution and displacement of the central maxilla and zagoma in the different load and various working conditions with the three-dimensional finite element method.Result:1.When the force act on the lateral aspect of the mandibular angle, the Von-Mises stress distribution was larger on the ipsilateral mandibular condylar neck, jaw eminence, retromolar triangle and tongue side of chin and load the low aspect, that was larger on the bilateral condyle neck, the lateral mandibular angle, the lower edge of the mandibular angle.2. The Von-Mises stress and stress concentration area become large with the load increase in the two directions.3. the smaller the loading area, the greater principal stress and the stress change was inverse proportion to the area change.4. When the loading on the central maxilla, the stress was the larger on the ipsilateral central maxilla,the medial, lateral and floor area of the orbit, the zygoma and contralateral medial orbital wall. The displacement of ipsilateral alveolar bone was the largest. When the loading on the zagoma, the stress was larger on the zygoma, lateral orbit, orbital floor area and the nose bottom and the displacement of zygomatic load part was the largest.5. The Von-Mises stress and stress concentration area become larger with the load increase in the two loading parts. 6. The change of Von-Mises stress was smaller and stress concentration area was larger with the loading angle changes.Conclusion:1.When the static load act on the mandibular angle, the stress size of each part of the mandible was in the direct proportion to loading force, and in the inverse proportion to the loading area.2. When the loading on the central maxilla, the it was stress concentration area that the on the ipsilateral central maxilla, the medial, lateral and floor area of the orbit, the zygoma and contralateral medial orbital wall. The displacement of ipsilateral alveolar bone was the largest.3. When the loading on the zagoma, the stress was larger on the zygoma, lateral orbit, orbital floor area and the nose bottom and the displacement of loading part of zygoma was the largest.4. The Von-Mises stress and stress concentration area become larger with the loading increase in the two loading parts and the stress size was in the direct proportion to loading force.5. The stress acting on the cranio-maxillofacial complex body was a significantly different with the angle and direction change of the stress.