Finite element analysis of zygomatic implants in bilateral restoration of maxillary defect

PURPOSE:To evaluate the distribution of biomechanical stress on the craniofacial skeleton for bilateral maxillectomy reconstruction by using the vascularized fibula graft and zygoma implants,in order to provide theoretical references for restoration of maxillary defects.METHODS:Based on digital imaging and communications in medicine(DICOM) data and the image process technology,a modularized geometrical and finite element model of the human skull was built to simulate the bilateral defect pattern of the maxilla.Biomechanical properties of the zygomatic implants and the connected implants were evaluated by using finite element analysis(FEA) method.RESULTS:The deformation tendency of the zygomatic implants was identical and the displacement of bending was not noticeable.The displacement of the zygoma fixture near the zygoma was close to zero.The neck of the zygoma fixture on the fibula bone and on the zygoma bored the largest stress,while the rest of the peri-implant bones bored a lower stress.CONCLUSIONS:Stress from occlusal forces is mainly supported by the zygomatic bone and the fibular bone.The occlusal force is effectively transmitted and the stress distribution of the peri-implant bone of such reconstruction protocol is reliable.Reconstitution of the buttresses system ensures a stable support for occlusion and stress.This is a safe and effective method to optimize bilateral maxilla rehabilitation.