Reliability Analysis of Zygomatic Implants Based on Quad Approach

Objectives: To perform stress analysis and fatigue lifetime prediction of a zygomatic implant-supported maxillary prosthesis based on quad approach using three-dimensional (3D) finite element analysis (FEA).
Methods: 3D models of a standardized human skull, a full-arch maxillary prosthesis, and four zygomatic implants were created and assembled in a medical image processing software (Mimics) based on the images generated by micro-computed and cone-beam computed tomography. Severe maxillary atrophy was simulated using segmentation and 3D editing tools. The final volume meshes were exported to a commercial FEA software ABAQUS, where the respective material properties and boundary conditions were applied. Stress analysis was conducted under various loading scenarios. Fatigue lifetime prediction was then performed using FE-Safe based on the static results.
Results: The peak stress in the zygomatic implants was located in the abutment connection area. Peak stress values were within the material strength limit for both implant and surrounding bone tissue. It has been predicted that the lifetime of zygomatic implants based on quad approach exceeded the equivalent of 40 years of service time with given loading condition.
Conclusions: A quad zygomatic implant-supported prosthesis is a viable and reliable option for the rehabilitation of severe maxillary atrophy. However, additional consideration should be placed on the abutment connection of zygomatic implants due to stress concentration.