Mechanical Influence of Edentulous Mandible Morphology on Peri-implant Bone in Implant Prosthetics: 3D Finite Element Analysis

Purpose: To examine the mechanical influence of edentulous mandible morphology on peri-implant bone in implant prosthetics via finite element analysis (FEA). Materials and Methods: Computed tomographic (CT) data from 25 patients with edentulous mandibles were selected. Measurements such as the radius of mandibular curvature and the height of the mandible at the midline were taken to clarify the morphologic characteristics of the mandible. From the measurements, two patients with the smallest and largest radii of the mandible were selected. Two types of 3D finite element models were created from the two selected edentulous mandibles (small and large radius), and they included superstructures (a cantilever bridge), implants, and abutments. In both models, four implants were placed between the right and left mental foramina. The upper surface of the mandibular condyle was constrained, and a vertical load of 100 N was applied on the occlusal surface of the right first molar. 3D FEA of each model was performed to examine the mechanical influence of the edentulous mandible morphology on the peri-implant bone. Results: The mandibular morphology measurement in the CT images indicated that the smaller the mandibular height, the larger the radius of the anterior mandibular curvature. FEA revealed that higher equivalent stress was generated in the model of the peri-implant bone with a larger radius
of curvature than that of the model with a smaller radius of curvature. The highest equivalent stress in the mandible was generated in the distal margin of the peri-implant bone posterior to the loaded side of the large-radius model. Conclusions: The mandibular morphology had a mechanical influence on the peri-implant bone.