This study aimed to clarify the mechanical stress distribution in the mandibular bone with implants supporting an overdenture using the finite element analysis (FEA) based on the morphological data and 3-dimensional (3-D) load measured in a subject. A couple of 3-D FEA models were created based on data from a 62-year-old edentulous woman, who had installed four implants in her mandible and wore an overdenture, using FEA software (Patran). One model furnished four implants aligned as in the patient. In the other model, each implant was aligned along the direction of the measured load vector in maximum clenching in the patient. The result showsthat the stress distribution was affected by the number of implants and the magnitude and the direction of occlusal load. In addition, changing the implants' alignment to the load direction reduced the von Mises stress to the result from the model as the patient.
