There are difficulties for dental implant use in posterior mandible when there is little bone height for implant placement. Among the treatment alternatives available, there is no direct comparison between short implants and conventional implants placed with lateralization of the inferior alveolar nerve. The present study aimed to comparatively evaluate the risk of peri-implant bone loss of the above treatments. With this aim, computed tomography scans of mandibles were processed, and implants and prosthetic components were reverse engineered for reconstruction of three-dimensional models to simulate the biomechanical behavior of 3-element fixed partial dentures supported by 2 osseointegrated implants, using simulations with the finite element method. The models of implants were based on MK III implants (Nobel Biocare) of 5- and 4-mm diameter by 7-mm length, representing short implants, and 4- and 3.75-mm diameter by 15-mm length, representing implants used in lateralization of the inferior alveolar nerve. All models were simulated with prestress concerning the stresses generated by the torque of the screw. Axial and oblique occlusal loads at 45% were simulated, resulting in 8 different simulations. The results showed that the risk for bone loss in osseointegrated implants is greater for treatments with short implants.