Purpose: Following resection of malignant tumors from the mandible, immediate reconstruction of the discontinuous jaw is commonly performed. The present study aims to define the risks associated with dynamic loading of the reconstructed mandible. Materials and Methods: Computer-aided design simulations of eight mandibles were produced and termed normal models. The normal models were then modified by removing part of the right body and restoring the defects with bone from the rib or fibula. These modified models were termed reconstructed models. Thereafter, an implant was embedded in the first molar region of the left side for all models. Using finite element analysis, the stresses occurring at the implant-bone interface with simulated mastication were calculated. The Wilcoxon signed rank test was applied to compare the magnitudes of stresses in both models. Results: In terms of the stress exerted at the implant-bone interface during mastication, the normal models and the reconstructed models showed no significant differences (P > .05). Conclusion: Placement of an implant on the nonreconstructed side following partial resection and mandibular reconstruction presents no significant risk. Keywords: fibula, implant, mandible, reconstruction, rib, stress