Purpose: To examine human mandibular angle integrity alterations accompanying a mandibular body block graft harvest surgical procedure. Materials and Methods: Hemimandibles from 24 human cadavers were resected and sorted into one of three groups by residual dental status. The height of each hemimandible body was obtained and recorded. Acrylic bone cement was utilized to mount the hemimandibles at the mandibular condyle. Using standard surgical instruments and techniques, cortical bone of the mandibular body buccal plate was resected from the right hemimandibles. Left hemimandibles were used as a control. Each hemimandible was secured in an Instron 5565 mechanical unit. With forces placed on and perpendicular to the occlusal plane, each hemimandible underwent sequential loading until osseous fracture occurred. Descriptive statistics between grouped data were compared and discussed in terms of mean, minimum, and maximum. The statistical relationship between the maximal load, sex, and mandibular body height were identified. Results: Donor and control hemimandible maximal load mean values were 423.63 N and 957.90 N, respectively. A statistically significant difference was present between maximal loads of donor and control hemimandibles (P .0001). Correlations of statistical significance were present between mandibular bone height and maximal load in the control hemimandibles (P = .009). Correlations of statistical significance were not found between mandibular bone height, displacement at maximal load, and maximal load in the grafted hemimandibles (P > .05). No statistically significant correlation between dental status and sex was found in the donor and control hemimandibles (P > .05). Conclusion: After being subjected to a typical block graft harvest surgical procedure, the human mandible's integrity is significantly altered. Sex, dental status, and mandibular bone height do not correlate with maximal load, and thus, integrity, of donor and control mandibles. Keywords: human mandible, mandible integrity, mandibular body block graft, osteotomy