Human Mandible: Anatomical Variation and Adaptations over the Last 2000 Years

Background/Objectives: This study explores the evolution and morphology of the human mandible, focusing on recent changes and adaptations over the last 2000 years. It aims to examine how functional, genetic, and environmental factors influence mandibular size, shape, and sexual dimorphism by analyzing key anatomical landmarks—the horizontal ramus (HR), ascending ramus (AR), and mandibular angle (MA). Methods: A retrospective approach was employed using computed tomography (CT) scans of 39 mandibular samples from various historical periods, ranging from the Roman Imperial Age to the present day. Imaging was conducted using a 64-slice multislice computed tomography (MSCT) scanner, and the resulting data were processed to generate detailed 3D reconstructions for morphological assessment. Results: The analysis reveals that present-day samples exhibit significantly less variation in AR and MA compared to archaeological specimens, suggesting a trend of gracilization over time. Statistically significant differences were found in MA, likely influenced by environmental, dietary, and cultural factors. Correlation analysis showed moderate to weak relationships between AR, HR, and MA across sample groups, with significant sexual dimorphism in AR within the archaeological sample. Principal Component Analysis (PCA) further supported these findings, demonstrating a clear distinction between gracile modern mandibles and more robust ancient ones. Conclusions: These findings provide insights into the evolutionary trajectory of the human mandible, underscoring the influence of dietary and cultural shifts on mandibular structure over the past two millennia.