Mandibular torus thickness associated with age: Postmortem computed tomographic analysis

Age estimation is an essential step in identifying human corpses. Several mandibular landmarks have been highlighted as skeletal sites for age estimation since aging causes morphological changes. Reports suggest that mandibular torus size may be associated with aging; however, thorough investigation has not been performed owing to the difficulty in measuring it. Therefore, this study aimed to determine the association between age and mandibular torus thickness using postmortem computed tomography data from Japanese corpses. This study included 2,792 corpses with mean (standard deviation) age of 58.0 (22.4) years (range, 0–101 years) and 67.6 % males. Further, 2,662 (95.3 %), 14 (0.5 %), 59 (2.1 %), and 57 (2.0 %) corpses were in the permanent, mixed, primary, and predental dentition periods, respectively. Multivariable analysis was performed to quantify the impact of age on mandibular torus thickness, adjusting for sex, height, weight, and occlusal contact status. The model also included an interaction term between age and occlusal status because of the potential effect modification by occlusion. Results of the multivariable regression analysis showed that mandibular torus thickness increased with age (the regression coefficients (95 % confidence interval) were 0.6 (0.2–1.0), 0.7 (0.3–1.0), 1.0 (0.6–1.4), 1.3 (0.9–1.7), 1.3 (0.8–1.8), and 1.1 (0.4–1.7) for age groups 30–39, 40–49, 50–59, 60–69, 70–79, and 80–89 years, respectively), especially in males with occlusal contact. A significant association between mandibular torus thickness and age, modified by occlusal status and sex, was identified. Therefore, data regarding the thickness of the mandibular torus and occlusal status may be useful for age estimation in human corpses.