Abstract:
This study explores the association between periodontal disease and periostosis in a sample of 874 individuals of known age at death originating from the Terry Collection, National Museum of Natural History. Because previous studies have found a potential hyper-inflammatory immunological reaction related to periodontal disease related to the dissemination of harmful bacteria it was expected that there would be a significant relationship between periodontal disease and periostosis independent of age. Log-linear analysis found a significant association between periodontal disease and periostosis when the two variables were considered without relation to age (P < 0.008). However, when age was included in the model, no significant association was found (P < 0.390). Instead, results indicate an age dependent association between periosteal lesions (P ≤ 0.0001) and periodontal disease (P ≤ 0.0001). The results suggest that both conditions become more common as individuals age, and that the association between the two variables was best explained as chronic infection. Chronic infection has also been associated with mortality rates, therefore the other portion of this study evaluated survivorship in relation to carious lesion manifestation. Kaplan-Meir survival analysis was used to examine mortality between groups based on sex and carious lesion location on tooth surface (either crown or CEJ/root) because older individual have higher rates of periodontal disease and it was expected that these individual would have higher frequencies of CEJ/root carious lesions. Females with lesions had higher survivorship than females without lesions (P ≤ 0.0001), males with lesions (P ≤ 0.0001), and males without lesions (P ≤ 0.0001). Females with CEJ/root lesions had significantly greater survivorship than males without carious lesions (𝑥2 = 24.517; P ≤ 0.0001), males with only crown lesions (𝑥2 = 19.591; P ≤ 0.0001), and males with CEJ/root lesions (𝑥2 = 6.532; P ≤ 0.011). Females with crown lesions had lower survivorship than females with CEJ/root lesions (𝑥2 = 18.310; P ≤ 0.0001) and males with CEJ/root lesions (𝑥2 = 10.961; P ≤ 0.001). Differences in carious lesion expression within females appears around reproductive lifespan, while CEJ/root caries are found to increase in post-menopausal females. It is likely that these results represent a combination of dietary and life-history based parameters.
