Doctoral Dissertation Research: Enamel Defects, Well-Being and Mortality in a Medieval Danish Village

重建过去种群的人口和健康状况一直是体质人类学的主要研究方向之一，这不仅是为了了解特定种群是如何生活和发展的，也是为了更好地理解人类与环境之间的一般生物相互作用。牙釉质内的发育缺陷被称为强化纹（AS），是在生理压力时期形成的，在以前的骨骼研究中被用来衡量过去人口的营养和疾病经历，因为对活着的人的研究表明，牙齿缺陷与营养压力和疾病时期有关。然而，骨骼样本中AS数量较高表明营养较差和疾病负荷较高的人群的假设受到两个因素的混淆。首先，尚不清楚一个人的牙列中存在AS是否一定意味着这个人比其他人有更高的死亡风险，因为这个人必须在压力事件中幸存下来才能获得缺陷。其次，即使AS与较高的死亡风险有关，但一个人群中个体的营养水平和疾病水平不同，这一事实将导致骨骼样本高度选择“最弱”的个体，从而提高了曾经活着的人群中营养压力和疾病的明显水平。本研究使用生存分析方法，在一个中世纪丹麦村庄的骨骼中测试AS与死亡年龄之间的关系，以确定那些死亡风险较高的个体（那些在年轻时死亡的人）是否有更高的AS发病率。使用生存分析校正了来自健康水平不同的人群的选择性骨骼样本。该项目可能表明，AS与健康的关系比以前认为的要复杂得多，但也提供了更多信息，并将有助于在古人口研究中继续使用一种方法，以了解骨骼病理与健康之间以及健康与工业化前人口过程之间的关系。

The reconstruction of the demography and health of past populations has been one of the major endeavors in physical anthropology, not only to understand how specific populations lived and developed, but to better understand the general biological interactions between humans and their environments. Developmental defects within tooth enamel called accentuated striae (AS), which form during periods of physiological stress, have been used in previous studies of skeletons as a measure of the past population's nutrition and disease experience, since studies of living people have shown that tooth defects are associated with periods of nutritional stress and disease. However, the assumption that a higher number of AS in a skeletal sample indicates a population with poorer nutrition and a higher disease load is confounded by two factors. First, it is not clear that the presence of AS in an individual's dentition necessarily means that the individual had a higher risk of death than other individuals, since the individual would have to have survived a stress event in order to acquire the defect. Second, even if AS are associated with a higher risk of death, the fact that individual levels of nutrition and disease vary within a population will result in a skeletal sample that is highly selected for the "weakest" individuals, thus elevating the apparent levels of nutritional stress and disease in the once-living population. This study uses survival analysis methods to test for a relationship between AS and age at death in skeletons from a medieval Danish village to determine whether those individuals with a higher risk of death (those dying at younger ages) had a higher incidence of AS. Using survival analysis corrects for the selective skeletal sample that results from a population with heterogeneous levels of health. The project may show that the relationship of AS to health is much more complex, but also more informative, than previously thought, and will contribute to a method that continues to be used in paleodemographic research to understand the relationship between skeletal pathology and health and between health and preindustrial population processes.