Doctoral Dissertation Improvement: Deciduous tooth emergence, nutritional status, and weaning and feeding decisions in the Brazilian Amazon

这项研究调查了产前和产后营养如何与牙齿萌出有关，反过来，发育中的牙齿在母亲断奶和喂养决定中的作用。断奶年龄是一个重要的生活史特征，因为母乳喂养和生育间隔之间存在公认的关系，最终影响到母亲一生的生育成功率。在非人类灵长类动物和人类中都发现了断奶年龄、母亲状况和婴儿营养和生长之间的联系。此外，人类母亲在做出断奶和喂养决定时，会将婴儿的生长发育状况作为线索。在Guatelli-Steinberg博士的指导下，由俄亥俄州立大学的博士生Jennifer Spence进行的这项研究，解决了一个相对未被探索但重要的问题：发育中的牙齿是如何参与这些关系的。本研究采用人体测量和民族志方法，1)采用可靠的妊娠期测量技术，准确评估产前产妇营养状况和产后婴儿营养状况与乳牙（乳牙）出现时间之间的关系；2)确定乳牙出现的时间与断奶过程开始的年龄的关系程度；3)调查乳牙的存在如何影响母亲的断奶和喂养决定。据推测，母亲和婴儿的营养都与乳牙出现的时间有关，这反过来又会影响断奶和喂养的决定。该项目以巴西东部亚马逊地区的Ribeirinho种群为背景，该地区的特点是营养紧张，断奶和喂养方式各不相同。这项研究是STEM计划的一部分，旨在让服务不足的公立学校学生熟悉社会科学，尤其是人类学。该项目通过让当地妇女参与数据收集，促进与巴西非学术界的合作，并通过大学研讨会促进与学术界的合作。计划开展一项运动，在当地社区制作和传播非技术材料，以鼓励良好的营养和牙齿健康。

This research investigates how prenatal and postnatal nutrition relate to dental eruption and, in turn, the role of the developing dentition in mothers' weaning and feeding decisions. Weaning age is a critical life history characteristic because of the recognized relationship between breastfeeding and inter-birth intervals, and, ultimately, mothers' lifetime reproductive success. Links among weaning age, maternal condition, and infant nutrition and growth have been found in both non-human primates and humans. In addition, human mothers use infants' growth and developmental status as a cue when making weaning and feeding decisions. This research, by doctoral student Jennifer Spence (Ohio State University), under the guidance of Dr. Guatelli-Steinberg, addresses a relatively unexplored yet significant question: how the developing dentition is involved in these relationships.Using anthropometric assessment and ethnographic methods, this research 1) employs a reliable technique of gauging gestation duration to accurately evaluate the association between prenatal maternal nutritional status and postnatal infant nutritional status, and the timing of deciduous (primary) tooth emergence; 2) determines the extent to which the timing of deciduous tooth emergence is related to the age at which the weaning process begins; and 3) investigates how the presence of deciduous teeth affects mothers' weaning and feeding decisions. It is hypothesized that both maternal and infant nutrition are associated with the timing of deciduous tooth emergence, which is in turn predicted to influence weaning and feeding decisions. This project is set among Ribeirinho populations in the eastern Brazilian Amazon, an area characterized by nutritional stress and with variation in weaning and feeding practices.This research is part of a STEM initiative familiarizing underserved public-school students with the social sciences, particularly anthropology. The project promotes collaboration with Brazilian non-academics through inclusion of local women in data collection and academics through a university seminar. A campaign is planned to create and disseminate nontechnical material in local communities to encourage good nutrition and dental health.