IOWA FLUORIDE STUDY

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。儿童和年轻人的骨矿物质量和密度是成人骨骼健康和骨质疏松症风险的重要决定因素。然而，对儿童时期骨骼发育的决定因素知之甚少，只有少数研究对儿童时期的骨骼发育和增生进行了纵向评估。在这项观察性研究中，研究人员对一组健康儿童的骨骼发育及其决定因素进行了评估。双能x线吸收仪和外围定量计算机断层扫描将用于评估9,11和13岁时的骨骼测量。结果将与儿童的纵向膳食摄入量（如钙、维生素D和蛋白质）、氟化物摄入量（饮食和非饮食）、身体活动和遗传因素有关。为了更好地了解儿童的骨量/密度，他们还评估了父母的骨量/密度，以及饮食、体育活动和遗传因素。这为深入了解儿童骨骼发育以及遗传、生活方式和家族因素的作用提供了一个独特的机会。这一点尤其重要，因为骨骼生长发生在儿童和青少年时期，骨量峰值通常在青春期晚期或成年期达到。结果可以作为未来关于改变生活方式（如饮食和体育活动）以增加骨量的建议的基础，并可能对预防骨质疏松症具有重要意义。在美国和加拿大，氟斑牙的患病率有所上升，而龋齿率却有所下降。在牙齿发育的关键时期摄入过量的氟化物是氟斑牙的主要决定因素。然而，引起氟中毒的关键时期和水平却知之甚少。很少有研究全面评估氟摄入量或氟斑牙的相关结果。在研究的牙科部分，研究人员对氟中毒和龋齿进行标准化的牙科检查，并将结果与从水、饮料、食物、膳食氟化物补充剂和牙膏中估计的氟化物摄入量的纵向数据库联系起来。在9岁（早萌牙）和13岁（晚萌牙）时进行恒牙检查。研究结果可作为今后提出更完善建议的基础，这些建议涉及氟化物的最佳使用，以最大限度地预防公共卫生龋齿，同时将氟斑牙的风险降至最低。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bone mineral mass and density in children and young adults are important determinants of bone health and osteoporosis risk in adults. However, little is known about determinants of bone development during childhood, and only a few studies have longitudinally assessed bone development and accretion in childhood. In this observational study these investigators are assessing bone development and its determinants among a cohort of healthy children followed from birth. Dual energy x-ray absorptiometry and peripheral quantitative computed tomography will be used to assess bone measures at ages 9, 11 and 13. Results will be related to children's longitudinal dietary intake (e.g., calcium, vitamin D and protein), fluoride intake (dietary and non-dietary), physical activity and genetic factors. To better understand children's bone mass/density, they are also assessing bone mass/density in the parents, along with dietary, physical activity and genetic factors. This offers a unique opportunity to provide insight into childhood bone development and the roles of genetic, lifestyle and familial factors. This is especially important since bone accrual occurs during childhood and adolescence, with peak bone mass generally achieved by late adolescence or adulthood. Results could serve as a basis for future recommendations regarding lifestyle modification (such as diet and physical activity) to enhance bone mass and could have important implications for prevention of osteoporosis. The prevalence of dental fluorosis has increased in the U.S. and Canada while caries rates have declined. Excessive fluoride intake during critical periods of tooth development is the major determinant of dental fluorosis. However, the critical periods and levels necessary to cause fluorosis are poorly understood. Few studies have asssessed fluoride intake comprehensively or related results to dental fluorosis. In the dental portion of the study these investigators conduct standardized dental examinations for fluorosis and caries and relate findings to a longitudinal database of estimated fluoride intake from water, beverages, foods, dietary fluoride supplements, and dentifrice. Examinations of the permanent teeth will be conducted at age 9 (early-erupting teeth) and at age 13 (late-erupting teeth). Results could serve as a basis for more refined, future recommendations concerning the optimal use of fluorides for maximum public health caries prevention with minimal dental fluorosis risk.