Department of Anthropology, Niigata College of Nursing, Joestu, Niigata, Japan.
Gerodontology. 2012 Jun;29(2):e520-4. doi: 10.1111/j.1741-2358.2011.00511.x. Epub 2011 Jul 19.
The aims of this study were to examine the number of missing teeth in the people of the Edo period (or number of remaining teeth) and to contribute to the 8020 movement proposed in Japan to help people retain 20 or more of their own teeth until the age of 80.
The study of dentition in ancient skeletal remains of our ancestors from multiple perspectives can yield information that can contribute to the study of physical anthropology and the leading edge of modern dental research.
The materials were 82 excavated individuals (52 males and 30 females) from 1603 to 1868 whose maxillas and mandibles were both examinable. The age and sex were estimated by anthropological methods, and the individuals were divided into five groups. The status of missing teeth was compared between groups, and a chi-square test was used to test significant differences between groups. The rates of tooth loss were examined in the maxillas and mandibles.
In the people of the Edo period, many teeth remained in good condition until early to late middle age. There were more remaining teeth in these individuals than in modern-day individuals. However, the Edo people clearly showed increased tooth loss with age. There were no differences in tooth loss by sex. The tooth type with a high rate of tooth loss was posterior teeth, but incisor loss also occurred with ageing. Mandibular canines were most likely to be remaining.
The Edo people had more remaining teeth than modern-day society. This finding was unexpected. The notion that "people of long past ages lost more teeth more quickly" does not seem to apply to people in the Edo period in Japan.
本研究旨在调查江户时期（或剩余牙齿数量）人们的缺牙数量，并为日本提出的 8020 运动做出贡献，该运动旨在帮助人们在 80 岁时保留 20 颗或更多自己的牙齿。
从多个角度研究古代祖先的牙列可以提供有助于体质人类学研究和现代牙科研究前沿的信息。
本研究的材料是 1603 年至 1868 年间 82 名可检查上颌骨和下颌骨的挖掘个体（52 名男性和 30 名女性）。年龄和性别通过人类学方法进行估计，并将个体分为五组。比较各组之间缺失牙齿的情况，并使用卡方检验检验组间差异的显著性。检查上颌骨和下颌骨的牙齿缺失率。
在江户时期的人们中，许多牙齿在中年之前保持良好状态。这些人的剩余牙齿比现代人大。然而，江户人显然随着年龄的增长牙齿脱落得更多。性别对牙齿脱落没有影响。牙齿脱落率较高的牙齿类型是后牙，但随着年龄的增长，切牙也会脱落。下颌尖牙最有可能保留。
江户人比现代社会有更多的剩余牙齿。这个发现出乎意料。“过去时代的人们更快地失去更多牙齿”的观点似乎不适用于日本江户时期的人们。
