Socio-economic inequality is known as one factor affecting human health, and it leads to health inequalities. This study aimed to clarify the relationship between socio-economic and health inequalities within one city during the Edo period. This study utilized 77 human skeletal remains, which were estimated to be from individuals of the samurai caste during the Edo period, across 2 sites (the Kaizenji Temple site and the Kyomachi site) within the city of Kokura in Northern Kyushu, Japan. This study examined the age at death, the frequencies of enamel hypoplasia, cribra orbitalia, dental caries, and antemortem tooth loss, and investigated archaeological information about the cemeteries, such as differential mortuary treatment, elaborateness of graves, density of graves, and the quantity of burial goods. Results showed that females from the Kaizenji temple site died significantly earlier than males from the Kaizenji temple site. Also, the frequencies of enamel hypoplasia, dental caries, and antemortem tooth loss in the Kaizenji Temple site tended to be lower than in the Kyomachi site. In addition, the density of graves and the proportion of jar coffins differed between the two sites and suggests the possibility that the Kaizenji Temple site contained a group with higher socio-economic status than the Kyomachi site. These results from two archaeological sites in Kokura city confirmed that socio-economic inequality indeed impacted health status during the Edo period.

In this study, we morphologically examined whether aristocratic characteristics are present in the skulls of the successive family heads and legal wives of the Nagai family, the hatamotos of the Tokugawa Shogunate, excavated in 2017 from the Kounji site in Minato, Tokyo. The skulls of the Shoguns and the Daimyos, who were at the top of a hierarchical society in the Edo period, show distinctive features that differ from those of the common people of Edo city, such as exceptionally high and narrow face, high and roomy orbit, extremely narrow and prominent nose, highly reduced mandible, and faint tooth wear. The skeletal remains of the Nagai family reveal genealogy spanning nearly 200 years, including ten patriarchs and seven legal wives, and constitute valuable ancestral material of the hatamoto family, which has never been reported before. The results of this study showed that the skulls of both, the heads and the legal wives of the Nagai family, demonstrate a tendency toward aristocratic characteristics, with the features of the heads resembling those of the Daimyos, and the features of the legal wives resembling those of the legal wives of the Shoguns and the Daimyos. However, the heads of the Nagai family had a sturdy mandible, similar to that of the common people, and the aristocratic characteristics did not tend to become stronger with successive generations. The relationship between the craniofacial morphology and the samurai hierarchy shows that the aristocratic characteristics were hierarchical. The supposed reason for the Nagai family’s aristocratic characteristics is that they were of the Daimyo lineage and had a high rank of 7000 koku among the hatamotos. Since the tooth wear of the heads of the Nagai family was minor, it is necessary to examine possibilities other than diet as factors in the robustness of the mandible.