Pathology of deciduous teeth in the samurai and commoner children of early modern Japan

Abstract

The strict class system in place during the Edo (early modern) period in Japan is thought to have encompassed customs that differed between the samurai (ruling class) and commoners. This study found that in samurai children, deciduous caries occurred only in maxillary incisors at 0.5-2 years of age and did not occur in the mandibular incisors and canines at 3-5 years of age. Conversely, in commoner children, deciduous caries occurred in all maxillary teeth and mandibular molars at 0.5-2 years of age and in all maxillary and mandibular teeth at 3-5 years of age. In commoner children, deciduous caries was seen in tooth types that have a low incidence of deciduous caries in modern Japanese. The present results show that deciduous carious lesions appear earlier and more frequently in the commoner children compared to the samurai children, probably because of differences in lifestyle between the two groups. There was no significant difference in the incidence of enamel hypoplasia in the deciduous dentition between samurai and commoner children, suggesting that the two classes had broadly comparable nutrition. In our previous study using the same skeletal series, similar results between samurai and commoners were found with respect to caries and enamel hypoplasia prevalence of the permanent dentition. Many of the samurai adults had slick polished teeth, which we believe were caused by regular brushing of the teeth in the samurai class. Such a custom might have functioned to prevent dental caries not only in the permanent dentition, but also in the deciduous dentition. Thus, oral hygiene practices in the samurai class are thought to have functioned to prevent dental caries not only in adults but also in children.

Dental diseases of human skeletal remains from the early-modern period of Kumejima Island, Okinawa, Japan

“…For example, although no apparent regional differences were seen between the early-modern series of main-island Japan and the Ryukyu Islands, as mentioned before, a population with a quite low rate is known from the early-modern Oterayama site in Honshu (Sakura, 1985), and a rate difference between classes was reported from the early-modern Sougenji and Kyomachi sites of northern Kyushu (Oyamada et al, 2004(Oyamada et al, , 2007b. Thus, it is suggested that the rate of dental caries varied among sites or villages in the early-modern period of the Japanese archipelago, due not only to diet but also to other behavioral factors such as oral hygiene.…”

Socioeconomic Influence on Caries Susceptibility in Juvenile Individuals with Limited Dental Care: Example from an Early Middle Age Population (Great Moravia, 9th-10th Centuries A.D., Czech Republic)

“…As often mentioned, posterior teeth are more affected than anterior teeth, which confirm the differential susceptibility of the molars to be suffering from dental caries (Klein & Palmer, 1941;Oyamada et al, 2008;Saunders et al, 1997). But it is interesting to point out that some individuals are attained by carious lesions on anterior deciduous teeth in both area of Mikulčice.…”

Preliminary analysis of regional differences in dental pathology of early modern commoners in Japan

“…Many of the samurai had slick, polished teeth, and wedge-shaped defects, most likely caused by regular brushing. Such a custom of regular tooth brushing might have functioned to prevent dental caries (Oyamada et al, 2004(Oyamada et al, , 2008.…”