**2. Relationship between root caries and alveolar bone loss Yayoi people of ancient Japan**

#### **2.1.1 Material**

We studied 5,010 teeth and the surrounding alveolar bones in 263 ancient human skeletal remains excavated at 49 archeological sites, and which are preserved at the Kyushu University Faculty of Medicine. The distribution of each site are shown in Figure 1. The remains, which were classified as belonging to the Yayoi period, included 152 males, 100 females, and 11 unknowns. The remains were further categorized by age as follows: young adults (estimated age 20–39 years, *n* = 126), and elderly (estimated age 40–59 years, *n* = 137). Gender and age were assigned in accordance with the standard procedures of the Department of Anatomy, Faculty of Medicine, Kyushu University. Only remains with teeth and alveolar bone were selected.

Fig. 1. Location of sites
