Alveolar Bone Loss in Rice-cultivating Yayoi People of Ancient Japan

Abstract

The purpose of the present study was to clarify the prevalence of periodontal disease in the rice-cultivating Yayoi people of ancient Japan. The cementoenamel junction-alveolar crest (CEJ-AC) distance was examined in 295 ancient human bodies, excavated from 57 archaeological sites considered to belong to the Yayoi period in Japan (ca. 500 B.C. -300 A.D.). They were categorized by age into the adolescent group (12-39 years old, n=140), elderly group (40-70 years old, n=147), and unknown (n=8). The severity of periodontal disease was mild in the adolescent group, whereas it was aggravated in the elderly group, who also showed marked alveolar bone loss. Periodontal disease tendency was most remarkably observed in the first molar. Periodontal disease tended to become aggravated with aging in Yayoi people. We concluded that there was a higher prevalence of severe periodontal disease in the present study population as compared to reports of other ancient human peoples.