Periodontal diseases in 104 skulls about 2,200 years ago

Objectives: The purpose of this study was to evaluate the state of periodontal disease of the people about two thousands years ago. Methods: 2,452 teeth of 104 skulls about two thousands year ago were observed which were excavated from the famous site of Emperor Qinshihuang's Mausoleum and Terra-Cotta Warriors and Horses in the Xi'an city, Shanxi Province of China. All the objects were male, from 15 to 45 years old. They were divided into three groups according to their age. The periodontal disease of each tooth was described. Results: The prevalence of periodontal disease was 49.04 per cent. There were 343 teeth suffered periodontal disease in 51 objects, which were 13.99 per cent in the whole teeth. There was a significant difference in the prevalence of periodontal disease among the different age groups (P<0.01). The prevalence of periodontal disease in the group that was above 30 years old of age was the highest (76.19 per cent) while the group that was less than 20 years old of age was the lowest (40.48 per cent). Among the whole teeth which had the periodontal disease, the proportion of the first molar was the highest (36.15 per cent) and the proportion of the central incisor was the lowest (5.25 per cent) according to the tooth position. The prevalence of periodontal disease in maxillary teeth and in mandibular teeth was 12.75 per cent and 15.27 per cent respectively. There was no significant difference between the two regions (P>0.05) yet. Conclusions: The periodontal disease was common two thousands years ago. And the prevalence of it increased with age.