Dai-yun Liu

Fourth Military Medical University, Xi’an, Liaoning, China

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Publications (2)1.65 Total impact

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    ABSTRACT: OBJECTIVES: This paper compares permanent dental dimensions between three ancient populations that belonged to the same biological population throughout a temporal range of 2000years to detect temporal trends and metric variation in dentition. MATERIALS AND METHODS: The samples analysed were dental remains of 4502 permanent teeth from 321 individuals, which were excavated from three archaeological sites: Chang'an (1000-1300years BP), Shanren (2200years BP) and Shaolingyuan (3000years BP) in the Xi'an region (northern China). For each tooth three standard measurements were taken: Mesiodistal (MD) diameter of crown, labiolingual or buccolingual (BL) diameter of crown and length of root (LR). RESULTS: Three ancient population samples generally displayed the same dental dimensions (p>0.05), whereas some tooth types varied. The Shaolingyuan had larger canine and the smallest maxillary second molars and the Chang'an had the largest mandibular first molars in the MD dimension. The Shanren had the smallest maxillary third molars and mandibular central incisors, and the Chang'an had the smallest maxillary lateral incisors in the BL dimension. In the LR measures, statistically significant differences of five tooth types showed that the Chang'an were smaller than the Shaolingyuan and the Shanren. Comparisons of coefficients of variation for teeth showed that the length of root and third molar usually displayed greater variation. CONCLUSIONS: Decreasing or increasing trend for crown size does not occur between the ancient populations, while changes in crown size of a few tooth types fluctuate. The root size is more variable than the crown size and is likely to reflect a degenerated trend in a few tooth types.
    Archives of oral biology 05/2012; · 1.65 Impact Factor
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    ABSTRACT: To investigate the status of dental caries in the human of Tang dynasty. All teeth in 62 human skulls of Tang dynasty excavated from the Chang'an county in Xi'an city were examined and analyzed by statistics. The difference of prevalence in different group including age, sex and tooth position was tested with Chi-square test. The prevalence of dental caries was 62.9%. And there were 92 caries teeth, which was 14.6% of the whole teeth. The root caries (33.3%) was more than the occlusal caries (28.7%). The most frequent recorded caries were the third molar, followed by the second molar, then the first molar. There was no significant difference between male and female. The dental caries was popular in human of Tang dynasty, but the prevalence lowers than the modern people. And with the human evolution and the improvement of the social productivity, the prevalence of dental caries was gradually ascending.
    Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 12/2008; 43(11):686-8.