The frequency and distribution of caries among the Iron Age population (about 2200 years BP) buried in the Mausoleum of Emperor Qinshihuang.

OBJECTIVES: The purpose of this study was to assess the prevalence, distribution, and intensity of dental caries in the Iron Age population of northern China in order to increase knowledge about the type of food, dietary habit, and social stratification in this Iron Age people. MATERIALS AND METHODS: The samples analyzed were dental remains of 1548 permanent teeth from 69 male individuals unearthed from the Qin archaeological site of Emperor Qinshihuang's Mausoleum in Lintong (northern China). The sex and the age-at-death of the samples were estimated. RESULTS: Overall frequency of antemortem tooth loss in the samples was 0.8%. The proportion of individuals with at least one carious tooth was 65.2%, and the frequency of carious lesions was 9.4%, both showing a trend to rise as age increased. Data obtained on dental caries and antemortem tooth loss provided a corrected rate of 9.5% of teeth with caries. The most frequent carious lesions were occlusal lesions (2.6%), followed by interproximal (2.5%) and buccal/lingual lesions (1.0%). Tooth type analysis showed that molars had the highest percentage of caries (18.6%), followed by premolars (4.5%), canines (3.0%), and incisors (3.0%). The total SRCI was 1.6, increasing with age. CONCLUSIONS: These findings indicate that dental caries may be related, at least in part, to the subsistence and diet of this Iron Age population.

[DNA extraction and sex determination for human teeth dated 3000 years ago unearthed in Xi'an].

OBJECTIVE: To extracted DNA from ancient human teeth dated 3000 years ago unearthed in Xi'an and determine the genders for the individuals. METHODS: Thirty five ancient human teeth were studied. A 'Reverse-root-canal' technique and a Chelex-100 solution were used to extract the DNA. Specific primers for Amelogenin gene were designed for PCR amplification. RESULTS: Genomic DNA was successfully extracted from 30 samples, for which 8 were determined to be males and 22 were females. CONCLUSION: The 'Reverse-root-canal' technique may be used for extracting DNA from ancient human teeth. Genetics method can supplement physical anthropology for determination of sex for ancient samples.

Variability in permanent tooth size of three ancient populations in Xi'an, northern China.

OBJECTIVES: This paper compares permanent dental dimensions between three ancient populations that belonged to the same biological population throughout a temporal range of 2000 years 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 (1000-1300 years BP), Shanren (2200 years BP) and Shaolingyuan (3000 years 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.

[Study of alveolar bone defects reparation by combination of bone marrow stromal cells and fibrin glue].

OBJECTIVE: To explore the effects and feasibility of the repairing alveolar bone by combination of bone marrow stromal cells (BMSCs) and fibrin glue (FG). METHODS: BMSCs were obtained from the sucking mouse and then separated, cultured to the second generation to get ready for use. The available cells were combined with FG and then immediately implanted into the defect that had been established in one lateral maxilla of 30 SD rats. At the same time pure FG without BMSCs was implanted into the other side. The rats were killed at the 3rd and 6th week after operation. The hematoxylin-eosin staining and Micro-CT were used to observe and evaluate the osteogenesis. RESULTS: New bone trabecula formed at experiment side of the rats at 3rd week. The repairing seemed better after 6th week of operation than the control side. There were only fibrous tissues in the control side or none. CONCLUSION: This experiment showed a feasible approach of repairing the defects in alveolar bone of the rats.

Prevalence of dental caries and tooth wear in a Neolithic population (6700-5600 years BP) from northern China.

OBJECTIVES: The purpose of this study was to assess the prevalence, distribution and intensity of dental caries as well as tooth wear in Neolithic population of northern China to increase our knowledge about the type of food, dietary habit and social stratification in this Neolithic population. MATERIALS AND METHODS: The samples analysed were dental remains of 1007 permanent teeth from 79 adult individuals, who were excavated from three Yangshao archaeological sites in the Xi'an district and adjacent Counties (northern China). The sex and the age-at-death of the samples were estimated. RESULTS: The frequency of antemortem tooth loss in the samples was 1.6%. The proportion of individuals with at least one carious tooth reached 41.8%, and the frequency of carious lesion was 5.7%. The most frequent carious lesions were occlusal lesions (4.4%), followed by interproximal (1.4%) and buccal/lingual lesions (0.4%). All 79 individuals were affected by attrition (100%) with various degrees of dental wear observed. The anterior teeth were much more worn than the posterior ones. The frequency of caries in men (3.9%) was significantly lower than that in women (8.1%), but the prevalence of tooth wear in men (99.0%) was significantly higher than that in women (95.2%). CONCLUSIONS: These findings indicate that both caries and tooth wear may be related to the subsistence and diet of this Neolithic population.

[Dental caries found in the human skull of Tang dynasty excavated fron Xi'an].

OBJECTIVE: To investigate the status of dental caries in the human of Tang dynasty. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.