Chen Shisheng, Lv Yanyi, Wang Dian, Yu Xiaojun
Department of Dentistry, Shantou University Medical College 2nd Affiliated Hospital, Shantou 515041, Guangdong Province, People's Republic China; Department of Forensic Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, People's Republic of China.
Department of Forensic Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, People's Republic of China.
Forensic Sci Int. 2016 Sep;266:234-238. doi: 10.1016/j.forsciint.2016.06.010. Epub 2016 Jun 14.
Aspartic acid racemization in teeth has been increasingly used to estimate chronological age with a considerably high accuracy in forensic practice. The Chaoshan population in South China is relatively isolated in geography, and has specific lifestyle and dietary inhibits. It is still unknown whether this method is suitable for this population. The aim of this study was to analyze the relationship between chronological age and the d/l aspartic acid ratio in dentin in the third molar tooth of the Chaoshan population. Fifty-eight non-carious third molar teeth (31 mandibles and 27 maxillae), from 58 living individuals of known age (24 males and 34 females), were retrieved. Dentin was extracted from these teeth. The d- and l-aspartic acids in dentins were separated and detected by high performance liquid chromatography (HPLC). Linear regression was performed between the d/l aspartic acid ratio of dentins and chronological age. Results showed that the correlation coefficient (r) was 0.969, and the mean absolute error (MAE) was 2.19 years, its standard deviation (SD) was ±1.53 years, indicating excellent correlation. There was no significant difference in racemization rates of dentin between sexes (P=0.113, F=2.6), or between mandibles and maxillae (P=0.964, F=0.000). Results indicate that the ratio of the d and l forms of aspartic acid of dentins, in the third molar, is closely correlated with chronological age, special lifestyle do no obviously affect the accuracy of the age estimations by aspartic acid racemization of the dentin in the third molar and that aspartic acid racemization in the third molar dentin can be used as an accurate method to estimate chronological age in the Chaoshan population in South China.
牙齿中天冬氨酸消旋作用已越来越多地用于法医实践中按时间顺序估算年龄，其具有相当高的准确性。中国南方的潮汕人群在地理上相对隔离，有着特定的生活方式和饮食禁忌。该方法是否适用于此人群仍不清楚。本研究的目的是分析潮汕人群第三磨牙牙本质中天冬氨酸d/l比值与按时间顺序估算的年龄之间的关系。从58名已知年龄的在世个体（24名男性和34名女性）中获取了58颗无龋的第三磨牙（31颗下颌牙和27颗上颌牙）。从这些牙齿中提取牙本质。通过高效液相色谱法（HPLC）分离并检测牙本质中的d-和l-天冬氨酸。对牙本质的d/l天冬氨酸比值与按时间顺序估算的年龄进行线性回归分析。结果显示，相关系数（r）为0.969，平均绝对误差（MAE）为2.19岁，其标准差（SD）为±1.5岁，表明相关性极佳。牙本质消旋率在性别之间（P=0.113，F=2.6）或下颌牙和上颌牙之间（P=0.964，F=0.000）均无显著差异。结果表明，第三磨牙牙本质中天冬氨酸d型和l型的比值与按时间顺序估算的年龄密切相关，特殊的生活方式并未明显影响通过第三磨牙牙本质天冬氨酸消旋作用估算年龄的准确性，且第三磨牙牙本质中的天冬氨酸消旋作用可作为一种准确方法用于估算中国南方潮汕人群按时间顺序的年龄。
