Ohtani S
Department of Forensic Medicine, Kanagawa Dental College, Japan.
J Forensic Sci. 1995 Sep;40(5):805-7.
An attempt was made to estimate the age of cementum using the racemization method, which focuses on the ratio of D- and L-aspartic acids (referred to as the 'D/L ratio'). Using the whole cementum, the correlation coefficients between the D/L ratio and age were r = 0.984 to 0.997. When the use of incisors and premolars was compared, the former gave better results than the latter. We then made a comparison of cementum, enamel and dentin, using a first premolar from the same individual. For each component tissue the correlation of D/L ratio with the actual age was calculated and the highest value was shown for dentin at r = 0.992, followed by cementum at r = 0.988 and enamel at r = 0.961. These results show that the racemization reaction in cementum proceeds at a constant rate, and confirm that cementum, like dentin, is a tissue with very low metabolism. Therefore, it is clear that accurate estimation of age is practically possible using the amino acid racemization method for cementum.
研究人员尝试采用消旋化方法来估算牙骨质的年龄，该方法聚焦于D-天冬氨酸和L-天冬氨酸的比例（称为“D/L比率”）。使用完整的牙骨质，D/L比率与年龄之间的相关系数为r = 0.984至0.997。当比较切牙和前磨牙的使用情况时，前者的结果优于后者。然后，我们使用同一个体的第一前磨牙，对牙骨质、牙釉质和牙本质进行了比较。对于每个组成组织，计算了D/L比率与实际年龄的相关性，结果显示牙本质的相关性最高，r = 0.992，其次是牙骨质，r = 0.988，牙釉质的相关性为r = 0.961。这些结果表明，牙骨质中的消旋化反应以恒定速率进行，并证实牙骨质与牙本质一样，是一种新陈代谢非常缓慢的组织。因此，很明显，使用氨基酸消旋化方法对牙骨质进行年龄的准确估算是切实可行的。
