Objective:To analyze the relationship between chronological age and the D/L aspartic acid ratio in dentin of the first premolar of Chaoshan population.Methods:Sixty first premolar teeth from living individuals of known age 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)system.Linear regression was performed between the D/L aspartic acid ratio of dentins and chronological age.Dentin from ano...