Determining the age of an individual is an important step in identification and a common challenge in forensic medicine. Age determination can be performed with high precision up to adolescence by analysis of dentition, but establishing the age of adults has remained difficult. Tooth wear and bone mineral density can provide clues, but both methods can vary widely among individuals. The enamel of individual permanent teeth is formed at distinct, well-characterized time points during childhood. After being laid down, there is no turnover of enamel, and the 14C concentration reflects the level in the carbon sources at the time of enamel formation. We measured 14C levels in portions of tooth enamel and related it to the known concentration in the atmosphere over time (1950 – present) to establish the time of tooth formation. The dates were then used to estimate the year of birth of the person. The technique matched 14C content in enamel to known age to 1.6 ± 1.3 years in individual measurements. Much of the variability can be attributed to inter-individual differences in tooth formation and possible variations in carbon food sources at the time of enamel formation. Enamel formed prior to 1950 contains no 14C elevation above atmosphere at the time. Analyzing multiple teeth with different formation ages (e.g., incisor and molar) from a single individual can place date of birth on the ascending or descending side of the anthropogenic 14C spike.
See more of Poster Session I
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)