By analyzing how much racemization of its aspartic acid occurred, scientists can determine how old the tooth's owner was at death - generally accurate to about 5.5 years, plus or minus 4.2 years.

通过分析其天冬氨酸发生了多少外消旋化，科学家可以确定牙齿主人在多大岁数死亡——通常精确到5年半左右，正负差4.2年。