One Tooth, Five Stories
Richard Jonathan O. Taduran, Ph.D. | 3 September 2026
A tooth is easy to underestimate. To most people, it is simply something used to bite and chew, occasionally repaired, extracted, or lost. To forensic scientists, however, a tooth can become a biological archive.
Researchers in Japan reported in Scientific Reports that they had extracted several different kinds of forensic information from a single mandibular first premolar taken from highly decomposed or skeletonized remains. By combining radiocarbon analysis, stable isotope analysis, amino-acid racemization, DNA profiling, and toxicology, they asked how much of a person’s story can survive in one tooth.
The answer was surprisingly extensive. One tooth could help estimate when a person was born, how old they were when they died, aspects of their childhood diet and geographic background, their genetic identity, and even traces of drugs or medications they had taken.
One tooth, in other words, could tell at least five stories.
Five Imperfect Answers
The first story is time. Tooth enamel forms during childhood and never remodels, preserving the carbon-14 signature incorporated during enamel formation. Atmospheric nuclear testing in the mid-twentieth century created the distinctive rise and fall known as the nuclear “bomb pulse.” Because the same carbon-14 value can fall on either the rising or declining side of that curve, radiocarbon testing may yield multiple possible birth years. But when paired with dentin racemization estimates of age at death, the researchers narrowed the birth-year error to roughly five years.
The second story is age. Amino acids in dentin slowly change their molecular form over time through a process called racemization. Measuring that change can provide an estimate of age at death.
The third story concerns environment. Stable carbon isotopes in enamel reflect aspects of childhood diet. They cannot reveal a hometown, but they can indicate the kinds of foods that dominated a person’s early life and sometimes help narrow geographic possibilities. Other isotope systems, including oxygen and strontium, can potentially add further information about geographic origin and mobility.
The fourth story is genetic identity. DNA recovered from the tooth allowed sex estimation in all 15 cases, while autosomal STR profiles suitable for individual identification were obtained in 12 of 15 cases. Mitochondrial and Y-chromosome markers could contribute additional information about maternal and paternal lineages.
The fifth story lies in chemistry. Drug residues found in dental tissues sometimes corresponded with medications or substances documented elsewhere in the body. Teeth may therefore preserve evidence of exposure even after blood and soft tissues have disappeared.
Each technique is imperfect and answers a different question. Together, however, they begin to describe a person.
How Much of a Tooth May We Spend?
The real significance of the study is not that any one of these methods is new. Radiocarbon dating, DNA profiling, isotope analysis, amino-acid racemization, and forensic toxicology have all existed independently for years. What is striking is that several can now be applied simultaneously to different anatomical components of a single tooth—enamel for radiocarbon and stable isotope analysis, dentin for amino-acid age estimation, dentin and cementum for DNA profiling, and pulp and dentin for toxicological screening.
That matters because forensic evidence is finite.
A skeleton recovered from a grave, disaster site, river, burned structure, or remote outdoor environment may be incomplete. Teeth may be among the best-preserved tissues available. Yet many forensic techniques are destructive: once enamel, dentin, pulp, or cementum has been consumed for analysis, that material cannot simply be replaced. Even this study had to divide a single premolar among tests. The racemization work used outer dentin rather than the more informative central dentin, and the authors noted that the compromise may have cost them accuracy.
This creates a practical and ethical problem. How much should investigators take? Which test should be prioritized? How much should be preserved for reanalysis, especially when future techniques may be more powerful than those available today? The question is no longer simply whether a laboratory can extract information from a specimen, but whether doing so is the best use of a limited biological resource.
These questions are particularly relevant in countries such as the Philippines, where heat, humidity, water exposure, fire, scavenging, and delayed recovery can rapidly reduce the amount of usable biological material. In mass disasters or cases involving fragmented and commingled remains, investigators may have very little tissue to work with.
The study therefore points toward a broader forensic principle: obtain as much reliable information as possible while consuming as little irreplaceable evidence as necessary.
It also reinforces the value of convergence. One method may suggest age, another environment, another sex, and another a possible identity. Every method carries its own uncertainty. But when independent lines of evidence repeatedly point in the same direction, investigators gain something more persuasive than any single measurement could provide.
The Body as Archive
A tooth cannot reconstruct an entire life. It cannot tell investigators a person’s name without comparison data, identify an exact hometown from one isotope ratio, or prove that a detected drug caused death. Forensic measurements still require interpretation, context, and caution.
But the study offers a compelling reminder of how much of human experience becomes embedded in the body.
Our genes record inheritance. Isotopes record aspects of what we ate and where we lived. Molecular changes record the passage of time. Drugs leave chemical traces. Dental tissues preserve childhood long after childhood itself has disappeared.
Death ends the life, but it does not immediately erase these records.
Forensic science has always depended on learning how to read what remains. What is changing is the amount of information that can be recovered from less and less material.
Sometimes, all that remains is one tooth.
And one tooth may still have five stories left to tell.