Even without a name, fingerprints, or facial features, our history leaves indelible marks on us, locked in the atoms of the toughest structures in our bodies: the enamel of our teeth. Subtle differences in tooth chemistry could help determine the identity of fallen soldiers and other human remains—if we can learn to read that history.

Gabe Bowen, the lead researcher for the FIND-EM project, takes a groundwater sample from a well. Credit: Bowen Lab.

Now, a collaboration between geography and dentistry researchers aims to find ways to map a person’s remains to the region where they grew up, based on slight differences in tooth enamel that are determined by the composition of local tap water.

While the researchers’ immediate goal is to help identify fallen soldiers, the project has the potential to strengthen the field of forensic investigation as a whole, according to Gabe Bowen, PhD, professor of geology and geophysics at the University of Utah and the lead on the project. “The ultimate goal is to produce a resource that will be very broadly useful,” Bowen says. “Cold cases, border crossers, humanitarian crises—any situation where we end up with individuals of unknown identity.”

The molar code:

To match someone’s teeth to where they grew up, the researchers are amassing a database of teeth donated by volunteers nationwide and comparing their enamel composition to groundwater data. They’re using wisdom teeth, which are commonly removed in modern dental care.

“I think it’s beautiful that in the natural progression of people’s treatment, we would be removing these teeth anyway,” says Michael Bingham, clinical research coordinator in the School of Dentistry at the University of Utah. “We can take something that would, in theory, be discarded, and use it to do this beautiful project of reuniting families with their service members’ remains.”

While the researchers need more tooth donors to get a comprehensive map, their results so far are promising.