It was a eureka moment for anthropologist Paola Cerrito.

“We weren’t expecting the results,” she said about a set of skeletons from Malawi, Central Africa. 

The skeletons were accompanied with extensive medical records and thoroughly documented personal histories.

“I had an ‘ah-ha moment’ when looking at the thin sections under the microscope and thinking that I could try to match what I saw with data regarding the specific life events of individuals,” says Ms. Cerrito.

The thin sections she talks about were cementum, the dense, rigid and hard material that covers the root of each tooth.

The bone-like cementum is a connective tissue that firmly puts in place a tooth’s fibers to the jawbone.

Over time, cementum forms layers, and there hangs a tale.

When a tooth emerges from the gumline, the cementum starts forming tell-tale signs much like those that appear on the rings of a tree.

And similar to the rings of a tree, the cementum forms layers or bands. Ms. Cerrito and the research team then connected the formation of each band to specific periods that the tooth has passed through – just like the rings on trees that chronicle the life stages of a tree.

The researchers did this by looking at the 47 sets of teeth from the 16 people of Malawi between the ages of 25 and 69. They matched the cementum to medical history and personal lifestyle data.

This is how Ms. Cerrito and her research team from New York University’s (NYU) Department of Anthropology and College of Dentistry were able to chronicle the specific life events connected to tooth formation.

“Our results make clear that the skeleton is not a static organ, but rather a dynamic one,” she says.

What they found was that the cementum chronicled past lives, putting in layers at the base of the tooth significant events that impact on personal lives, according to her study published in March in the journal “Scientific Reports.”

“The discovery that intimate details of a person’s life are recorded in this little-studied tissue, promises to bring cementum straight into the center of many current debates concerning the evolution of human life history,” says Timothy Bromage, a professor at NYU’s College of Dentistry and the study’s co-researcher.

According to Mother Nature Network, the life story written on teeth is so meticulous that it was like a life diary, recording experiences from birth to divorce to disease to menopause – all etched in stone, in this case the cementum.

“Just like tree rings, we can look at ‘tooth rings’: continuously growing layers of tissue on the dental root surface,” Ms. Cerrito explains in a press statement.

“These rings are a faithful archive of an individual’s physiological experiences and stressors from pregnancies and illnesses to incarcerations and menopause that all leave a distinctive permanent mark.”/WDJ