When one stops to ponder the signs of a full life, a few physical characteristics come to mind; wrinkled skin, gray hair, scars, rough hands. Now, thanks to a truly groundbreaking new study conducted at New York University, it looks like teeth will have to be added to that list.
Besides perhaps a few extra cavities, teeth have never really been seen as a physical feature that changes all that much throughout one’s life. These findings change that entire narrative by suggesting that one’s teeth display a “biological archive” of their entire life. Major life events like giving birth and menopause (among women) or developing a serious illness are recorded in the teeth.
These findings just go to show the profound impact that stress can have on the body. Even upsetting ordeals such as being imprisoned are recorded in the teeth.
“Our results make clear that the skeleton is not a static organ, but rather a dynamic one,” explains lead study author Paola Cerrito, a doctoral candidate in NYU’s Department of Anthropology and College of Dentistry, in a press release.
Our teeth change in response to the events of our life. Similar to the rings in a tree, layers of tissue are continually growing around our teeth that record major life events and stressors.
More specifically, the study’s authors focused on cementum or the dental tissue that covers the root of a tooth. As early as the moment our teeth surface, cementum begins forming annual layers or rings around the roots.
“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,” comments Professor Timothy Bromage of NYU’s College of Dentistry.
Researchers hypothesized that the microstructure of cementum would reveal permanent changes that coincide with major live events. Sure enough, a thorough examination of a group of cementum microstructures validated their theory. It appears to even be possible to ascertain an individual’s age when said events took place.
“The cementum’s microstructure, visible only through microscopic examination, can reveal the underlying organization of the fibers and particles that make up the material of this part of the tooth,” Cerrito notes.
To come to their conclusions, the research team analyzed 50 human teeth, collected from samples of varying ages (25-69 years old). The teeth were provided by a skeletal bank that also included medical and lifestyle data on the teeth’s owners. With the samples in hand, various imaging techniques were used to examine the cementum rings and make connections between ring fluctuations and life events.
“A tooth is not a static and dead portion of the skeleton. It continuously adjusts and responds to physiological processes,” Cerrito concludes. “Just like tree rings, we can look at ‘tooth rings’: continuously growing layers of tissue on the dental root surface. 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.”
After all these years and countless medical breakthroughs, the human body still has a few secrets we’re just now uncovering. Beyond just the fascinating nature of this discovery, these findings have far-reaching implications across numerous fields. More in-depth tooth examinations may now help crack decades-old crime cases by providing more information on the victim, and centuries-old tooth samples may hold more insight into the behavior of ancient humans than originally thought.
We all have a story to tell, but who knew that we’d be able to tell it with nothing more than our teeth.
The full study can be found here, published in Scientific Reports.