Your teeth are not just a set of pearly white food munchers, they can also act as a diary of major life events.
A new study has shown how our teeth can bear the signs of impactful life events and our lifestyle, from birth and diet to hard times and menopause. They can even indicate whether a person has ever suffered a long-term illness or spent time in prison.
The research specifically looked at the calcified dental tissue that covers the tooth’s root, known as the cementum. Since this tissue grows a new layer every year or so, it’s possible to track back through a person’s life by looking at the different layers, just like a tree ring.
Reported in the journal Scientific Reports, the researchers analyzed 47 teeth from 15 individuals with a known life story and medical history. By closely studying the structure of the cementum, they were able to accurately detect a wide range of life events.
“Just like tree rings, we can look at ‘tooth rings’: continuously growing layers of tissue on the dental root surface," Paola Cerrito, a doctoral candidate at New York University's Department of Anthropology and College of Dentistry, explained in a 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,” Cerrito continued.
The researchers were able to tell whether female participants had given birth and experienced menopause. With the male participants, all featured unexpected changes to their cementum that appeared around the age of 20, which the team suspect is linked to changes of free testosterone levels that occur around this age. The study authors write that “other stressful events such as systemic illnesses and incarceration are also detectable.”
The method does need some fine-tuning, however. Although the analysis of cementum can identify a traumatic experience, it's not always possible to identify the specific nature of that event. For example, it can't reliably tell whether the change in cementum relates to imprisonment or another big lifestyle change. Equally, different teeth of the same individual can also show different timings for events, suggesting the dating based on the cementum might be more complex than it first appears.
“Our results make clear that the skeleton is not a static organ, but rather a dynamic one,” added Cerrito. “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.”
Speaking to CNN, the researchers explain that the research actually started as a way of investigating the reproductive patterns of extinct human ancestors. Indeed, this new method could be an invaluable tool in the fields of archeology and anthropology, providing all manner of insights into ancient humans and our extinct hominid cousins, such as the food they ate and the diseases they faced.