Cartoon of science tooth fairy
Illustration by Rebecca Mullins

Erin C. Dunn, ScD, MPH, is a social and psychiatric epidemiologist in the Departments of Psychiatry and Pediatrics as well as the Center for Genomic Medicine at Massachusetts General Hospital. Her research uses interdisciplinary approaches to better understand the social and biological factors that influence the cause of depression among women, children and adolescents. Over the last few years, she’s collected hundreds of baby teeth from participants in her study and begun studying teeth as a potential sign of early trauma in children. She shares more about what this research may tell us in the Q&A below.  

Q. How did this research study start? What made you think teeth could show signs of trauma?

My lab works on understanding how childhood adversities, like growing up in poverty, losing a loved one, witnessing a traumatic event, experiencing a natural disaster or some other type of stressful event, can affect people’s health in childhood and beyond. Unfortunately, it is difficult to find objective and concise ways to measure whether people were exposed to childhood adversity—and if so when it occurred in development.

A faculty colleague, recalling her experience in an undergraduate anthropology class, suggested I look to teeth as a possible marker. I learned that teeth develop incrementally and contain growth marks, like the rings in a tree marking its age. Sometimes these growth marks are especially pronounced and are referred to as stress lines. These stress lines appear in response to important life events such as the day you are born—this stress line is known as the neonatal line.

Q. Can adult teeth show signs of trauma or just children’s teeth?

Adult teeth are also rich sources of information about a person’s life history. It is common practice in biological anthropology to study the teeth of ancient humans to understand what humanity was experiencing across time. Researchers can pinpoint changes in enamel thickness (the thin, white outer coating of teeth) or tooth size that correspond to important and often difficult transitions in human history, like the move from being hunter-gatherers to growing our own food.

Because each tooth type develops on its own time scale, it’s possible that every tooth can tell a unique story about what was occurring to the child at multiple stages of their development.  

The Dunn Lab has collected hundreds of baby teeth since 2019 as part of our Stories Teeth Record of Newborn Growth (STRONG) Study to discover what a tooth can tell us about early trauma and more positive life experiences. We’re continuing to collect baby teeth from new participants who want to be part of our research.

Learn more about the STRONG study

Q. What have you discovered through this research so far?

We have analyzed teeth from different research cohorts and have so far published three papers on this topic. In our first paper, published in 2020, we summarized our hypotheses related to how we think teeth might be new biomarkers, capable of recording children’s early life stress and therefore could be tools to help identify children at greater risk for mental health and other health problems in the future.

In the other two papers, one published and one accepted, we showed connections between stressors and teeth, and then tooth characteristics and child mental health. For example, we showed in one study from 2021 that children born to mothers with a lifetime history of depression or anxiety or depressive symptoms towards the end of their pregnancy had wider neonatal lines, a sign of more stress. In that study, we also showed that children’s whose mothers reported high social support had narrower neonatal lines.

In another study, we found that there may be a link between measures in children’s teeth and their mental health.

Q. What does the STRONG Study entail?

We study women who were pregnant or raising newborns during the timing of the events surrounding the Boston Marathon bombing and their children. We conduct phone interviews with each mom enrolled in the study to better understand not only their experience with the Boston Marathon bombings, but any traumatic experience they may have had during pregnancy or after the birth of the child. We also take their personal health history and their child’s health history to better understand risk and protective factors that could play a role in their child’s tooth development.

To date, we’ve recruited 251 families for our STRONG study. Mothers complete a phone interview and online survey with our research team to give us more information about their experiences during the Boston Marathon bombing and subsequent manhunt, their child’s health, and their own health and life history around the time of their pregnancy.

Since the start of the pandemic, we’ve also collected information about STRONG participants’ experiences dealing with quarantine and COVID-19-related changes to their life. We have already collected over 450 teeth from STRONG kids and have started to analyze these.  

Q. What are you still hoping to discover or confirm with new teeth still coming in?

For the STRONG study, we are still collecting teeth from currently enrolled families, with more coming in each week! New families are still able to enroll in the study as additional participants will help strengthen our results and better confirm our findings.

With the teeth we currently have, we’re beginning the process of analyzing them. We hope to find markers that are associated with trauma related to the Boston Marathon bombing. We also hope to discover factors that may prevent teeth from having these markers.

Q. What’s the future of this research? Where is it going? Do you think one day you’ll be asking for the teeth of the babies born during the COVID-19 pandemic?

The more we learn about how different life experiences show up in children’s teeth, the better we can monitor children’s risk for mental illness and pinpoint when to intervene. Maybe one day, collecting and analyzing teeth will be as commonplace as drawing blood to give crucial insights into a child’s health that may not be apparent on the surface or not become apparent until many years down the line.

We are hoping to eventually collect teeth from children who were conceived, born or infants during the pandemic to better understand social and physical exposure to COVID-19 in children.

Read more about Dr. Dunn’s research and findings to date: