Adverse childhood experiences or ACEs — traumatic events occurring during childhood — are common and, in many individuals, have long-term consequences, affecting vulnerability to chronic medical problems, mental illness, and substance use. Because exposure to childhood adversity is ubiquitous, there is an urgent need to understand why some individuals are more susceptible to childhood adversity. Erin Dunn, ScD MPH is a social and psychiatric epidemiologist whose research has focused on understanding how these early exposures lead to mental illness, with the goal of translating this information into population-based strategies which could mitigate the negative consequences of adversity and prevent the onset of psychiatric illness.
One of the challenges in doing this research has been finding an accurate and objective measure of adversity. Most studies rely on parental reports of adverse events, which may be limited by recall and are likely to have certain biases. Dr. Dunn and her team have recently started looking at children’s teeth to better understand exposure to adversity. In humans, primary or baby teeth start to develop before birth (around 6 to 8 weeks of gestation) and continue to accumulate layers of enamel during pregnancy and the early years of the child’s life. Like the rings of a growing tree, these layers of enamel reveal what the child has been exposed to — environmental toxins, chemicals, nutritional deficiencies, as well as adverse life experiences. In response to stressful events, “stress lines” appear — disruptions in the layers of enamel — which can help researchers identify which children have experienced significant adversity and can also pinpoint the timing of this exposure.
Stress lines have been used by anthropologists to identify stressful gestational events. For example, prolonged or complicated delivery and preterm births have been associated with wider neonatal lines. However, it is unknown whether measuring the width of these neonatal lines could be used as biomarkers for prenatal and perinatal psychosocial stress in living pediatric populations. In a recent article authored by Rebecca Mountain, PhD, researchers from the Dunn Lab, explore the feasibility of using exfoliated baby teeth to study adverse life events, specifically assessing whether the growth marks in tooth enamel correlate with exposure to prenatal and perinatal maternal psychosocial stressors in a well-characterized sample of women and their children.
The study included 70 children enrolled in the Avon Longitudinal Study of Parents and Children, a birth cohort based in Bristol, England. Exfoliated teeth were collected from children at 5 to 7 years of age. Four types of prenatal and perinatal maternal psychosocial factors were evaluated: stressful life events, history of psychiatric illness, neighborhood disadvantage, and social support. This information was derived from questionnaires completed by mothers during and shortly after pregnancy. Neonatal line width was measured in three portions of the tooth crown (the cuspal, middle, and innermost third) in exfoliated primary canine teeth.
The children included in the analysis were 48.7% male, predominantly White (94.0%), and most of the children were born full term (83.8%). The researchers observed that neonatal lines were wider in the canines of children born to mothers who self-reported a lifetime history of severe depression (β = 3.35; 95% CI, 1.48-5.23; P = .001), any lifetime psychiatric problems (β = 2.66; 95% CI, 0.92-4.41; P = .003), or elevated anxiety or depressive symptoms at 32 weeks’ gestation (β = 2.29; 95% CI, 0.38-4.20; P = .02).
In contrast, neonatal lines were narrower in children born to mothers who self-reported higher levels of social support shortly after birth (β = -2.04; 95% CI, -3.70 to -0.38; P = .02). Other stressors, including loss of a family member or close fiend and neighborhood disadvantage, were not associated with the neonatal line width. The magnitude of these associations was large and persisted after adjusting for other risk factors.
The current study demonstrates that neonatal line width was associated with exposure to certain types of maternal perinatal psychosocial stress and suggests that this technique may be used to identify early adverse life events in children. These results must be replicated in larger and more diverse samples; if the findings are verified across different samples, this technique could have important implications for future interventional strategies.
How Can We Use This Information?
Because more than half of mental health disorders emerge before early adolescence, identifying at-risk children at an early age is essential for the implementation of strategies designed to mitigate risk of psychiatric illness. Children typically begin to shed their baby teeth around 6 years of age. In the future, children’s exfoliated teeth could be collected by pediatricians or dentists during routine checkups and then sent to specialized laboratories for analysis. The teeth could be examined to detect adverse exposures that would be otherwise difficult to assess. In turn, the results could help identify children at risk and direct them toward evidence-based intervention programs, long before the onset of mental health symptoms.
Now that’s a new kind of tooth fairy.
Ongoing Study of Boston Mothers Exposed to the Marathon Bombing
Because replication and validation of these findings is necessary to further evaluate neonatal lines in teeth as possible new biomarkers, the Dunn Lab is looking at other populations of women who have experienced stressful life events during pregnancy. The Dunn Lab is now recruiting Boston-area women to participate in a study using baby teeth to look at the impact of the Boston Marathon bombings on child development.
You can learn more about this study and sign up to participate at Teeth for Science or at the MGB Rally website.
Other Mass General Researchers Contributing to This Project
Read More
Davis KA, Mountain RV, Pickett OR, Den Besten PK, Bidlack FB, Dunn EC. Teeth as Potential New Tools to Measure Early-Life Adversity and Subsequent Mental Health Risk: An Interdisciplinary Review and Conceptual Model. Biol Psychiatry. 2020 Mar 15; 87(6):502-513.
Mountain RV, Zhu Y, Pickett OR, Lussier AA, Goldstein JM, Roffman JL, Bidlack FB, Dunn EC. Association of Maternal Stress and Social Support During Pregnancy With Growth Marks in Children’s Primary Tooth Enamel. JAMA Netw Open. 2021 Nov 1; 4(11):e2129129.
In the News
The tooth fairy is calling: Boston researchers seeking baby teeth for health study. (Boston Globe)
The Secret Lives of Baby Teeth (Vox)
Baby teeth may be window to child’s risk of mental health disorders (Harvard Gazette)
Children’s Teeth May be a Strong Indicator of Future Mental Health Issues (Boston Magazine)
