Teeth contain growth lines that may reveal clues about childhood experiences. A team analysed 70 primary teeth collected from 70 children enrolled in the Children of the 90s study based at the University of Bristol.
The results of this study could one day lead to the development of a tool for identifying children who have been exposed to early-life adversity, which is a risk factor for psychological problems.
Senior author Erin C. Dunn was intrigued to learn that anthropologists have long studied the teeth of people from past eras to learn about their lives. Exposure to sources of physical stress can affect the formation of dental enamel and result in pronounced growth lines within teeth, called stress lines. Thicker stress lines are thought to indicate more stressful life conditions.
Dunn developed a hypothesis that the width of one line, called the neonatal line (NNL), might serve as an indicator of whether an infant’s mother experienced high levels of psychological stress during pregnancy and in the early period following birth.
To test this hypothesis, the width of the NNL was measured using microscopes. Mothers completed questionnaires during and shortly after pregnancy. Children whose mothers had lifetime histories of severe depression or other psychiatric problems, as well as mothers who experienced depression or anxiety at 32 weeks of pregnancy, were more likely than other kids to have thicker NNLs. Meanwhile, children of mothers who received significant social support shortly after pregnancy tended to have thinner NNLs.
If the findings of this research can be replicated in a larger study, Dunn believes that the NNL and other tooth growth marks could be used in the future to identify children who have been exposed to early life adversity. Dunn says: “Then we can connect those kids to interventions, so we can prevent the onset of mental health disorders”.