Can Baby Teeth Show Early-Life Stress?
The thickness of growth marks in primary (or 'baby') teeth may help identify children at risk for depression and other mental health disorders later in life, according to a ground-breaking investigation.
Possibly, according to early research. A 2021 study found that a growth line formed in baby teeth around birth, called the neonatal line, was wider in children whose mothers had a history of depression or had depression or anxiety late in pregnancy, and narrower when mothers had strong social support after birth. The study was small and needs to be repeated. It isn't a test you can ask a dentist for, and it can't tell you anything about your own child.
What is the neonatal line?
Teeth form in layers, a little like tree rings. Enamel for the baby teeth starts forming before birth, and the stress of birth leaves a visible line in it, called the neonatal line. Anthropologists have long studied growth lines in teeth to learn about illness and poor nutrition in past populations. The researchers wanted to know whether the width of this line also reflects a mother's psychological stress around the time of birth.
What did the study do?
A team at Massachusetts General Hospital, led by psychiatric epidemiologist Erin Dunn, studied 70 baby canine teeth donated by families in the Children of the 90s study (the Avon Longitudinal Study of Parents and Children) in Bristol, England. The teeth had fallen out naturally when the children were 5 to 7 years old. The team measured the width of each neonatal line under a microscope.
Mothers had filled in questionnaires during and shortly after pregnancy about stressful life events, their mental health history, their neighborhood and how much social support they had.
What did they find?
Neonatal lines were wider in children whose mothers reported severe depression or other psychiatric problems at some point in their lives.
Lines were also wider when mothers had high levels of depression or anxiety at 32 weeks of pregnancy.
Lines were narrower when mothers reported strong social support shortly after birth.
These links held after accounting for other things known to affect the line, such as length of pregnancy and maternal weight.
What are the study's limits?
Seventy children is a small group, and nearly all were White and from one region of England. The study shows that certain experiences and a wider line tend to occur together. It doesn't show what causes the line to widen, and it didn't measure the children's own mental health. The researchers called for larger studies to confirm the findings before teeth could be considered a possible marker of early stress.
What does this mean for parents?
For now, nothing changes in how baby teeth are cared for, and there's no reason to have a child's teeth examined for growth lines. The more useful takeaway is the role of support. Mothers who had strong social support after birth had children with narrower lines, which fits a broad body of research on how much support matters for parents and babies.
If you're pregnant or a new parent and feel depressed or anxious, tell your doctor. For everyday care of young children's teeth, see our parent's guide to early childhood dental problems. Related research summaries cover childhood stress and early molars and parents' wellbeing and toddler toothbrushing.
Sources
Mountain RV, Zhu Y, Pickett OR, et al. Association of maternal stress and social support during pregnancy with growth marks in children's primary tooth enamel. JAMA Netw Open. 2021;4(11):e2129129. doi:10.1001/jamanetworkopen.2021.29129. Retrieved via PubMed (PMID 34751761).
Massachusetts General Hospital. Baby teeth may one day help identify kids at risk for mental disorders later in life. Press release, November 2021.
About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.
Can Childhood Stress Make Molars Come In Earlier?
Research shows that children from lower-income backgrounds and those who go through greater adverse childhood experiences get their first permanent molars sooner. The findings align with a broader pattern of accelerated development often seen under conditions of early-life stress.
A 2021 study suggests it may be linked. Researchers at the University of Pennsylvania found that children from lower-income families and children who had more adverse childhood experiences tended to get their first permanent molars earlier. It's an association, not proof of cause, and the researchers stress that the timing of a child's molars says nothing useful about that individual child. For parents, nothing about routine dental care changes.
What did the study look at?
The researchers wanted an inexpensive, early sign of whether stress speeds up a child's development. Earlier puberty is a known marker, but it comes too late to be much help. In other primates, the timing of molar eruption tracks the length of childhood, so the team looked at teeth.
They started with 117 children aged 4 to 7 who were already in brain-imaging studies at Penn. The MRI scans happened to show the developing molars clearly. Working with Penn Dental Medicine, the team rated how far each first permanent molar had come in, then compared those ratings with family income and the number of adverse childhood experiences each child had, after accounting for age and sex.
To check the result, they repeated the income analysis with 1,973 children in the National Health and Nutrition Examination Survey, a national U.S. dataset.
What did they find?
In the Penn group, both lower family income and more adverse childhood experiences were linked with earlier eruption of the first permanent molars.
In the national dataset, the link between lower income and earlier molars held up.
The team also saw differences by race, which they said need further study.
What are the study's limits?
The first group was small and came from one city. The national dataset measured teeth differently and could only test income. Most importantly, the study shows that two things tend to occur together across groups of children. It doesn't show that stress causes earlier molars, and it can't predict anything for a single child. The researchers were clear that parents shouldn't worry, or feel reassured, based on when their child's molars arrived.
What does this mean for your child's teeth?
First permanent molars usually come in around age six, behind the last baby teeth, and children often don't notice them. Whenever they arrive, they need the same care:
Brush them twice a day with fluoride toothpaste. They sit far back and are easy to miss.
Ask your child's dentist whether sealants make sense once the molars are in. The deep grooves on these teeth are where many childhood cavities start.
Keep up regular dental visits.
If you'd like more on what teeth can record about early life, read about growth marks in baby teeth. For young children's care in general, see our parent's guide to early childhood dental problems.
Sources
McDermott CL, Hilton K, Park AT, et al. Early life stress is associated with earlier emergence of permanent molars. Proc Natl Acad Sci U S A. 2021;118(24):e2105304118. doi:10.1073/pnas.2105304118. Retrieved via PubMed (PMID 34103399).
Penn Today. A link between childhood stress and early molars. June 7, 2021. Retrieved 2026-10-06.
About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.