When seven-year-old Maja placed her wiggly front tooth in a tiny envelope and mailed it to a lab in Bergen, she became part of something much bigger—a growing scientific archive that’s rewriting how we understand early life. At the University of Bergen, Dr. Synnøve Stokke Jensen is unlocking secrets held within thousands of naturally shed baby teeth, revealing a hidden timeline of environmental exposures from before birth through early childhood. These unassuming teeth, once tucked under pillows for the tooth fairy, are now proving to be powerful biological diaries.
The research, rooted in the Norwegian Mother, Father and Child Cohort Study (MoBa), taps into the MoBaTooth Biobank—the world’s largest collection of primary teeth linked to comprehensive health data. Because teeth grow in layers like tree rings, they capture a chronological record of what a child was exposed to during critical developmental windows, from essential nutrients to harmful contaminants. This offers scientists a rare, stable, and precise way to look back at prenatal and early-life environments—something no blood or urine sample can do decades later.
Stokke Jensen’s doctoral thesis, supervised by Professor Kristin S. Klock, weaves together three groundbreaking studies. The first established reference levels for a wide range of trace elements in children’s teeth, proving that dentin can reconstruct exposure patterns from fetal life onward. The second revealed a strong correlation between lead levels in mothers during pregnancy and the lead preserved in their children’s teeth—confirming that baby teeth reliably reflect fetal exposure to toxic substances. The third study compared trace-element patterns in children with and without autism spectrum disorder, identifying distinct prenatal exposure profiles that could help unravel environmental influences on neurodevelopment.
These findings are more than academic—they open new pathways for understanding how early-life exposures shape long-term health. With over 10,000 teeth now stored in the MoBaTooth Biobank, researchers have an unprecedented resource to explore links between environment and disease. As more families contribute, the data could one day help predict health risks before symptoms appear, guiding early interventions.
"Primary teeth provide a unique timeline of early life," Stokke Jensen says. "They preserve information from pregnancy and childhood that cannot be captured retrospectively in other ways." In a world where prevention is increasingly valued over treatment, these tiny biological archives may hold outsized promise for the health of future generations.