BERGEN — Dr. Synnøve Stokke Jensen successfully defended her doctoral thesis, "Biomarkers in Human Primary teeth in Epidemiological Research," at the University of Bergen. Her research focused on the use of primary teeth as biomarkers for early-life environmental exposures.

The doctoral thesis comprised three studies that examined biomarkers measured in human primary teeth. The research utilized data and biological samples from the Norwegian Mother, Father and Child Cohort Study (MoBa) and specifically samples from the MoBaTooth biobank.

The first study established reference levels for trace elements in children's primary teeth. This study also demonstrated that tooth dentine can be used to reconstruct exposure patterns from prenatal life through early childhood. "Primary teeth provide a unique timeline of early life," Jensen said. "They preserve information from pregnancy and childhood that cannot be captures retrospectively in other ways."

A second study showed a relationship between lead levels in mothers during pregnancy and lead levels preserved in their children's primary teeth. These findings confirm that primary teeth can provide a record of fetal exposure to environmental contaminants. "This allows us to investigate environmental exposures during sensitive developmental periods with unprecedented detail," Jensen said.

The third study explored trace-element patterns in children with and without autism spectrum disorder. It identified differences in certain prenatal and early-life exposure profiles between children with and without autism spectrum disorder. Professor Kristin S. Klock, leader of the MoBaTooth Biobank, was the main supervisor for the thesis.