“Primary teeth provide a unique timeline of early life”, Dr. Synnøve Stokke Jensen at the University of Bergen says.
“They preserve information from pregnancy and childhood that cannot be captures retrospectively in other ways. This allows us to investigate environmental exposures during sensitive developmental periods with unprecedented detail.”
Using data and biological samples from the Norwegian Mother, Father and Child Cohort Study (MoBa) (1) and the world`s larges biobank of primary teeth, MoBaTooth biobank, Stokke Jensen`s doctorial research shows that primary teeth can serve as a detailed biological archive of exposures occurring during critical stages of human development. The findings open new opportunities for researchers studying how environmental factors influence children`s health and neurodevelopment.
The doctoral thesis brings together three studies examining biomarkers measured in human primary teeth.
The first study established reference levels for a broad range of trace elements in children`s primary teeth, demonstrating that tooth dentine can be used to reconstruct exposure patterns from prenatal life through early childhood (2).
The second study showed a strong relationship between lead levels in mothers during pregnancy and lead levels preserved in their children`s primary teeth. The findings confirm that primary teeth can provide reliable record of fetal exposure to environmental contaminants (3).
The third study explored trace-element patterns in children with and without autism spectrum disorder, the results identified differences in certain prenatal and early-life exposure profiles, highlighting the potential of tooth biomarkers as a tool for investigating environmental influences on neurodevelopment (4).
Together, the studies demonstrate the scientific value of primary teeth as biomarkers in epidemiological research. Because teeth develop layer by layer, much like three rings, and are very stable they preserve a chronological record of exposure to both essential nutrients and environmental contaminants during key developmental windows.
The research is based on samples from the MoBaTooth Biobank, the world`s larges collection of naturally shed primary teeth linked to comprehensive health and environmental data.
“These findings strengthen the role of primary teeth as an innovative research tool for understanding how early-life environments may shape health across the lifespan,” Stokke Jensen says.
Dr. Synnøve Stokke Jensen submitted and defended her thesis, Biomarkers in Human Primary teeth in Epidemiological Research, at the University of Bergen, Norway. The main supervisor was the leader of MoBaTooth Biobank, Professor Kristin S. Klock.
The doctoral thesis is available here: https://nva.sikt.no/registration/019b22068f9d-481f3c72-df44-4826-941c-021240ae42a7
1. Brandlistuen RE, Kristjansson D, Alsaker E, Valen R, Birkeland E, Royrvik EC, et al. Cohort Profile Update: The Norwegian Mother, Father and Child Cohort (MoBa). Int J Epidemiol. 2025;54(5).
2. Jensen S, Austin C, Arora M, Lie S, Oilo M, Klock K. Toxic and essential trace elements in human primary teeth: A baseline study within The MoBaTooth Biobank and The Norwegian Mother, Father and Child Cohort Study (MoBa). Environmental Advances. 2023;13:100418.
3. Jensen SS, Arora M, Austin C, Brantsaeter AL, Haug LS, Knutsen HK, et al. Toxic and essential elements in primary teeth and maternal blood during pregnancy: The Norwegian Mother, Father and Child Cohort Study (MoBa) and the MoBaTooth Biobank. Environ Res. 2025;274:121316.
4. Jensen S, Midya V, Arora M, Brandlistuen R, Havdahl A, Andersen G, et al. Pre- and postnatal trace element levels in primary teeth of children with and without an autism spectrum diagnosis. Environmental Research. 2026;295:124001.