The tooth exposome in children's health research

Abstract

Purpose of review The exposome concept proposes a comprehensive assessment of environmental exposures from the prenatal period onwards. However, determining exposure timing especially over the prenatal period is a major challenge in environmental epidemiologic studies. Recent findings For decades teeth have been used to estimate long-term cumulative exposure to metals. Recently developed high-dimensional analytical methods that combine sophisticated histological and chemical analysis to precisely sample tooth layers that correspond to specific life stages have the potential to reconstruct the exposome in the second and third trimesters of prenatal development and during early childhood. Summary A retrospective temporal exposomic approach that precisely measures exposure intensity and timing during prenatal and early childhood development would substantially aid epidemiologic investigations, particularly case–control studies of rare health outcomes.

Polymorphisms in manganese transporters show developmental stage and sex specific associations with manganese concentrations in primary teeth

“…The strength of the study is the advanced methodology of using teeth Mn biomarkers allowing us to study early human development in a unique and non-invasive manner. Tooth Mn measures have been validated in human and animal studies and are a direct fetal biomarker of exposure (Andra et al, 2016). Having multiple time points of fetal exposure, as opposed to a single measure, allowed us to uncover developmental stage specific differences in Mn uptake across genotypes, something that has not been reported before.…”

Tooth-Matrix Biomarkers to Reconstruct Critical Periods of Brain Plasticity

“…The absence of direct fetal biomarkers that provide information on both the magnitude and timing of fetal exposure to multiple chemicals has been a major barrier [4]. Multiplexed mass-spectrometry methods have been recently applied to the tooth-matrix to reconstruct prenatal and early postnatal exposure to thousands of compounds, including environmental chemicals and their internal reaction products [5]. For example, neurodevelopmental deficits from excessive exposure to manganese were uncovered in children exposed to pesticides high in this metal.…”

“…For example, neurodevelopmental deficits from excessive exposure to manganese were uncovered in children exposed to pesticides high in this metal. Recently, we also showed that a broad range of homeostatic disruptions caused by physical trauma, infections and even psychosocial stressors, such as separation from the mother, are captured in the dentine matrix [5] [6]. …”

“…In light of recent studies of toxicants and markers of homeostatic disruptions [5] [6], we deduced that we could use deciduous teeth to determine perinatal critical periods for brain plasticity. Given that 1) teeth commence development in the prenatal period, extending to early childhood [5], 2) teeth share evolutionary homology with the neurosensory system [7], 3) markers specific to glial cells are expressed in dental tissue [8] and 4) glial cells function as stem cells for neurons in the cerebral cortex [9], it is possible that the timeline of key neurodevelopmental events is imprinted in an individual’s teeth.…”

“…Given that 1) teeth commence development in the prenatal period, extending to early childhood [5], 2) teeth share evolutionary homology with the neurosensory system [7], 3) markers specific to glial cells are expressed in dental tissue [8] and 4) glial cells function as stem cells for neurons in the cerebral cortex [9], it is possible that the timeline of key neurodevelopmental events is imprinted in an individual’s teeth. To uncover the molecular profile of brain plasticity across development, we propose a model in which the two categories of plasticity regulators, accelerators and brakes are studied simultaneously in a single tooth.…”