Stress exposure histories revealed by biochemical changes along accentuated lines in teeth

The regular incremental secretion of enamel and dentine can be interrupted during periods of stress resulting in accentuated growth lines. These accentuated lines, visible under light microscopy, provide a chronology of an individual's stress exposure. Previously, we showed that small biochemical changes along accentuated growth lines detected by Raman spectroscopy, coincided with the timing of medical history events and disruptions of weight trajectory in teeth from captive macaques. Here, we translate those techniques to study biochemical changes related to illness and prolonged medical treatment during early infancy in humans. Chemometric analysis revealed biochemical changes related to known stress-induced changes in circulating phenylalanine as well as other biomolecules. Changes in phenylalanine are also known to affect biomineralization which is re-flected in changes in the wavenumbers of hydroxyapatite phosphate bands associated with stress in the crystal lattice. Raman spectroscopy mapping of teeth is an objective, minimally-destructive technique that can aid in the

Automated summary

The regular secretion of enamel and dentine can be interrupted by stress, leading to the formation of accentuated growth lines. By using Raman spectroscopy, we have found that small biochemical changes along these accentuated lines coincide with medical events and disruptions in weight trajectory in captive macaques. In this study, we applied these techniques to investigate biochemical changes related to illness and medical treatment during early infancy in humans. Chemometric analysis revealed changes in phenylalanine and other biomolecules, indicating stress-induced alterations. Raman spectroscopy mapping of teeth can provide objective and minimally-destructive insights into an individual's stress exposure.