Steroid hormones are important modulators of many physiological processes, and
measurements of steroids in blood, saliva, and urine matrices are widely used to
assess endocrine pathologies and stress. However, these matrices cannot be used to
retrospectively assess early-life stress and developmental endocrine pathologies,
because they do not integrate steroid levels over the long term. A novel biological
matrix in which to measure steroids is primary teeth (or “baby teeth”). Primary teeth
develop early in life and accumulate various endogenous molecules during their
gradual formation. Here, we developed and validated the first assay to measure
steroids in human primary teeth using liquid chromatography-tandem spectrometry
(LC-MS/MS). Our assay is highly sensitive, specific, accurate, and precise. It allows for
the simultaneous quantification of 17 steroids in primary teeth (16 of which have not
been examined previously in primary teeth). Overall, steroid levels in primary teeth
were relatively low, and 8 steroids were quantifiable. Levels of
dehydroepiandrosterone, cortisol, and progesterone were the highest of the 17 steroids
examined. Next, we used this assay to perform steroid profiling in primary teeth from
males and females. The same 8 steroids were quantifiable, and no sex differences
were found. Levels of androgens (androstenedione and testosterone) were positively
correlated, and levels of glucocorticoids (cortisol, cortisone, corticosterone, 11-
dehydrocorticosterone) were also positively correlated. These data demonstrate that
multiple steroids can be quantified by LC-MS/MS in human primary teeth, and this
method potentially provides a powerful new way to retrospectively assess early-life
stress and developmental endocrine pathologies.