Human “barcode”: Link between phosphate intensity changes in human enamel and light microscopy record of accentuated lines

Abstract

Disruption of metabolic processes during human enamel mineralization may result in the appearance of accentuated lines in enamel. These accentuated lines in the enamel relate to stress events that were experienced and overcome in early ontogenetic phases. Accentuated lines are visible in transmitted light microscopy as dark areas. However, their appearance is variable even within single tooth. The objective of this study is to analyze the distribution of phosphate in human enamel with a focus on accentuated stress lines by Raman microscopy. Transmitted light microscopy and Raman microscopy records of 15 human teeth (11 samples from archaeological excavations, 4 from recent population) were compared, using visual evaluation and statistical methods (correlation of pixel light intensities in the microscopic images). The data obtained by Raman microscopy suggests a relationship between low phosphate content (signal at 960 cm−1) and accentuated stress lines in human enamel.