Striae of Retzius are incremental markers that represent a normal cessation of enamel growth every 8 to 9 days on average (Fitz-Gerald and Saunders 2005; Reid and Ferrell 2006).
Wilson bands are defined by their differences in relation to regular striae of Retzius in that they are accentuated, longer, and consist of an atypical prism structure (FitzGerald and Saunders 2005).
Wilson bands were differentiated from regular striae of Retzius if they were accentuated, if they travel at least 75% of the distance from the dentin-enamel junction (DEJ) to the surface of the tooth, if they were visible on both the labial and lingual side of the tooth, and if they were characterized by a bending and discontinuity of prism rods (FitzGerald et al.
The developmental timing associated with dentin increments used for isotopic analysis was microscopically determined by counting the number of striae of Retzius along the DEJ in 1.5 mm increments of enamel that corresponded with each 1.5 mm increment of dentin.
Figure 4 provides an example of a dental thin section with observed Wilson bands and striae of Retzius. All of the individuals subsampled for incremental isotopic analysis exhibited at least one Wilson band.
This phenomenon was supported by structure analysis revealing that CEPs and enamel pearls have characteristics of enamel including enamel rods, striae of Retzius
, Hunter-Schreger bands, and areas of prism-free enamel.