“…Long‐period incremental lines, commonly referred to as “Retzius lines,” are observable in the imbricational (lateral) enamel using light microscopy (Figure 2c) (Retzius, 1837) and emerge on the surface as perikymata (Cares Henriquez & Oxenham, 2017; Goodman & Rose, 1990). Short‐period incremental lines, prism cross‐striations, are also visible in thin sections (Antoine et al, 2009; Hillson, 2005; Lemmers et al, 2021), appearing as alternating dark and light bands in histological cross‐sections and represent approximately 24 h of enamel secretion, denoting the circadian repeat interval of secretory ameloblasts (Antoine et al, 2009; Goodman & Rose, 1990; Hillson, 2005; Smith et al, 2007). Although widely used and accepted in enamel odontochronological investigations, the mechanism through which they form is not fully understood, and it has been proposed that they reflect structural variation within enamel in relation to diurnal rhythmicity or crystallite organization (Hillson, 2005; Nanci & TenCate, 2018).…”