Relating metric crown dimensions to underlying internal daily secretion rates in antimeric premolars.

OBJECTIVES: The underlying cause for metric differences in antimeric tooth pairs is an important question for understanding dental variation. We hypothesize that localized variation in crown dimensions will be reflected in localized variation in daily enamel secretion rate.

DESIGN: Casts of pairs of human premolars from a tissue bank were 3D scanned using an optical scanning system (n = 32). Histological slides were created, and daily secretion rates (DSRs) were recorded in two areas of enamel that corresponded to scanner measurements. Antimeres were compared for both metric measurements and DSRs. Outliers for scanner measures were compared to significant differences in DSRs measurements in right and left teeth in corresponding areas.

RESULTS: Thirteen of the 16 individuals differed significantly in antimeric metric measurements, but only ten of those also differed in the underlying DSR. Fifteen of the 16 total individuals differed significantly in at least one DSR area.

DISCUSSION: While some individuals were outliers for metric measurements and had multiple areas of DSR differences, the majority of individuals had antimeric DSR differences regardless of metric differences. While there was no conclusive correlation between 3D metric analysis and underlying DSR differences, the most important result of this study is that DSR differences between antimeres are common.