Inter-microscope comparability of dental microwear texture data obtained from different optical profilometers: Part I Reproducibility of diet inference using different instruments.

Dental microwear texture analysis (DMTA) has become a well-established method for dietary inference and reconstruction in both extant and extinct mammals and other tetrapods. As the volume of available data continues to grow, researchers could benefit from combining published data from various studies to perform meta-analyses. However, the different optical profilometers used to capture three-dimensional surface scans for DMTA are known to produce variation even when measuring the same surface. In this study, we compare DMTA data of 36 guinea pigs that received different diets in a controlled feeding experiment, measured using five different instruments: three confocal-scanning microscopes and two confocal laser-scanning microscopes. Each dataset is filtered according to in-house standards of the respective laboratories. Our findings reveal inter-microscope differences in the majority of the 40 DMTA parameters analyzed. Height and volume parameters were the most consistent across instruments, whereas density and complexity parameters exhibited pronounced differences. We thus propose DMTA parameters that were stable regardless of microscope. Despite these inter-microscope variations, the overall results from all instruments consistently show the same dietary differentiation among the guinea pig feeding groups, supporting the suitability of DMTA for reproducible and objective dietary inferences. To enhance data exchange, inter-lab comparability, and collaboration in the future, we propose a roadmap that includes the introduction of device-specific correction equations.