Application of Sliding Landmark Method for Morphological Analysis of Modern Japanese Neurocranial Shape

We apply the sliding semi-landmark method for the analysis of morphological variability in the modern Japanese population. Specifically, we prepare two kinds of template landmark configurations that will be projected onto and slid along each of the samples. We then analyze the variability in the neurocranial shape in the modern Japanese population by means of a landmark-based geometric morphometric method. We also analyze the differences in the patterns of extracted morphological variances due to different landmark configurations. Our results demonstrate that the morphological variabilities extracted by the two different template configurations generally correspond to each other, and indicate that if a sufficient number of semi-landmarks are evenly distributed across the neurocranial surface, the global tendency of the morphological variability to be extracted may not be affected by the choice of template configurations. Furthermore, the most predominant shape variability found in the cranial vault in the modern Japanese population is the brachycephalic/dolichocephalic tendency. The present semi-landmark-based approach will serve as a basis for detailed quantification and comparisons of the human neurocranial shape.