Abstract
Secular changes in facial flatness were examined using plaster models of male Japanese faces. Two groups of models from subjects differing in birth year were compared. The 1894 group comprised 52 death masks kept in the Department of Anatomy at Tohoku University School of Medicine. The median birth year of subjects was 1894 (range, 1872-1910), and the mean age at death was 29.5 years (range, 20-45 years). The 1974 group comprised 56 life masks taken in a sitting posture. The median birth year of subjects was 1974 (range: 1960-1980), and the mean age at measurement was 26.1 years (range: 18-38 years). The 3-dimensional (3D) coordinates of 11 landmarks were defined on each plaster model, and measurements and indices (depth/breadth) were calculated. Crania were also available for 11 death masks. The 3D coordinates of 10 landmarks on each cranium were defined and digitized, and measurements and indices calculated. Only variables related to flatness in the inter-orbital region showed significant correlations between plaster and cranial variables. The 1974 group showed significantly larger depth and flatness indices and a significantly less flat nose bridge and face on t-testing. Possible causes of inter-generation differences other than secular changes were examined, and a significant secular change in flatness of the nasal bridge was concluded to be present.
