Fig 1.
Landmarks for polygon modelinga.
a Identical frontal and rotated [30°, left side] views of polygon models (averaged form) used in the present study. The abbreviations for the right and medial landmarks were indicated in the frontal view, and those for the left and the medial landmarks were indicated in the rotated view of the polygon models. The red dotted line represents a contour line in the z-axis that passes along both ectocanthions (lateral corners of the eyes, see Supporting Information 1–2) to describe the locations of the landmarks a4R and a4L. This line was not used in the analysis. b These landmarks were not used to create the homologous polygon models.
Fig 2.
Schematic illustration of the three-dimensional (3D) measurements and homologous polygon modeling.
a Images of averaged faces were used instead of actual participant images in this schematic illustration. b Measured data were obtained from a mannequin head instead of actual participants. c The average form of all participants was used instead of homologous polygon models of actual participants. d The Dhaiba Model was used for the template meshes.
Table 1.
Principal component analysis (PCA) of the homologous polygon models, Pearson’s rs between perceived ages, and principal component (PC) scores.
Fig 3.
Simulated forms that reflected age-related principal components (PCs).
a Each normalized PC score varied from −3.0 σ to +3.0 σ. The 1st, 12th, and 20th PCs were in direct proportion to perceived age (red borders), and the 9th and 10th PCs were in inverse proportion to perceived age (blue borders). b Frontal view image of simulated form (−1.0 σ and +1.0 σ for the 1st PC, −3.0 σ and +3.0 σ for the 9th, 10th, and 12th PCs).
Fig 4.
Relationship between the perceived ages of the simulated modelsa and the age-related principal component (PC) scoresb.
a Bars represent standard errors. b Each normalized PC score varied from –3.0 σ to +3.0 σ.
Fig 5.
Ratio of age-manifesting participantsa in each age cohort and number of age-manifesting principal components (PCs)b.
a Participants who had one or more age-related PC score greater than +1.0 σ in the age-related direction. b Age-related PCs scores greater than +1.0 σ in the age-related direction (bars represent standard errors).
Table 2.
Results from cluster analysis and characteristic age-related principal components (PCs) for each group.
Fig 6.
Differences in facial forms between younger and oldera participants in each group.
a Participants under and over the mean age of each group.