Fig. 1

Facial landmarks and anthropometric measurements used in the study. Parts (a) and (b) show an example of a 3D facial surface model with the 24 standard landmarks used in the shape analysis. Landmarks shown in frontal view (a) are n nasion; prn pronasale; sn subnasale; ls labiale superius; sto stomion; li labiale inferius; sl sublabiale; gn gnathion; en endocanthion; ex exocanthion; al alare; sbal subalare; cph crista philtri; ch chelion (for bilateral points, only right side is labeled). Landmarks shown in the lateral view (b) are ac alar curvature point and t tragion (only left landmark shown for these two bilateral points). Part (c) shows the approximate location of the 29 linear distances listed in Table 2. From top left to bottom right, these are as follows: maximum cranial width, minimum frontal width, maximum facial width, mandibular width, maximum cranial length, cranial base width, upper facial depth (left), middle facial depth (left), lower facial depth (left), morphological facial height, upper facial height, lower facial height, intercanthal width, outercanthal width, palpebral fissure length (left), nasal width, subnasal width, nasal protrusion, nasal ala length (left), nasal height, nasal bridge length, labial fissure width, philtrum width, philtrum length, upper lip height, lower lip height, upper vermilion height, lower vermilion height, and cutaneous lower lip height. The first five measurements were collected manually with spreading calipers. The remaining 24 measurements were calculated from the 3D landmarks shown in parts (a) and (b)