New approaches to human facial morphology using automatic quantification of the relative positions of the orbital and nasal apertures

The purpose of this study was to define and quantify the relative positions of the orbital and nasal apertures in the human face. The material consist ed of 44 skulls (32 males, 12 females). For each skull, an image of the pro jection of the face was captured perpendicular to the palatal plane, using a CCD camera. The orbital and nasal apertures were segmented and characteri zed using classical image analysis procedures. New quantitative parameters were automatically determined from the centres of area of the facial apertu res, and from horizontal and vertical lines of reference. Sexual difference s were only significant for orbital height, nasal height, and orbitonasal h eight. A medio-lateral orbitonasal overlap, as well as a vertical orbitonas al overlap, existed in all individuals; the vertical overlap was always muc h more marked than the medio-lateral overlap. Significant proportions of th e human face were also demonstrated: on average, the interorbital breadth c orresponded to a fifth of the biorbital breadth, and thus to half of the me an orbital breadth; the nasal breadth corresponded to one fourth of the bio rbital breadth, and the vertical orbitonasal overlap to one fourth of the o rbitonasal height. Some instructive significant correlations were observed between these new parameters. The applications of the present methodology s eem of great potential interest in anthropology and clinical biometry.