Tolerance of deviations in eye and mouth position

Abstract

To develop and refine a technique for measuring the tolerance for deviations in facial appearance. A psychophysical method was administered using photocopies of altered facial photographs to measure tolerances for deviations in eye position and mouth angulation and judges' reaction time. Stimulus photos were displayed as Kodachrome slides to 76 individuals grouped by their familiarity with craniofacial anomalies, i.e. dental professionals, orthodontic and craniofacial patients, also a group of normal patients. (1) Tolerance for deviation of facial appearance varies inversely with the magnitude of the physical deviations from normal; (2) tolerance varies directly as a function of assumed familiarity with deviation; (3) response and reaction time varied inversely with the tolerance for facial deviation. Significant differences in tolerance and reaction time were found among the groups and depended on whether an isolated feature was judged or if the feature was judged in the context of the whole face.