The Influence of Measures of Socioeconomic Status on Human Facial Asymmetry

Minor variations between the left and right sides of all human faces exist and are considered normal. These are called asymmetries and result from the effects of genes or environment on the developing face. The environmental factors include but not limited to socioeconomic status and its influence on the facial asymmetry was only studied in the Caucasians. The aim of the present study is to test the effects of socioeconomic status on the facial asymmetry in the less privileged population. Four hundred and twenty-six subjects were randomly recruited, and their faces scanned, using ExaSurface Laser Scanner, after getting an informed consent and ethical approval from the appropriate authority. Scans were prepared and mirrored images merged with the original to estimate the asymmetry between sides. Sociodemographic characteristics of the subjects were acquired using a questionnaire, where socioeconomic status of the individuals was categorized into 3 based on the economic, occupation and education condition of the participants. The overall facial asymmetry and asymmetry around the eye region were recorded using a Geomagic software version 12 USA. The socioeconomic status (SES) and asymmetry data were analyzed using IBM SPSS statistics software version 20. Wilcoxon's, Analyses of variance (ANOVA) and Kruskall Wallis' tests were conducted to test the effects of the SES on the face asymmetry. However, results indicated no significant differences in the mean values of facial asymmetry between the three SES groups but there was a significant mean difference of asymmetry around the eye region between the 3 groups of SES in both sexes. Conclusively, facial asymmetry may not be a good measure of developmental instability since mean difference of the facial asymmetry between the three classes of SES is not significant.

Key Words: Face, Asymmetry, Influence, Sub-Saharan African, Socioeconomic status