Abstract

The Influence of Age, Sex and Facial Size on Facial Asymmetry in Hausa Population of Kano and Kaduna States, Nigeria

Author(s): ANAS IY

A substantial body of literature has reported a quantified level of facial symmetry but major gaps persist, with nearly all data originating from Western industrialized populations. The aim of this study was to determine the influence of age and sex on facial asymmetry of the Hausa ethnic group of Nigeria. The faces of 426 (215 males, 211 females) Hausa subjects of northern Nigeria were scanned using a 3D surface laser scanner. Facial asymmetry data were generated from the resulting virtual 3D models. The Mean whole face asymmetry (WFACE), the asymmetry around the eyes (EYES), the whole face surface area (WFSA) and the mean age were determined in both male and female subjects.
The results showed that males were 12% more facially asymmetric than the females and males were 15% more asymmetric around the eyes than females. It also demonstrates that males’ faces were 20% larger than the females’. The Mann Whitney U test indicated a statistically significant sexual dimorphism (p<0.0001) in all the tested variables. In females, linear regression analyses indicate statistically significant positive association between WFACE & age (F=5.32, P=0.0221), and EYES & age (F=5.10, P=0.0249) but not between WFACE and WFSA or between EYES and WFSA. Similarly, in males, there was a statistically significant positive association between WFACE & age (F=6.61, P=0.0108), but none between EYES & age (F=1.41, P=0.2365). Again, there was a statistical significant positive association between WFACE & WFSA, and between EYES & WFSA. The results however reveal that as the men get older, their whole face asymmetry increases, and as their faces grow their whole face asymmetry and asymmetry around the eyes also increase. However, it is important to note that, although some relationships are statistically significant, all are weak, with no r2 value higher than 0.05. PDF