Phenotypic characteristics of adolescents with concave and convex facial profiles - The National Health Examination Survey

It has been suggested that facial traits are informative on the inherited susceptibility to tuberculosis and obesity, two current global health issues. Our aim was to compare the phenotypic characteristics of adolescents with dental markers for a concave (n = 420), a convex (n = 978), and a straight (n = 3542) facial profile in a nationally representative sample of United States adolescents. The results show that adolescents with a concave facial profile, when compared to a straight facial profile, had an increased waist-to-height ratio (Δ, 1.1 [95% CI 0.5-1.7], p < 0.003) and an increased acne prevalence (OR, 1.5 [95% CI 1.2-1.9], p < 0.001). Adolescents with a convex facial profile, when compared to a straight facial profile, had an increased prevalence of tuberculosis (OR, 4.3 [95% CI 1.4-13.1], p < 0.02), increased ectomorphy (Δ, 0.3 [95% CI 0.2-0.4], p < 0.0001), increased left-handedness (OR, 1.4 [95% CI 1.1-1.7], p < 0.007), increased color-blindness (OR, 1.7 [95% CI 1.3-2.3], p < 0.004), and rhesus ee phenotype (OR, 1.3 [95% CI 1.1-1.5], p < 0.008). Adolescents with a concave facial profile, when compared to a convex profile, had increased mesomorphy (Δ, 1.3 [95% CI 1.1-1.5], p < 0.0001), increased endomorphy (Δ, 0.5 [95% CI 0.4-0.6], p < 0.0001), lower ectomorphy (Δ, 0.5 [95% CI 0.4-0.6], p < 0.0001), and lower vocabulary test scores (Δ, 2.3 [95% CI 0.8-3.8], p < 0.008). It is concluded that population-based survey data confirm that distinct facial features are associated with distinct somatotypes and distinct disease susceptibilities.