Childhood obesity may accelerate timing of human facial growth

Objective: We hypothesize that childhood obesity influences both facial and mandibular size and form in children and adolescents. Design: Pre-treatment records of patients (n = 181; 86 males, 95 females) from the Department of Orthodontics at the University of Illinois at Chicago representing six different ancestry groups (Asian, African-American, Caucasian Non-Hispanic, Hispanic, Multiracial, Unknown) were reviewed retrospectively. Body mass index (BMI) scores and categories were calculated using the Center for Disease Control and Prevention (CDC) guidelines. Twenty-two landmarks were collected on lateral cephalometric radiographs. The landmark dataset was analyzed as a whole (facial shape) and a subset of landmarks was also used to study mandibular shape in isolation. Results: Evidence of allometry (size related shape differences) was detected. Principal Component Analyses (PCA) were performed on the allometric regression residuals. Overall facial shape did not correlate with BMI. A series of one-way ANOVA tests on PC1-6 on a mandible-only subset of the landmarks using BMI category (normal, overweight, obese) showed PC5 and PC6 were significant (p = 0.003; p = 0.027). Centroid size was positively correlated with BMI when controlling for age (facial: p = 0.011, r = 0.196; mandibular: p < 0.001, r = 0.256). Conclusions: Our results mostly did not support a relationship between high BMI and facial shape. However, we found larger facial skeletal sizes in high BMI children, providing tentative evidence that childhood obesity may lead to accelerated timing of facial growth.