Nutritional supplementation and the development of linear enamel hypoplasias in children from Tezonteopan, Mexico.

The purpose of this study was to compare the effect of nutritional intake during tooth-crown formation on the subsequent development of linear enamel hypoplasias (LEHs) in Mexican nonsupplemented (control) adolescents (n = 42) and adolescents who had received daily nutritional supplements since birth (n = 42). The proportion of individuals with LEHs was nearly two-fold greater (74.4%; 95% CI 64.7-84.1%) in the control than in the supplemented group (39.5%; 95% CI 28.6-50.4%; chi 2 = 9.44; P = 0.001). Although the estimated peak age at formation, approximately 2-2.5 y, is similar in both groups, the proportion of early (before 1.5 y) and late (after 3.0 y) LEHs was greater in the control group. LEH was also more common in females and was associated with an increase in illness days and a decrease in growth velocity. Results of this study suggest that mild to moderate undernutrition during enamel formation is causally linked to the formation of LEHs.