Special attention should be given to the enamel defects characterised as MIH. Although the majority of affected children present mild enamel defects, the adverse impact of these defects on the development of the carious lesion in a population with high caries experience. The regional difference in the MIH prevalence deserves attention from health professionals and administrators, especially in a country with an uneven distribution of oral diseases, where the contextualization of health promotion and prevention actions are necessary.