The prevalence and characteristics of molar-incisor hypomineralisation in Natal, Brazil

Objectives: To determine the prevalence and presentation patterns of molar-incisor hypomineralisation (MIH) in Brazilian children. Methods: A cross-sectional study was carried out with 715 individuals aged 8-17 years. MIH was diagnosed according to European Academy of Paediatric Dentistry (EAPD) criteria, using intraoral photographs. Data were analysed using Chi Square and Pearson's Correlation tests at alpha = 0.05. Results: The prevalence of MIH was 15.66 %. Mild defects represented by demarcated yellow and brown opacities comprised 83.5 % of the total MIH lesions and the severity of MIH lesions increased significantly as age increased. The average number of first molars affected by MIH per child was 2.26, and 36 children (32.14 %) had at least one affected incisor. With the increase of affected molars, the number of incisors with opacities showed an obvious increasing. The maxillary left first molar was the most affected tooth, and the maxillary central incisors were the anterior teeth most frequently affected by MIH. Conclusion: The prevalence of MIH was within the range of published studies and the severity of the defects was mostly mild.