Factors associated with molar-incisor hypomineralisation in schoolchildren aged 8-10 years: a case-control study.

BACKGROUND: The aetiology of molar-incisor hypomineralisation (MIH) is multifactorial and may involve genetic and environmental factors. AIM: To verify the factors associated with MIH in schoolchildren from 8 to 10 years of age. DESIGN: This is a case-control study with a sample consisting of children aged 8 to 10 years, paired by gender and school type, in a ratio of 1:3. The case group included 186 children with MIH and the control included 558 children without MIH. Data were collected through a semi-structured questionnaire and clinical examination. Chi-square, linear-by-linear, Mann-Whitney, and logistic regression tests were conducted. A value of P < 0.05 was considered significant. RESULTS: The prevalence of mild MIH was 19.5%, moderate MIH 2.2% and severe MIH 3.2%. An association was observed between MIH with treatment need and a higher mean DMF-T and decayed and missing teeth (P < 0.05). According to the aetiological factors studied, mothers who presented a fever during pregnancy had a 2.54 times greater chance of having children with severe MIH than mothers who did not present a fever (P = 0.045). CONCLUSION: The presence of fever during pregnancy and the need for treatment were associated with MIH.