Prevalence of Molar–Incisor Hypomineralization by Tooth Element in Children from Diamantina, Minas Gerais

Abstract

Introduction/Justification: Molar–Incisor Hypomineralization (MIH) is characterized as a developmental defect of dental enamel resulting from deficient mineralization, leading to porous enamel with increased susceptibility to post-eruptive fractures. Clinically, asymmetric opacities can be observed in molars, with colors ranging from white-cream to yellow-brown, the latter indicating a more severe form. This condition primarily affects the first permanent molars and may also involve incisors, being frequently associated with hypersensitivity, increased risk of dental caries, and restorative challenges.Diagnosis is based on the patient’s age, severity, and extent of the lesion in order to establish an appropriate treatment plan. Therefore, research on MIH highlights the need for standardized criteria for diagnosis and accurate recording of this condition. Given the increasing global prevalence of MIH and its associated impacts, it has gained significant attention among pediatric dentists. Thus, epidemiological studies assessing the distribution and severity of MIH are essential to improve early diagnosis and to support the development of effective preventive and therapeutic strategies. Objectives:The present study aimed to evaluate the prevalence and severity of Molar–Incisor Hypomineralization, as well as the distribution of affected teeth in schoolchildren from Diamantina, Minas Gerais, in order to provide epidemiological data to support preventive and therapeutic interventions. Methodology:This is a cross-sectional observational study that evaluated the presence and severity of MIH in schoolchildren aged 8 to 12 years in Diamantina, Minas Gerais, Brazil. The sample size was calculated considering a prevalence of 50%, with an additional 20% to account for possible losses, totaling 796 participants. A socioeconomic questionnaire was applied, and clinical examinations were performed using diagnostic criteria proposed by Ghanim, conducted by two calibrated examiners (kappa > 0.80).Diagnosis was established based on clinically recognized criteria, including the presence of demarcated opacities, post-eruptive fractures, and atypical restorations. After data tabulation, descriptive analyses and the Mann–Whitney test were performed, adopting a significance level of 5% (p < 0.05).Results:A total of 99 teeth affected by MIH were analyzed, including incisors and first permanent molars. A significant predominance of the mild form was observed (64.6%), followed by moderate (21.2%) and severe (14.1%) forms. Regarding incisors, 35.4% were unaffected, 54.5% presented mild MIH, and 10.1% moderate MIH, with no severe cases observed. In the first permanent molars, the mild form was present in 67.7%, moderate in 17.2%, and severe in 15.2% of cases. When analyzed by tooth element, a higher occurrence of severe forms was observed in upper and lower molars, particularly tooth 46. In contrast, incisors predominantly exhibited mild forms.Conclusion:It was observed that MIH in incisors predominantly presented as mild, whereas molars were more frequently affected by moderate and severe forms. Therefore, early detection of moderate and severe cases is essential to prevent functional complications and to improve the quality of life of affected children.Despite methodological limitations, this study contributes significantly to the understanding of the distribution and severity of MIH, highlighting the need for longitudinal studies with greater population representativeness to support more effective clinical management strategies.