Prevalence of Molar Incisor Hypomineralization in Thai Children

Molar incisor hypomineralization (MIH) is enamel hypomineralization of systemic origin of one or more first permanent molars frequently associated with affected incisors. No data exist on its prevalence in the Asian populations. Objectives: This study aimed to determine the prevalence of MIH in 6-7 year-old children in rural, non-fluoridated area of Khon Kaen, Thailand. Methods: This cross-sectional survey was conducted among 627 children who participated in the Prospective Study of Thai Children. MIH was examined by one calibrated dentist using the criteria suggested by the European Academy of Paediatric Dentistry. The analyses included 479 children (50.1% female, 49.9% male) with at least one erupted permanent molar. Results: The prevalence of MIH was 20.3%. The average number of affected teeth among children with MIH was 2.07 (SD=1.18) out of which 1.87 (SD=0.96) were first permanent molars. There was no difference in prevalence of MIH between boys (19.3%) and girls (21.3%, chi-square test, p=0.59). Children with MIH had more permanent teeth affected by dental caries (DMFT=0.33) than children without MIH (DMFT=0.14, Mann-Whitney U test, p<0.01). Conclusion: The high prevalence of MIH in this young population poses a great challenge in both clinical and public health perspectives. Further research is clearly needed to elucidate its etiology and to identify effective preventive strategies. Funded by the Graduate School of Khon Kaen University.