Molar incisor hypomineralization and dental caries in six- to seven-year-old Thai children.

Purpose: This study aimed to determine the prevalence of molar incisor hypomineralization (MIH) in Thai children and evaluate the association between MIH and dental caries in the permanent dentition.

Methods: A cross-sectional study was conducted among six- to seven-year-old participants of a birth cohort study in Khon Kaen, Thailand. MIH was examined by one calibrated dentist using European Academy of Pediatric Dentistry criteria. The association between MIH and caries was determined by logistic regression at subject level, and generalized estimating equations at tooth level.

Results: Of 484 children who had at least one erupted permanent first molar, the prevalence of MIH was 20 percent, with no difference between genders. Children with MIH had increased odds of having caries in the permanent dentition compared to those without MIH (odds ratio [OR] equals 4.6; 95 percent confidence interval [CI] equals 2.7 to 7.9). MIH molars had approximately 10 times higher odds of developing caries than non-MIH counterparts (OR equals 9.9; 95 percent CI equals 5.7 to 16.9). Caries risk was higher in the upper molars than in the lower molars.

Conclusions: Molar incisor hypomineralization is common and associated with increased risk for dental caries among this group of Thai children.