Molar incisor hypomineralization (MIH) can lead to many clinical conditions and affect oral health-related quality of life (OHRQoL).

Molar incisor hypomineralization (MIH) can lead to many clinical conditions and affect oral health-related quality of life (OHRQoL). The aim of this study was to determine the prevalence, etiology and impacts of MIH on oral health status and OHRQoL.

Six hundred and fifty-five parents and their children aged 9 years were included in the study. After parents completed the questionnaire about the etiology of MIH, children's OHRQoL was measured by the Child Perceptions Questionnaire (CPQ8-10). Children were evaluated for presence and severity of MIH, dental caries experience and oral hygiene status. Qualitative data were analyzed with the Pearson chi-square and Fisher's exact tests. For the quantitative data, if the normal distribution was not satisfied, Kruskal Wallis/Mann-Whitney U tests were used. Also, Binominal logistic regression analysis was performed and p<0.05 was statistical significant.

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Inclusion Criteria:

• Being 9-year-old,
• Mentally and physically capable of completing the questionnaire,
• Presence of fully erupted 4 permanent molars and 8 permanent incisors.

Exclusion Criteria:

• Children were receiving orthodontic treatment during the examination,
• Children had enamel hypoplasia or developmental defects,
• Children had amelogenesis imperfecta or dental fluorosis.

9-year-old children who were enrolled in the primary schools in the city of Rize, Turkey.