Haleh Hali - Assistant Professor, Department of Pedodontics, School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran.
Tahereh Molania Jelodar - Assistant Professor, Department of Oral & Maxillofacial Medicine, School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran.
Mahan Emadian - Dentistry student, School of Dentistry, Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran.
Shiva Gohardehi - Dentistry student, Student research Committee, Faculty of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran.
Mahmood Moosazadeh - Ph.D. in Epidemiology, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran.
Maede Salehi - Assistant Professor, Department of Oral & Maxillofacial Medicine, School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran.

Background: The purpose of this study was to estimate the prevalence of molar incisor Hypomineralisation (MIH) in a group of school children aged ۷ to ۱۲ years, in sari. Materials and Methods: ۷۰۰ school children (۳۵۰ males and ۳۵۰ females) were randomly selected for participation in this descriptive cross-sectional study. The prevalence of MIH was, initially, determined through clinical examination. The participants with MIH were also interviewed, and Related Data was recorded in questionnaires filled by the examiner. The data of study was analyzed using the Chi-square, Fisher’s exact, and Mann-Whitney U tests through SPSS version ۱۷. P-vale less than ۰.۰۵ was considered statistically significant. Results: The prevalence of MIH was ۲۰.۲ % (n =۱۴۲). Prevalence rate calculated in the studied group was ۲۱.۱% (males=۷۴) and ۱۹.۴% (females=۶۸).There was no significant difference between the two genders in terms of the prevalence and intensity of the MIH (P=۰.۴).   Conclusion: The results revealed that MIH is of moderate prevalence in Sari primary schools, and its prevalence is not significantly associated with gender. tically significant. Results: The prevalence of MIH was ۲۰.۲ % (n =۱۴۲). Prevalence rate calculated in the studied group was ۲۱.۱% (males=۷۴) and ۱۹.۴% (females=۶۸).There was no significant difference between the two genders in terms of the prevalence and intensity of the MIH (P=۰.۴). Conclusion: The results revealed that MIH is of moderate prevalence in Sari primary schools, and its prevalence is not significantly associated with gender.  

Hypomineralization, Incisors, molar, Prevalence