The Prevalence and Etiology of Molar-Incisor Hypomineralization among Female School Children

Background: Molar-Incisor Hypomineralization (MIH) is a developmental defect affecting teeth. The prevalence of MIH and its clinical implications form a challenge for patients and dentists. Objective: The purpose of this study was to determine the prevalence of MIH among female school children in Makkah, Saudi Arabia. Methods: A cross-sectional study was conducted including 7- to 9-year-old school girls from the public and private sectors. Invitations to participate in the study were sent to the parents of 1,000 randomly selected children, along with questionnaire and consent form. All included children were examined by two dentists who had been previously calibrated in the assessment of MIH (K=0.9), which was diagnosed according to the European Academy of Paediatric Dentistry 2003 criteria. Data analysis was done using SPSS V.22.0 and various statistical tests were conducted to determine significant differences at P<0.05. Results: A total of 711 children participated in this study, with a response rate of 82.2%. The prevalence rates of MIH and Molar Hypomineralization (MH) were 20.96% and 26.58%, respectively. The most common form of MIH was the mild form (87.24%), while 18 children (12.08%) were diagnosed with the moderate form. A single child (0.67%) was diagnosed with the severe form. No statistically significant associations were found between MIH/MH and prenatal, perinatal or postnatal factors. Conclusion: The prevalence of MIH in school girls in Makkah was 20.96%. Despite its high prevalence, the severity of MIH was relatively mild. The etiology of MIH remains unclear and warrants further investigation in future studies.