Context: The prevalence of molar incisor hypomineralization (MIH) varies considerably around the world. South America is one of the regions with the highest prevalence.
Aim: The aim of the study was to determine the prevalence and severity of MIH in children residing in urban and rural areas of Puno, Peru.
Design: This was an observational cross-sectional study that included 404 children, aged 7-10 years old, from urban and rural public schools in Puno, Peru.
Subjects and methods: A previously calibrated examiner established the MIH diagnosis based on the index that integrates the criteria of the European Academy of Paediatric Dentistry and the modified index of developmental defects of enamel (mDDE index), as well as the caries experience based on the DMFT index.
Statistical analysis used: The information was analyzed using descriptive statistics and bivariate analysis.
Results: Eighty children (19.8%) presented MIH, and the prevalence was higher in the urban area. Demarcated opacities were the most prevalent type of lesion (52.1%), followed by atypical caries lesions (36.7%). The more severe the defects, the greater their extent. Similarly, the greater the extent of tooth defects, the greater the number of teeth affected per child. Children with MIH had slightly higher rates of tooth decay experience (DMFT). However, no significant association was found between caries experience and MIH.
Conclusions: The population studied showed a high prevalence of MIH, similar to other studies in South American populations. The prevalence varied among residence areas, being more prevalent in the urban area. Mild lesions were more frequent.
Keywords: Child (DeCS); dental caries; dental enamel; dental enamel hypoplasia; prevalence.