Prevalence and Clinical Patterns of Molar-Incisor Hypomineralisation and Hypomineralised Second Primary Molars among Children with Special Healthcare Needs: A Comparative Cross-Sectional Study

Purpose: Developmental enamel defects, commonly seen in children, have proven to pose clinical challenges for pediatric dentists. Among these, Molar-Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) are among the most common enamel defects and each of these has important clinical implications. Children with special healthcare needs (CSHCN) may be more likely to have developmental enamel defects due to systemic, perinatal & environmental factors. The aim of this study was to assess and compare the prevalence, distribution and clinical patterns of molar-incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) in children with special healthcare needs and neurotypical children aged 7–13 years. Methods: A comparative cross-sectional study was conducted among 216 children (108 neurotypical children and 108 CSHCN) by a calibrated examiner following the EAPD Diagnostic criteria for MIH/HSPM. Prevalence, severity and lesion extension of MIH and HSPM were noted. Data was analysed using the Chi-square test (p < 0.05 considered statistically significant). Results: The overall prevalence of MIH was 19.4%. MIH prevalence was greater in CSHCN (30.6%) than neurotypical children (8.3%). HSPM prevalence was 4.2% and showed no significance. Severity of MIH was greater within the CSHCN group with 42.1% having atypical caries and 15.8% showing post-eruptive breakdown due to MIH compared to neurotypical peers. Lesion extension was also greater in CSHCN. In CSHCN, most cases involved only molars (84.8%) while neurotypical children showed more molar-incisor involvement. Conclusion: Children with special healthcare needs have a significantly greater prevalence and severity of MIH. These findings emphasize the need to implicate early preventive strategies, proper parental awareness and timely intervention, thereby improving the overall well-being and quality of life in such individuals.