Oral Health-Related Quality of Life in Pediatric Subjects with Molar Incisor Hypomineralization: An Umbrella Review of Domain-Specific Impact and Treatment-Related Changes.

BACKGROUND/OBJECTIVES: Molar incisor hypomineralization (MIH) is a qualitative enamel defect affecting pediatric populations, predisposing to hypersensitivity, caries, and post-eruptive breakdown, and potentially impacting oral health-related quality of life (OHRQoL). Therefore, the primary aim of the present umbrella review was to evaluate the overall OHRQoL among pediatric subjects with MIH, as well as individual domains from both children and parents. Secondary aims were to evaluate the influence of MIH severity, extent/distribution pattern, age, and dentition status on overall- and domain-specific OHRQoL outcomes, and to assess the impact of different dental treatments on OHRQoL. METHODS: Following PRISMA guidelines and PROSPERO registration, six systematic reviews were included. To address metric heterogeneity, mean scores were normalized into a 0-100% descriptive percentage impact index. Treatment-related changes were calculated as percentage improvements. RESULTS: A total of 4028 respondents (3193 children and 835 parents/caregivers) were evaluated for OHRQoL. The overall impact on children and parents was highest in the oral domain (26.43%), followed by the psychological (20.25%), functional (19.50%), and social (11.75%) domains. Parental underestimation of MIH was consistently observed across all domains. Children in early mixed dentition reported a higher perceived impact than those in late mixed/permanent dentition (26.77% vs. 14.43%). In an exploratory subsample (n = 494), MIH severity appeared to impact OHRQoL, particularly in oral and functional domains. Overall, post-treatment OHRQoL improved across all domains, although evaluated in a limited sample (n = 491). CONCLUSIONS: MIH showed a relevant impact on pediatric OHRQoL. Notably, children consistently report a greater perceived impact than parents, suggesting potential parental underestimation. However, findings regarding dentition stage, MIH severity, and post-treatment improvements should be interpreted with caution, as heterogeneity in assessment tools, limited subsamples, and variable follow-up intervals precludes definitive conclusions.