Differential diagnosis of molar incisor hypomineralisation and hypomineralised second primary molars: a scoping review.
Abstract
Background
Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) have been extensively studied; however the specific diagnostic boundaries distinguishing them from other developmental enamel defects remain unclear.
Objectives
This review aims to systematically map the literature describing clinical, radiological, histological or structural features and patient-reported symptoms useful for the differential diagnosis of MIH and HSPM, and additionally to identify knowledge gaps for future research.
Methods
Primary studies addressing the differential diagnosis of developmental defects of enamel published in the period 1985-2025, written in English and involving human subjects were considered for inclusion in this scoping review. PubMed/MEDLINE, EMBASE, Cochrane Library and Scopus were searched. Two reviewers screened retrieved papers independently for eligibility and charted the data. The protocol was registered with the Open Science Framework registration number 10.17605/OSF.IO/P9UKD.
Results
A total of 23 reports were included in the review. More than half of the studies were case series (39.1%) and case reports (17.4%), including small samples (in 50.0% of the studies the sample size was fewer than 10 subjects). Amelogenesis Imperfecta (AI) was found in most papers (65.2%); other conditions included dental fluorosis, white spot lesions, and developmental defects associated with cleft lip and palate, antineoplastic therapy, syphilis, Turner syndrome and vitamin D-dependent rickets type 1. No single study directly compared MIH and HSPM with other enamel developmental defects in a controlled manner, representing a major limitation in establishing evidence-based differential diagnostic criteria.
Conclusions
Future studies should include well-designed comparative analyses using standardized diagnostic criteria and objective measures in larger and more diverse patient samples.