Evidence mapping and quality assessment of randomised trials related to molar incisor hypomineralisation

Molar-incisor hypomineralisation (MIH) as an oral health condition has been known for the past 25 years. Several randomised clinical trials (RCTs) have been conducted pertaining to the management of different manifestations of MIH. This study aims to identify these RCTs, distribute them in domains and subdomains, describe their characteristics, and analyse their quality.

The systematic search strategy was formulated based on the key elements of the research question and performed electronically on six databases: PubMed, EMBASE, Scopus, Cochrane, Web of Sciences, and LILACS on February 28, 2025. Any study that is a RCT related to any domain of MIH was included. The data was extracted and analysed, and their quality was assessed using the Cochrane Risk of Bias (RoB 2.0) tool.

A total of 39 RCTs were included. The majority of them were in the domain of Therapeutics-General followed by Therapeutics-Molar and Therapeutics-Incisor. More than half of the RCTs followed the CONSORT guidelines and displayed methodological variability. Amongst the included studies, 20 had low risk of bias (ROB), 13 had some concerns, and six studies had high ROB.

This study may serve as a roadmap for MIH researchers for identifying the areas where new, high-quality trials are urgently needed, such as pulp therapy, prognostic severity, extraction of MIH affected molars, caries risk, oral health related quality of life, health economics evaluation, and complications. The researchers may also take note of methodological characteristics of existing RCTs and improve future trials. Moreover, the study can help identify areas ready for systematic reviews or their updates, ultimately guiding evidence-based clinical practice guidelines.