Effects of Palatal Plate Treatment Duration on Orofacial Functions of Children With Trisomy 21: Mapping the Evidence Through a Scoping Review

AIM: The aim of the present study was to synthesize the available evidence on the short- and long-term effects of Palatal Memory Plate in children with Trisomy 21. METHODS: A scoping review was conducted, and followed the Preferred Reporting Items for Systematic Review and Meta-Analysis with extension for scoping reviews. The review was registered in Open Science Framework, under registration number 10.17605/OSF.IO/ZDNCQ. Two independent reviewers conducted searches in PubMed, Embase, Web of Science, Scopus, Cochrane Library, and Google Scholar for gray literature, in April, 2026. The critical evaluation of the included studies was done with Oxford-CEBM Levels of Evidence for intervention questions. RESULTS: Of the 191 potentially eligible articles for selection, 19 were included. In treatments lasting 4 months to 1 year, improvements were observed in lip sealing, tongue posture, and early speech, as well as an increase in orofacial muscle tone. From 3 to 4 years, results remained stable. CONCLUSION: The evidence suggests potential improvements in orofacial functions at different follow-up periods, with some studies reporting maintenance or progression over time. However, results should be interpreted with caution due to the lack of higher evidence level.