Stability of palatal rugae after orthodontic/orthopaedic expansion: a scoping review

Abstract Objective The palatal rugae are connective tissue located in the anterior third of the hard palate and present asymmetrically on each side of the palatine raphe. The stability and individualistic features of the palatal rugae have been suggested as an alternative human identification method in forensic medicine. However, there are different views about the tissue’s stability and reliability in individuals undergoing orthodontic expansion, as the palatal mucosa is stretched which likely alters palatal rugal morphology. The present review aims to summarise the available evidence regarding the stability of the palatal rugae after orthodontic expansion. Method Following the PRISMA-Scr guidelines, an extensive search was conducted using three databases (PubMed, Web of Science, and Scopus). Only studies that had control groups were included to allow for comparison. Results A total of six studies were identified. One report did not mention the type of expansion used, another used slow maxillary expansion (SME), and the other four used rapid maxillary expansion (RME). The results related to rugal length, morphological shape, and root mean square were inconclusive, likely because of data heterogeneity in expansion mechanics, the age of inclusion, and measurement outcomes. Conclusion More high-quality research is needed to substantiate the importance of palatal rugae in forensic medicine.