The effects of lingual training: a systematic review with meta-analysis

Purpose: To assess the effectiveness of myotherapy exercises in increasing tongue pressure and strength. A secondary aim was to analyze the exercise types, training parameters, and functional results. Research strategies: This systematic literature review was based on the Prisma protocol guidelines. Selection criteria: The review included clinical trials that assessed the effects of tongue muscle training, with no restriction on the language or year of publication. Data analysis: The steps included eliminating duplicates; reading abstracts and excluding studies that did not meet the inclusion criteria; reading selected articles in full text, extracting important data, and gathering them in a table; and meta-analysis, using the inverse variance method. The methodological quality of the studies was assessed with the Joanna Briggs Institute ' s tool. The quality of evidence was assessed with the Grading System of Recommendations Assessment, Development and Evaluation. Results: The meta-analysis indicated a significant increase in maximum anterior and posterior pressure as an effect of training. The most performed exercise was tongue pressure against the palate. However, training parameters varied between studies, and whether exercises alone led to functional improvement cannot be stated. The quality of the evidence was considered low. Conclusion: Myotherapy exercises increased anterior and posterior tongue pressure in adults, but the quality of this evidence is low. The studies used various exercise types and training parameters. It cannot be stated whether exercises alone led to functional improvement.