Effectiveness of orofacial myofunctional therapy in improving orofacial function and oral habits: a scoping review.

Background: The effectiveness of orofacial myofunctional therapy (OMT) has yet to be confirmed in the literature. This scoping review aimed to answer the question, "What evidence exists to support the effectiveness of OMT in treating/managing orofacial myofunctional disorders (OMDs) affecting orofacial structures' function and oral habits?" Methods: A librarian at the University of Alberta, Canada, developed a comprehensive search strategy and applied it to 6 databases and grey literature. The reference lists of included studies were cross-checked. Two independent reviewers screened the retrieved records in 2 phases; 1 extracted data. The evidence level of each article was assessed using the Oxford CEBM Levels of Evidence. A third reviewer solved conflicts. Results: After screening 11,518 records, 58 were included (50 primary studies and 8 reviews). The addressed OMDs were ankyloglossia (8 studies), atypical swallowing (9 studies), lip incompetence (13 studies), mouth breathing (10 studies), non-nutritive sucking habit (10 studies), low tongue position at rest (2 studies), and simultaneous OMDs (9 studies). Only 11 studies (19%) were randomized controlled trials. Most presented no proper randomization process and no allocation concealment description; half were open-label studies. Although 86% of primary studies reported positive results using OMT, of 12 comparisons found, only 9 were considered plausible (6 at level of evidence 3, 2 at level 2, and 1 at level 1). None was deemed to have confirmed the effectiveness of OMT. Discussion: Conducting methodologically sound clinical trials with larger samples and longer follow-ups is crucial to answering the research question. Conclusion: In some scenarios, OMT produces clinical changes. However, insufficient high-level evidence exists to fully confirm OMT's effectiveness.