Oropharyngeal and tongue exercises (myofunctional therapy) for snoring: a systematic review and meta-analysis

Oropharyngeal and tongue exercises (myofunctional therapy) have been shown to improve obstructive sleep apnea. However, to our knowledge, a systematic review has not been performed for snoring. The study objective is to perform a systematic review, with a meta-analysis, dedicated to snoring outcomes after myofunctional therapy. PubMed/MEDLINE and three other databases were searched through November 25, 2017. Two authors independently searched the literature. Eligibility (1) patients: children or adults with snoring, (2) intervention: oropharyngeal and/or tongue exercises, (3) comparison: pre and post-treatment data for snoring, (4) outcomes: snoring frequency and snoring intensity, (5) study design: publications of all study designs. A total of 483 articles were screened, 56 were downloaded in their full text form, and nine studies reported outcomes related to snoring. There were a total of 211 patients (all adults) in these studies. The snoring intensity was reduced by 51% in 80 patients from pre-therapy to post-therapy visual analog scale values of 8.2 +/- 2.1 (95% CI 7.7, 8.7) to 4.0 +/- 3.7 (95% CI 3.2, 4.8). Berlin questionnaire snoring intensity reduced by 36% in 34 patients from 2.5 +/- 1.0 (95% CI 2.2, 2.8) to 1.6 +/- 0.8 (95% CI 1.3, 1.9). Finally, time spent snoring during sleep was reduced by 31% in 60 patients from 26.3 +/- 18.7% (95% CI 21.6, 31.0) to 18.1 +/- 20.5% (95% CI 12.9, 23.3) of total sleep time. This systematic review demonstrated that myofunctional therapy has reduced snoring in adults based on both subjective questionnaires and objective sleep studies.