Laryngeal Manual Therapies for Behavioral Dysphonia: A Systematic Review and Meta-analysis

Objectives. The aim of this study was to review systematically the literature and to analyze the effectiveness of laryngeal manual therapy in addressing the overall severity of vocal deviation, the intensity of vocal and laryngeal symptoms, and musculoskeletal pain in adults with behavioral dysphonia. Study Design. This is a systematic review and meta-analysis. Methods. Two independent authors selected clinical trials that analyzed the effectiveness of laryngeal manual therapy compared with other interventions in the treatment of adults with behavioral dysphonia from the Cochrane Library, PubMed, Web of Science, and LILACS. The analyzed outcomes were the overall severity of vocal deviation, the intensity of vocal and laryngeal symptoms, and musculoskeletal pain. Data analysis was conducted based on the following steps: the assessment of the risk of bias, the measures of treatment effect and descriptive data analysis, the assessment of heterogeneity, subgroup analysis, sensitivity analysis, and the assessment of reporting biases. Results. A total of 2135 studies were identified, three of which met the selection criteria. Data analysis showed an unclear risk of 100% of performance bias and 66% of detection bias, in addition to a 33% high risk of selection bias. Low statistical and clinical heterogeneities were found. In addition, no significant difference was found in the relative risk of improvement with laryngeal manual therapy and with other interventions in the analyzed outcomes. Conclusions. Various types of laryngeal manual therapies are available with similar objectives and effects, but their effectiveness is equivalent to that of other interventions involving direct voice therapy in the rehabilitation of adults with behavioral dysphonia.