Behavioral Interventions Targeting Base of Tongue to Posterior Pharyngeal Wall Approximation: A Scoping Review

Pharyngeal pressure generated by approximation of the base of tongue to the posterior pharyngeal wall (BOT-PPW approximation) is critical for efficient pharyngeal bolus passage and is a frequent goal of dysphagia management. This scoping review evaluated behavioral interventions available to improve BOT-PPW approximation. We searched MEDLINE, CINAHL, Ovid Emcare, Web of Science, SCOPUS, and ProQuest for studies that met the following criteria: (i) behavioral interventions targeting BOT-PPW approximation, which (ii) were assessed using BOT-PPW-specific outcome measures, and (iiia) performed over a period of time (Review Part 1) or (iiib) studied immediate effects (Review Part 2). Study quality was rated using the GRADE framework. Data were extracted and synthesized into dominant themes. Of the 150 studies originally identified, three examined long-term effects (two single cases studies of individuals with dysphagia, and a third study evaluating effortful swallowing in healthy individuals). BOT-PPW approximation only increased in the two single case studies. Twenty-one studies evaluating immediate effects were categorized as follows: (1) effortful swallowing, (2) Mendelsohn maneuver, (3) tongue-hold maneuver, (4) super supraglottic swallowing maneuver, and (5) non-swallowing exercises. Across all studies, varying levels of success in increasing BOT-PPW approximation were reported. Four of 21 immediate effects studies evaluated patients with demonstrated swallowing impairment, whereas 17 studies evaluated healthy adults. Quality assessment revealed low strength of the existing evidence base. The evidence base for rehabilitative interventions targeting BOT-PPW approximation is severely limited and translation is hindered by small sample sizes and methodological limitations. Further clinical research is warranted.