RESUMO
OBJECTIVE: Retrospective videofluoroscopic swallowing study (VFSS) evaluations of pharyngeal swallowing were used to evaluate the types of dysphagia alleviated by the chin-down maneuver. MATERIALS AND METHODS: The study population consisted of 64 patients who underwent VFSS evaluations during neutral and chin-down maneuvers presenting specifically penetration or aspiration. The assessment of the VFSS movie clips of each maneuver was performed using parameters of the Modified Barium Swallow Impairment Profile (MBSImP) and the presence and degree of airway invasion(PDAI) by three blinded raters in the following five subcategorized groups, 1. patietns presenting penetration or aspiration during swallow 2. after swallow, patients of 3. head and neck, 4. digestive and 5. neuromuscular disorders, respectively. The scores registered for the two maneuvers were statistically compared. Additionally, we examined statistically which factors had the impact on the improvement of the PDAI using fisher's exact test. RESULTS: Compared with the neutral position, PDAI, pharyngeal constriction, anterior hyoid movement, pharyngeal constriction, laryngeal elevation, laryngeal closure, upper esophageal sphincter opening, initiation of the pharyngeal swallow, and pharyngeal clearance in pyriform sinus were significantly (p < 0.01-0.05) improved with the chin-down maneuver. In a subcategory comparison with group 1, 3 and 4, the PDAI improved significantly (p < 0.01) with the chin-down maneuver, in which laryngeal elevation and laryngeal closure had statistically the impact (p < 0.01-0.05) on improvement of PDAI. CONCLUSION: The chin-down maneuver was most effective in improving swallow function when the impairment included penetration and aspiration during swallow caused by inadequate laryngeal elevation and laryngeal closure.