Fig. 1

Comparison of FEES findings between symptomatic patients with OSA and healthy subjects. In the box plots, vertical solid lines (whiskers) show lower and upper scores of the different ordinal scales. Box stretches from lower hinge (25th percentile) to upper hinge (75th percentile). Median is shown as line across each box. Outsiders are represented by dots, extreme values are represented by asterisks. a Comparison of the bolus location at swallow onset, scored with the 5-point ordinal scale by Langmore et al¹⁶, between patients with OSA and healthy subjects (Mann–Whitney U test p = 0.077 for solids, p < 0.05 for all other bolus types). b Comparison of penetration and aspiration events, scored with the PAS, between patients with OSA and healthy subjects (Mann–Whitney U test p < 0.05 for all bolus types). c Comparison of the pharyngeal residue in the valleculae, scored with YPRSRS, between patients with OSA and healthy subjects (Mann–Whitney U test p < 0.05 for all bolus types). d Comparison of t the pharyngeal residue in the pyriform sinus, scored with YPRSRS, between patients with OSA and healthy subjects (Mann–Whitney U test p < 0.05 for all bolus types). PAS, Penetration-aspiration scale; YPRSRS, Yale Pharyngeal Residue Severity Rating Scale