Predictive value of lingua/pharynx ratio for retroglossal obstruction in patients with obstructive sleep apnea hypopnea syndrome

Conclusions: The lingua/pharynx (L/P) ratio has high sensitivity and specificity in predicting the severity of retroglossal obstruction in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Objective: To evaluate the diagnostic value of the L/P ratio in predicting the severity of retroglossal obstruction in patients with OSAHS. Methods: Airway computed tomography (CT) was performed in 115 patients with OSAHS. The retroglossal cross-sectional area (RCSA) was measured at the axial level of the hypopharynx, immediately superior to the tip of the epiglottis. Moreover, nine lines, which were lined up in the order of n = 1, 2, 3, ..., 9, were drawn from the genial tubercle (point G) to nine points (point P-n) proximally on the posterior pharyngeal wall and hard palate in the sagittal plane. Meanwhile, the nine lines intersected the lingual surface at point Ln, respectively. The L/P ratios of the lingual segment (G to L-n distance) to the pharyngeal segment (G to P-n distance) were measured. We analyzed the correlations between nine L/P values (L/P-n) and RCSA. Results: Both simple linear correlation analysis and multiple linear regression analysis showed that L/P-6 and L/P-9 had significant negative correlations with RCSA.