Obstructive site localization using multisensor manometry versus the Friedman staging system in obstructive sleep apnea

The aim of this study was to find the correlation between an anatomy-based staging system and pressure manometry performed during sleep. A retrospective study of 45 patients with obstructive sleep apnea (OSA) was carried out. All patients were evaluated by polysomnography, and obstruction sites were localized using a multisensor manometer during the full night. Obstruction sites were classified into retropalatal and retroglossal. The patients were also staged by anatomic findings of tonsil size and palate position. The % retroglossal obstruction was 29.4, 33.5 and 48.6% in stages I, II and III, respectively. There was no significant difference between stages. In contrast, when compared according to the Friedman tongue position (FTP), the mean % retroglossal obstruction of FTP grade 3 was significantly higher than that of FTP grade 1 (P = 0.009) although apnea hypopnea index, body mass index and lowest SpO₂ were not different among FTP grades. It seems that FTP correlates with retroglossal obstruction and may be used to select patients in need of retroglossal modification of the airway. C. H. Lee and T.-B. Won contributed equally to the content of this article.