Tongue Pressure as a Predictor of Tongue Base Collapse in Patients with Obstructive Sleep Apnea Syndrome

Background: This study investigated the association between tongue strength, measured using the Iowa Oral Performance Instrument (IOPI), and upper airway collapse patterns observed during drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea syndrome (OSAS). Methods: Thirty patients who underwent polysomnography, DISE, and tongue pressure measurement were retrospectively analyzed. Upper airway collapse was assessed using the VOTE classification. The tongue strength task performed using the IOPI requires participants to compress an air-filled bulb placed on the hard palate with anterior tongue to generate maximum isometric tongue pressure. Group comparisons and ordinal logistic regression with Firth's penalized likelihood were performed to evaluate associations between tongue pressure and collapse patterns. Results: The participants had a mean age of 41.5 ± 12.5 years, including 27 males and 3 females. The mean tongue strength was 50.4 ± 15.3 kPa, with no significant sex-related differences. Patients with tongue strength <40 kPa showed significantly higher odds of tongue base collapse (adjusted OR 12.79, 95% CI 1.30-126.91) and epiglottic collapse (adjusted OR 54.05, 95% CI 1.66-1760.25). No significant differences were observed for velum or oropharyngeal collapse. Conclusions: Lower tongue strength was associated with increased likelihood of tongue base collapse during DISE. Tongue strength measurement may serve as a practical, non-invasive tool for identifying patients with reduced tongue muscle function and potential tongue-related airway obstruction.