Is there Weakness Area in Airway

Purpose: In our previous study, it was reported that the cross-section airway of OSA presented triangle shape, especially in the obese patients. From this finding, we hypothesized that there is structural weakness of airway in the bilateral posterior region. In this short report, to discover the weakness region in the airway, the airway configuration change under the negative pressure loading was observed. Methods: Subject was 33 year-old female, who had no OSA. It was investigated the pressure level of which she was able to keep same the same level stably and constantly for 15 seconds using a pressure gauge. This pressure level was applied during scanning CBCT (S_NP).The airway was scanned via a CBCT with 15 seconds, under following conditions; normal breathing and under S_NP. The airway volumes between the level of the posterior nasal spine and the tip of epiglottis were measured. Results: The airway configuration during normal breathing was elliptical shape. On the other hand, the airway under S_NP presented triangle shape. The airway volumes were 16040mm 3 during normal breathing, and 6567mm 3 under S_NP. The airway volume under S_NP decreased to 41%, compared with normal breathing. Conclusion: In this short report, it could observe the airway configuration under the negative pressure. As a result, the airway may be obstructed from posterolateral direction by fat tissue or negative pressure. This short report provided an importance of research regarding to the structural weakness in the airway.