Abstract:Objective To study the relationship between hyoid bone position and PSG data and the prognosis of modified uvulopalatopharyngoplasty (H-UPPP) in OSA patients, and to explore the influence of hyoid bone position in maxillofacial CT images on severity of OSA and prognosis of H-UPPP. Methods Preoperative hyoid bone position in maxillofacial CT images and preoperative and postoperative PSG data of 47 OSA patients who underwent H-UPPP from June 2020 to October 2021 were collected.SThe vertical distance from the mandible menton to the lower margin of the hyoid bone (MH-v), the horizontal distance from the mandible mental spine to the hyoid bone (MH-h), and the Friedman tongue position (FTP) was conducted correlation analysis with AHI, AvSpO2 (mean oxygen saturation), LSpO2 (lowest oxygen saturation) and the CT90 (ratio of cumulative time of oxygen saturation below 90% to total sleep time) in PSG respectively.SThe correlation between MH-v or FTP and prognosis of H-UPPP was further analyzed. Results MH-v was moderately correlated with AHI, LSpO2 and AvSpO2 (r=0.540, P=0.000;Sr= 0.523, P=0.000;Sr=-0.514, P=0.000), MH-v was weakly correlated with CT90 (r=0.495, P=0.000).SMH-h had no correlation with the above polysomnography data (P> 0.05).S FTP was weakly correlated with AvSpO2, LSpO2, CT90 and AHI (r=-0.370, P=0.01; r=-0.309, P=0.034; r=0.325, P=0.026; r=0.329, P=0.024).SThere was a statistically significant difference in MH-v between the effective and ineffective groups after H-UPPP (t=5.908, P=0.000), while there was no statistically significant difference in FTP between the two groups (U=258.5, P=0.693). The area under ROC curve of MH-v was 0.884,Swhich has moderate diagnostic value in predicting the effectiveness of H-UPPP surgery. Conclusions As an anatomic factor affecting OSA patients, the vertical distance from mandible menton to the lower margin of the hyoid bone (MH-v) has a higher correlation with PSG data than FTP,which is of certain value in predicting the effectiveness of H-UPPP surgery.