Research on the changes in upper airway shape and respiratory function before and after upper airway treat⁃ ment of patients with mild and moderate OSAHS by wearing mandibular advancement snore stopping devices

Objective To investigate the changes of the upper airway shape and respiratory function in patients with mild and moderate obstructive sleep apnea⁃hypopnea syndrome (OSAHS) before and after wearing mandibular ad⁃ vancement snore stopping devices (MASSD), providing a reference and basis for the treatment mechanisms and clinical efficacy of MASSD for patients with mild and moderate OSAHS. Methods Sixty patients who were diagnosed with mild and moderate OSAHS by polysomnography were selected. Snoring frequency, the apnea hypopnea index and lowest oxygen saturation in 60 patients before and after treatment were compared. The patients’upper airways were scanned by CBCT before and after wearing MASSD. In Vivo Dental software was used to reconstruct the three⁃dimensional shape of upper airway. The upper airway sagittal diameter, the coronal diameter, the minimum cross⁃sectional area and the vol⁃ ume of each segment were measured. The snoring frequency, the apnea hypopnea index and the lowest oxygen satura⁃tion were compared before and after treatment. Results Before wearing MASSD, the snoring frequency, the apnea hy⁃ popnea index, and the minimum oxygen saturation of 60 patients were [946 (542,1 010)], (20.61 ± 5.19), and (78 ± 8)%, respectively. After wearing MASSD, the snore frequency [19(11,30)] and the respiratory disorder index (10.86 ± 4.31) decreased significantly and the minimum oxygen saturation increased (92 ± 3)% . Compared with before wearing MASSD, no statistically significance differences were detected (P > 0.05) except for the sagittal diameter and coronal di⁃ ameter of the surface of the palatum durum. The sagittal diameter and the coronal diameter of each plane of the airway increased, and the minimum cross⁃sectional area of each section of the airway and the volume of each section of the air⁃ way displayed varying degrees of significant increases (P < 0.001) after wearing MASSD. Conclusion Wearing MASSD can open the airways of patients with mild and moderate OSAHS and increase the airway volume of the upper airway to improve the respiratory function.