[Position change of hyoid bone induced by oral appliance of double-pull rods in patients with obstructive sleep apnea and hypopnea syndrome and analysis of relevant factors].

OBJECTIVE

The objective of this study is to investigate the position change of hyoid bone in obstructive sleep apnea and hypopnea syndrome (OSAHS) induced by oral appliance (OA) of double-pull rods and analyze relevant factors, subsequently investigate treatment mechanism of OA for OSAHS.

METHODS

Nine OSAHS patients (male), confirmed by polysomnography and excessive daytime sleepiness, were treated with OA of double-pull rods. After a 3-months treatment period, CT scan and three-dimensional reconstruction were made to each patient in central relation with and without OA respectively. The volume of upper airway and hyoid bone position were three-dimensional reconstructed and measured.

RESULTS

After treatment with OA of double-pull rods, the hyoid bone position was obviously changed in horizontal (5.90 +/- 2.27) mm and vertical position (3.31 +/- 1.82) mm, the volume of upper airway was enlarged (32.36 +/-14.58)%. deltaH-C3hor and deltaH-C3ver were positively related to deltavolume% (r = 0.77, P < 0.05; r = 0.79, P < 0.05), negatively related to FH-MP (r = -0.83, P < 0.05; r = -0.76, P < 0.05).

CONCLUSION

The hyoid bone position significantly change after using OA of double-pull rods. Patients with smaller FH-MP have larger horizontal change of hyoid bone.