Effect of modified genioglosuss advancement on hyoid bone position: Cephalometric study.

OBJECTIVE: To assess Hyoid bone position and retrolingual airway space after Modified Genioglossus Advancement Surgery by cephalometry in patients with obstructive sleep apnea (OSA). STUDY DESIGN: Prospective study. SETTING: Zagazig University Hospital. METHODS: Eighteen patients with moderate to severe OSA having multilevel airway obstruction confirmed by fiberoptic endoscopy during Muller's maneuver and DISE. All patients underwent modified genioglossus advancement surgery associated with antrolateral advancement pharyngoplasty. Beside Polysomnography and Drug induced sleep endoscopy, Cephalometry was done preoperatively and 6 months postoperative. RESULTS: Improved Polysomnography parameters as Postoperative mean ± SD apnea hypopnea index decreased from 52 ± 17.1 to 17 ± 3 (P < 0.001, 95% confidence interval 27.71 to 42.41). LOS increased from 79.89 ± 4.43% to 83 ± 4.05% (P 0.07, 95% confidence interval -0.31 to 6.97). Cephalometry analysis showed a significant difference between preoperative and postoperative findings, including: Retrolingual airway space at three levels significantly increased; Level 1 from 6.1 ± 1.6 to 8.5 ± 1.7, Level 2 from 10.5 ± 2.4 to 13.9 ± 2.1, Level 3 from 15.7 ± 3.1 to 21 ± 4, H-GN decreased from 51 ± 7 to 39 ± 8, H-MP decreased from 31.6 ± 7.7 to 24.9 ± 7.3, HS decreased from 121 ± 15 to 102 ± 12, H-PH increased from 29 ± 8 to 43 ± 9. With a success rate defined as AHI <20 and a 50% decrease in AHI of the preoperative value, the surgical success rate was 83.33%. CONCLUSION: This study showed that Modified genioglossus advancement procedures done for OSA patients significantly changed the position of hyoid bone into a more anterior and superior position and this was reflected in the postoperative Polysomnography.