Aim: To compare pre- and post-operative values of ventilation parameters during sleep, to evaluate the effectiveness of genioglossus advancement and hyoid myotomy in the therapy of OSAS. Introduction: GAHM is surgical methods used for the dilation of the upper airways. It is based on ventral shifting the m. genioglossus attachment. A set of patients and methods: In 1999–2004 we operate 31 patient (8 female and 23 male) using GAHM. We measured the fundamental polygraphic parameters before surgery and at the average interval of 7.3 months (range 3–16) after the operation. Results: Cumulated success was achieved in 74.2 %. Before operation the average RDI was 20.9 and decreased to 10.3 after operation. ODI of 15.1 before operation dropped to 8.8, the average pre-operative values of basal hemoglobin oxygen saturation and average desaturation were 95.1% and 86.5%, respectively, after surgery they elevated to 96.0% and 90.3%, respectively. On the average, desaturation before surgery lasted for 36.7 seconds and after surgery it was shortened to 31.0 seconds. Conclusion: GAHM is a method that changes the morphology of the upper airways in the sense of their dilation. Using polygraphic monitoring, the authors have demonstrated that a change of the upper respiratory airways can have favorable effects on the ventilation parameters during sleep.

        Key words: obstructive sleep apnea syndrome, surgical therapy, genioglossus advancement