Inclusion criteria:  Obstructive apnea-hypopnea index > 15 events/hour Patients who do not tolerate or do not accept positive airway pressure therapy  Main exclusion criteria:  Body mass index < 18.5 or > 32 kg/m2 Unable or incapable of providing informed written consent Unwilling or incapable of returning to all follow-up visits and sleep studies, including evaluation procedures and filling out questionnaires Significant co-morbidities making the patient unable or inappropriate to participate in the trial