Nine patients with severe obstructive sleep apnea syndrome (OSAS)--for whom several therapeutic approaches, including palatopharyngoplasty, had failed--were treated with a combined maxillary, mandibular, and hyoid advancement. Objective evaluation--performed before and 4 to 18 months after surgery, using nocturnal polysomography--indicated that the OSAS had improved or had disappeared. This surgical approach is beneficial for specific cases of OSAS, which can be identified by mandatory presurgical tests.