In this article, a patient is presented who was treated by a maxillo-mandibular advancement osteotomy, in order to increase the volume of the oropharynx as a final treatment of the obstructive sleep apnea syndrome. This syndrome is a common affliction, characterized by excessive daytime sleepiness and unintentionally falling asleep. It can be diagnosed by patient history and polysomnography. Nasal-continuous positive airway pressure is the golden standard of treatment. However, in mild to moderate cases of the syndrome, treatment with a mandibular reposition appliance is also an option. The extraoral device of the first treatment option as well as the intraoral appliance of the second treatment option are demanding patients’ compliance. Therefore, research into other treatments is necessary. The initial results of the advancement osteotomy among six patients were very good and in accordance with other literature reports. These results justify further research to clarify the importance of this treatment option of the obstructive sleep apnea syndrome.