This article describes the role of the dentist in the recognition of obstructive sleep apnea syndrome (OSAS), and in the management of this condition by advancing the mandible with a mandibular advancement device (MAD). OSAS is characterized by recurrent obstruction of the upper airway. The opening of this blockage is often accompanied by loud snoring noises, resulting in the patient awakening. MADs are recommended for the treatment of mild to moderate OSAS. The goal of MAD treatment is to expand the upper airway and reduce its tendency to become obstructed. In addition to recognizing OSAS and performing a thorough dental examination before treatment, MAD selection, fabrication, and adaptation are some of the main responsibilities of the dentist. Once the patient has become accustomed to the MAD, a sleep study (polysomnography) should be performed to objectively evaluate the efficacy of the MAD. The physician and dentist should also regularly check to monitor the effectiveness of the MAD, to identify potential side effects, and to evaluate the patient's adherence to treatment (compliance). Keywords: obstructive sleep apnea syndrome, OSAS, snoring, diagnosis, treatment