Obstructive sleep apnea syndrome (OSAS) is one of the most common respiratory disorders in humans. It is characterized by repetitive episodes of pharyngeal collapse with increased airflow resistance during sleep and is often accompanied by extensive snoring. Hypoxia and sleep fragmentation, which accompany the disease, cause a number of serious consequences such as excessive daytime sleepiness, arterial hypertension and pulmonary hypertension, arrhythmia and ischemic heart disease. The gold standard diagnostic investigation for OSAS is polysomnography. Oral appliances have occupied an important place among all conservative methods of therapy. They should be considered in patients with mild‑to‑moderate OSAS or in those unable to tolerate continuous positive airways pressure, CPAP.

Key words: obstructive sleep apnea syndrome, diagnosis, treatment, oral appliances.