Polysomnography is a golden standard in the diagnosis of obstructive sleep apnea (OSA). During the recent several years, numerous investigations devoted to the diagnostic value of this complex method in children and adults presenting with OSA and snoring have emerged. The publications proving the effective applicability of polysomnography in dental medicine and, especially, in orthodontics, are of undoubted interest. Apnea Graph is a modern tool for sleep analysis in ambulatory setting. By using this method, the localization of airway obstruction during snoring and OSA as the type of sleep apnea as obstructive or central can be defined. Apnea Graph is applied not only alone but also following polysomnography and in combination with other clinical and apparatus diagnostic methods. It is of particular value in screening investigations.