RESUMO
Obstructive sleep apnea (OSA) is a common type of sleep apnea and is caused by obstruction of upper airway. Sleep apnea is clinically defined as frequent episodes of apnea, hypopnea and symptoms of functional impairment, which could be life-threatening and associated with extreme daytime hyper somnolence, dysfunction, discrements in health-related quality of life, automobile accidents, and cardiovascular morbidity and mortality. Etiopathogenic factors that contribute to OSA include reduced upper-airway dilator muscle activity during sleep, upper-airway anatomical features, ventilatory control insufficiency, lung volume, and rostral fluid shifts. The presence of risk factors such as age, gender and obesity increases the incidence of OSA. The repetitive nocturnal hypoxemia experienced by patients with OSA is associated with activation of a number of neural, humoral, thrombotic, metabolic, and inflammatory disease mechanisms, all of which have also been implicated in the pathophysiology of various systemic diseases. This article summarizes the etiopathogenesis, epidemiology, associated systemic diseases such as cardiovascular diseases, diabetes, and dental diseases with OSA and the influence of tongue on oropharyngeal airway in OSA patients.