Obst ructive sleep apnea and hipoapnea syndrome (OSAHS) is a disorder that affects about 4% of the adult population, and besides the social problems associated to snoring and extreme day time sleepiness, it is preoccupying since it may cause pulmonary hypertension and cardiac failure. Review and discussion -Through a literature review, we discuss the use of oral appliances to treat this condition, in regards of therapy effectiveness and limitations, main clinical symptoms, major occlusal side effects, rate of improvement and patient satisfaction. Conclusions -We concluded that the use of oral appliances should be a first choice treatment for mild to moderate OSAHS, being dental, joint and muscular discomforts, hypersalivation and xerostomia, the most frequent clinical symptoms, with light occlusal side effects that normally do not bother the patients, with a good degree of improvement and high satisfaction index.