A study involving 541 snorers (Lofaso et al Eur Respir J 2000) found that patients with Sleep Apnea had higher nasal resistance than patients without Sleep Apnea. Daytime nasal obstruction was determined to be an independent risk factor for Sleep Apnea. However, other studies have failed to show this relationship. A review of the literature suggests that nasal obstruction may play a more meaningful role in non-obese patients with Sleep Apnea. The role nasal obstruction plays in Oral Appliance success is not clear. However, non-obese apneic patients with nasal obstruction may benefit from an Ear Nose and Throat evaluation to determine the possibility of improving nasal breathing and possibly improving their Apnea level.