Acoustic Pharyngometry in Obstructive Sleep Apnea Syndrome Patients, With Indication of Continuous Positive Air Pressure

The investigators are performing AP exams in severe apneics (cases) and primary snorers (control group),first basal, and then at the same time of using CPAP with a nasal mask, at progressive pressures (from 4 to 10 cmH20 in snorers, and until 2 pressures above the polysomnography determined pressure in apneics). The wave tube of pharyngometer is connected to the patient´s mouth by a mouthpiece, and to the computer. It makes a graphic of area x distance for each measurement. Then the investigators compare the changes in area, distance and volume of oral cavity and pharynx, determined by CPAP pressures, in both groups, and compare the measurements inside each group and between the two groups. Finally, the investigators analyse the CPAP pressure that most modifies the AP graphic, observing if it has some relationship with the polysomnography determined CPAP pressure. The investigators intend this way to show the kind of modifies determined by CPAP in oral cavity and oropharynx and, secondarily, observe some relationship of AP and polysomnography in determine the CPAP ideal pressure for severe apneic patients.