[Treatment of obstructive sleep apnea syndrome with a mandibular positioning device and other nonsurgical modalities].

The therapeutic approach to a patient with obstructive sleep apnea syndrome (OSAS) must be individualized because of the heterogeneity in the pathogenesis of the disorder. Although nasal continuous positive airway pressure (CPAP) is effective no matter what the pathogenesis, risk factors for this disorder should be identified in each patient. Nasal CPAP will be discussed by others. Weight loss is one of the best nonsurgical treatments of OSAS and it should be strongly recommended to obese patients with the disorder, even though only a few achieve satisfactory weight reduction. Sleeping in the lateral position or upright may be effective in some patients with OSAS. Acetazolamide, medroxyprogesterone, or protriptyline may also have a role in some patients, although the efficacy must be weighed against the considerable side effects. The cross-sectional area of the oropharynx measured by computed tomography in patients with OSAS was significantly lower than that in control subjects. Lateral cephalograms revealed a retarded mandible in many patients. A dental device designed to advance the mandible 2 to 7 mm and to eliminate the airway obstruction at the base of tongue was used in 20 consecutive patients (17 men and 3 women, average age 53.8 years) to treat the obstructive sleep apnea. The body mass index of the patients was 27.6 +/- 4.2 kg/m2 (mean +/- SD). The device moved the mandible forward (p = 0.038) and increased the airway space in the lower part of the oropharynx (p = 0.031) as assessed with lateral cephalograms. After nightly use of the device for 24 to 211 days, overnight polysomnography was performed for two nights: without the device for the first night and with it for the second night. The apnea index was reduced from an average of 30.7 to 18.5 events/hour (60.4% of the pretreatment value, p = 0.004). The number of desaturations (more than 5% decrease from the base line SaO2) decreased and the lowest level of SaO2 increased: from 26.5 to 14.4 events/hour (p = 0.009) and from 63.6 to 70.1% (p = 0.005), respectively. Not every patient improved sufficiently. Eleven of 20 patients were classified as good responders, because of a reduction in apnea index of at least 50% of the pretreatment value, and the remaining nine patients were classified as poor responders. Use of the device reduced the severity ratings of snoring and excessive daytime sleepiness not only in the good responders but also in the poor responders. No serious complications were observed. The mandibular positioning device is an effective treatment for some patients with OSAS. The effectiveness of the device should be predicted from polysomnographic and cephalometric data, and from CT measurements of the upper airway and other characteristics of the patients.