The objectives of this study is to compare short-term outcomes of CPAP and Adjustable thermoplastic oral appliance in the treatment of obstructive sleep apnea. Study design is a randomized cross-over trial during 6-week period of each treatment in 50 patients. Primary outcomes are quality of life, degree of sleepiness, and severity of OSA determined by FOSQ ESS, and AHI or RDI, respectively.

The objectives of this study is to compare short-term outcomes of CPAP and Adjustable thermoplastic oral appliance in the treatment of obstructive sleep apnea. Study design is a randomized cross-over trial during 6-week period of each treatment in 50 patients. Primary outcomes are quality of life, degree of sleepiness, and severity of OSA determined by FOSQ ESS, and AHI or RDI, respectively. Wash-in period 2 weeks and Wash-out periods 2 weeks are required before start each treatment.

Inclusion Criteria:

1. OSA patients aged over 18 YO at Siriraj hospital
2. AHI 5 - 30 events/ h or AHI > 30 events/h but lowest O2 saturation > 70%
3. Positive consented form

Exclusion Criteria:

1. Patients with severe Temporomandibular joint diseases or limited mandible advancement (< 5 mm)
2. Patients with severe periodontal diseases or inadequate teeth (< 3 teeth in each quadrant)
3. Patients with unstable medical problems i.e. poorly controlled cardiovascular diseases, COPD, cancers, cerebrovascular diseases, epilepsy, dementia, etc.
4. Patients who could not tolerate the side effects of CPAP or SMG
5. Patients who could not follow-up until finishing the protocol or withdraw themselves from the study for any reasons.