I was diagnosed moderate obstructive sleep apnea two years ago, and i am using somnodent AP Pro, which is custom made oral device. Effective and comfortable, wife no complaint of loud snoring since i wore this appliance. And i wake up fresh everyday. My advice, find a good sleep apnea dentist to do this, i went through several adjustment and finally engaged with the correct protrusion of lower jaw, i cant sleep well without the oral device now. A properly trained sleep apnea dentist will refer you for sleep test for diagnosis first, as my dentist told me that oral device can only treat obstructive sleep apnea, not the central sleep apnea. She referred me to government hospital, but private wing, more affordable, and fast, around rm400 that time. Then she explained to me my sleep test results, took mould for the oral device, surprisingly it is comfy. After the adjustment i wore it for two months then went for follow up sleep test, and my sleep apnea index improved. So my advice, get a well trained sleep dentist if you really want an oral appliances.