They are probably referring to Mandibular Advancement Devices. I had the same kind of thing, but more of an acute event precipitated by stressful work, late night partying/drinking, and years of sleep apnea. The device was magic. The morning after the first night wearing it felt like heaven.

I _highly_ recommend calling around and finding a "sleep dentist" who will bill the device as a medical device (not a dental device). This is the only way to get American health insurance to pay for it (they are ~$5k). The down-side is you can only use the device for ~10 years before you get permanent forward lower jaw displacement. But those 10 years allowed me to get everything in order and gracefully switch to a nasal pillow CPAP (which is also heaven once you get the settings right).

If you live in the Boston area or LA area, I can recommend a fantastic sleep dentist that specializes in these devices. PM me.

The manufacturer for my nighttime inserts or "stilts" is Prosomnus Sleep Technologies. I'm not sure who manufactures the day insert. But the other commenter is correct, I am using a medical credit card and the balance is $13,000.