MRD or a mandibular repositioning device works in two basic ways. One, it keeps your jaw from falling down and back and two, by moving your jaw forward. We move your tongue and at least part of your palate further away from the back of your throat. This helps to both prevent the airway from collapsing onto itself, as well as make the airway bigger. Remember that your upper teeth don’t move, only your lower jaw. And then a mouth open, jaw down and back posture as many of us do when we sleep results in a more collapsed airway, more severe sleep that mean more significant oxygen de-saturations. MRD’s reposition the lower jaw for creating a more Patton airway, better oxygen exchange, better sleep and feeling more rested. A follow up sleep test with your oral appliance in place should be a part of your treatment plan, and should be discussed with us as well as your referring physician.