Dentists have been using OAT for over 30 years. At the Maryland Center for Dental Wellness, we fabricate a custom fitted oral appliance to be worn while sleeping. Research has shown that by designing an appliance to reposition the lower jaw, the tongue is positioned away from the airway. This makes it easier to get air to the lungs. The oral appliance is a plastic device that is similar to an orthodontic retainer or mouth guard used in sports except there is an upper jaw and lower jaw component.