A removable intraoral device designed to alleviate sleep-disordered breathing conditions (e.g., snoring, obstructive sleep apnoea) by repositioning and/or controlling the lower jaw (mandible), typically in a downward and forward position. It works by locking the mandible (e.g., holding the teeth) and preventing it from retruding, thus increasing the patency of the airway and decreasing both air turbulence and airway obstruction. A number of different fixed (non-adjustable) and adjustable types using several techniques and materials are available. This is a reusable device.