The occlusal plate, also known as the joint plate, is a transparent plastic tray that covers the upper teeth, lower teeth, or both, depending on the appearance of the bruxer. The purpose of the occlusal plate is to prevent the upper teeth from touching the lower teeth. It is the most commonly used device to protect teeth from wear caused by grinding and clenching teeth, as well as to absorb the forces involved.

Reference : https://www.guidedessoins.com/en/occlusal-plate/  ,july 6th,2019