Nightguards, also known as dental guards or mouth guards, are oral devices specifically designed to alleviate the potential effects of teeth grinding. Usually crafted from durable clear plastic, such as acrylic resin, these devices can vary in flexibility, ranging from soft to hard. Typically, your dentist will advise wearing the nightguard on the upper front teeth to prevent contact with the lower front teeth during sleep. In cases of severe teeth grinding, a dental guard for the lower teeth may be suggested. In addition to providing protection, mouthguards also help cushion the jaw muscles.