Custom designed nightguards are made of firm plastic and molded to fit the shape of your teeth. Nightguards are recommended for patients with TMJ disorders or for patients who clench or grind their teeth at night. The appliance serves to improve the bite relationship, protects the teeth, and aids in relaxing the muscles of the face and jaw. Impressions are taken of your teeth, which are then sent to a dental lab to make the custom appliance.