A TMJ splint is a specific type of mouth splint designed to minimize pressure on your jaw joints and teeth to treat TMD. Splint therapy supports the temporomandibular joint (TMJ) by stabilizing the mouth and keeping the teeth and jaw in an aligned position. Treatments for TMD vary, but one of the most effective solutions is a TMJ splint. TMJ splints can be worn both day and night to eliminate the symptoms of TMD and reduce dental pain, damage, and discomfort. Splints allow jaw muscles and ligaments to relax, preventing teeth grinding, clenching, and other jaw reactions that can cause discomfort and pain. A splint is a removable dental appliance that covers several or all of the upper or lower teeth.splints are typically made of hard acrylic resin and molded from an impression of your teeth.