What Is a Mouth Splint?

A mouth splint is a device that a patient inserts into the mouth to help alleviate a range of conditions such as jaw pain or teeth-grinding. Typically, the splints are made of plastic and require a dentist's skill to tailor them to the patient. Although a mouth splint may benefit the patient through a reduction in grinding or pain from a strained jaw, in other people a splint may make the condition worse. Alternative names for a mouth splint include occlusal splint or mouth guard.

The structure of the mouth is made up of the upper and lower jawbones and two rows of teeth. Muscles are also present, allowing the mouth to move enough for eating, breathing and speaking. Medical issues may arise if these components do not work efficiently together, causing such problems as damage to the teeth or strain in the jaw muscles.

Teeth grinding is a significant cause of chronic pain in the mouth. This condition involves unconscious movement of the top teeth against the bottom teeth and can produce enough wearing of the teeth, and stress in the jaw muscles, to result in localized pain and even headaches. As this grinding is unconscious, it tends to occur during the night, when the affected person is unable to control it. A mouth splint for this issue is typically therefore only worn during sleep.

Generally, a mouth splint is made from acrylic plastic, which is harder material than products such as mouth guards used in sports. It may be made from two separate pieces or one, and these fit over the top and bottom rows of teeth to keep the jaws aligned and prevent grinding damage. As each patient has a different mouth structure, from jaw size to arrangement of teeth, a dentist usually fits the mouth splint to an individual.

Evidence for the benefits of mouth splints for teeth grinding is mixed, as some people may benefit but others may see a worsening in the symptoms. A mouth splint may be used to treat temporal-mandibular joint problems, which involve issues with the joints of the jaw, and injuries to the jaw. In these cases, a mouth splint can help to keep the jawbones in the correct placement until the associated pain and strain can resolve itself. For this reason, these devices may be worn during the day instead of just at night.