When properly fitted to a person’s teeth, mouth guards can prevent the teeth from becoming chipped, fractured or knocked loose during physical activity. This is particularly important during athletics. Athletes who do not wear mouth guards are 70 times more likely to experience damage to their teeth, according to the Academy of General Dentistry.

Mouth guards also move soft tissue in the mouth away from the teeth, which helps to protect the lips, tongue or cheek. This is particularly important for people who have braces that may injure the mouth or gum tissue during an accident.

In addition to protecting the mouth, mouth guards can act as a shock absorber to prevent the lower jaw from being jammed into the upper jaw during blows to the head, face or neck. This can help prevent conditions such as concussions, cerebral hemorrhages, unconsciousness, temporomandibular joint (TMJ) dislocation and neck injuries.

Mouth guards may be recommended or prescribed for patients who grind or clench their teeth. This activity (bruxism) can lead to many problems ranging from jaw pain and joint problems (e.g., TMJ disorder) to excessive wearing of the teeth. These mouth guards are often designed for use at night, while a patient sleeps, because this is the time when most teeth grinding occurs. They do not prevent the grinding, but keep the teeth from being damaged, alleviate muscle tension and reduce pressure on the jaw. Mouth guards used for this purpose are sometimes called night guards.

Over-the-counter mouth guards may also be used to protect against bruxing. However, these mouth guards are much less likely to precisely fit a patient’s teeth and therefore may come dislodged during bruxing.

Patients who regularly use a mouth guard to help prevent bruxing-related problems should be examined regularly by a dentist. The dentist will look for signs of tooth movement or cavities that may be associated with using a mouth guard overnight.