What is A Nightguard? Many people clench or grind their teeth whether it be during the day or while they sleep. This habit can be damaging to the teeth and jaw joint. If someone presents with signs or bruxism, temperomandibular joint (TMJ) disorder your dentist may recommend an appliance called a nightguard. A nightguard is a tray that overlays the upper or lower teeth separating them slightly. This helps protect wear of the biting surfaces of the teeth and relieves pressure on the jaw joint and surrounding muscles. Chronic clenching and grinding of the teeth can cause significant damage to the teeth and cause discomfort to the structures that hold your jaw and TMJ in place. Your teeth, jaw joint and surrounding musculature is routinely evaluated during your dental exams. If you have any questions regarding nightguards or bruxism feel free to ask your dentist at your next visit.