Two forms are recognized. Sleep bruxism is rhythmic muscle activity occurring during sleep, generally associated with micro-arousals; the person is usually unaware of it. Awake bruxism consists mainly of sustained clenching, often linked to periods of concentration or tension. The two forms do not share the same triggers or the same management, and they can coexist. In an otherwise healthy person, bruxism is not considered a disease in itself, but a behaviour that can become a risk factor when it causes tooth wear, muscle pain, or breakage of restorations.
Possible signs and consequences Wear of the occlusal surfaces, enamel cracks or fractures, tooth sensitivity, breakage or loosening of restorations and crowns, jaw stiffness or fatigue on waking, cervicalgia (neck pain), tenderness of the temporalis and masseter muscles, masseter hypertrophy, scalloped tongue borders or a white line along the cheek mucosa. A sleep partner sometimes reports a grinding sound.
Associated factors Bruxism is now understood as centrally mediated rather than caused by the bite itself. Commonly associated factors include stress and anxiety, sleep quality and sleep-related breathing disorders, smoking, alcohol or caffeine intake, certain medications (notably some antidepressants), and stimulant substances. When signs suggest a sleep-related breathing disorder, appropriate medical assessment is recommended before dental management is undertaken.
Management options Management aims to protect the teeth and restorations and to reduce muscle discomfort; no approach eliminates bruxism permanently. - Botulinum toxin injections in the masticatory muscles - Custom occlusal splint (a device worn at night, mainly to protect the tooth surfaces and distribute forces). Its effect on muscle activity itself varies. If you already have an occlusal splint and are not satisfied with the results, botulinum toxin injections can be administered as well.
Bruxism, implants and restorations Bruxism generates forces exceeding those of normal chewing. It is a factor to document before implant rehabilitation, as it is associated with an increased risk of mechanical complications: fracture or loosening of prosthetic components, ceramic chipping, prosthesis breakage. When bruxism is identified, it is factored into planning — material selection, force distribution, and night-time protection after loading.