Bruxism: Diagnosis and Treatment Options

The distinction between sleep bruxism and awake bruxism, the clinical signs to recognize in the chair, and treatment options from occlusal splints to botulinum toxin.

Bruxism is defined as repetitive activity of the masticatory muscles, characterized by clenching or grinding of the teeth and/or bracing or thrusting of the mandible. The most recent literature distinguishes two clinically distinct phenotypes: sleep bruxism, occurring during nighttime rest and now considered a motor behavior related to micro-arousals, and awake bruxism, occurring during waking consciousness and more often associated with stress, anxiety or intense concentration, often without actual tooth contact but with simple muscle contraction.

Clinical recognition relies on a combination of signs and symptoms: abnormal tooth wear not explainable by the patient's age, particularly on occlusal and incisal surfaces; hypertrophy of the masseter and temporalis muscles, sometimes visible even aesthetically; recurring fractures of restorations or cusps; pain or stiffness of the chewing muscles on waking (a characteristic sign of nighttime bruxism); and sometimes morning temporal headache. The patient's partner, if any, may also report hearing grinding noises during sleep, valuable history information though not always available.

A definitive diagnosis of sleep bruxism would require polysomnography with electromyographic recording, but in everyday clinical practice, diagnosis is almost always based on history and clinical examination, supplemented when possible by the partner's account. It's important to distinguish bruxism from other parafunctions and from temporomandibular joint pathological conditions, which can present partly overlapping symptoms but require a different therapeutic approach.

Treatment options mainly aim to protect the teeth from wear rather than eliminate the underlying motor behavior, which often has a central origin not fully under voluntary control. The occlusal splint, worn during sleep, remains the most widely used tool: it doesn't necessarily reduce the frequency of bruxism episodes, but effectively protects tooth surfaces from direct contact. In more pronounced cases, particularly when significant muscle hypertrophy or myofascial pain resistant to other treatments is present, botulinum toxin injected into the masseter and temporalis muscles has shown results in reducing clenching intensity, although its use requires specific expertise and isn't first-line treatment in every case.

On Oralzon you'll find materials for making custom occlusal splints and diagnostic instruments for assessing tooth wear and chewing muscle function.