A normal movement of the mandible at an abnormal frequency (e.g. tooth grinding or clenching). It can take many forms such as single episodes (clenching) or rhythmic contractions (grinding). It can lead to tooth attrition and more rarely to temporomandibular joint dysfunction. Significant parafunction occurs during sleep. Symptoms of parafunction include headache, migraine, facial pain, jaw or neck pain often associated with restriction of movement, sinus pain, or feeling of pressure. Therapeutic management is directed at the parafunction's four components of intensity, duration, frequency, and position.
Porter R., Poyser N., Briggs P., Kelleher M. Demolition experts: Management of the parafunctional patient: 1. Diagnosis and prevention. Dent Update 2007;34:198–207.