Bruxism should be conceptualize as a plural, since it groups different oral motor behaviors that are performed by all individuals during sleep and wakefulness.In the early era, bruxism was considered a synonym of teeth grinding linked to the psychological sphere, thus having a specific meaning (e.g. manifestation of anxiety, anger, frustration). Since the '90s, focus has progressively shifted towards the identification of generator patterns for a rhythmic masticatory muscle activity (RMMA) associated with sleep arousals, considered a biomarker for sleep bruxism (SB). This model lacks validity.In this commentary, a biopsychosocial model of bruxism is presented, based on the hypothesis of a neural load discharge that may explain the multifaceted bruxism activities over the 24 hours. They may be just a purposeless sign of motoneuronal activation, or purposeful, goal-oriented behaviors from the perspective of the human being, regardless of the clinical consequences, if any.
Manfredini et al. (2026) studied this question.