[Etiology of bruxism: morphological, pathophysiological and psychological factors]

Bruxism is a controversial phenomenon, but there is consensus about the multifactorial nature of the etiology. Besides peripheral (morphological) factors, central (pathophysiological and psychological) factors can be distinguished. In the past, morphological factors, like occlusal discrepancies and the anatomy of the bony structures of the orofacial region, have been considered the main causative factors for bruxism. Nowadays, these factors play only a minor role, if any. Recent focus is more on the pathophysiological factors. For example, bruxism has been suggested to be part of a sleep arousal response. In addition, bruxism appears to be modulated by various neurotransmitters in the central nervous system. More specifically, disturbances in the central dopaminergic system have been linked to bruxism. Further, factors like smoking, alcohol, drugs, diseases, and trauma may be involved in the bruxism etiology. Psychological factors like stress and personality are frequently mentioned in relation to bruxism as well, but research shows controversial results. Taken all evidence together, bruxism appears to be mainly regulated centrally, not peripherally.