Temporomandibular disorders and bruxism in childhood and adolescence: review of the literature.

OBJECTIVE: The aim of this article was to review the literature about temporomandibular disorders and bruxism and their relationships in children and adolescents.

METHODS: The literature was searched using Medline, ISI, Cochrane Library, Scielo and the Internet, from March 1970 to the end of June 2007. The inclusion criteria were: they evaluated a possible association between TMD and bruxism, and they dealt with child and/or adolescent samples. Furthermore, interim reports, related Internet sites and chapters in textbooks were considered. From 64 records found, 30 fulfilled the inclusion criteria.

RESULTS: The prevalence of temporomandibular disorders in children and adolescent varies widely in the literature. Temporomandibular disorders are often defined on the basis of signs and symptoms, of which the most common are: temporomandibular joint sounds, impaired movement of the mandible, limitation in mouth opening, preauricular pain, facial pain, headaches and jaw tenderness on function, having mainly a mild character, fluctuation and progression to severe pain and dysfunction is rare. One of the possible causal factors suggested that temporomandibular disorders in children is a functional mandibular overload variable, mainly bruxism. Bruxism, defined as the habitual nonfunctional forceful contact between occlusal tooth surfaces, is involuntary, excessive grinding, clenching or rubbing of teeth during nonfunctional movements of the masticatory system. Its etiology is still controversial but the multifactorial cause has been attributed, including pathophysiologic, psychologic and morphologic factors. Moreover, in younger children, bruxism may be a consequence of the masticatory neuromuscular system immaturity. Complications include dental attrition, headaches, temporomandibular disorders and masticatory muscle soreness. Some studies have linked oral parafunctional habits to disturbances and diseases of the temporomandibular joint, mainly bruxism, suggesting its association with temporomandibular disorders in the primary and mixed dentition, whereas other authors did not observed respective relationship in primary dentition. The unreliability for the clinical assessment of bruxism also reduces confidence in conclusions about the relationship with temporomandibular disorders.

CONCLUSIONS: Taken all evidence together, the relationship between bruxism and temporomandibular disorders, if it exists, seems to be controversial and unclear.