Bruxism as a new risk factor of musculo-skeletal disorders?

Objectives: Musculoskeletal disorders (MSDs), particularly neck and low back pain, constitute a major public health issue worldwide with a heavy morbidity and economic impact. However, the relationships between the stomatognathic system and MSDs are subjected to debate, data sorely lacking. The study objective was to investigate the association between bruxism (BR) and MSDs. Secondary objective includes the study of the association between tooth wear (TW) and MSDs.Methods: This is a cross-sectional study on 425 participants frequenting a university dental clinic. The presence of MSDs was evaluated with the standardized Nordic questionnaire. The sleep and awake BR assessments were based on clinical examination and self-report. TW was measured with the BEWE index. Socio-demographic factors, medical history, life habits and stress were analyzed as potential confounding variables.Results: 91% of patients reported at least one MSD during the preceding 12 months and 75.5% were diagnosed as bruxers. In multivariate analyses, BR was associated with a 5-fold increased risk of prevalent MSD (OR=5.88 (2.7-12.5), p<0.0001). Regarding TW, for a one-point increase in anterior BEWE score, the risk to present an MSD was increased by 53% (OR=1.53 (1.12-2.08), p = 0.0076). Moreover, BR was independently associated with neck, shoulder, upper back, low back, hip & thigh and knee MSDs. Anterior TW was independently associated with neck, low back and hip & thigh MSDs, and global TW with knee MSDs.Conclusions: BR and TW were shown to be associated with MSDs. The cause-and-effect relationships between those factors needs to be analyzed to optimize prevention and therapeutic care.Clinical significance: Results suggest that the body is a whole, a balanced muscular system, where every part constitutes a link of the chain. MSDs management and prevention may require a multidisciplinary team approach and future perspectives include defining the dentist's role in this context, particularly with respect to BR diagnostic and treatment.