The relationship of bruxism with craniofacial pain and symptoms from the masticatory system in the adult population

The association of bruxism with craniofacial pain and symptoms of dysfunction of the masticatory system was assessed in a sample of 483 adult subjects, aged 18-75 years and selected from the general population living in the municipality of Segrate, a metropolitan area in northern Italy. Subjects were interviewed by a questionnaire about oral conditions, occurrence of symptoms of masticatory disturbances, craniofacial and neck pain. The overall prevalence of bruxism was 31.4% (95% confidence interval (CI): 27.3-35.5%). At univariate analysis bruxism was significantly associated with craniofacial. pain, difficulty in closing the mouth, difficulty in opening the mouth wide or in locking the mouth, temporomandibular joint sounds, pain on movement, a feeling of stiffness or fatigue of the jaws, and neck pain. After adjustment for reciprocal influences and confounding variables, logistic regression analysis disclosed a strong independent association of bruxism with difficulty in closing the mouth (adjusted odds ratio, (OR): 2.84, 95% CI: 1.68-4.48), and a weaker relationship with craniofacial pain (adjusted OR: 1.84, 95 % CI: 1.16-2.93) and temporomandibular joint sounds (adjusted OR: 1.64, 95% CI: 1.00-2.69). The findings show that in the general adult population there is a complex connection among bruxism, craniofacial pain and symptoms of masticatory disturbances. Furthermore, they suggest that the most direct relationship of bruxism may be with difficulties in mouth movements, but also an independent association may exist with craniofacial pain and other symptoms of temporomandibular disorder.