Perceived orofacial pain and its associations with reported bruxism and insomnia symptoms in media personnel with or without irregular shift work

A standardized questionnaire was mailed to all employees of the Finnish Broadcasting Company with irregular shift work (n = 750) and to an equal number of randomly selected controls in the same company with regular 8-hour daytime work. The aims were to investigate the prevalence and severity of perceived orofacial pain (Research Diagnostic Criteria for Temporomandibular Disorders Axis II) and to analyze whether current orofacial pain was associated with reported bruxism and insomnia symptoms ( Diagnostic and Statistical Manual of Mental Disorders-IV and the International Classification of Sleep Disorders Revised). The response rate in the irregular shift-work group was 82.3% (56.6% men) and in the regular daytime-work group 34.3% (46.7% men). Current orofacial pain was found overall in 19.6%, of which 88.3% had experienced the pain over 6 months. All claimed that their pain fluctuated. No subjects with chronic orofacial pain reported disabling pain, and grades III and IV were not found. Insomnia symptoms and frequent bruxism were significantly more prevalent in chronic pain grade II than in lower grades. According to logistic regression, current orofacial pain was significantly positively associated with frequent bruxism (p < 0.001), female gender (p < 0.001), and disrupted sleep ( p < 0.01), and significantly negatively associated with age over 45 years (p < 0.01). Our results revealed a clear-cut association between perceived orofacial pain and reported bruxism. The association held with both chronic orofacial pain intensity and current pain. Based on the multivariate analyses, it can be concluded that disrupted sleep and bruxism may be concomitantly involved in the development of orofacial pain.