Evaluation of correlation among sleep bruxism and depression levels, chronic pain and nonspecific physical symptoms according to axis II of the Research Diagnostic Criteria/ Temporomandibular disorders

Sleep Bruxism (SB) is considered as a parasomnia and defined as a stereotyped movement disorder characterized by grinding (eccentric), hitting or shaking (central) of teeth while sleeping unconsciously, and classified according to their etiology in primary (idiopathic) or secondary (associated with medical or psychiatric conditions) of multifactorial etiology. Certain risk factors such as alcohol/tobacco, caffeine, use of certain medications, conditions associated with sleep, psychological factors, among others, may trigger or enhance certain oral parafunctions. Objective: The present study aimed to observe statistically the existence of a possible correlation between SB and psychological aspects studied by the Research Diagnostic Criteria/Temporomandibular disorders (RDC/TMD): chronic pain, depression, nonspecific physical symptoms (NSPS) including pain, NSPS excluding pain. Material and methods: 50 patients with SB and 49 patients without SB were assessed, aged between 18 and 70 years at the TMD/Orofacial Pain Clinics of the School of Dentistry, Federal University of Juiz de Fora. These individuals were investigated by RDC Axis II on the severity levels of chronic pain, depression, nonspecific physical symptoms (NSPS) including pain, NSPS excluding pain, to verify the correlation of these variables with the SB. Results: There was a statistically significant correlation between BS and chronic pain severity (p = 0.001), and SB and NSPS including pain (p = 0.026), and SB and NSPS excluding pain (p = 0.018). There was no significant correlation between SB and depression. Regarding the severity of chronic pain, there was a higher prevalence of grade 2 (79.60%) in patients with BS and grade 1 (52%) in the patients without SB. According to the other assessed levels, a greater severity of psychological aspects evaluated by RDC/TMD were seen in patients with BS and more normal levels in patients without SB. Conclusion: Levels of chronic pain severity, nonspecific physical symptoms with or without pain (somatization) appeared as aspects involved in sleep bruxism. These findings emphasize the importance of an accurate assessment of the parafunction etiology for each case, which often requires a multidisciplinary approach.