The Association of Sleep, Awake, or Combined Sleep/Awake Bruxism and Temporomandibular Disorders Subtypes: A Cross- Sectional Population Study.

Abstract

Objectives: To assess the association of the role of sleep (SB), awake (AB), and combined SB/AB bruxism with temporomandibular disorders (TMD) subtypes.

Materials and methods: The sample (n=1,463) were registered users of the Brazilian Public Health Care System (SUS). The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I was used to classify TMD subtypes; and the RDC/TMD Axis II, to assess Graded Chronic Pain Scale (GCPS), depression, somatization with or without pain, sociodemographic data, pain history, and bruxism. Sleep quality was assessed by the Sleep Assessment Questionnaire (SAQ®).

Results: The results in this study have demonstrated that all three bruxer groups (SB, AB, and combined SB/AB) increased the risk of developing TMD measured by the GCPS and muscle diagnoses, and AB increased the risk in disk displacements. The combined SB/AB group increased the risk (adjusted odds ratio - OR) for GCPS and muscle diagnoses in 3.8 and 4.1 times, respectively; while the AB group alone increased the risk for disk displacements in 1.8 times. The OR was adjusted for sleep quality and psychosocial variables: depression, somatization (physical symptoms) without pain, gender, income level, and employment; which have shown in the univariate analysis to differ among all bruxer groups.

Conclusions: Bruxism increased the risk for TMD subtype development, but it varied among the three bruxism types assessed (SB, AB, or combined SB/AB), and it was also modulated by sleep and psychosocial variables. SB and AB, separately and in combination, contribute to TMD subtype development and must be assessed in all studies.