Association between psychological distress and possible, probable, and definite sleep bruxism - a comparison of approved diagnostic procedures

The relationship between sleep bruxism (SB) and psychological distress has been investigated in numerous studies. In general it seems to be problematic that SB is determined with different diagnostic procedures, especially when some of them might not be very valid. The aim of this study was to directly compare the association between psychological distress and SB diagnosed by different accepted methods. In a sample of N = 45 subjects, possible, probable, and definite SB was determined. Psychological distress was measured using the global severity index (GSI) of the Symptom-Checklist-90-Standard. Statistical analysis included group comparisons and correlation analyses. The GSI did not differ significantly between subjects with and without SB, regardless of the underlying diagnostic classification. However, a deeper analysis of specific variables reveals that subjective and clinical SB-specific criteria have a higher correlation with psychological distress. Variables of instrumental methods such as the SB index of the polysomnographic (PSG) examination show almost no correlation with psychological distress. Possibly, non-instrumental methods (self-assessment and clinical examination) capture more psychological components related to SB, such as somatization tendencies. Original SB activity like grinding and muscle contraction of instrumental methods (polysomnography and new diagnostic sheet) shows no correlation with psychological distress.