Sleep architecture and factors associated with sleep bruxism diagnosis scored by polysomnography recordings: A case-control study

Objective: This study evaluated the association between the diagnosis of sleep bruxism (SB), scored by way of polysomnographic (PSG) recordings, clinical conditions and sleep architecture. Design: A case-control study was conducted. All records from adults who had undergone polysomnography (PSG) recordings at a private medical outpatient clinic between January 2015 and December 2017 were reviewed. The sample included 58 bruxers (case group) and 58 non-bruxers (control group), identified based on the PSG recording and matched by sex and age. Results: Obese individuals had significantly lower chance (OR 0.18; 95 % CI: 0.05-0.62; P = 0.005) of an SB diagnosis than individuals with normal BMI. Alcohol consumption significantly increased (OR 2.74; 95 % CI: 1.11-6.78; P = 0.029) and OSA decreased the chances (OR 0.55; 95 % CI: 0.23-1.30; P = 0.173) of an SB diagnosis. Bruxers had a significantly shorter wake time after sleep onset (WASO) (p = 0.002). As far as nonrapid eye movement (NREM) is concerned, the duration of stage N1 was statistically shorter (p = 0.034) and the duration of stage N3 was statistically longer (p = 0.001) in bruxers. Arousals (p = 0.013), arousals per hour (p = 0.009), respiratory disturbance index (RDI) values (p < 0.0005) and the apnoea-hypopnea index (AHI) (p = 0.002) were all lower in bruxers than in non-bruxers. Conclusion: The results of this study support a significant association between SB diagnosis, BMI and alcohol consumption. SB modified the sleep architecture as statistically significant differences were found between bruxers and non-bruxers for WASO, NREM stage N1 and N3, arousals, arousals per hour, RDI and AHI.