Sleep stage dynamics in young patients with sleep bruxism

Abstract

Study Objectives We hypothesized that sleep stage dynamics are different in patients with sleep bruxism (SB) and that these changes are associated with the occurrence of rhythmic masticatory muscle activity (RMMA). Methods Fifteen healthy controls and 15 patients with SB underwent overnight polysomnography. Sleep variables and survival curves of continuous runs of each sleep stage were compared between the groups. Stage transition dynamics and the probability of stage fragmentation were analyzed for three epochs before and after the epoch with RMMA. Survival curves of continuous runs of each sleep stage, terminated with or without RMMA, were also compared. Results There were no significant differences in sleep variables between the groups, except for shorter sleep latency, shorter rapid eye movement (REM) latency, and longer total N1 duration in SB patients than in controls. REM sleep and N2 were significantly less continuous in SB patients than in controls. In the SB group, stage fragmentation probability was significantly increased for the epoch with RMMA compared with the baseline for all stages. Meanwhile, the occurrence of RMMA did not affect the continuity of N2 or REM; however, the occurrence of RMMA was preceded by more continuous N3 runs. Conclusions Sleep stage dynamics differed between SB patients and controls. RMMA does not result in sleep disruption but is likely associated with dissipation of sleep pressure. Less continuity of REM sleep in SB may provide insights into the underlying pathophysiological mechanisms of SB, which may be related to REM sleep processes such as cortical desynchronized states or brainstem activation.

Sleep structure in sleep bruxism: A polysomnographic study including bruxism activity phenotypes across sleep stages

“…In terms of SE, there were no differences between the SSB and MSB groups and the CG, which is consistent with most previous studies (Kishi et al, 2020;Lavigne et al, 1996Lavigne et al, , 2002Macaluso et al, 1998). In two of the previous studies (Kishi et al, 2020;Macaluso et al, 1998), both healthy and control participants presented SE above 85%, but the CG participants had significantly higher mean values than those with bruxism (Neu et al, 2018;Palinkas et al, 2017;Yoshida et al, 2017). According to Neu et al (2018), this difference might be explained by the fact that participants with OSA were not excluded from their study, and the study group presented a higher mean AHI than that of control participants (AHI in SB was above 5, which suggests the presence of at least mild OSA).…”

“…The difference is especially visible in SSB, which is a novel finding. Previous studies have either reported that REM percentage is not affected by SB (Kishi et al, 2020;Lavigne et al, 1996Lavigne et al, , 2002Neu et al, 2018;Yoshida et al, 2017) or that it is even lower in the SB group than in the CG (Macaluso et al, 1998).…”

“…in this study, the mean duration of slow-wave sleep (SWS) was very short in both the CG and SB group. According to Kishi et al (2020), longer NREM1 sleep was found in the SB group than in the control group. Interestingly, mean duration of NREM1 sleep was relatively long in both the CG and SB group (43.8 vs. 57.2 min).…”

“…So far, most of the studies have reported that SB does not significantly affect the sleep structure and sleep quality of the affected individual; however, there are many inconsistencies with regard to the commonly measured parameters reported in these studies (Kishi et al, 2020; Lavigne et al, 2002; Lavigne, Rompré, & Montplaisir, 1996; Macaluso et al, 1998; Neu et al, 2018; Palinkas et al, 2017; Yoshida et al, 2017). In addition, most of the aforementioned studies included relatively small study samples.…”

The Relationship between Simple Snoring and Sleep Bruxism: A Polysomnographic Study

“…Furthermore, a statistically significant relationship was demonstrated by Maluly et al This population-sampled study showed a positive association between SB and insomnia, higher degree of schooling, and a normal/overweight BMI [58]. On the other hand, in the study by Kishi et al, sleep latency was shorter in bruxers compared with controls [61]. These suggest that further research with the instrumental approach is needed to confirm our novel findings.…”