Polysomnographic assessment of sleep bruxism as a potential protective factor in primary snoring

Primary snoring (PS), defined as snoring in non-apneic patients, often coexists with sleep bruxism (SB), which may have a protective role. This study aimed to evaluate the impact of SB on PS in adults with attention to its potential protective effect. Data from patients who underwent polysomnography between January 2018, and June 2025 were analyzed. Patients with PS were classified using two bruxism episode index (BEI) cut-offs: SB (BEI ≥ 2; n = 156) vs. non-SB (BEI < 2; n = 68) and severe SB (BEI ≥ 4; n = 99) vs. mild/no-SB (BEI < 4; n = 125). Snore train duration did not differ between groups. In the BEI ≥ 2 group, the snore index (overall and supine) was increased in non-rapid eye movement sleep (NREM) 1 (63.40 ± 61.11 vs. 55.16 ± 67.70; p = 0.0312 and 61.67 ± 66.42 vs. 48.50 ± 63.25; p = 0.0447 respectively) and decreased in NREM 2 and NREM 3 in non-supine position (34.81 ± 70.06 vs. 64.84 ± 107.23; p = 0.0460 and 48.29 ± 124.44 vs. 82.79 ± 171.65; p = 0.0154 respectively) when compared with control. Similar results were observed for the BEI = 4 cut-off. SB did not shorten snore trains duration. These findings suggest that SB influences upper airway dynamics, but further research is needed to clarify the possible protective effects.