Clinical Features and Device-Based Sleep Bruxism: An Exploratory Study.

OBJECTIVES

Clinical findings are commonly used to assess sleep bruxism (SB), although their validity as indicators of SB activity remains uncertain. This cross-sectional and exploratory study investigated associations between device-based SB activity and clinical and physiological findings.

MATERIALS AND

METHODS

Fifty-nine healthy participants (33 men, 26 women; aged 24-40 years) underwent clinical and physiological examinations and two-night portable electromyography (EMG). Mean hourly EMG event frequency was analyzed continuously. Secondary analyses compared high-/low-frequency SB (HSB/LSB; ≥19/<19 events/h) and self-reported SB-positive versus SB-negative (SR-SB+/SR-SB-) groups.

RESULTS

In the primary analysis, no significant association was detected between mean hourly EMG event frequency and any clinical or physiological finding; the largest effect was for cheek bite marks (OR 1.35 per 10-event/h increase; 95% CI, 0.90-2.09). PPT (β = 3.46 kPa per 10-event/h increase; 95% CI, -6.35 to 13.27) and masseter muscle stiffness (β = 8.26 N/m; 95% CI, -4.71 to 21.24) were not associated with EMG event frequency. Secondary HSB/LSB analyses similarly showed no significant differences in clinical or physiological findings. In the self-report analysis, masseter muscle pain was associated with SR-SB+ status (OR 7.03; 95% CI, 1.22-133.8).

CONCLUSIONS

No significant association was detected between device-based SB activity and individual clinical or physiological findings in this exploratory sample. Clinical findings should not be used in isolation to identify SB activity.

CLINICAL SIGNIFICANCE: Commonly used clinical findings may not reliably reflect current SB activity and should be interpreted together with patient history and self-reported symptoms.