Common Clinical Signs Did Not Track Measured Sleep Bruxism Activity in Study

Edited by Dentaltown staff

Clinical signs commonly used to assess sleep bruxism showed no significant association with nighttime jaw muscle activity measured by portable electromyography, according to an exploratory study published online Oct. 6 in the Journal of Dentistry.

Researchers examined 59 healthy adults, 33 men and 26 women aged 24–40. Each participant underwent clinical and physiological examinations and two nights of portable EMG recording. The primary analysis compared each finding against mean hourly EMG event frequency.

No clinical or physiological finding was significantly associated with EMG activity. Cheek bite marks showed the largest effect, with an odds ratio of 1.35 per increase of 10 events an hour, but the 95% confidence interval of 0.90–2.09 included no effect. Pressure pain threshold and masseter muscle stiffness were also not associated with event frequency.

Secondary analyses comparing high- and low-frequency bruxism groups, divided at 19 events an hour, likewise found no significant differences.

One association emerged when participants were grouped by self-report. Those who reported bruxism were more likely to have masseter muscle pain, with an odds ratio of 7.03, although the confidence interval was wide (1.22–133.8).

The authors concluded that clinical findings should not be used in isolation to identify sleep bruxism activity. They recommended that clinical findings be interpreted together with patient history and self-reported symptoms.

The study was conducted by researchers in the Department of Oral Function and Prosthodontics at Nihon University School of Dentistry at Matsudo in Japan, with a co-author from the National University of Singapore. The authors reported no competing interests.

The sample was small and limited to young, healthy adults, and the authors describe the cross-sectional design as exploratory.

Sources:
Journal of Dentistry, “Clinical Features and Device-Based Sleep Bruxism: An Exploratory Study,” published online Oct. 6, 2026: doi.org/10.1016/j.jdent.2026.107092
PubMed, PMID 42838420: pubmed.ncbi.nlm.nih.gov/42838420