Jaw tremor as a physiological biomarker of bruxism

Clin Neurophysiol. 2015 Sep;126(9):1746-53. doi: 10.1016/j.clinph.2014.11.022. Epub 2014 Dec 4.

Abstract

Objective: To determine if sleep bruxism is associated with abnormal physiological tremor of the jaw during a visually-guided bite force control task.

Methods: Healthy participants and patients with sleep bruxism were given visual feedback of their bite force and asked to trace triangular target trajectories (duration=20s, peak force <35% maximum voluntary force). Bite force control was quantified in terms of the power spectra of force fluctuations, masseter EMG activity, and force-to-EMG coherence.

Results: Patients had greater jaw force tremor at ∼8 Hz relative to controls, along with increased masseter EMG activity and force-to-EMG coherence in the same frequency range. Patients also showed lower force-to-EMG coherence at low frequencies (<3 Hz), but greater coherence at high frequencies (20-40 Hz). Finally, patients had greater 6-10 Hz force tremor during periods of descending vs. ascending force, while controls showed no difference in tremor with respect to force dynamics.

Conclusion: Patients with bruxism have abnormal jaw tremor when engaged in a visually-guided bite force task.

Significance: Measurement of jaw tremor may aid in the detection/evaluation of bruxism. In light of previous literature, our results also suggest that bruxism is marked by abnormal or mishandled peripheral feedback from the teeth.

Keywords: Bruxism; Electromyography; Periodontal mechanoreceptors; Physiological tremor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bite Force*
  • Cohort Studies
  • Female
  • Humans
  • Jaw / pathology*
  • Jaw / physiology
  • Male
  • Masseter Muscle / physiology
  • Muscle Contraction / physiology
  • Sleep Bruxism / diagnosis*
  • Sleep Bruxism / physiopathology*
  • Tremor / diagnosis*
  • Tremor / physiopathology*
  • Young Adult