Research Information System
Clinical Neurophysiology, vol.126, no.9, pp.1746-1753, 2015 (SCI-Expanded)
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. = 20. s, 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.