Minimum measurement time of masseteric electromyogram required for assessment of awake bruxism during the daytime.

Objective: Assessments of diurnal awake bruxism (d-AB) using masseteric electromyogram (EMG) during various lengths of measurement time within a day were examined as the first step of research to clarify the minimum measurement time required for assessment of d-AB by subject.Methods: Subjects were 33 outpatients. Assessment of d-AB by EMG during partial measurement time (PMT) with durations ranging from 30 minutes to 6 hours was compared with that during total measurement time (TMT) used as the reference standard.Results: No significant difference was found between TMT data and PMT data. There were significant correlations in all combinations between TMT data and PMT data. Accuracy was 0.909 or more for 2.5 hours or longer.Discussion: The results suggest that the tendency of daytime muscle activity in 1 day can be assessed even by using masseteric EMG data obtained during a relatively short measurement time.