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Background: Masseter muscle activity during wakefulness may be associated with temporomandibular disorder (TMD)‐related symptoms, psychosocial status and pain‐related disability; however, this relationship is unclear. Objectives: This study aimed to determine the relationship between masseter muscle electromyography (EMG) burst/duration during wakefulness and TMD‐related symptoms, psychosocial status and pain‐related disability. Methods: Sixty participants were assessed masseter muscle activity during wakefulness using a data‐logger‐type ultraminiature EMG system and TMD‐related symptoms, psychosocial status and pain‐related disability through Axis I and II of the diagnostic criteria for TMD (DC/TMD). EMG bursts lasting longer than 0.25 s but less than 2.0 s and those lasting longer than 2.0 s were classified as phasic and tonic bursts, respectively. Results: Participants with palpation‐related pain in the temporalis and masseter muscles, as assessed through the DC/TMD examination form in Axis I, had more bursts (number/h) (p =.035 and p =.009, respectively) and longer duration (time/h) (p =.013 and p =.004, respectively) of tonic bursts of the masseter muscle during wakefulness. Participants with palpation‐related pain in the masseter muscles had higher oral behaviour scores during wakefulness using Axis II (p =.001), which affected the number and duration of tonic bursts of the masseter muscle activity during wakefulness (p =.011 and p =.007, respectively). Conclusion: As tonic bursts mainly reflect clenching, individuals with pain in the masseter muscles by palpation may have a high frequency and longer duration of clenching, as well as a high frequency of oral behaviours during wakefulness. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to elucidate the relationship between diurnal masseter muscle activity and awareness of diurnal awake bruxism (d-AB) by conducting a comparative analysis of electromyographic (EMG) data from individuals with and without awareness of diurnal awake bruxism (d-AB), utilizing EMG data gathered from multiple subjects., Methods: Unilateral masseter electromyography (EMG) recordings were performed during the daytime using an ultraminiature wearable EMG device. A total of 119 participants (59 with awareness of diurnal tooth clenching [d-TC] and 60 without awareness of d-TC) were included. Waveforms longer than 0.25 s with the two amplitude conditions, exceeding twice the baseline and >5% of maximum voluntary clenching, were extracted. In addition, the number of bursts and episodes (groups of bursts), burst duration, and burst peak amplitude were calculated for each participant., Results: There were no significant differences in the EMG parameters between the groups with and without awareness of d-TC. Additionally, the frequency distribution of the number of EMG waveforms exhibited wide ranges and substantial overlap between the two groups., Conclusions: The variability in the number of bursts and episodes, burst peak amplitude, and burst duration among subjects suggests the need for an objective classification of d-AB severity based on EMG values. The absence of significant differences and large overlap in frequency distributions between the groups with and without awareness of d-TC indicate difficulty in predicting muscle activity solely based on awareness of d-AB.