Masticatory Muscle ActivityMasticatory Muscle Activity Using a 24-Hour Wearable Device

Patients with chronic masticatory myofascial pain (MFP) often report that stress and parafunctional oral habits aggravate their pain, consistent with the widespread belief that stress and parafunctional habits lead to increased/sustained jaw muscle activity and subsequent pain. Yet, these assumptions have never been directly tested, given the lack of tools to measure masticatory muscle activity in real-world settings. This protocol describes a prospective, longitudinal, case-control observational study that will enroll 50 patients total (25 with clinician-diagnosed chronic MFP and 25 age- and sex-matched healthy controls) from the university-based dental clinics at Midwestern University, Illinois. Consenting participants will be instructed to complete a baseline biopsychosocial battery assessing self-reported awake and sleep bruxism (using the Oral Behavior Checklist, OBC), anxiety/depression symptoms (using the Patient Health Questionnaire, PHQ-4), perceived stress (using the Perceived Stress Scale, PSS), insomnia symptoms (using the Insomnia Severity Index, ISI) and chronic pain intensity (using the Graded Chronic Pain Scale, GCPS). All participants will be provided a 24-hour electromyograph (EMG) device (dia-BRUXO, Biotech-Novations, Sanremo, Italy) placed on the left masseter, recording jaw muscle activity. Brief ecological momentary assessments will be sent during the 24-hour period, assessing pain intensity, self-reported parafunctional habits, stress and anxiety. The primary aim will be to establish if self-reported awake and sleep bruxism and/or biopsychosocial distress are as-sociated with EMG-recorded masticatory muscle activity. The secondary aim will test if masticatory muscle activity is associated with jaw pain intensity.