Brain Connectivity Patterns in Chronic Temporomandibular Joint Disorders

Eligibility Criteria

• * Provide signed and dated informed consent form.
• * Willing to comply with all study procedures and be available for the duration of study participation.
• * All participants will be females (biological sex by self-report) between ages 18 to 65 years (inclusive), as this includes the majority of the patient population at risk for chronic TMD pain.
• * Cases and controls will be matched for age within ±3 years, and all participants must be able to understand commands in English to follow study procedures (e.g., during sensory testing).
• * TMD-Pain screener score less than 3 out of 7 (Screener available as part of the DC/TMD)
• * No previous diagnosis for the most common pain-related TMD as defined in the DC/TMD criteria (myalgia, arthralgia, headache attributed to TMD)
• * No significant orofacial pain (jaw pain, TMJ pain) in past 3 months ("significant" meaning 5 or more days in any month or any pain during the past month)
• * No report of significant pain in the last 3 months elsewhere in the body ("significant" meaning 5 or more days in any month or any pain during the past month), e.g., low back pain, fibromyalgia, migraine headaches
• * Not meeting any of the most common pain-related TMD diagnosis as described in the DC/TMD criteria (myalgia, arthralgia, headache attributed to TMD) upon clinical examination following the DC/TMD protocol
• * TMD-pain screener score equal to or greater than 3
• * Primary TMD caseness criteria: myalgia (masticatory muscle pain) based on clinical exam following the DC/TMD protocol
• * Concurrent arthralgia (TMJ pain) and/or headache attributed to TMD allowed
• * Myofascial pain must meet the following criteria:
• * Onset \>3 months, occurring \>15 days/month on average for \>3 months
• * Minimum 10 jaw pain episodes since onset, each episode lasting at least 30 minutes and no less than 2 hours within the day, OR unremitting
• * Low-impact TMD pain cases: Graded Chronic Pain Scale (GCPS) grade IIa or lower
• * High-impact TMD pain cases: GCPS grade IIb or greater
• * Traumatic facial injury or surgery on the face/jaw, arms or hands
• * Presence of pain related to dental or periodontal pathology
• * Currently undergoing active orthodontic treatment
• * Pregnant or nursing
• * Has any of the following medical conditions by self-report:
• * Renal failure or dialysis
• * Heart disease (examples: uncontrolled arrhythmia or hypertension, cardiomyopathy) or heart failure
• * Non-allergic bronchospasm (chronic obstructive pulmonary disease and emphysema)
• * Diabetes (Type I or II) that is not controlled with medication or diet
• * Hyperthyroidism
• * Uncontrolled seizures
• * Used any injection therapy (i.e. tender or trigger point injections, steroid injections), acupuncture, biofeedback, or TENS for the management of facial pain within 2 weeks prior to the screening assessment
• * If undergoing botulinum toxin injections in the head and neck areas, must be 3 months since last set of injections and refrain from this treatment until study has ended
• * History of major depression or other major psychiatric disorder requiring hospitalization within the last 6 months prior to the screening assessments
• * History of treatment for drug or alcohol abuse within the last 12 months
• * Current pain medication use (e.g. opioids, ibuprofen, acetaminophen) that cannot be stopped \<24 hours prior to each study visit
• * Other conditions/diseases associated with altered pain perception: neurological or developmental disorders (dementia, autism spectrum disorder), neoplasm, multiple sclerosis, trigeminal neuralgia
• * MRA contraindications including claustrophobia
• * GCPS grade assigned at Visit 1 that does not match grade from screening GCPS (low-, high-impact pain) and it is not possible to assign the potential participant to the correct final group, due to the latter having met their recruitment quota
• * Strictly left-handedness by self-report
• * Thermal threshold for Pain-50 (determined at Visit 1) is outside the temperature range of 40-49 degrees Celsius
• * Lack of access to electronic device with internet connection during the study
• * Inability or unwillingness to receive daily text messages during the study
• * Inability to complete at least four daily ratings between the Informed consent, Pre- visit 1 procedures and in-person visit 1
• * Anything that would place the individual at increased risk or preclude the individual's full compliance with study procedures or completion of the study.