Evaluating Noninvasive Brain Stimulation for TMD Pain: A Feasibility Study

Inclusion Criteria: * Age 18 to 65 years. * Diagnosis of temporomandibular disorder (TMD) based on the Diagnostic Criteria for Temporomandibular Disorders (DC-TMD). * Pain intensity of at least 4/10 on the Numeric Rating Scale (NRS) over the past two weeks. * Chronic pain duration of at least three months, consistent with diagnosis of chronic TMD. * Willingness to self-administer transcutaneous auricular nerve stimulation (tAN) at home and comply with study procedures. * Fluency in English to ensure comprehension of study materials and assessments. * Access to a smartphone or computer with internet to complete electronic study surveys and check-ins with the research team. Exclusion Criteria: * Neurological conditions that may interfere with study outcomes, including epilepsy, stroke, multiple sclerosis, or traumatic brain injury. * Use of implanted neuromodulation devices, such as vagus nerve stimulators, deep brain stimulators, or cochlear implants. * Unstable or severe psychiatric disorders, including active psychosis or severe depression with suicidal ideation. * Pregnancy or intention to become pregnant during the study period. * Skin conditions or other contraindications that prevent safe electrode placement on the auricular region (e.g., metal in the cymba concha that is unable or not willing to remove). * History of trauma (e.g., skull fracture) or periauricular surgery (e.g., temporomandibular joint replacement, acoustic neuroma removal) which would affect the location and function of the target peripheral innervation. * Use of both surgical and non-surgical bone conduction hearing devices.