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.