Evaluating Noninvasive Brain Stimulation for TMD Pain: A Feasibility Study

May 28, 2026 updated by: University of Minnesota
This study is a randomized, double-blind, sham-controlled feasibility trial designed to assess the acceptability and preliminary efficacy of Transcutaneous Auricular Neurostimulation (tAN) for individuals with Temporomandibular Disorders (TMD). Approximately 40 participants will be enrolled to evaluate whether daily, home-based tAN sessions-which deliver mild electrical pulses to the auricular branch of the vagus nerve-can effectively reduce chronic orofacial pain and improve associated cognitive and psychosocial dysfunctions. The study monitors feasibility through retention and adherence rates while tracking secondary outcomes such as pain intensity, cognitive flexibility, and mood changes using validated scales and wearable smartwatch data . Ultimately, this research aims to generate the critical data necessary to inform larger clinical trials and potentially offer a non-pharmacological, non-invasive treatment option for patients refractory to traditional TMD therapies.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Carla Campbell
  • Phone Number: 612-625-6976
  • Email: ohcrc@umn.edu

Study Locations

  • United States
    • Minnesota
      • Minneapolis, Minnesota, United States, 55455
        • Recruiting
        • University of Minnesota
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Active tAN
After the baseline assessments, participants will be trained to self-administer tAN at home according to their assigned condition (active or sham). They will be instructed to use the device daily for a minimum of two hours (maximum is 24 hours) while recording any side effects. The device's internal log will track session compliance, stimulation parameters, and usage frequency.
Device: Transcutaneous Auricular Neurostimulation
The intervention in this study is Transcutaneous Auricular Neurostimulation (tAN), a noninvasive neuromodulation technique that delivers mild electrical stimulation to the auricular branch of the vagus nerve (ABVN) via electrodes placed on the external ear.
Placebo Comparator: Sham Stimulation
The sham condition will mimic active stimulation without delivering therapeutically active parameters, defined as electrical stimulation being provided to the earpiece electrode. The sham stimulation will be passive stimulation meaning that no electrical stimulation will be provided to the participant.
Device: Sham Stimulation
the sham condition will mimic active stimulation without delivering therapeutically active parameters, defined as electrical stimulation being provided to the earpiece electrode. The sham stimulation will be passive stimulation meaning that no electrical stimulation will be provided to the participant.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Retention Rate
Time Frame: Week 6
The proportion of enrolled participants who complete both baseline and post-treatment assessments. A retention rate of ≥50% is considered feasible.
Week 6
Intervention Adherence
Time Frame: Week 4
The percentage of prescribed tAN sessions completed by each participant, as recorded in the internal device log. Feasibility is defined as ≥50% adherence to scheduled sessions.
Week 4
Acceptability
Time Frame: Week 4
Measured using a post-treatment Likert scale survey, where participants will rate comfort, usability, and willingness to use tAN again on a 1 to 5 scale. A mean acceptability score of ≥3/5 indicates feasibility.
Week 4

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Minnesota

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Donald Nixdorf, MD, University of Minnesota

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 20, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 2, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 1, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 8, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • DENT-2025-34560

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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