Effects of Vagus Nerve Stimulation on Temporomandibular Disorders.

August 27, 2026 updated by: Arpana Church

Pilot Study of the Effects of Transcutaneous Non-Invasive Vagus Nerve Stimulation (nVNS) on Symptoms and Brain Mechanisms in Premenopausal Women With Temporomandibular Disorders (TMD)

The study aims to examine the effects of transcutaneous non-invasive vagus nerve stimulation (nVNS) on symptoms and brain mechanisms in premenopausal women with temporomandibular disorders (TMD). Non-invasive vagus nerve stimulation (nVNS) is the most well researched and possibly the most effective non-invasive neuromodulation treatment for chronic pain conditions that targets the brain-gut-microbiome (BGM) axis.

Participants will be asked to come in for 2 in-clinic visits, at baseline and post treatment. Participants will also be asked to come in 2x/week for 8 consecutive weeks to receive the nVNS treatment. The in-clinic visits will include physical measures, blood draw, saliva sample, and brain MRI. Participants will be asked to collect a stool sample at home and answer online questionnaires regarding, mood, pain, and health behaviors at home, prior to the in-clinic appointments.

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.
10

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.

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90095
        • Recruiting
        • University of California, Los Angeles

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

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Ages 18-50
  • Premenopausal menstruating women*
  • Participants report or present with at least 1 of 3 cardinal signs of TMD: jaw pain, limited mouth opening, or TMJ noise.
  • Specific screening reveals clinical findings that include TMJ and/or masticatory and cervical muscle pain.
  • Must have a negative urine test for pregnancy
  • Ability to speak the English language fluently due to the standardized assessments involved

  • Right-handed (participants are limited to right-handed individuals to reduce variability in brain lateralization and ensure more consistent, interpretable data).

    • Only premenopausal women are included to control for hormonal variability that may influence the results. Participants will be scheduled during their follicular phase based on self-reported last menstrual period to further reduce hormonal confounds.

Exclusion Criteria:

  • Medical condition, laboratory finding, or physical exam finding that precludes participation, such as systemic arthritides, juvenile idiopathic arthritis, idiopathic condylar resorption, connective tissue disorders, mandibular osteonecrosis, mandibular and condylar fractures, salivary gland disorders (incl. history of stones or swelling), neoplasms, neurologic/neuropathic, endocrine, or immune/autoimmune diseases and congenital or developmental disorders.
  • Pathologic processes found on imaging including neoplasm (Exception: disc displacements and osseous pathology including osteoarthritis/osteoarthrosis).
  • Radiation treatment to head and neck
  • Prior jaw or open TMJ (including contralateral joint) surgery including plication, chondroplasty, joint replacement, disectomy, and discoplasty.
  • Intra-articular therapies of TMJ being sampled that include arthrocentesis, visco-supplementation, and steroid, platelet-rich plasma/platelet-rich fibrin administration within the last 6mo
  • Recent febrile illness within the past 8 weeks that precludes or delays participation by more than 90 days
  • Trauma to jaw in the last 2mo
  • Presence of non-TMD orofacial pain disorders excluding comorbidity of interest (fibromyalgia).
  • Pregnancy or lactation
  • Undergoing or previously undergone bone anabolic or other hormonal therapies for medical needs
  • Unable to participate due to language barrier or mental/intellectual incompetence
  • Use of antidepressant drugs unless the participants have been on a stable dose for 60 days.
  • Drug and/or alcohol abuse in the past year
  • Ongoing dental treatments requiring invasive procedures (e.g. implant placement, tooth extractions, etc.)
  • Recent dental treatments within past two weeks that required sustained mouth opening for more than 20 minutes.
  • Wearing removable or implant supported dentures or fixed orthodontic appliances
  • Unable or unwilling to give informed consent
  • Participation in another clinical study that interferes with participation in this study
  • Anything that would place the individual at increased risk or preclude the individual's full compliance with or completion of the study.
  • Presence of non-TMD orofacial pain disorders such as that from periodontal disease and carious lesions.
  • Presence of major psychiatric diagnosis such as schizophrenia, bipolar disorder, post-traumatic stress disorder, obsessive compulsive disorder, or current history of drug or alcohol abuse.
  • Individuals with current regular use of narcotics and/or opioids. Use of centrally acting medications that will interfere with neuroimaging testing, such as systemic steroids, opiate analgesics.
  • Smokes/Vapes tobacco more than 1/3 pack per day

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

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.
Experimental: Active nVNS Treatment
nVNS Treatment 2x/week for 8 weeks
Device: nVNS Treatment
nVNS treatment 2x/week for 8 consecutive weeks.
Other Names:
  • vagus nerve stimulation
  • non-invasive vagus nerve stimulation

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
Pain Intensity
Time Frame: From the baseline in-clinic visit through 8 weeks of biweekly visits, assessed immediately before and after each nVNS session.
To be measured using a numeric rating scale 0-10.
From the baseline in-clinic visit through 8 weeks of biweekly visits, assessed immediately before and after each nVNS session.
Pain Unpleasantness
Time Frame: From the baseline in-clinic visit through 8 weeks of biweekly visits, assessed immediately before and after each nVNS session.
To be measured using a visual analog scale.
From the baseline in-clinic visit through 8 weeks of biweekly visits, assessed immediately before and after each nVNS session.
Positive and Negative Affect
Time Frame: From the baseline in-clinic visit through 8 weeks of biweekly visits, assessed immediately before and after each nVNS session.
To be measured using the positive and negative affect scale (PANAS).
From the baseline in-clinic visit through 8 weeks of biweekly visits, assessed immediately before and after each nVNS session.

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.
Arpana Church

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: Arpana Church, Ph.D., The Regents of the University of California, Los Angeles
  • Principal Investigator: Sunil Kapila, B.D.S., M.S., Ph.D., The Regents of the University of California, Los Angeles

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 (Estimated)

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.
September 1, 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.
December 31, 2026

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.
December 31, 2026

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).
December 5, 2025

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.
December 15, 2025

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.
December 17, 2025

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.
September 1, 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.
August 27, 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.
August 1, 2026

More Information

Terms related to this study

Keywords

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.
  • IRB 25-0801

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings