The Effect of Non-Invasive Vagal Nerve Stimulation Combined with Self-Managed Therapy in Individuals with Myogenic Temporomandibular Dysfunction

Not Applicable

Not yet recruiting

• Conditions: Temporomandibular Disorders (TMD)

• Registration Number: NCT06802445
• Lead Sponsor: Toros University

Brief Summary

The aim of our study is to determine the benefit of non-invasive Vagal Nerve Stimulation in combination with self-administered therapy on the symptoms associated with jaw joint dysfunction in individuals with jaw joint dysfunction.

If you agree to participate in the study, you will fill out a form containing your information such as age, height, body weight. Then, Visual Analog Scale (VAS) and Central Sensitisation Scale will be used to assess the severity of jaw and neck joint pain. The 8-question Jaw Function Restriction Scale will be used to assess the limitation of jaw function.

An algometer will be used to evaluate the pressure-pain threshold, and Therabite range of motion scale will be used to evaluate the range of motion of the jaw joint. One photograph will be taken from the side profile to evaluate the head-neck posture, this photograph will be used for craniocervical angle measurement and will not be shared elsewhere. Myotonmetry will be used to evaluate muscle mechanical properties and non-invasive superficial electromyography (yEMG) will be used to evaluate muscle activation.

The treatments to be applied within the scope of the study will be carried out 3 days a week and the evaluation sessions will last 30 minutes.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-01
• Study First Submitted: 2025-01-19
• Study First Submitted QC: 2025-01-24
• Last Update Submitted: 2025-01-24
• Study First Posted: 2025-01-31
• Last Update Posted: 2025-01-31
• Study Start: 2025-02-08
• Primary Completion: 2025-03-22
• Study Completion: 2025-05-03

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 48

Inclusion Criteria

• between the ages of 18-45,
• Diagnosed with myogenic TMDs according to TMD-DC Axis I and II criteria,
• Pain intensity of 3 or more during rest and/or chewing according to the Visual Analogue Scale,
• Volunteered to participate in the study and signed the informed consent form,
• Individuals who do not have communication difficulties and whose native language is Turkish will be included in the study.

Exclusion Criteria

• Diagnosed with arthrogenic or mixed type TMDs,
• Severe psychiatric illness such as schizophrenia,
• Previous vagal nerve stimulation or history of vagotomy,
• Have extensive joint damage affecting the jaw, head, neck and shoulder areas, have a history of major trauma, fracture or surgery to these body parts, or are undergoing radiotherapy,
• Diagnosed with cervical disc herniation, cervical radiculopathy or cervical myelopathy,
• History of cardiac disease and being treated for cardiac problems,
• Active implant users such as pacemakers, defibrillators, neurostimulators, cochlear implants and ventricular shunts,
• Failure to understand the study protocol
• Have a history of progressive neurological diseases (such as Parkinson's disease, MS, ALS, epilepsy, Alzheimer's disease)
• Acute tinnitus
• Skin problems such as dermatitis, infection, psoriasis, urticaria, acne or eczema at the stimulation site,
• Has any anatomical abnormality that prevents successful placement of the ear electrode,
• and reporting acute tinnitus,
• Pregnant subjects will be excluded from the study

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Pain Intensity	First Interview: Initial Assessment/ End of Week 2: Second Evaluation /End of Week 6: Third Evaluation /At the end of Week 12: Fourth and final assessment	Jaw and neck joint pain intensity will be assessed using the Visual Analogue Scale (VAS),which is reported to be valid and reliable.The individuals included in the study will be asked to indicate the jaw and neck joint pain intensity they have experienced at rest and during chewing in the last 1 week on a 100 mm long line positioned vertically.The marked points will be measured and recorded in millimetres.An increase in VAS indicates pain of higher intensity Pressure-pain threshold measurement will be performed using a digital algometer.Before starting the tests, the individuals will be informed about the test and one trial session will be performed. The tests will be performed using a 1 cm2 headgear with a 1 kg/cm2 increase in pressure intensity every second and the participants will be asked to tell the evaluator the point at which the pressure to be applied turns into mild pain. The average of three consecutive tests performed at 30 s intervals will be taken and recorded in kg/cm2.

Secondary Outcome Measures

Name	Time	Method
Evaluation of Temporomandibular Joint Range of Motion	First Interview: Initial Assessment/ End of Week 2: Second Evaluation /End of Week 6: Third Evaluation /At the end of Week 12: Fourth and final assessment	The TheraBite® Range of Motion Scale (TheraBite ®, Platon Medikal Ltd., United Kingdom) will be used to assess the range of motion of the participants' jaw joint. TheraBite is a scale with high intra-observer reliability that is frequently used in the literature for the assessment of jaw joint range of motion and is accepted as the standard for clinical use. Participants will be placed supine on a therapy table in an examination room and asked to open their mouths as far as they can and the range of motion will be recorded in millimetres (mm). The measurements will be repeated three times and the average of the three measurements will be taken as reference.Higher values obtained from this scale represent an increase in the range of motion of the mouth.
Craniocervical Posture Assessment	First Interview: Initial Assessment/ End of Week 2: Second Evaluation /End of Week 6: Third Evaluation /At the end of Week 12: Fourth and final assessment	The craniocervical postures of the individuals included in the study will be evaluated using photogrammetry method based on angle calculation on photographs. For the measurement, the seventh cervical vertebral processes and ear tragus of the individuals will be determined as reference points and these points will be clearly marked before photographing. After the marking is completed, the individual will be asked to perform neck flexion and extension repeatedly to ensure neutral head position in the standing position, and then photographed with a mobile phone camera placed on a tripod 1.5 metres away from the left side of the individual. A craniocervical angle of less than 50 degrees means a forward head posture.
Muscle Activity Measurements	First Interview: Initial Assessment/ End of Week 2: Second Evaluation /End of Week 6: Third Evaluation /At the end of Week 12: Fourth and final assessment	In the study, a 4-channel superficial EMG (yEMG) device (Ultium EMG Sensor, Noraxon, USA), which is reported to be valid and reliable, will be used to evaluate the activation of masticatory muscles (masseter and temporalis).
Muscle Stiffness	First Interview: Initial Assessment/ End of Week 2: Second Evaluation /End of Week 6: Third Evaluation /At the end of Week 12: Fourth and final assessment	Stiffness \[N/m\], is a biomechanical property of a muscle, provides information about the resistance of the tissue to an external force or contraction. stiffness will be measured using a myotonometer (MyotonPRO, Myoton AS, Tallinn, Estonia), which has been reported to be valid and reliable. Assessments will be conducted in study, masseter, upper trapezius, tibialis anterior muscles.The measurement will be repeated 3 times and the arithmetic mean of the measurements will be recorded.
Logarithmic Decrease	First Interview: Initial Assessment/ End of Week 2: Second Evaluation /End of Week 6: Third Evaluation /At the end of Week 12: Fourth and final assessment	Logarithmic decrease (D) gives information about the elasticity of the evaluated tissue. Logarithmic decrease will be measured using a myotonometer (MyotonPRO, Myoton AS, Tallinn, Estonia), which has been reported to be valid and reliable.Assessments will be conducted in study, masseter, upper trapezius, tibialis anterior muscles.The measurement will be repeated 3 times and the arithmetic mean of the measurements will be recorded.