Effects of Cervical Manual Therapy for Temporomandibular Disorders With Myalgia

Summary

Background: Temporomandibular disorders (TMDs) are the leading cause of non-odontogenic orofacial pain interfering with daily activities. TMDs consist of a group of conditions affecting the masticatory muscles, the temporomandibular joint (TMJ), or the associated structures. Previous studies showed alterations in TMJ kinematics, cortical excitability, electromyographic (EMG) activity of the masticatory muscles, and tongue pressure in individuals with TMDs compared to healthy controls. Furthermore, several studies have demonstrated that manual therapy applied to the cervical joint could reduce pain and improve jaw function in individuals with TMDs. However, the effects of upper cervical mobilization on TMJ kinematics, cortical excitability, tongue pressure, and EMG of masticatory muscles during mouth opening in individuals with myogenous TMDs remain unknown.

Purpose: This study aims to investigate the immediate effects of upper cervical mobilization on TMJ kinematics, EMG of masticatory system muscles, cortical excitability, and tongue pressure in individuals with myogenous TMDs.

Methods: A randomized controlled trial will be conducted with a total sample size of 48 participants. Individuals diagnosed with myogenous TMDs, defined as chronic myalgia (lasting \>3 months continuously or \> 6 months intermittently) according to the Diagnostic Criteria for Temporomandibular Disorders, will be recruited for this study. Participants will be randomly assigned to either the experimental or the control group, stratified by age and sex. The experimental group will receive a single session of upper cervical mobilization, while the control group will receive a placebo maneuver. The primary outcomes will include TMJ kinematics and EMG activity of the masseter and suprahyoid muscles, while the secondary outcomes will include cortical excitability, tongue pressure, pain intensity, and upper cervical mobility. All measurements will be taken before and immediately after the intervention.

Statistical analysis: The continuous and categorical variables of clinical and demographic characteristics will be analyzed by an independent t test/Mann-Whitney U test and a Chi-square test, respectively. A 2×2 mixed-model analysis of variance (ANOVA) will be used to analyze the outcome measures and to test the main effects and interactions between time and group. If there is a significant interaction effect, post hoc pairwise comparisons with Bonferroni correction will be used. The alpha level is set at 0.05.

Conditions

• Temporomandibular Disorders (TMDs)

Interventions

OTHER

upper cervical mobilization

Upper cervical mobilization will focus on the atlanto-axial joint. All techniques will adhere to the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) guidelines to minimize the risk of adverse effects 75. Participants will remain in a supine position with their head in a neutral alignment. The physical therapist will apply translatoric mobilization, aligning the transverse process of the atlas (C1) as closely as possible with the transverse process of the axis (C2) in the transverse plane. The intervention will be considered complete once C1 and C2 are properly aligned.

OTHER

placebo maneuver

Participants will also remain in a supine position with a neutral head posture. However, instead of performing mobilization, the physical therapist will simply place their hands on C1 and C2 without applying any force.

Sponsors & Collaborators

• National Yang Ming Chiao Tung University

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-07-01

Primary Completion

2027-12-01

Completion

2027-12-31