Jaw Kinematics and Muscle Activation in Patients With Non-specific Chronic Neck Pain

Temporomandibular disorder (TMD) is a collective term for pain and dysfunction of the masticatory muscles and temporomandibular joint (TMJ). Typical signs and symptoms of TMD includes regional pain, noises from the TMJs and limitations in jaw movements. Altered jaw kinematics and muscle activity have also been reported. TMD may be related to neck problems. Over 50% of patients with TMD suffer from nonspecific neck pain. Patients with TMD often have symptoms over neck, including upper cervical spine movement impairment and reduced cervical muscles endurance. Conversely, TMD may also develop in patients with neck pain. Twenty to thirty-three percent of patients with neck pain also have TMD. Subjects with neck pain present with a twofold higher prevalence of TMD than those without neck pain. In patients with neck pain, the development or perpetuation of TMD may be due to the anatomical connection between TMJ and neck: neck posture affects the mandible position and sensory inputs from the cervical-mandibular region converge at the trigemino-cervical nucleus. Early identification of TMD is essential but to our knowledge, no study has investigated whether patients with neck pain demonstrate altered jaw movement and muscle activity, which is associated with TMD. The purposes of this proposal are to compare the jaw kinematics, muscle activity and muscle sensitivity in healthy individuals and patients with non-specific chronic neck pain (NCNP). This study also aimed to investigate the relationship between forward-head posture and the jaw kinematics, muscle activity as well as muscle sensitivity. With a cross-sectional exploratory study design, 30 healthy control subjects and 30 subjects with NCNP will be recruited. Clinical assessments will include cervical range of motion (CROM), pressure pain threshold (PPT) over the cervical-mandibular region and the cranial-cervical angle (CCA). Jaw kinematics will be measured by Ultrasonic Jaw Motion Analyzer (Zebris GmbH) during functional jaw movements. Muscle activities are record from bilateral anterior temporalis, masseter, sternocleidomastoid muscle and upper trapezius by surface electromyography during resting and clenching.

Study Overview

• Status: Completed
• Conditions: Temporomandibular Disorder; Nonspecific Chronic Neck Pain; Biomechanical Phenomena
• Intervention / Treatment: Other: Cervical range of motion (CROM); Other: Pressure pain threshold (PPT); Other: Cranial-cervical angle (CCA); Other: Jaw kinematics; Other: Muscle activation

• Study Type: Observational
• Enrollment (Actual): 44

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan, 112
    • National Yang-Ming University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with nonspecific chronic neck pain for at least 3 months and the matched healthy control subjects

Description

Inclusion Criteria (nonspecific chronic neck pain group):

• Aged between 20 to 65 years old
• Mechanical pain that provoked by sustained neck postures or specific neck movements without any identifiable diseases or structure anomalies
• Chronic or recurrent neck pain of at least 3 months duration
• Minimum of 3 points on the numerical pain rating scale (NPRS) over cervical region
• Without any pain, clicking or range of motion limitation over TMJ

Inclusion Criteria (healthy control group):

• Age (± 5 years) and gender match to NCNP group
• No pain or clinical pathology involving the masticatory system or cervical spine for at least one year prior to the start of the study

Exclusion Criteria (both groups):

• Serious injury, tumor, infection
• Recent cervical-cranial surgery
• Neurologic involvement
• Inflammatory rheumatic diseases
• Pregnancy
• Nonmechanical cause of neck pain (e.g. herniated disk, spinal fractures)
• Had been diagnosed with spinal conditions (e.g. spondylolisthesis)
• Shoulder pain within 1 years
• Loss of posterior tooth
• Dental pain or periodontal problems
• Orthodontic, orofacial myofunctional or TMD treatment within 3 months
• Use of analgesic or anti-inflammatory drugs within 3 days

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Nonspecific chronic neck pain (NCNP) group; Subjects with nonspecific chronic neck pain will be included to perform clinical test and assess their jaw kinematics and muscle activation.	Other: Cervical range of motion (CROM); Subjects will perform full-range cervical flexion, extension, side-bending and rotation actively in sitting position. In supine position, cervical flexion-rotation will be performed passively by the assessor.; Other: Pressure pain threshold (PPT); A digital algometer with rubber head will be used to apply pressure on the muscles of subjects. When the subjects start to feel pain, the algometer will be removed immediately.; Other: Cranial-cervical angle (CCA); Subjects will stand in a relaxed position with colour markers on the earlobe and C7 spinous process. A photo of the head posture will be taken to calculate the included angle between the markers and the horizontal line.; Other: Jaw kinematics; Jaw kinematics is measured by Ultrasonic Jaw Motion Analyzer (Zebris). The subjects will perform jaw opening, closing, lateral left, lateral right and protrusion for three times.; Other: Muscle activation; Surface electromyography is used to assess the activities of bilateral masseter, anterior temporalis, sternocleidomastoid muscle and upper trapezius. Subjects will perform jaw resting and clenching.
Control group; Healthy control subjects will be included to compare the differences in jaw kinematics, muscle activation and clinical tests between healthy subjects and subjects with nonspecific chronic neck pain. Subjects in this group will received the same assessment as the NCNP group.	Other: Cervical range of motion (CROM); Subjects will perform full-range cervical flexion, extension, side-bending and rotation actively in sitting position. In supine position, cervical flexion-rotation will be performed passively by the assessor.; Other: Pressure pain threshold (PPT); A digital algometer with rubber head will be used to apply pressure on the muscles of subjects. When the subjects start to feel pain, the algometer will be removed immediately.; Other: Cranial-cervical angle (CCA); Subjects will stand in a relaxed position with colour markers on the earlobe and C7 spinous process. A photo of the head posture will be taken to calculate the included angle between the markers and the horizontal line.; Other: Jaw kinematics; Jaw kinematics is measured by Ultrasonic Jaw Motion Analyzer (Zebris). The subjects will perform jaw opening, closing, lateral left, lateral right and protrusion for three times.; Other: Muscle activation; Surface electromyography is used to assess the activities of bilateral masseter, anterior temporalis, sternocleidomastoid muscle and upper trapezius. Subjects will perform jaw resting and clenching.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Jaw maximum range of motion	Including maximum mouth opening, lateral right, lateral left, and protrusion, which will be described with millimeter (mm)	Immediately during the experiment
Jaw velocity	Jaw opening and closing velocity, which will be described with millimeter per second (mm/s)	Immediately during the experiment
Condylar rotation	The rotation will be described with degree (°).	Immediately during the experiment
Condylar translation	Including condylar translation and condylar path length, which will be described with millimeter (mm)	Immediately during the experiment
Muscle activation	The root mean square of electromyography (EMG) data of the masseter, anterior temporalis, sternocleidomastoid muscle and upper trapezius will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %).	Immediately during the experiment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cervical and jaw range of motion	Including range of motion of cervical flexion, cervical extension, cervical side-bending,cervical rotation and cervical flexion-rotation as well as maximum mouth opening, jaw lateral right, jaw lateral left, protrusion. The motion will be described with degree (°).	Immediately during the experiment
Pressure pain threshold	Pressure pain threshold of masseter, anterior temporalis, sternocleidomastoid muscle, upper trapezius and suboccipitals will each be averaged and will be described with kg/cm2.	Immediately during the experiment
Cranial-cervical angle	Cranial-cervical angle will be measured as the included angle between the ear lobe, C7 spinous process and the horizontal line and will be described with degree (°).	Immediately during the experiment

Collaborators and Investigators

• Sponsor: National Yang Ming University
• Collaborators: Cheng-Hsin General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 11, 2019
• Primary Completion (Actual): August 30, 2020
• Study Completion (Actual): August 30, 2020

Study Registration Dates

• First Submitted: July 28, 2019
• First Submitted That Met QC Criteria: July 31, 2019
• First Posted (Actual): August 1, 2019

Study Record Updates

• Last Update Posted (Actual): November 10, 2020
• Last Update Submitted That Met QC Criteria: November 9, 2020
• Last Verified: September 1, 2020

More Information

Terms related to this study

• Keywords: Temporomandibular disorder; Nonspecific chronic neck pain; Jaw kinematics; Muscle activity; Muscle sensitivity; Forward head
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Joint Diseases; Musculoskeletal Diseases; Muscular Diseases; Stomatognathic Diseases; Jaw Diseases; Craniomandibular Disorders; Mandibular Diseases; Myofascial Pain Syndromes; Neck Pain; Temporomandibular Joint Disorders; Temporomandibular Joint Dysfunction Syndrome
• Other Study ID Numbers: (717)108A-33

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No