An observational study in Masseter Muscle, Ultrasonographic and Chronic Neck Pain, sponsored by Hasan Kalyoncu University. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-13.
Sponsored by Hasan Kalyoncu University · Observational
The primary objective of our study is to compare the thickness of the masseter muscle, measured by ultrasound, in individuals with chronic neck pain to that of healthy individuals. The secondary objective of the study is to examine the relationships between masseter muscle thickness and pain intensity, neck disability level, pain catastrophizing level, and clinical diagnostic criteria in individuals with chronic neck pain.
The aim of this study is to evaluate masseter muscle thickness in individuals with chronic neck pain using ultrasonography and to compare it with healthy individuals. Thus, it is intended to reveal possible morphological changes related to the craniomandibular system in chronic neck pain and to determine whether these changes contribute to clinical evaluations. The literature reports that there are biomechanical and neuromuscular connections between the temporomandibular system and the cervical spine, and that changes in masseter muscle activity and morphology may be related to neck pain. The literature emphasizes that there are biomechanical, neuromuscular, and sensory connections between the temporomandibular system and the cervical spine, and that dysfunctions in these two regions may influence each other reciprocally. The masseter muscle, in particular, being one of the primary muscles of the temporomandibular system, may exhibit increased muscle activity, parafunctional habits, and morphological adaptations due to central sensitization mechanisms in chronic pain conditions. Chronic neck pain is reported to be more common in individuals with temporomandibular disorders, along with increased muscle sensitivity and functional limitations, and this condition is associated with cervical pain severity and disability level. Ultrasonography is a reliable, valid, and non-invasive method for assessing muscle thickness and is widely used to evaluate the morphological characteristics of the masseter muscle. Measuring masseter muscle thickness by ultrasonography allows for the evaluation of the muscle's structural response to functional loading and enables comparisons between different clinical groups. However, the literature shows that studies comparing possible changes in masseter muscle thickness in individuals with chronic neck pain with healthy individuals are limited, and this relationship has not been sufficiently elucidated. Accordingly, the primary objective of this study is to compare the masseter muscle thickness measured by ultrasonography in individuals with chronic neck pain with that in healthy individuals. The secondary objective of the study is to examine the relationships between masseter muscle thickness and pain intensity, neck disability level, pain catastrophizing level, and clinical diagnostic criteria in individuals with chronic neck pain.
The study will include individuals aged 18-45 who have experienced neck pain for at least 3 months but do not have a diagnosed cervical pathology. The control group will include individuals aged 18-45 who do not have any health problems.
Exclusion Criteria:
The study will include individuals aged 18-45 who have experienced neck pain for at least 3 months but do not have a diagnosed cervical pathology.
The control group will also include individuals aged 18-45 with no health problems.
Ultrasonographic Measurement
Masseter muscle thickness will be assessed using the B-mode ultrasound method with a 7.5-10 MHz frequency linear probe on an ALEXUS brand ultrasound device. During measurements, participants will be positioned sitting upright, with the head in a neutral position and the jaw at rest (teeth not in occlusion). Prior to measurement, participants will be instructed to avoid activities such as intense chewing or gum chewing for the last 24 hours. The measurement point will be determined as the midpoint of the line between the zygomatic arch and the mandibular angle. The linear probe will be placed parallel to the long axis of the masseter muscle fibers, perpendicular to the skin surface, and with minimal pressure applied. The ultrasound image will clearly distinguish the skin, subcutaneous tissue, and superficial and deep fascial borders of the masseter muscle.
Time frame: through of the study, average 3 months
Visual Analog Scale (VAS)
The VAS is a one-dimensional measurement tool used to assess the intensity of pain as perceived by the individual. The scale consists of a horizontal line with endpoints defined as "0 = no pain" and "10 = unbearable pain," on which the individual marks their current pain level. Participants are asked to rate the intensity of their neck pain, and the distance from the starting point to the marked point is measured in centimeters or millimeters and scored. Higher scores indicate higher pain intensity.
Time frame: through of the study, average 3 months
Neck Disability Index - NDI
The Neck Disability Index (NDI) is a multidimensional self-report scale developed to assess the level of functional limitation associated with neck pain, covering activities of daily living. The scale consists of a total of 10 items covering pain, personal care, lifting, reading, headaches, concentration, work, driving, sleep, and recreation. Each item is scored from 0 to 5, and the total score ranges from 0 to 50. Higher scores indicate an increased level of disability related to the neck. The validity and reliability study of the 7-item questionnaire in Turkish was conducted by Emine Aslan and colleagues in 2008.
Time frame: through of the study, average 3 months
Pain Catastrophizing Scale
The Pain Catastrophizing Scale was developed to assess an individual's negative cognitive and emotional responses to their pain experience. The scale consists of three subscales: rumination (persistent thinking), magnification, and helplessness. The scale is answered using a Likert-type rating, and a total score is calculated. High scores indicate an increased tendency to catastrophize pain.
Time frame: through of the study, average 3 months
Northwick Park Neck Pain Questionnaire (NPQ)
The Northwick Park Neck Pain Questionnaire (NPQ) is a self-report measure that assesses functional impairment and symptom severity associated with neck pain. The scale consists of items covering pain, paresthesia, sleep, social life, and daily activities. Participants select the statement that best applies to them for each item. The total score reflects the level of functional impairment, with higher scores indicating greater disability and symptom severity.
Time frame: through of the study, average 3 months
Plan to share: No
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Hasan Kalyoncu University