Neck disability in chronic neck pain: Associations with temporomandibular disorders, sleep quality, and cervical sensorimotor function.

BACKGROUND

Chronic neck pain is a major cause of disability, and temporomandibular disorders (TMD) frequently co-occur with this condition. However, clinical factors associated with neck disability in individuals presenting with both conditions have not yet been fully clarified.

OBJECTIVES

This study aimed to investigate the role of TMD in neck-related disability and to determine the extent to which sleep quality, cervical proprioception, muscle endurance, and postural variables predict neck-related disability.

MATERIALS AND

METHODS

Eighty individuals with chronic neck pain lasting at least three months were included in this cross-sectional study. Participants were classified as TMD-positive (n = 42) or TMD-negative (n = 38) according to the DC/TMD symptom questionnaire. Neck disability was assessed using the Neck Disability Index (NDI), and sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Cervical proprioception was measured using a laser-guided joint position error test. Deep neck flexor endurance was assessed using the craniocervical flexion test protocol, and head-neck posture was evaluated by measuring the craniovertebral angle.

RESULTS

NDI scores were significantly higher in the TMD-positive group compared with the TMD-negative group (24.6 ± 7.8 vs. 17.3 ± 6.2, p < 0.001). Sleep quality was also poorer in individuals with TMD (PSQI: 8.6 ± 3.4 vs. 6.2 ± 2.8, p < 0.001). Proprioceptive error was higher and muscle endurance was lower in the TMD-positive group. The multiple regression model explained 48% of the variance in disability (R2 = 0.48), with TMD presence, sleep quality, and proprioceptive error were identified as independent predictors.

CONCLUSION

These findings suggest that neck disability in individuals with chronic neck pain and TMD symptoms are multifactorial and cannot be explained by pain alone. Assessment of sleep quality, proprioceptive function, and muscle performance together may contribute to improved clinical assessment and treatment planning in this patient population.