Association Between Temporomandibular Disorders and Cervical Muscle Pressure Pain

Aims: The aims of this study were to identify the association between cervical muscle pain and TMD by pressure pain response, and to find cervical muscles showing moderate to severe pressure pain that are correlated with masticatory muscle pain. Methods: Patients (n = 129, female 65.9%, mean age 28.8 years) answered a TMD questionnaire asking about headache, neck pain, emotional stress, sleep disturbance, parafunction habits, and pain intensity. A clinical examination of the masticatory system was performed. Of the neck muscles, ⑴ the upper sternocleidomastoid, ⑵ the middle sternocleidomastoid, ⑶ the upper trapezius, ⑷ the splenius capitis, ⑸ the semispinalis capitis, ⑹ the scalene medius, and ⑺ the levator scapulae muscles were examined by palpation. Pressure pain or tenderness of all palpation sites was scored from 0 to 3 according to the pain response. The variables of sum of pressure pain scores were calculated from pressure pain scores and were used for statistical analyses. Results: Eighty patients (62.0%) answered that they suffer from neck pain in the TMD questionnaire. More than 40% of sternocleidomastoid and upper trapezius examination sites showed moderate to severe tenderness in the cervical muscles, and 36% of middle masseter in the masticatory muscles. For the 129 patients, the sum of cervical muscle pain scores (mean = 12.88, SD = 8.06) and the sum of TMD pain scores (mean = 5.36, SD = 5.10) were moderately correlated (ρ = 0.502, P In a partial correlation analysis of the sum of unilateral pain scores, the sum of right cervical muscle pain scores and the sum of left cervical muscle pain scores showed the highest correlation (r = 0.802, P Conclusions: TMD is associated with cervical muscle pain on condition of pressure pain response to palpation. Of the cervical muscles, sternocleidomastoid and upper trapezius frequently exhibit moderate to severe pressure pain, and they are closely related to the masticatory muscle pain. The characteristic of symmetric involvement of pain is prominent in cervical muscles; however, TMD can affect the level of cervical muscle pain to modify its symmetric nature.