Risk and Health Factors for Temporomandibular Disorders Following Radiotherapy for Head and Neck Cancer

Temporomandibular disorders (TMD) are multifactorial and complex musculoskeletal conditions frequently associated with pain or dysfunction, including impaired jaw function and pain in the temporomandibular joint, masticatory muscles and/or related structures. Recent studies have found that personality, behaviour and environment can affect the development of TMD.

This study investigates whether patient-related factors can predict TMD among patients with head and neck cancer (HNC) after radiotherapy.

We randomised 58 consecutive patients with squamous cell carcinoma in the head and neck area into two groups: training with a jaw mobiliser once a day or a control group (no training). A comprehensive examination for TMD was conducted at baseline (before oncologic treatment) and 6 and 12 months after radiotherapy. Potential predictors were analysed using linear and logistic regression analyses.

Myalgia was associated with TMD diagnosis at baseline, and jaw exercise lowered the risk of developing myalgia at the follow-ups. The degree of pain at baseline and jaw exercise were associated with the changes in pain at follow-ups. Jaw exercise was associated with a lower degree of pain. A high degree of pain at baseline was associated with less pain at follow-ups. Jaw exercise was associated with a reduced risk of decreased maximal incisal mouth opening post treatment.

No psychosocial or other background factor reduced risk for myalgic pain or pain to the same degree as jaw exercise. Therefore, we recommend using jaw training to prevent the deterioration of maximal incisal opening and the development of pain associated with TMD.