Trauma in patients with temporomandibular disorders: frequency and treatment outcome.

Controversy exists on the aetiological importance and the effect of jaw macrotrauma (fractures excluded) on the occurrence of temporomandibular joint disorders (TMD). The purpose of this study was to assess the incidence of jaw injury in TMD patients and to compare the severity of the symptoms, the clinical characteristics and the treatment outcome in TMD patients with or without a history of trauma to the head and neck region directly linked to the onset of symptoms. The study sample included 400 consecutive TMD clinical patients. In 24.5% of patients the onset of the pain and dysfunction could be linked directly to the trauma, mainly whiplash accidents. No significant differences could be found between the two groups in daily recurrent headache, dizziness, neck pain, joint crepitation and pain in the joints. Maximal mouth opening was less than 20 mm in 14.3% of patients with a history of trauma and in 4.1% of those without such a history. According to the Helkimo dysfunction index (DI), more trauma than non-trauma TMD patients belonged to the severe dysfunction groups (DI 4 and 5) at first examination. The outcome of a conservative treatment procedure (counselling, occlusal splint, physiotherapy, occasionally occlusal therapy and non-steroidal anti-inflammation drugs was not different between the two groups at the 1 year evaluation. The degree of maximal opening was similar: less than 20 mm in 3.7% and 2.2% in trauma and non-trauma patients respectively. Forty percent and 41% respectively were symptom free or had DI = 1. The results suggest that external trauma to the joint or to the jaw in general is an important initiating factor in the aetiology of TMD but also that the prognosis is favourable.