Does the procedure of arthrography affect the range of movement in patients with locking of the temporomandibular joint?

The aim of this study was to investigate whether arthrography itself altered the range of mandibular movements, in a group of patients with locking of the temporomandibular joint (TMJ). The clinical records of a series of 161 patients who were diagnosed with locking of the TMJ were retrospectively analysed. Mouth opening had improved in 57 out of 161 patients (35%). Twenty-three patients (14%) had improved by 5 mm or less. Nineteen patients (11%) had improved by more than 5 mm but less than 10 mm, whereas 15 patients (9%) had improved by more than 10 mm. Of the patients who experienced an improved mouth opening, only nine (15%) had improved from their pre-arthrography restricted maximum opening to beyond the lower limit of normal. This suggests that the injection of contrast medium had an effect on the range of vertical opening in patients with displacement of the disc without reduction.