OBJECTIVETo compare the efficacy and radiographic changes after arthrocentesis followed or not followed by intra-articular corticosteroid injection in patients with temporomandibular disc displacement without reduction.

METHODSNinty patients were enrolled in the randomized clinical trial. After receiving arthrocentesis, either 0.5 mL triamcinolone acetonide plus 0.5 mL saline (experimental group, n = 46) or 1 mL saline solution as control (control group, n = 44) was injected. Patients were assessed by visual analogue scale (VAS) pain scores and Fricton temporomandihular joint (TMJ) index at first visit before treatment, 3-4 weeks and 6 months after treatment respectively. Transpharyngeal and lateral transcranial projections for temporomandibular joints were taken for imaging evaluation. The pain score of patients with pain complaint were recorded everyday for 1 week after treatment.

RESULTSGlucocorticoid injection showed more effective pain control over the first week (P < 0.05), and both groups reported symptom and clinical sign relief significantly after treatment (P< 0.001). However, quantitative evaluation for pain reduction, maximal mouth opening improvement and Friction TMJ index showed no significant difference between two groups at 3-4 weeks and 6 months after the treatment. Also there was no significant difference for condylar bone changes radiographically between the two groups.

CONCLUSIONArthrocentesis is an effective treatment for temporomandibular joint disc displacement without reduction, but it is not necessary to inject corticosteroid after arthrocentesis. Intra-articular corticosteroid injection after arthrocentesis is indicated for only those patients with severe pain.