Tumor necrosis factor-α as a biochemical marker of pain and outcome in temporomandibular joints with internal derangements

Objective: Previous studies have demonstrated the presence of tumor necrosis factor-α (TNF) in human temporomandibular joint (TMJ) synovial fluid. The present study continues the investigation of the role of TNF in TMJs with internal derangements. Materials and Methods: Synovial fluid was obtained from 18 TMJs in 12 patients undergoing either arthroscophy (14 joints) or arthrotomy (four joints) for internal derangements. Standardized clinical data were collected preoperatively, intraoperatively, and postoperatively. Results: When pain on palpation was absent, the mean preoperative TNF level was 14 ± 6 ng/mL. When pain on palpation was present, the mean TNF level was 42 ± 39 ng/mL (significant difference at P = .05). When the surgical outcome was poor, the mean preoperative TNF level was 26 ± 9 ng/mL. When the outcome was within the stated guidelines for a favorable result, the mean TNF level was 12 ± 7 ng/mL (significant difference at P = .05). In addition, a significant reduction (P = .05) in TNF following joint lavage (preoperative, 48 ng/mL to postoperative, 7 ng/mL) was found. Conclusions: The finding of a positive correlation between preoperative pain and TNF values suggests a biochemical basis for the origin of the pain associated with internal derangements. The relationship between preoperative TNF levels and surgical outcome suggests that the prognosis for surgery may be predicted by measuring biochemical markers of joint disease.