Temporomandibular joint (TMJ) pain is a predominant sign and symptom in patients with temporomandibular disorder, and a common cause of chronic orofacial pain. Arthrocentesis of the upper joint space proved to be effective in reducing TMJ-related pain and reestablishing normal mandibular range of movement in patients diagnosed for a 'closed lock'. Using the therapeutic approach of arthrocentesis in TMJ-related instances of capsulitis/ synovitis (C/S) with a recency of first pain onset of < or =6 months, the purpose of the present study was to evaluate whether the TMJ-related variable synovial fluid (SF) level of TNF-alpha may be linked to the cessation of related signs and symptoms associated with the performance of arthrocentesis and hydraulic distension. In 23 patients with a specific temporomandibular disorder diagnosis of unilateral C/S with a recency of first pain onset of < or =6 months, TMJ SF aspirates were obtained from the pain and contralateral non-pain sides immediately before and after arthrocentesis. Visual analog scales were used for pre- and postoperative self-assessment of TMJ-related pain during function, while enzyme-linked immunosorbent assays were applied for measurement of the tumor necrosis factor-alpha (TNF-alpha) concentration. With a mean SF TNF-alpha level of 13.91 ng/ml associated with the pain side, and a mean SF TNF-alpha level of 7.73 ng/ml associated with the non-pain side, a statistically significant difference was found between the sample groups (P=0.001). Arthrocentesis led to a significant intraoperative decrease of the respective preoperative SF TNF-alpha levels, namely 61.64% (P=0.000) on the pain side and 89.50% (P=0.000) on the non-pain side, while reduction of TMJ-related pain during function was 73.17%, (P=0.000). Clinical evaluation showed a significant reduction in the prevalence of TMJ-related diagnoses of C/S (P<0.001). There was no change in the prevalence of associated TMJ-related diagnoses of internal derangement. In view of the fact that the described technique of TMJ SF analysis may be suggested as a valuable diagnostic method for the detection of biochemical SF events, the results of this study should encourage research in its potential uses so that it can become established as a reliable diagnostic approach. Further, the findings may support the concept of bilateral arthrocentesis to be effective in the treatment of patients with a unilateral specific TMD diagnosis of non-chronic C/S.

Objectives. The purpose of this study was to investigate whether patients with temporomandibular joint (TMJ)-related pain classified as capsulitis/synovitis may be linked to magnetic resonance imaging (MRI) Findings of internal derangement, osteoarthrosis, or the synovial fluid aspirate findings of tumor necrosis factor-alpha (TNF-alpha) level.Study design. The study comprised 23 patients with temporomandibular disorders (TMD), who had nonchronic pain (pain onset less than or equal to 6 months) and a unilateral TMJ-related diagnosis of capsulitis/synovitis. Bilateral sagittal and coronal magnetic resonance images were obtained to establish the presence or absence of internal derangement, osteoarthrosis, or both. TMJ synovial fluid aspirates were obtained from the pain and contralateral nonpain sides to determine the TNF-alpha level.Results. Comparison of the TMI side-related data showed a significant relationship between the clinical TMD diagnosis of capsulitis/synovitis and the MRI diagnoses of TMJ internal derangement (P = .002) and of TMJ internal derangement type(P = .04). The mean TNF-alpha level in synovial fluid aspirates from TMJs assigned a clinical TMD diagnosis of capsulitis/synovitis was significantly higher than in those obtained from contralateral nonpain sides (P = .001). There was no correlation between the clinical diagnosis of capsulitis/synovitis and the MRI diagnosis of TMJ osteoarthrosis (P = .13) or between the MRI diagnosis of TMJ osteoarthrosis and that of TMJ internal derangement (P = .70) or TMI internal derangement type (P = .33).Conclusions. The results suggest that the TMJ pain condition of capsulitis/synovitis is related to TMJ-side specific MRI diagnoses of internal derangement and internal derangement type, and synovial fluid aspirate findings of TNF-alpha level. The data confirm the concept of elevated mediator level as a diagnostic approach For patients presenting with TMJ-related pain. MRI and synovial fluid aspirates may be used as diagnostic methods for evaluating TMJ-related pain conditions.