Determining predictor variables for treatment outcomes of arthrocentesis and hydraulic distention of the temporomandibular joint.

PURPOSE: Arthrocentesis and hydraulic distention of the temporomandibular joint (TMJ) has been described as an effective modality in the treatment of patients demonstrating clinical findings consistent with the diagnosis of disc displacement without reduction. The purpose of this study was to investigate whether the clinical variable of TMJ pain chronicity and the magnetic resonance (MR) imaging variable of osteoarthrosis (OA) may predict treatment outcomes of arthrocentesis and hydraulic distention of the TMJ.

PATIENTS AND METHODS: The study consisted of 29 TMJ pain patients, who were assigned a unilateral clinical temporomandibular disorder (TMD) of "TMJ pain associated with an internal derangement (ID) type III (disc displacement without reduction)," and a TMJ pain side-related MR imaging diagnosis of disc displacement without reduction. Bilateral sagittal and coronal MR images were obtained immediately preoperatively to establish the presence or absence of ID and OA. TMJ pain level of function and mandibular range of motion were assessed preoperatively and compared with the respective 2-month follow-up findings. Outcome criteria of success were 1). an absence of signs and symptoms characteristic of a diagnosis of ID type III and/or 2). a reduction in pain level of 85% or greater. A multiple logistic regression analysis was used to compute the odds ratio for TMJ pain chronicity (duration >6 months and <2 years) and OA for successful outcomes versus nonsuccessful outcomes.

RESULTS: The pretreatment data revealed no significant relationship between the clinical disorder "TMJ pain associated with ID type III" and the MR imaging finding of OA (P =.103). At 2-month follow-up, clinical evaluation showed a significant reduction in TMJ pain during function (P =.000), a significant reduction in clinical diagnoses of TMDs (P =.000), and a significant increase in mandibular range of motion (P =.000). Significant increase in risk of a nonsuccessful outcome (pain reduction <85%) occurred with TMJ pain chronicity (odds ratio of 41.0) (P =.018). Significant increase in benefit of a successful outcome (absence of ID type III) occurred with TMJ OA (odds ratio 1:16.7, P =.06) (P =.044).

CONCLUSIONS: Arthrocentesis in chronic TMJ pain patients was less successful than in nonchronic patients with regard to treatment outcome of pain reduction. Arthrocentesis in patients with TMJ OA was more beneficial with regard to the disappearance of ID type III than in non-OA patients. Predictive modeling may provide clinicians with the opportunity to identify "at-benefit" patients early and initiate specific treatments.