Arthrocentesis and hydraulic distention of the temporomandibular joint (TMJ) has proven to be an effective modality in treating patients exhibiting clinical findings consistent with the diagnosis of disc displacement without reduction. The purpose of this study was to investigate whether the magnetic resonance imaging (MRI) variables of effusion and/or bone marrow edema may predict treatment outcomes of arthrocentesis and hydraulic distention of the TMJ.
The study group comprised 37 consecutive patients with TMJ pain, who were assigned a unilateral clinical TMJ disorder of TMJ pain associated with an internal derangement (ID) type III (disc displacement without reduction) and a TMJ pain side-related MRI diagnosis of disc displacement without reduction associated with osteoarthrosis (OA). Bilateral sagittal and coronal MRI images were obtained immediately before the operation to establish the presence or absence of ID, OA, TMJ effusion, and bone marrow edema. Pain level and mandibular range of motion (ROM) were assessed preoperatively and compared with the respective 2-month follow-up findings. Outcome criteria for success were a ROM >or=35 mm and pain reduction >50%. A logistic regression analysis was used to compute the odds ratio for TMJ effusion and bone marrow edema for successful outcomes (n = 21) versus unsuccessful (n = 16) outcomes.
At the 2-month follow-up, clinical evaluation showed a significant reduction in TMJ pain during function (P = .000), a significant reduction in clinical diagnoses of TMJ disorders (P = .016), and a significant increase in ROM (P = .000). A significant increase in the risk of an unsuccessful outcome of ROM <35 mm and/or pain reduction >or=50% occurred with MRI findings of effusion (odds ratio 1:10.8 = 0.09; P = .007).
TMJ effusion may prove to be an important prognostic determinant of successful arthrocentesis. However, the data re-emphasize the concept that the prediction of a specific outcome is not a matter of simple linearity, in which the presence of 1 factor may equate with predictive ability, but rather is a function of a complex interaction among different biological variables.