Magnetic resonance imaging evaluation of temporomandibular joint and associated soft tissue changes following acute condylar injury.

PURPOSE: This study evaluated the role of magnetic resonance imaging (MRI) in cases of acute condylar injury and assessed soft tissue damage such as disc displacement, capsular tear, and hemarthrosis within the temporomandibular joint (TMJ).

PATIENTS AND METHODS: This prospective study was conducted in 15 patients who presented with unilateral or bilateral condylar fracture or contusion with a unilateral or bilateral diagnosis of TMJ sprain/strain. Patients with trauma of less than 7 days previously with a unilateral or bilateral condylar fracture or contusion with a diagnosis of TMJ sprain/strain were included in the present study. The clinical diagnosis of TMJ sprain was made and further classified and graded according to the severity and type of injury. On confirmation of the diagnosis of condylar injury, patients underwent evaluation by MRI. All patients were treated by closed reduction of the condylar fracture and intermaxillary fixation for 14 to 21 days.

RESULTS: Of the 15 patients, 5 were children and 10 were adults. Of all 17 TMJ cases (2 bilateral, 13 unilateral), 2 condylar fractures were of the high variety and 13 were of the low variety. MRI diagnosis of disc displacement was established in 8 of 17 TMJ cases. There was a significant association between degrees of condylar injury and the MRI diagnosis of displaced disc and hemarthrosis. However, an MRI finding of capsular tear was not significantly associated with the degree of condylar injury.

CONCLUSIONS: Soft tissue changes of the TMJ can be predicted accurately by MRI and are in direct proportion to the severity of the condylar injury of the mandible. Among the soft tissue changes, disc displacement and hemarthrosis seem to affect the outcome of functional treatment.