Condylar injury: magnetic resonance imaging findings of temporomandibular joint soft-tissue changes.

Recent studies have suggested magnetic resonance imaging (MRI) as useful in the evaluation of soft-tissue changes that occur in the temporomandibular joint (TMJ) after acute condylar trauma. The aim of this study was to investigate whether MRI findings of disc displacement, capsular tear and haemarthrosis are linked to the degree of condylar injury. Nineteen patients were assigned a diagnosis of uni- or bilateral condylar fracture (n=17), or condylar contusion with a uni- or bilateral diagnosis of TMJ sprain/strain (n=2). Condylar injuries were classified as grade I (absence of condylar fracture), grade II (type I, II or III condylar fracture), and grade III (type IV, V or VI condylar fracture). Bilateral sagittal and coronal MR images were obtained immediately after injury to establish the presence or absence of disc displacement, haemarthrosis and capsular tear. The data revealed a significant relationship between the degree of condylar injury and the MRI findings of capsular tear (P=0.000) and haemarthrosis (P=0.000), and between the MRI diagnoses of capsular tear and haemarthrosis (P=0.000). There was good diagnostic agreement between the presence of grade III condylar injury and the MRI diagnoses of capsular tear (K=0.62) and haemarthrosis (K=0.60). The results suggest that degree of condylar injury is related to MRI findings of capsular tear and haemarthrosis, and that MRI to supplement diagnosis of grade III condylar injury is warranted.