Magnetic resonance imaging findings of temporomandibular joint soft tissue changes in type V and VI condylar injuries.

PURPOSE: The objective of this study was to describe the incidence of acute temporomandibular joint (TMJ) soft tissue lesions associated with the occurrence of type V (high condylar fractures with dislocation) and type VI condylar fractures (condylar head fractures).

PATIENTS AND METHODS: The study comprised 11 consecutive patients, who were assigned a diagnosis of a uni- or bilateral type V or type VI condylar fracture. Bilateral sagittal and coronal magnetic resonance (MR) images were obtained immediately after injury to establish the presence or absence of disc disruption, capsular tear, retrodiskal tissue tear, and hemarthrosis.

RESULTS: There was 1 condylar fracture site showing signs of disc disruption (16.7%). Tears in the capsule and retrodiscal tissue were found with an incidence of 77% and 71%, respectively, while the incidence of hemarthrosis accounted for 100%. MR imaging failed to show any signs of soft tissue lesions for condylar nonfracture sites.

CONCLUSIONS: Type V and type VI condylar fracture sites are associated with a high incidence of injuries to the joint capsule and retrodiscal tissue. Investigation of longitudinal evidence, including risk factors, natural history, and response to treatment appears warranted and necessary.