Acute soft tissue injury to the temporomandibular joint and posttraumatic assessment after mandibular condyle fractures: a longitudinal prospective MRI study

OBJECTIVE: Evaluation of acute soft tissue injury of the temporomandibular joint (TMJ) with type I–VI fractures immediately after trauma and investigation of the longitudinal evolution including response to conservative treatment using MRI. METHODS: The joints of 24 patients with 33 condylar fractures (15 unilateral, nine bilateral) were imaged on a 1 Tesla MR system within the first 24 h post-trauma. 12 of these patients with 16 condylar fractures (eight unilateral, four bilateral) were clinically re-evaluated using MRI after 3 months of closed treatment. The position, morphology, and signal intensities of the disc, capsule, retrodiscal tissue, and osseous structures were documented. RESULTS: In the acute phase, disc displacements (DDs) were diagnosed in 8 out of 33 joints with fracture, including posterior DDs in two joints and tears of the inferior retrodiscal lamina in 11 joints. The follow-up MRI in 12 patients revealed new DD in four joints on the fractured side (FS) including a posterior DD and an increased degree of displacement, and new DDs in two joints in the non-fractured side (NFS). CONCLUSION: Preexisting and traumatic DD and soft tissue injuries are frequent findings in patients with condylar fracture. Independent of the degree of trauma, condylar fractures may determine the subsequent development of DD on both FS and NFS. Early MR imaging may help initiate well-directed specific measures for better outcomes in the acutely injured TMJ.