MR Imaging Assessment of Temporomandibular Joint Soft Tissue Injuries in Dislocated and Nondislocated Mandibular Condylar Fractures

Patient with dislocated mandibular condyle fracture. Sagittal proton attenuation-weighted image (A) and T2-weighted image (B) demonstrate that the fractured condyle (c) is anteroinferiorly displaced. The TMJ disk (d) is located superior to the fractured fragment but is anteroinferiorly displaced relative to the remaining mandibular ramus. The tear of the inferoposterior attachment of the disk (black arrow on A) is shown. T2-weighted image (B) demonstrates the dotted high signal intensity of retrodiskal tissue (black arrow), joint effusion of the upper joint compartment (e), and well-defined superior posterior attachment (black arrowhead) of the disk. Coronal proton attenuation-weighted image (C) reveals the tear of the joint capsule (black arrows) and fractured fragment (c) located on the medial side of the mandibular ramus.

Patient with a dislocated mandibular condylar fracture. Sagittal proton attenuation-weighted image (A) and T2-weighted image (B) demonstrate that both the fractured condyle (c) and the TMJ disk (d) are displaced in the same direction (anterior and inferior direction). The joint effusion (e) with well-defined superior (black arrow) and inferior (black arrowhead) posterior attachments is identified in both the upper and lower compartments of the TMJ on T2-weighted image (B). Coronal proton attenuation-weighted image (C) shows the ill-defined joint capsule (black arrow) and fractured condyle (c) located in the medial side of the mandibular ramus.