MRI findings of soft tissue damages involving the temporomandibular joint after dislocated condylar fracture / 中华放射学杂志

ABSTRACT

Objective To document MRI findings of soft tissue damages involwing the temporomandibular joint (TMJ) after dislocated condylar fracture. Methods Seventy-seven subjects (103 TMJs), who suffered from the dislocated condylar fractures, underwent both sagittal and coronal MR imaging including proton density-weighted image ( PDWI ) and TzWI.Results On MR images, the TMJ structural changes after dislocated condylar fractures included ( 1 ) displacement of the dislocated fragment in the anterior-inferior direction ( 102 TMJs, 99.0% ) and in the anterior direction ( 1 TMJ, 1.0% ) ; (2)disc displacement (100 TMJs, 97.1% ) in the anterior-inferior direction (99 TMJs) and in the anterior direction (1 TMJ) along with the dislocated condylar fragments on sagittal MR images; (3) joint effusion (103 TMJs, 100%);(4) abnormal signal intensity in the retrodiskal tissues of the TMJ ( 91 TMJs ,88.3% ) ; (5) abnormal changes of inferior posterior attachments of disc ( 89 TMJs, 86.4% ) ; ( 6 )abnormal changes of joint capsule ( 89 TMJs, 86.4% ) ; ( 7 ) abnormal changes of superior posterior attachments of disc ( 37 TMJs, 35.9% ) ; ( 8 ) disc deformation ( 8 TMJs, 7.8% ) ; ( 9 ) disc avulsion (8 TMJs, 7.8% ) and ( 10 ) glenoid fossa fractures (4 TMJs, 3.9% ). Conclusion On sagittal MR images, the TMJ soft tissue changes after dislocated condylar fracture were mainly presented as the disc displacement in the same direction (anterior-inferior direction) as the dislocation of the fractured fragments,usually in association with joint effusion.