MR of osteochondritis dissecans and avascular necrosis of the mandibular condyle

Abstract
We studied 40 patients exhibiting radiologic changes of either osteochondritis dissecans (OCD) or avascular necrosis (AVN) involving the mandibular condyle to evaluate the structural changes associated with these lesions when using high-field-strength MR imaging. Various clinical indications for imaging each patient with routine radiography, tomography, and surface-coil MR included headache, temporomandibular joint (TMJ) and/or ilsilateral facial pain, joint crepitus, clicking, locking, and either recently acquired or changing (unstable) occlusal disorder. Radiologic findings included alterations in condyle morphology and MR signal characteristics compatible with either OCD or AVN or, in some cases, both. Previous nonsurgical mandibular trauma was temporally related to the onset of symptoms in eight patients. Five patients exhibiting either unilateral or bilateral AVN involving the condyles and condylar necks had undergone previous orthognathic surgery, including sagittal split mandibular osteotomies foll...