Chip fractures of the mandibular condyle.

Four patients suffered from trauma of the temporomandibular (TM) joints. They were examined by routine x-ray procedures. The x-ray films failed to demonstrate a chip fracture of the head of the mandibular condyle. A coronal computed tomographic (CT) view established the fracture shortly after the trauma in three patients. These patients improved clinically after physiotherapy. The fourth patient was retrospectively diagnosed as having a chip fracture of the mandibular head. She underwent CT scan 10 months posttrauma , and ankylosis of the TM joint was established. The mechanism and the clinical symptoms of this injury, which have not been previously described, are reported in this article.