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.