Therefore, these pathologies are often initially overlooked, as patients are treated conventionally for TMD.[2,4] OC of TMJ is not a common lesion. The etiology is uncertain. Trauma and inflammation are thought to be the selleck chemicals contributory factors.[1] There are controversies whether such lesions should be considered of developmental, neoplastic or reparative nature.[1,2,3,4,5] Porter and Simpson suggested that a genetic component might also be involved in the neoplastic pathogenesis due to somatic mutations found in chromosomes 8 and 11. Differently from long bones, the craniofacial OCs occur at older age and most frequently affecting women.[1,4] The symptoms vary depending on the location of the tumor. The condylar OCs are frequently situated on the antero-medial surface of the condylar head.

The TMJ osteochondroma causes a progressive enlargement of the condyle, usually resulting in facial asymmetry, prognathic deviation of chin, TMJ dysfunction, limited mouth opening, cross bite to the contra lateral side and malocclusion with open-bite on the affected side. Pain is rarely associated with this tumour.[1,2,6] The present case was also associated with similar features and was situated at antero-medial surface of the condyle. The growth of an OC is usually slow, causing gradual displacement and elongation of the mandible.[1,2,7] The careful assessment of the patient’s history provides valuable information for the diagnosis and treatment of neoplasm of TMJ. The purpose for imaging of TMJ is to graphically depict clinically suspected disorders of the joint.

The diagnosis of OC in the present case was based on clinical and radiographic findings. Imaging techniques are the valuable aid for accurately diagnosing and determining treatment for variety of diseases, and are supportive to clinical examination. Computed tomography (CT) helps in evaluating complex cases in the maxillofacial field and provides information that leads to more accurate and specific diagnosis of TMJ pathologies. CT scans can easily demonstrate the continuity of cortex and medulla of the bone tumor and is considered the best tool to demonstrate calcified cartilage.[1,6] Radiographically, OC manifests as a radiopaque lesion with distinct borders and is easily identified on panoramic radiograph and CT imaging.

[2,3] In the present case, the radiopaque-radiolucent appearance of the lesion may be based on the amount of marrow tissues and proportion of calcification of the tumour. CT was useful in determining the margins of the OC. Scintigraphy may also be used to detect the presence of intense uptake in the lesion.[1,4] Histologically, the diagnosis of an OC includes chondrocytes of the cartilaginous cap arranged in clusters parallel to lacunar spaces. Most of the lesions show growing Brefeldin_A bone surrounded by cartilages.[1,2,4] Differential diagnosis of TMJ lesions is not always easy.