Cherubism

Cherubism was originally described as familial multi-locular cystic disease of the jaws in 1933. When it became apparent that the jaw lesions were not cysts, it was retermed as familial FD of the jaws, which was subsequently abandoned when it was observed that it differed histologically from FD of bone. The swollen jaws so characteristic of this disease resemble full-faced cherubs in Renaissance art, thus "cherubism." Most cases of cherubism are inherited as an autosomal dominant trait. Symptoms may appear as early as three years. Painless swelling of one or both jaws is common and failure of teeth to erupt on time or to erupt ectopically may call attention to the disorder. Expression is variable in that some children have minimal swelling, and others may experience massive enlargement. Penetrance of the gene is approximately 70% in females. Clinically normal mothers may pass cherubism to their children, and new mutations account for sporadic cases. The gene for cherubism has been mapped to chromosome 4p16.3; the candidate gene codes for a fibroblastic growth factor receptor. Mutations in this gene have been implicated in a variety of other skeletal disorders including achondroplasia, thanatophoric dysplasia type I, and Crouzon syndrome. Patients exhibiting both cherubism and the Noonan phenotype have been described. The radiographic features of cherubism are characteristic and easily recognized on panoramic films. In the early stage, bilateral multi-locular radiolucent lesions appear in the angles of the mandible and the ascending rami.

Lesions in the maxilla are more difficult to see because of the presence of the nasal cavities and the maxillary sinuses. More sophisticated imaging such as computed tomography may be required. As the condition progresses, the jaws enlarge painlessly and the radiolucent lesions advance and occupy virtually the entire volume of the jaws. Maxillary lesions impinge on the orbit and press the globe upward producing the heavenly gaze. Most patients have jaw lesions only, but occasionally a solitary extragnathic lesion may be found. The histopathologic features of cherubism resemble those of giant cell granuloma. Multi-nucleated giant cells lie in a stroma of mononuclear fibroblasts. The giant cells are osteoclasts which synthesize tartrate-resistant acid phosphatase, express the receptor for vitronectin, and are capable of resorbing bone, a property that is inhibited by calcitonin. The treatment of cherub-ism is determined by the severity of the disease. The established fact that this disease tends to slow with age and may completely regress in the early adult years is the rationale for treatment that does not exceed that which functional and esthetic considerations require. When treatment is required, the only option is surgical reduction by curettage and recontouring.

0 0

Post a comment