Osteosarcoma of the jaw bones. Analysis of 18 cases.

A series of 18 jaw osteosarcomas is reviewed. The ages of the 11 males and 7 females ranged from 11 to 65 years with a mean age of 37.4 years. The maxilla was involved in 10 cases whereas the mandible was the site of disease in 8 patients. A widened periodontal space was an invariably present radiological feature in those patients in whom the tumour involved the tooth-bearing area of the jaw. Treatment consisted of radical surgery with incidental radiotherapy or chemotherapy as adjuvant therapy. The local recurrence rate was 36% whereas the rate of metastasis was 40%. A five year survival time free of disease was shown by 47%. Prognosis was found to be adversely influenced by a high age and a high grade of histological malignancy as determined by counting mitoses. Features that distinguish jaw osteosarcoma from tumours elsewhere in the skeleton are a higher mean age of occurrence, a lower rate of metastasis, a longer period of time before clinical manifestation of metastasis and a more favourable prognosis. Factors that could be responsible for this variation in behaviour are discussed.