Osteosarcoma is a primary malignant tumor of bone which can involve JAWS. Ibis article reviews osteosarcoma of the JAWS referred to the Department of oral pathology, dental faculty of Tehran University of Medical Sciences and Pathology Department of Cancer Institute in Imam Khomeini Hospital during 30 years from 1349 to 1378 and also reviews jaw Osteosarcoma in English literature. The purpose of this review is comparing the clinical behaviour of jaw tumors with Osteosarcoma from elsewhere in the body and reporting the observations of clinical, histological and diagnostic findings. For this retrospective review the clinical, radiographic and histopathologic records of 42 patients were obtained, furthermore follow up results were also obtained from patients records. The mean age of patients was 35 years (range 9 to 61 years) with slight male predilection. The most common presenting features were swelling, pain and ulcer. Histologically, the lesions ranged from well differentiated tumors with prominent osteoid formation to poorly differentiated tumors which had bizarre cells and numerous mitosis especially atypical ones. Most of the lesions had areas of chondroid formation, but all of tumors showed neoplastic osteoid, of course in different degrees. The most important problem after treatment was local recurrence. Primary osteosarcomas of the JAWS are a group of lesions which are biologically distinct from long bones osteosarcoma and have better behaviour than them. More accurate determination of their clinical behaviour and their management will depend on complete follow up of patients and actual records of patients data.

Background: Bisphosphonates‎ inhibit osteoclasts, prevent bone resorption and decrease bone turnover. This study examined radiography finding in bisphosphonate-associated osteonecrosis of JAWS. Materials and Methods: This is a retrospective series of 12 clinically diagnosed patients between 7 to 21 year old (average 13 years). They required emergency dental conditions requiring management by dentist: non healing ‎extraction sockets and pain of bone exposure. The panoramic radiography and cone beam computed tomography was performed ‎to assess the problem.Thickening of the lamina dura was observed in 7 patients (58.3%). But full-thickness sclerosis was seen in 6 patients (50%). Sclerotic changes in the mandibular canal were noted in 3 patients (25%). 5 patients (41.6%) had poorly healing or non-healing of socket in extracted tooth and periapical lucencies.4 people (33.3%) had widening of periodontal ligament (PDL) space and osteolysis. Sequestra were seen in 3 persons (25%). Finally in 2 children (16.6%) were found oroantral fistula. Only one child (8.3 %) had thickening of soft tissue mid periosteal reaction.Results: Most patients had some degree of osteosclerosis, especially in the area of alveolar bone. Thickening of the lamina dura was also seen in children. Other findings include: osteolysis, sequestra, periosteal new bone formation, widening of PDL, soft tissue thickening, non healing extraction sockets, oroantral fistula and periapical lucencies (P-value<0.05).Conclusion: Common radiographic features in patients taking bisphosphonate, was osteosclerosis. This sclerosis had different views that thickening of the lamina dura and alveolar crest were most common.