Introduction: Osteosarcoma (OS) is primary malignant bone tumor in which mesenchymal cell produce osteoid. OS of jawbones is uncommon. representing 4-8% of all OS. Case Report: This paper reports the case of a- 29 year-old female with an OS in mandibular first molar as exophitic lesion with smooth surface during 1 year. https://www.roneverhart.com/Paistinpannu-rst-kupari-o-28-cm-3-L/