Ameloblastoma arises from the enamel-forming cells of the odontogenic epithelium that have failed to regress during embryonic development. The tumor most commonly occurs in the posterior mandible, typically in the third molar region, with associated follicular cysts or impacted teeth. The slow growth of the tumor can lead to significant expansion of the mandible. Patients typically present in the third to fifth decades of life with a slow-growing, painless mass. The expansile, radiolucent tumor can be unilocular or multilocular, with a characteristic "soap bubble–like" appearance. CT findings include cystic areas of low attenuation with scattered isoattenuating regions, representative of soft-tissue components. The lesion can also erode through the cortex with extension into the surrounding oral mucosa. In addition, erosion of the roots of adjacent teeth is unique to ameloblastoma and indicates the aggressive behavior of the tumor. However, only histopathologic findings can help determine benignity and the absence of carcinomatous change.