Fig. 1

Imaging, gross appearance, and histopathological findings of primary lesion. (a) Panoramic radiograph and (b) coronal cone-beam computed tomography image show a radiopaque mass with a uniform radiolucent rim, including the root of a third molar in the right mandible. Expansion and perforation of cortical bone were observed. (c) The gross appearance of the primary lesion is divided into halves. The mass was fused to the tooth root. (d) Although the staining property was not good due to over-decalcification, cementoblast-like plump cells around the rim of radiated hard tissue are observed (Hematoxylin and eosin staining, 40×) scale bar: 50 μm