FIG 2. Case 2.

A, Lateral plain radiograph of the mandible shows a large well-defined expansile radiolucency containing several small peripheral radiopacities. Focal resorption of the first molar with inferior displacement of the unerupted second molar is seen. Note the upper displacement of the germ of the third molar.

B, Axial CT view of the mandible shows a well-delineated expansile lesion with a large, smooth expansion of the thinned cortical plates. Small peripheral calcifications are seen.

C and D, MR images. Axial noncontrast spin-echo T1-weighted image (420/11/2) (C) shows a homogeneous, slightly hyperintense lesion. Axial fast spin-echo T2-weighted image (4000/104/1) (D) shows a markedly hyperintense lesion.

E, Photomicrograph shows the characteristic patterns of a COC close to a small odontoma (hematoxylin-eosin, original magnification x200). Epithelial cyst lining (thin arrows) is seen with focal areas of necrosis (asterisks). Dentinoid component of the odontoma (thick arrow) is associated