A 45-year-old male presented for a routine dental checkup. All teeth in the lower right quadrant were vital. A panoramic radiograph was taken as shown below. Which of the following can be the most probable diagnosis?

A Stafne bone cyst (Stafne defect, static bone defect) is not a true cyst. It represents a developmental defect in which the submandibular gland causes a depression on the lingual aspect of the mandible. This depression either contains a portion of submandibular salivary gland tissue or fibrous tissue and muscle. These lesions classically present as an asymptomatic radiolucency near the angle of the mandible and below the level of the mandibular canal. Literature states that 80% to 90% of Stafne lesions occur in male patients and, once recognized, require no treatment. Dentigerous cysts, by definition, are associated with the crown of an impacted tooth. There is no tooth associated with this radiolucency. Although certain malignant lesions do metastasize to the jawbones, their radiographic appearance tends to be ill-defined, indicating a destructive process. This lesion is well defined with a sclerotic border around it. In this particular case, a metastatic lesion should be considered low on the differential. Calcifying odontogenic cyst is an uncommon lesion. They can occur in both the maxilla and mandible and approximately 65% of them are found in the incisor and canine region. Lesions can be unilocular and well defined, and often exhibit calcifications within the lesion. Although this lesion could, theoretically, represent a calcifying odontogenic cyst (COC), there are other lesions that this is more likely to be. Periapical or radicular cysts are associated with the apex of a nonvital tooth. Besides the fact that these teeth were stated to be vital, this lesion does not appear to be associated with the apex of a tooth in any way.   ORAL RADIOLOGY PRINCIPLES AND INTERPRETATION,7th EDITION, Stuart C. White,Michael J. Pharoah; Page no 323