A Case of an Ossifying Fibroma of the Mandible Suspected as a Static Bone Cavity.

Ossifying fibroma (OF) is a benign fibro-osseous lesion characterized by the proliferation of fibrous connective tissue containing immature bone and/or cementum-like hard tissue. Although the pathogenesis of OF remains unclear, trauma, previous extractions, and periodontitis are considered potential trigger factors. OF is more common in women aged from the second to fourth decades. Clinically, OF is characterized by slow-growing and asymptomatic swelling, often observed incidentally on radiological examinations. OF occurs more frequently in the mandible, particularly above the mandibular canal. Herein, we present a rare case of OF in an 18-year-old man initially misdiagnosed as a static bone cavity. The lesion was first observed as a radiolucent finding below the left mandibular canal on a panoramic radiograph. Later, cone-beam computed tomography (CBCT) imaging revealed the presence of calcifications within the lesion. Additionally, CBCT confirmed the presence of the lesion within the lingual cortical bone, revealing lingual swelling and thinning of the outer cortex. Enucleation was successfully performed under general anesthesia without any postoperative complications. Histopathological examination confirmed the diagnosis of OF, revealing mineralized tissue and proliferating fibrous connective tissue. This case underscores the challenges in diagnosing OF, particularly when it is located below the mandibular canal, emphasizing the importance of thorough imaging and differential diagnosis to avoid misinterpretation as a static bone cavity.