Simple bone cyst of the mandible

Simple bone cysts (SBCs) are nonneoplastic intraosseous cavities without an epithelial lining, surrounded by bony walls and either empty or containing liquid and/or connective tissue: they were first described in 1929 as a distinct entity of disease. The characteristic that distinguishes SBCs from true cysts is the absence of epithelial lining, that allow us to regard SBCs as pseudocysts.

In the literature, SBCs have been referred to as solitary bone cysts, idiopathic bone cysts, unicameral cysts, traumatic bone cysts, hemorrhagic bone cysts, primary bone cysts, and extravasation cysts.

The pathogenesis of SBC remains uncertains. Radiographically, SBCs usually present as isolated unilocular radiolucencies with well-defined borders. When SBC extends to the interdental bone, the characteristic radiographic “scalloping effect” can be observed. The differential diagnosis includes apical periodontitis, odontogenic keratocyst, central giant cell granuloma, ameloblastoma, odontogenic myxoma, and central and neurogenic neoplasms.

Surgery (curettage) is the gold standard treatment as it allows both diagnosis and treatment by generation of a blood clot in the vacant cavity of SBCs: bone usually regenerates progressively within 6–12 months. Recurrence rate is almost negligible.

The aim of the present article is to present and discuss the diagnosis and management of a case of SBC.