A case of simple bone cyst in the mandible with remarkable tooth resorption

This case report presents an unusual case of a simple mandibular bone cyst with remarkable tooth resorption. A 52-year-old woman was referred to our clinic for examination of a radiolucent lesion located in the right third mandibular molar region. The lesion could not be identified on panoramic radiograph at 6 years ago. Imaging examinations demonstrated a relatively well demarcated radiolucent lesion in the right mandible with marked resorption of the third molar. Based on the tentative diagnosis of an intraosseous benign tumor, biopsy was performed. The lesion was a simple bone cavity containing sanguineous fluid with no evidences of a cystwall lining or tumoral tissue. Intraoperative diagnosis was a simple bone cyst, and the lesion including the remained third molar was carefully removed. Histopathologically, thin fibrous connective tissue without epithelial cover was observed on the surface of the bony wall. The histopathologic findings were consistent with those of a simple bone cyst. However, myxofibromatous connective tissue and woven bone were observed only on the surface of the resorbed dental hard tissue. This case may be associated with the fibro-osseous lesion to some degree. One year later, complete healing was observed.