A case of multiple cemento-osseous dysplasia associated with simple bone cysts resembling bone cavities

Cement-osseous dysplasia is a disease of localized fibrotic connective tissue proliferation accompanying cementum or bone-like hard tissue at the tooth apex, while simple bone cyst is a specific disease featuring a bone cavity without epithelial lining. Here, we report a case of cement-osseous dysplasia associated with multiple simple bone cysts resembling bone cavities. A 60-year-old woman was referred to our hospital due to a complaint of recurring pain and swelling at her right mandibular molars over several years. Her dentist had found abnormalities in X-ray imaging. X-ray images showed a crescent shaped radio-opacity at the apex of the mandibular right first and second premolars, and also radiolucent areas in the right second molar mandible body, and the mandibular left second premolar and maxillary left canine apexes. Enucleation of the cement-osseous dysplasia and cystectomy were planned under a clinical diagnosis of cement-osseous dysplasia and residual and radicular cysts. However, the cystic lesions were revealed to be hollow, with no lining epithelium and only slight granulation-like tissue on the bone wall, except for hard tissue at the right mandibular premolars. The histopathological diagnosis was cement-osseous dysplasia. There has been no recurrence in the seven years since surgery and the patient has been doing well.