A rare case of bilateral odontoma in the retromolar region of the mandible

Among oral pathologic lesions, odontomas are one of the most common odontogenic tumor of the jaw. Odontomas are generally asymptomatic and most cases involve only one region of the maxilla or mandible. An 18-year-old man visited our department for examination and treatment of cystic lesions in the bilateral mandibular retromolar area. Surgery was performed with the patient under general anesthesia for a diagnosis of the lesions. The histopathological diagnosis was immature stages of odontomas, partially including a findings of benign mixed epithelial and mesenchymal odontogenic tumor. These findings suggested the possibility of ameloblastic fibro-odontoma, which was excluded from current WHO classification. It consists of proliferation of odontogenic epithelial and mesenchymal components combined with hard tissues such as dentin and enamel. Recently, the majority of such cases have been identified as immature odontoma. However, because of previous reports of cases of recurrence and malignant transformation, the possibility of a true tumor has not been completely ruled out. Herein, along with a literature review, we report the case of bilateral odontoma containing a findings of benign mixed epithelial and mesenchymal odontogenic tumor in the retromolar region of the mandible.