Odontogenic myxofibroma of the jawbone is a rarity in children, and there are few reports of cases with long-term follow-up, which mainly describe the growth process of odontogenic myxofibroma. We herein report a case of odontogenic myxofibroma that arose in the mandibular angle of a pediatric patient with a long-term follow-up of more than 14 years. The patient, when he was 10-years-old, first approached us with a complaint of painless swelling in the right mandibular angle that was palpable and showed bone-like hardness. Computed tomography revealed an ill-defined bone defect measuring 20 mm in diameter with bone protrusion in the margin. A biopsy was performed to differentiate the mass from osteosarcoma, giving a preliminary diagnosis of odontogenic myxofibroma or chondromyxofibroma. Therefore, tumorectomy was performed under general anesthesia. We curetted the bone surrounding the tumor and filled defect with iliac cancellous bone. The final diagnosis was odontogenic myxofibroma. At present, 14 years after the surgery, the patient had experienced an uneventful post-operative course without recurrence.

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