Ameloblastoma

Ameloblastoma is the most common benign epithelial odontogenic tumor, accounting for about 10–30% of odontogenic tumors. It is clinically classified as a “critical tumor” because of its biological characteristics of local invasion, high recurrence rate and distant metastasis [1–6]. Ameloblastoma occurs more frequently in young adults, with no significant gender difference. It is more common in the mandible than the maxilla, especially the mandibular body and mandibular angle. Among all jaw tumors, ameloblastoma has the most complex histopathological changes. The 2017 WHO classifies it into classic, unicystic, peripheral/extraosseous and metastatic ameloblastoma, with metastatic ameloblastoma as a benign tumor [1–4]. Ameloblastoma grows slowly with no obvious symptoms at the beginning but gradually expands and evolves into jaw swelling, resulting in deformity, occlusive disorder, lower lip numbness, pathological fracture and other symptoms. The typical X-ray findings show single-locular or multi-locular cystic low-density images of different sizes overlapping with clear boundaries or appearing as solid lesions [7, 8]. The lesions involving teeth may exhibit root resorption in the form of amputation. Due to the local invasive characteristics, the surgical treatment for other types of ameloblastoma, except for single cystic ameloblastoma, which can be attempted with fenestration or curettage, often requires resection of the tumor 0.5 cm outside the lesion [9, 10].