[Benign "mixed" odontogenic tumors]

Benign "mixed"odontogenic tumors consist of an epithelial and ectomesenchymal tumor component, distinguishing them from pure epithelial and pure ectomesenchymal odontogenic tumors. In addition, they may have the ability to produce dentin, enamel or cementum. Therefore, they can sometimes already be differentiated radiologically from epithelial odontogenic tumors. Some of the mixed odontogenic lesions are regarded as true tumors (ameloblastic fibroma, odontoameloblastoma, dentinogenic ghost cell tumor), while others are assumed to represent hamartomatous lesions (complex and compound odontoma, probably also ameloblastic fibrodentinoma and ameloblastic fibroodontoma). Preceded by keratocystic odontogenic tumor, complex and compound odontomas are the second most common odontogenic tumors, while other members of the "mixed" odontogenic tumor group are far less frequently diagnosed. Odontoameloblastoma and dentinogenic ghost cell tumors are locally aggressive lesions that require total resection. All other lesions of this group are treated by local excision. Since ameloblastic fibrosarcoma may evolve from ameloblastic fibroma, patients with ameloblastic fibroma should remain in long-term follow-up.