Cemento-ossifying fibroma is a true neoplasm that belongs to the group of benign fibro-osseous lesions. It is characterized by the replacement of bone tissue with fibrous connective tissue that undergoes mineralization, and its diagnosis can be challenging due to its similarity to other lesions. Its origin has been theorized to be odontogenic or from the periodontal ligament, as it can produce cementum-like material within the bone trabeculae. We present the case of an 8-year-old female patient diagnosed with a cemento-ossifying fibroma in the mandible, measuring 50 × 32 mm, who underwent lesion excision along with the dental organs, without recurrence during follow-up. This neoplasm is relatively rare in patients in the third and fourth decades of life and even less common in pediatric patients; therefore, its diagnosis must be carried out comprehensively.

The calcifying odontogenic cyst (COC) is rare and represents <1% of all odontogenic cysts, it belongs to the lesions known as “ghost cell tumors”, these are a family of lesions that vary in clinical presentation of cyst or solid neoplasia, in their behavior biological from benign to locally aggressive or metastatic, this diversity has generated extensive debate on the classification, terminology, management and prognosis of these pathologies. We present the clinical case of a 17-year-old male patient with a diagnosis of calcifying odontogenic cyst associated with a complex odontoma located in the posterior region of the maxilla, in the literature there are only 27 reported cases of (COC) in that area, he was treated by surgical enucleation, curettage, rotation of the buccal fat pad and placement of titanium mesh to reconstruct the anterior wall of the maxillary sinus. The clinical...