Clinical Case Description: A 52-year-old melanodermic female patient with no relevant medical history, referenced to an appointment of Surgery and Oral Medicine in FMDUL due to an exuberant bone swelling at the posterior region of the right maxilla. An hard palpation lesion of about 2.5 cm, painless, with slow growth and radiographic expression on retroalveolar radiography and orthopantomography was observed. Computed tomography (CT) scanning revealed a well-defined radiopaque mass with high density, involving teeth 17 and 18, suggestive of a calcifying epithelial odontogenic tumor (Pindborg's Tumor). A surgical procedure was performed for extracting the dental pieces and concomitant excisional biopsy of the lesion. Histhologic examination confirmed that it was an osteoma of the mixed subtype due to the identification of compact lamellar bone with areas of spongy bone. Discussion: Osteoma is a benign neoplasm, composed of mature bone, limited almost exclusively to craniofacial bones. It occurs predominantly between the third and fifth decades of life, with a male predilection. All osteomas, central or superficial, are more frequent in the mandible than in the maxilla, with the mandibular condyle being a common site. The differential diagnosis of these bone lesions should include exostoses, enostosis, osteoid osteoma, odontoma, osteoblastoma and cementoblastoma. Conclusion: Osteoma is an unusual entity in the jaw, so its approach can be a real challenge. The correct definitive diagnosis should be based on clinical and imaging examination, always requiring histopathological confirmation. Its treatment consists of surgical excision and the recurrence is rare, contributing to the good prognosis of this pathology. Schlagwörter: osteoma, tumor, maxilla, surgery, oral pathology