Large erupted complex odontoma with dentigerous cyst

Odontomas, the most common benign odontogenic tumors, are usually asymptomatic. Eruption of these lesions in the oral cavity can rarely be occurred, and accompanied by a wide range of clinical signs and symptoms. Among the developmental odontogenic cysts, the dentigerous cyst is the most common type. However, a dentigerous cyst associated with an erupted odontoma is an extremely rare finding. A case of a large erupted complex odontoma is presented in a 23-year-old man. Intraoral examination revealed an irregular, solid yellowish tumor-like mass measuring about 2 cm with calcified surface. Radiographic examination showed a dense well-defined radiopaque lesion located distal of the mandibular left second molar and above the crown of the impacted third molar. The mandibular molars and the attached hard and soft tissues were surgically removed. The histopathological diagnosis of complex odontoma combined with the eruption of the lesion in the oral cavity set the diagnosis of erupted complex odontoma. Histopathological examination revealed that the attached soft tissue associated with odontoma was an inflamed dentigerous cyst. In conclusion, the exposure within the oral microflora of a large in size erupted odontoma may contribute as predisposing factor for a local inflammation that needs surgical intervention.