Bilateral mandibular odontogenic fibroma (WHO type): Report of a case with 5-year radiographic follow-up

Abstract

Odontogenic fibromas are a rare benign odontogenic neoplasia, characterized by the presence of odontogenic epithelium with an inactive appearance in a cellular fibrous stroma. Histopathologically there are two types of odontogenic fibromas: an epithelium-poor type (simple type) and an epithelium-rich type (WHO or complex type). Depending on its primary location, two variables can be distinguished, one central or intraosseous and one peripheral or extraosseous. Several cases were published in the literature, but always as unique lesions, and when seen in a multiple manner, they were described as hamartomas associated with enamel dysplasia and other dental malformations. The following report describes a case of bilateral WHO-type central odontogenic fibromas in the premolar area of the mandible in a 13-year-old boy, with 5-year radiographic follow-up. The patient showed no clinical evidence of the lesions, just inclusion of the premolars, so the lesions were a radiographic finding. The teeth were extracted together with the lesions and they were sent for biopsy with a presumptive diagnoses of dentigerous cysts. Both samples were examined using routine techniques (hematoxylin and eosin with light microscopy), and a diagnosis of an odontogenic fibroma was made. The samples were stained with picro-sirius red and were examined under polarized light, which confirmed the diagnosis. We present the complete case with 5-year complete radiographic follow-up with the corresponding histopathological and histochemical characteristics.