Peripheral ossifying fibroma: A clinicopathologic study of 27 cases and review of the literature with emphasis on histomorphologic features

The peripheral ossifying fibroma (POF) is a relatively uncommon, reactive gingival overgrowth usually composed of cellular fibroblastic tissue containing one or more mineralized tissues, namely bone, cementum-like material, or dystrophic calcification. The aetiology and pathogenesis of POF are yet not clear, but some authors have hypothesized a reaction originating from the periodontal ligament, as a result of irritating agents such as dental calculus, plaque, orthodontic appliances, and ill-fitting restorations. The aim of our study was to report the clinicopathologic features of a case series of POF from a single Italian institution. A total of 27 cases were collected over an 18-year period. Detailed relevant medical history, clinical and histological information were recorded for each patient. The age range of patients (m = 6; f = 21) was 17.2-80.1 years with a mean of 42.9 ± 18.1 years. Occurrence of the lesion in the mandibular and maxillary arches was similar, and 67.0% occurred in the incisor-cuspid region. The lesions ranged in size from 0.3 to 5.0 cm (mean, 1.3 cm ± 1.1 cm). All the different types of mineralization were present, with higher prevalence of lamellar bone. The lesions were treated by surgical excision and four lesions in three patients recurred after surgery. Surgeons should consider the high recurrence rate of POF and remove the lesion down to the bone involving also the adjacent periosteum and the periodontal ligament. Professional prophylaxis should precede any surgical procedure, and periodical dental hygiene recalls are important in order to remove any possible irritating factor.