Peripheral Odontogenic Fibroma: Histologic Predictors of Recurrence

Objectives: Peripheral Odontogenic Fibroma (POdF) is a benign neoplasm of the gingiva containing odontogenic epithelium. Controversy exists regarding the histogenesis, clinicopathologic parameters and recurrence of this odontogenic lesion. This study examined the clinicopathologic features of 151 cases of POdF and investigated histopathologic features associated with recurrence of POdF. Methods: Histopathologic findings of 151 surgically excised cases of POdF at the department of Oral and Maxillofacial Pathology, LSUSD were recorded. A questionnaire was sent to the referring dentists to obtain follow-up information on each case. Association between recurrence and histologic features was statistically assessed by Fisher's exact test and multivariate stepwise logistic regression. Results: Follow-up information of over 3 months was available for 58 of the 151 cases. Of these 58 cases, 29 recurred, establishing a recurrence rate of 50%. A statistically significant relation was found between recurrence and (1) inductive effect, (2) rete ridge activity, with the Fisher's exact test. Budding of the basal cell layer of the surface squamous epithelium was associated with higher recurrence (p=0.0186). The presence of calcification in direct apposition to epithelial rests was associated with reduced recurrence (p=0.0076). In the multivariate stepwise logistic regression presence of calcification in apposition to epithelial rests was associated with reduced recurrence (p=0.0225). There was no statistically significant relation between recurrence and gender, race, age, site of lesion, quantity, size and nature of epithelial rests and nature of connective tissue. Conclusions: This study suggests POdF has a recurrence rate of 50%. Basal cell layer budding of the surface epithelium is associated with increased recurrence. Presence of calcification in apposition to the odontogenic epithelial rests is associated with decreased recurrence. The value of this study lies in the fact that this is the largest case series on POdF, and is the only study which investigates factors associates with recurrence.