RESUMEN
BACKGROUND: Ossifying fibroma (OF) is a fibro-osseous lesion of the jaws and craniofacial bones. Accurate diagnosis can be challenging due to significant overlap of clinicopathological features. This study aimed to evaluate the clinical, radiological and histological features that can aid in diagnosis and identify characteristics that allow categorisation into the three subtypes: juvenile trabecular, psammomatoid and cemento-ossifying OF. METHODS: A total of 74 cases of OF were systematically reviewed for their principle features. Of these, 46 cases were evaluated for their radiographic features including size, location and relationship to the teeth. Histological assessment and stereological point counting were performed in 69 cases to assess the pattern, type and proportion of calcification, the nature of the stroma, the border of the lesion and the presence of secondary changes. Fisher's exact test and Chi-squared tests were used to determine associations between clinicopathological parameters and maxillary, mandibular, odontogenic, non-odontogenic and psammomatoid or trabecular lesions. RESULTS: OF showed a female predilection (F: M; 2:1) and a slight bimodal age distribution with peaks in the second (23%) and fourth decades (27%) (Mean age: 32.4 years). 83% of cases presented as an intra-oral swelling, with the mandible being the most common site (73%). Histologically, a range of morphological patterns were seen, with 50% of cases showing mixed trabecular and psammomatoid features. However, there were no significant differences between the variants of OF in terms of age, gender or histological features. CONCLUSION: Histological features of OF cannot be used to differentiate between the subtypes.
