DISTINGUISHING FEATURES OF FOCAL CEMENTO-OSSEOUS DYSPLASIA AND CEMENTO-OSSIFYING FIBROMAS .1. A CLINICAL AND RADIOLOGIC SPECTRUM OF 316 CASES

The distinguishing histopathologic features of focal cemento-osseous d ysplasia (FCOD) (including lesions occurring in both anterior and post erior jaws) and cemento-ossifying fibroma (COF) (ossifying fibroma and cementifying fibroma) were demonstrated in our earlier work. The aim of the current study was to further refine their clinical and radiogra phic features. We have assessed 18 clinical and radiographic parameter s by univariate comparisons (chi-squared and Student t tests), and a m ultivariate assessment (logistic regression) in 241 cases of FCOD and 75 of COF. These cases were diagnosed from a combination of clinical, radiographic, and histopathologic information. FCOD was seen predomina ntly in black women, with a peak incidence in the fourth and fifth dec ades, whereas COF showed no female predilection except in the fourth d ecade (p < 0.005). COF occurred in patients an average of 10 years you nger than patients with FCOD (p < 0.0001). Most patients with FCOD wer e asymptomatic (62%); the average lesion size was 1.8 cm. More than ha lf of patients with COF displayed jaw expansion and a considerably lar ger size lesion (mean 3.8 cm, p < 0.001). The mandible was the most fr equent site for both FCOD (86%) and COF (70%). Radiographically, a wel l-defined border was observed in 53% of cases of FCOD and 85% of cases of COF (p < 0.01). Cases of FCOD mostly demonstrated an irregularly m ixed radio-opacity (69%), whereas 53% of COFs presented as a radioluce ncy (p < 0.005). In FCOD, there was a close association with tooth api ces (70.6%, p < 0.0001) or with previous extraction sites (21%, p < 0. 05); however, the majority of COF cases (86%) showed no relationship w ith either. Combining the radiographic feature of a periapical locatio n with the pathology of multiple curetted fragments and ''ginger root' ' bony trabeculae, allowed 90% sensitivity and 89% specificity in a lo gistic regression model to predict the lesion to be an FCOD. These fin dings provide guidelines not only to distinguish these two entities cl inically, but also to aid in reaching an accurate diagnosis histopatho logically.