Distinguishing features of focal cemento-osseous dysplasia and cemento-ossifying fibromas. II. A clinical and radiologic spectrum of 316 cases.

The distinguishing histopathologic features of focal cemento-osseous dysplasia (FCOD) (including lesions occurring in both anterior and posterior 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 radiographic features. We have assessed 18 clinical and radiographic parameters by univariate comparisons (chi-squared and Student t tests), and a multivariate 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 predominantly in black women, with a peak incidence in the fourth and fifth decades, whereas COF showed no female predilection except in the fourth decade (p < 0.005). COF occurred in patients an average of 10 years younger than patients with FCOD (p < 0.0001). Most patients with FCOD were asymptomatic (62%); the average lesion size was 1.8 cm. More than half of patients with COF displayed jaw expansion and a considerably larger size lesion (mean 3.8 cm, p < 0.001). The mandible was the most frequent site for both FCOD (86%) and COF (70%). Radiographically, a well-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 mixed radio-opacity (69%), whereas 53% of COFs presented as a radiolucency (p < 0.005). In FCOD, there was a close association with tooth apices (70.6%, p < 0.0001) or with previous extraction sites (21%, p < 0.05); however, the majority of COF cases (86%) showed no relationship with either. Combining the radiographic feature of a periapical location with the pathology of multiple curetted fragments and "ginger root" bony trabeculae, allowed 90% sensitivity and 89% specificity in a logistic regression model to predict the lesion to be an FCOD. These findings provide guidelines not only to distinguish these two entities clinically, but also aid in reaching an accurate diagnosis histopathologically.