Idiopathic Bone Cavity: Clinicopathologic Features from a Case Series with Emphasis on Differential Diagnosis of Chronic Apical Periodontitis.

INTRODUCTION: Idiopathic bone cavity (IBC) is an uncommon bone lesion that usually affects youngsters as an unilocular radiolucency with predilection for the posterior mandible. Because the lesion is frequently located in proximity to the adjacent teeth, chronic apical periodontitis is commonly included as a differential diagnosis. The aim of the present study was to analyze the clinical and radiologic features of a series of IBCs diagnosed in a single service. METHODS: All cases diagnosed as IBC were retrieved from the files of an oral pathology laboratory, and the clinical and radiologic characteristics were described with a focus on the differential diagnosis with chronic apical periodontitis. RESULTS: Thirty cases composed the final sample. The mean age of the affected patients was 22 years old; there was no sex predilection, and most lesions were located on the posterior (47%) and anterior (43%) mandible. Most lesions presented as unilocular radiolucencies (87%), and 90% were located in close association with the adjacent teeth. The associated teeth presented no endodontic involvement, and all proved to be vital. CONCLUSIONS: IBC usually affects young patients as an unilocular radiolucency in close association with the adjacent teeth. Careful radiologic analysis and vitality tests of the adjacent teeth are essential to rule out chronic apical periodontitis, thus avoiding any unnecessary endodontic treatment.