Discrimination of orthokeratinized odontogenic cysts from odontogenic keratocysts and unicystic ameloblastomas by clinical and cone-beam computed tomography features

Abstract Purpose The aim of the study was to compare the clinical and cone-beam computed tomography features of orthokeratinized odontogenic cysts (OOCs) and odontogenic keratocysts (OKCs), and to fully understand features of these two odontogenic cysts. Materials and Methods This retrospective cross-sectional study included patients with mandibular OOCs and OKCs. The predictor variables included age at the time of diagnosis, sex, anatomic location of the cysts, lesion size, cortical bone expansion rate, and presence of cortical bone destruction, impacted tooth, tooth displacement, and root resorption. The outcome variable was the type of cystic lesion. A one-way ANOVA test was used to analyze the differences among the cases of OOCs and OKCs. The specificity and sensitivity of the radiological features were calculated to differentiate OOC from OKC. Result The sample was composed of 12 patients with OOC and 36 patients with OKC. The mean ages of the patients with OOC (30.50 ± 6.14 years) and OKC (38.39 ± 19.44 years) were concentrated in the third decade. The cystic lesions occurring in areas Ⅱand Ⅲ accounted for 66.67 and 52.78% of the OOC and OKC cases, respectively. The cortical bone expansion rate of the OOC was larger than that of the unilocular OKC (OOC, 2.20 ± 1.05; OKC, 1.48 ± 0.50; P Conclusion The results of this study suggest clinical and radiological features of OOCs and OKCs mostly overlap, but OOC has distinctive characteristics. Most cystic lesions of OOC are unilocular cysts, rarely accompanied by tooth displacement. The cortical bone expansion rate is larger than that of unilocular cysts of OKC.