Orthokeratinised odontogenic cyst: A case series

Orthokeratinised odontogenic cyst (OOC) is a distinct and an uncommon odontogenic cyst of jaw. It was previously considered as orthokeratinized variant of Odontogenic Keratocyst, owing to its same site, age and occurrence and origin. In 2017 WHO classified OOC under odontogenic cysts as a distinct entity, clearly separating it from Odontogenic Keratocyst (OKC). In cases of malignant transformation, the cyst shows unclear boundaries. The cases that reported to the department during the period 2019-2021 were retrieved and then reviewed by the authors. A total of 7 cases that met the histopathological criteria for OOC were included in the study. There was a clear male predilection. Age of patients ranged between 17 to 65 years. Most of cases showed Unilocular radiolucency but one case revealed Multilocular pattern. Grossly specimens ranged between 0.5 cm to 3.0cms. Histopathological findings showed all classic features of OOC. FNAC was also done and it is clearly evident that the use of Cytology can help us diagnose the cyst early and is a less invasive method. OOC is a rare type of odontogenic cyst, but while making the diagnosis one should not forget about the fact that it is less aggressive and needs to be differentiated from OKC. Majority times it has been seen that Clinico-radiographic diagnosis given of any circumscribed radiolucency around an impacted tooth is Dentigerous cyst, which is not correct. Diagnosing such lesions require thorough histopathological and radiographical correlation along with molecular analysis to reach final diagnosis.