Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 5 4 2019 06 10 180 183 Mohammad Bayat Professor, Department of Oral and Maxillofacial Surgery, Craniomaxillofcial Research Center, Tehran University of Medical Sciences, Tehran, Iran. Samira Derakhshan Assistant Professor, Department of Oral and Maxillofacial Pathology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Fatemeh Hamid Zadeh Dental Student, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. 2019 01 13 2019 03 04 One specific type of keratinized odontogenic cysts is orthokeratinized odontogenic cyst which is different from odontogenic keratocyst in clinical and pathological features completely. Also orthokeratinized odontogenic cyst can mimic typical characteristic clinicopathologic features of some other developmental odontogenic lesions such as dentigerous cyst and the odontogenic keratocyst, there is no previous report based on transforming of dentigerous cyst to orthokeratinized odontogenic cyst. We described a case of orthokeratinized odontogenic cyst originated from a dentigerous cyst in a 30-year-old female discovering accidentally in routine radiography. https://jcr.tums.ac.ir/index.php/jcr/article/view/273 https://jcr.tums.ac.ir/index.php/jcr/article/download/273/255