Orthokeratinizing odontogenic cysts （OOC） are keratocystic lesions that often occur in the mandibular molars of males. The frequency of occurrence is rare, and it was clearly classified as an odontogenic keratocyst independent disease in the new classification of odontogenic cysts described under head and neck tumors by the WHO in 2017.
A woman in her thirties was referred to our department for the purpose of examining transparent lesions on a panoramic radiograph around the right maxillary third molar. A biopsy revealed a diagnosis of a right maxillary odontogenic cyst. The patient underwent right maxillary cystectomy under general anesthesia. A large amount of keratinized substance was found in the cyst. The cyst was completely removed and no perforation of the maxillary sinus was observed. The diagnosis was an OOC. No recurrence was observed five months after surgery.
