How uncommon is the occurrence of orthokeratinized odontogenic cyst in the maxilla? A systematic review and a new case report.

Background: The orthokeratinized odontogenic cyst (OOC) is a benign intraosseous lesion, typically found in the posterior mandible in male patients in the third and fourth decades of life. Although there has been a growing number of documented cases in the last decade, the prevalence and unique characteristics of maxillary OOC remain poorly understood. Material and Methods: To assess how uncommon is OOC occurrence in the maxilla, a systematic review of the literature was conducted using the major electronic databases and rigorous criteria, including a new case report involving a young male patient. Results: A total of 36 OOC located specifically in the maxilla was analyzed. The results demonstrated that OOC in the maxilla is a rare finding. Interestingly, the majority of instances are associated with an impacted tooth, mainly unerupted third molars and canines, a pattern previously unexplored in the literature. An isolated occurrence of an OOC in the posterior maxilla without involvement of a third molar tooth, as observed in this present case, is relatively uncommon and has been reported in only five other cases. Careful enucleation and curettage with removal of the impacted teeth, when present, followed by histopathological analysis, has proven to be the most effective approach for accurate diagnosis and clinical success. Conclusions: This study reinforces that orthokeratinized odontogenic cysts should be included in the differential diagnosis of intraosseous lesions in the maxilla, especially when associated with unerupted third molars and canines, which may clinically resemble dentigerous cysts.