An unusal presentation of bilateral orthokeratinised odontogenic cysts of the mandible

Objectives The orthokeratinised odontogenic cyst (OOC) is a relatively new histological entity, only gaining universal recognition as recently as 2017. As a result, the OOC is not routinely considered in the differential diagnosis of unilocular or multilocular radiolucencies of the jaws, and is likely a diagnosis with which many clinicians are relatively unfamiliar. Methods Ours represents only the second reported case of OOC presenting with a neck space infection, and only the fifth report of multiple OOCs in a single patient. Results A 29-year-old male admitted via the Emergency Department with sudden onset right submandibular and parapharyngeal space infection, underwent urgent drainage of the submandibular abscess, along with enucleation of the associated cyst in the right body of mandible and removal of the involved impacted lower right wisdom tooth, under general anaesthetic. This procedure followed an urgent anaesthetic review in light of parapharyngeal space involvement. An incidental finding of a similar lesion in the left body of mandible required a second elective procedure a short time later to enucleate this cyst and remove the involved molar teeth. The histopathology from both specimens revealed a diagnosis of orthokeratinised odontogenic cyst. The patient made a satisfactory recovery, with no clinical or radiographic signs of recurrence at one-year follow-up. Conclusions This case highlights the importance of multidisciplinary management of the acutely unwell patient. It also demonstrates the need for regular monitoring of impacted and unerupted teeth, with both cysts in this instance associated with impacted wisdom teeth. The OOC’s frequent association with unerupted teeth, and predilection for the site of the posterior mandible, often lead to it being mistaken for dentigerous and odontogenic keratocysts, respectively. As a relatively new entity, the orthokeratinised odontogenic cyst is a diagnosis with which clinicians should be familiar to ensure optimum patient outcomes. Early detection could have prevented this patient’s hospitalisation.