An odontogenic keratocyst is a rare and benign but locally aggressive developmental cyst. It most often affects the posterior mandible and most commonly presents in the third decade of life. Odontogenic keratocysts make up around 19% of jaw cysts.In the WHO/IARC classification of head and neck pathology, this clinical entity had been known for years as the odontogenic keratocyst; it was reclassified as keratocystic odontogenic tumour (KCOT) from 2005 to 2017. In 2017 it reverted to the earlier name, as the new WHO/IARC classification reclassified OKC back into the cystic category. Under The WHO/IARC classification, Odontogenic Keratocyst underwent the reclassification as it is no longer considered a neoplasm due to a lack of quality evidence regarding this hypothesis, especially with respect to clonality. Within the Head and Neck pathology community there is still controversy surrounding the reclassification, with some pathologists still considering Odontogenic Keratocyst as a neoplasm in line with the previous classification. Signs and symptoms
Odontogenic keratocysts can occur at any age, however they are more common in the third to sixth decades. The male to female ratio is approximately 2:1. The majority are found in the mandible, with half occurring at the angle of the mandible. Early odontogenic keratocysts usually do not display symptoms. Typically, clinical signs and symptoms present with bony expansion, or infection. However, bony expansion is uncommon as odontogenic keratocysts grow due to increased epithelial turnover rather than osmotic pressure. When symptoms are present they usually take the form of pain, swelling and discharge due to secondary infection.
Contributing causes include thin and fragile epithelium leading to incomplete removal, cyst extensions extending into cancellous bone, satellite cysts found in the wall, experience of the surgeon, formation of further new cysts from other remnants of the dental epithelium. With current treatment techniques the recurrence rate is around 2-3% but can be as high as 50%. Recurrence can occur as early as 5 years and as late as 40 years after removal. Recurrence is usually seen within 5 years of treatment. Early findings of recurrence can be easily treated with minor surgery and curretage. Any fragment of the cyst that is left behind has the potential to survive and grow. Therefore, the success of enucleation depends on how well the cyst is removed. Larger cysts have a higher rate of recurrence after enucleation as they are more difficult to remove. Pronto genie keratocysts are well known to recur in the posterior mandible. A substantial amount of odontogenic keratocysts also recur in the tooth-bearing area of the jaws, requiring attention from clinicians.The neoplastic nature of odontogenic keratocysts has been debated. Due to high recurrence rate, late detection when the cyst has grown very large and causation by tumour suppressor gene inactivation, some have classified OKCs as benign neoplasms. The best evidence to suggest that this type of cyst is not a neoplasm is that it responds very well to marsupialisation. See also
Cysts of the jaws

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