Signs and Symptoms
- Odontogenic keratocysts are more common in the third to sixth decades of life.
- The male to female ratio is approximately 2:1.
- Most commonly found in the mandible, with half occurring at the angle of the mandible.
- Early odontogenic keratocysts usually do not display symptoms.
- Symptoms may include pain, swelling, and discharge due to secondary infection.

Pathogenesis
- Odontogenic keratocysts originate from the odontogenic epithelium in the alveolus left from tooth development stages.
- They are mainly thought to arise from rests of Serres.

Genetics
- Sporadic and syndromic odontogenic keratocysts are associated with mutations in the PTCH gene on chromosome 9q.
- PTCH is a tumor suppressor gene.
- Loss of PTCH activity leads to a brake in the cell cycle.
- A third of odontogenic keratocysts show mutations in PTCH, resulting in highly proliferative activity.
- This leads to growth of the cyst wall and favors recurrence if the epithelium is incompletely removed.

Nevoid basal-cell carcinoma syndrome
- Multiple odontogenic keratocysts are a feature of nevoid basal cell carcinoma syndrome (NBCCS).
- NBCCS is also known as Gorlin-Goltz Syndrome.
- Almost all individuals with NBCCS have odontogenic keratocysts.
- Diagnosis of multiple odontogenic keratocysts in a child necessitates referral for genetic evaluation.
- Over 80% of NBCCS-related odontogenic keratocysts will have PTCH mutations.

Diagnosis, Treatment, and Follow-up
- Diagnosis of odontogenic keratocysts is usually radiological.
- Definitive diagnosis is through biopsy.
- Aspirational biopsy of odontogenic keratocysts contains a pale, greasy fluid with keratotic squames.
- Protein content of cyst fluid below 4g% is diagnostic of odontogenic keratocysts.
- Smaller and unilocular lesions resembling other types of cysts may require a biopsy to confirm the diagnosis.
- Treatment options include marsupialization, peripheral ostectomy, simple excision, enucleation and cryotherapy, and decompression followed by enucleation.
- Annual radiographic review is recommended for follow-up.
- Long-term clinical follow-up is necessary due to potential recurrences.
- Recurrences can occur many years after treatment.
- Early detection of recurrence allows for minor surgery and curettage.
- Pronto genie keratocysts are known to recur in the posterior mandible.
- Malignant transformation to squamous cell carcinoma is unusual.
- Simple enucleation has a high likelihood of recurrence.
- Recurrence can occur as early as 5 years and as late as 40 years after removal.
- Enucleation success depends on complete removal of the cyst.
- Odontogenic keratocysts may be classified as benign neoplasms due to high recurrence rates.

See also: Cysts of the jaws.

References:
- MacDonald-Jankowski DS (January 2011). Keratocystic odontogenic tumour: systematic review.
- Crispian S (2008). Oral and maxillofacial medicine: the basis of diagnosis and treatment.
- Barnes L, Eveson JW, Reichart P, Sidransky D, eds. (2005). World Health Organization Classification of Tumours: Pathology and Genetics of Head and Neck Tumours.
- Madras J, Lapointe H (March 2008). Keratocystic odontogenic tumour: reclassification of the odontogenic keratocyst from cyst to tumour.
- El-Naggar AK, Chan JK, Grandis JR, Takata T, Slootweg PJ, eds. (2017). WHO Classification of Head and Neck Tumours.