Odontogenic keratocyst (OKC) is derived from:

# The odontogenic keratocyst (OKC) is derived from:
A. Hertwig's epithelial root sheath
B. The reduced enamel epithelium
C. Remnants of the dental lamina
D. A pre-existing osteoma

The correct answer is: B. Reduced enamel epithelium.

Keratocysts differ from other odontogenic cysts in their microscopic appearance and clinical behavior.

They may resemble periodontal, primordial, or follicular cysts. Usually, they cannot be distinguished

radiographically. 

Clinical features:

• Wide age range. peak occurrence in 2nd and 3rd decades

• Lesions found in children are often reflective of multiple odontogenic keratocysts as a component

of the nevoid basal cell carcinoma syndrome

• More common in males than females

• The chief site of involvement is the mandible, in approximately a 2 to 1 ratio

• In the mandible. most occur within the posterior portion of the body and ramus region

• Typically asymptomatic

Radiographic features:

• Well-demarcated area of radiolucency with a scalloped, radiopaque margin

• Unilocular or multilocular

Microscopicall y:

• The lining epithelium is thin and parakeratinized.

• The basal layer is palisaded with prominent, polarized, and intensely staining nuclei of uniform

diameter

• The lumen may contain large amounts of keratin debris or clear fluid similar to serum transudate

• The parakeratotic type fonns 85 to 95% of all odontogenic keratocysts; the balance is made

up of the orthokeratinized variant.