- Incidence: 3-11% of all cysts. found in infancy to old age; 60% found between 10 and 40; male > female
- Cause: Growth is related to unknown factors inherent in epithelium or enzymatic activity in the fibrous wall.
- Clinical presentation: small OKCs are asymptomatic. Larger cysts associated with pain, swelling, drainage. Grow in antero-posterior direction within the medullary cavity without causing obvious bone expansion or root resorption. May be filled with clear liquid similar to transudate or a cheesy material (contains keratinaceous debris)
- Location: 60-80% in mandible, with marked tendency for posterior mandible and ascending ramus. 25-40% involve unerupted tooth – thought to arise from dental lamina rests
- Radiographic Features: well-defined radiolucent area with smooth and often corticated margins; large lesions may appear multilocular; can be associated with crown of unerupted tooth (20 to 40%); root resorption is less common than that noted with dentigerous cyst and radicular cysts
- Compare to: multiple OKCs found in nevoid basal cell carcinoma (Gorlin) syndrome; radiographically similar to dentigerous cyst, a radicular cyst, a residual cyst, a lateral periodontal cyst; OKCs in anterior midline maxilla can mimic nasopalatine duct cysts
- Histopathology: epithelial lining composed of uniform later of stratified squamous epithelium, usually 6-8 cells thick; luminal surface shows flattened parakeratotic epithelial cells which exhibit a corrugated appearance; basal epithelial layer is composed of a hyperchromatic palisaded layer of cuboidal or columnar epithelial cells; lacks rete ridges
- Treatment: decompression, enucleation and curettage; intraluminal Carnoy’s injections, 5-FU
Carnoy’s solution, composed of 3 ml of chloroform, 6 ml of absolute ethanol, 1 ml of glacial acetic acid, and 1 g of ferric chloride
Orthokeratinized Odontogenic Cyst
- AKA:
- Incidence: young adults. 2:1 male-to-female.
- Cause:
- Clinical Presentation: Location: Mandible > maxilla with tendency to involve posterior mandible
- Radiographic Features: most often involve unerupted mandibular third molars. Can appear multiloculated.
- Compare to:
- Histopathology: cyst lining composed of stratified squamous epithelium, which shows an orthokeratotic surface. 6-8 cells thick with NO palisade basal layer as seen in parakeratinized OKC
- Treatment:
