Odontogenic Keratocyst

Definition: Benign, fluid-filled cysts developing in jaw bones, likely originating from tooth-forming tissues.

Radiographic Features:

  • Location:
    • 70% in posterior mandible
    • Can occur in maxilla
  • Edge:
    • Smooth and well-defined (corticated)
    • Often scalloped around tooth roots
  • Shape:
    • Unilocular
    • Tends to expand jaw bone
  • Internal:
    • Radiolucent
  • Other:
    • Grows along jaw length with minimal outward expansion
    • May cause root resorption of adjacent teeth
    • Potential for bone perforation and soft tissue involvement
  • Number:
    • Usually single
    • Multiple in 5-10% of cases (associated with basal cell nevus syndrome)

Key Diagnostic Signs:

  • Well-defined, radiolucent lesion in posterior mandible
  • Tendency for anteroposterior growth
  • Scalloped borders

Clinical Significance:

  • High recurrence rate after treatment
  • Requires careful surgical management and long-term follow-up
  • Multiple OKCs may indicate basal cell nevus syndrome
  • Differential diagnosis from other jaw cysts is crucial

Note: Classification of OKCs as cysts or tumors is debated. Genetic factors, especially PTCH1 gene mutations, may play a role in their development. Radiographic appearance alone is not definitive; biopsy is often necessary for diagnosis.