Simple Bone Cyst

Definition: A pseudocyst without an epithelial lining, of unknown etiology, sometimes associated with trauma. Also known as traumatic bone cyst, solitary bone cyst, or hemorrhagic bone cyst.

Radiographic Features:

  • Location: Most commonly in posterior mandible
  • Edge:
    • Well-defined to well-localized
    • May have a thin, delicate corticated border
  • Shape: Scalloping between roots of adjacent teeth
  • Internal:
    • Radiolucent
    • Unilocular
  • Number: Single

Key Diagnostic Signs:

  • Radiolucent lesion with scalloped superior border
  • Typically asymptomatic
  • No displacement of tooth roots

Clinical Significance:

  • Often discovered incidentally on routine radiographs
  • Rarely causes expansion or resorption of adjacent teeth
  • May spontaneously resolve, especially after surgical exploration
  • Differential diagnosis from other radiolucent lesions is important

Note: Despite its various names, it is not a true cyst due to the absence of an epithelial lining. Surgical exploration often reveals an empty cavity or minimal fluid content, which can aid in diagnosis and potentially trigger healing.