Definition• A traumatic bone cyst is an empty intrabony cavity that lacks an epithelial lining.• The designation of pseudocyst relates to the cystic radiographic appearance and gross surgical presentation of this lesion It is seen mostly in the mandible.
Etiology and Pathogenesis• The pathogenesis is not known, in some cases seem to be associated with antecedent trauma.• It has been hypothesized that a traumatically induced hematoma forms within the intramedullary portion of bone.• Rather than organizing, the clot breaks down, leaving an empty bony cavity.• Alternative developmental pathways include cystic degeneration of primary tumors of bone, such as central giant cell granuloma, disorders of calcium metabolism, and ischemic necrosis of bone marrow.
Clinical Features• Teenagers are most commonly affected• The most common site of occurrence is the mandible• Swelling is occasionally seen• pain is infrequently noted.
Radiograph finding Radiographically, a well-delineated area ofRadiolucent area with scalloping borders between the roots of the teeth
Diagnosis• Have no epithelial lining . Appear empty at operation or contains pale fluid .• Diagnosis suggested by radiographic features (especially extension between tooth roots)
Histopathology• Grossly, only minimal amounts of fibrous tissue from the bony wall are seen. The lesion may occasionally contain blood or serous fluid.• Microscopically: delicate, wellvascularized, ibrous connective tissue without evidence of anepithelial component is identified