Fibro osseous

• Fibro-osseous Lesions


  A group of lesions characterized microscopically by fibrous stroma containing various combinations of bones and/or cementum-like material
• Fibro-osseous Lesions of the jaw

  • Fibrous dysplasia
  • Cemento-osseous dysplasia
  • Ossifying fibroma
• Fibrous Dysplasia (FD)


  • Normal bone is replaced and distorted by poorly organized & inadequately mineralized, immature, woven bone & fibrous connective tissue
  • May affect a single bone (monostotic) or multiple bones (polyostotic)
• Etiology & Pathogenesis of FD


  • Sporadic condition that results from a postzygotic mutation in the GNAS1 gene
  • Mutation in early embryonic life affects osteoblasts, melanocytes and endocrine cells
  • Mutation during later stages of embryonic development affects multiple bones
  • Mutation during postnatal life affects a single bone
• Clinical Features of FD

  • Asymptomatic, slow enlargement of the involved bone
  • Monostotic FD (one bone) is more common than polyostotic FD (multiple bones)
  • Jaw involvement is common, usually the maxilla
  • Onset during 1st & 2nd decade of life
  • Equal sex distribution, polyostotic form more common in females
• Radiographic Findings of FD

  • Variable appearance from radiolucent to radiopaque, with a characteristic ground-glass effect
  • Poorly defined radiographic and clinical margins that blend into surrounding normal bone
• Lab Findings in FD

  Serum calcium, Phosphorus & Alkaline phosphatase are normal in monostotic FD, but altered in McCune-Albright syndrome
• Histopathology of FD


  Fibrous connective tissue stroma containing foci of irregularly shaped trabeculae of immature bone, without osteoblastic activity at the bone trabeculae margins
• Treatment & Prognosis of FD

  • Small lesions require no treatment, large lesions may require surgical recontouring
  • After a variable period of prepubertal growth, FD stabilizes, with a slow advance into adulthood
• Cemento-osseous Dysplasia (COD)


  A disease process of the jaws with unknown etiology, including periapical COD, focal COD, and florid COD
• Periapical COD


  • A reactive or dysplastic process at the apex of vital teeth, rather than a neoplastic one
• Focal COD


  • Occurs not associated with a tooth apex, more common in the mandible, especially the anterior periapical region, in females around 40 years old
• Radiographic Features of Focal COD

  Progresses from a periapical lucency to a mixed or mottled pattern, and finally a solid, opaque mass surrounded by a thin, lucent ring
• Florid COD (FCOD)


  • An exuberant form of periapical COD, typically bilateral and affecting all four quadrants, more common in black females between 25-60 years old
• Radiographic Features of FCOD


  Appears as diffuse radiopaque masses throughout the alveolar segment of the jaw, with a ground-glass or cyst-like appearance
• Diagnosis of COD


  Clinical and radiographic features, with histopathology to confirm if necessary, in the presence of vital teeth
• Histopathology of COD


  A mixture of benign fibrous tissue, bone, and cementum, with variable proportions of the mesenchymal and mineralized components
• Treatment of COD


  No treatment required, except for instruction on good oral hygiene to prevent infection in the sclerotic stage of FCOD
• Ossifying Fibroma (OF)


  A benign neoplasm of bone with a significant growth potential and the potential for bone destruction and recurrence
• Clinical Features of OF

  • Tends to occur during the 3rd & 4th decades of life, more common in females, a slow growing asymptomatic & expansile lesion, mostly in the jaw and craniofacial bones, usually a solitary lesion
• Radiographic Findings of OF

  Well circumscribed, sharply demarcated border, may be radiolucent, radiopaque or mixed, may displace or less commonly resorb the roots of teeth
• Histopathology of OF


  Composed of fibrous connective tissue with well-differentiated spindle fibroblasts, containing evenly distributed bone trabeculae or islands, with immature bone and infrequent osteoblasts
• Treatment & Prognosis of OF


  Surgical removal by curettage or enucleation, with a low recurrence rate
• Juvenile Ossifying Fibroma


  • A well circumscribed rapidly growing neoplasm that lacks continuity with adjacent normal bone, including trabecular and psammomatoid types