• Reactive/dysplastic/neoplastic lesions → replacement of normal bone by fibrous tissue
• Contains mineralized product – deposited by metaplastic cells (derived from the fibrous tissue)
• Include:
  • Dystrophic normal bone
  • Dense sclerotic cementum-like calcifications
  • Or mixed hard tissues

Common fibro-osseous lesions

1. Fibrous dysplasia of bone
2. Cemento-osseous dysplasia
   • Periapical cemento-osseous dysplasia
   • Focal COD.
   • Florid COD – all 4 quadrants
3. Ossifying fibroma
4. Cherubism – Hereditary craniofacial malformations

Common radiology

• Early – well circumscribed radiolucencies.
• Late – mixed radiolucency to ”cotton wool” appearance

Difference between fibrous dysplasia and ossifying fibroma