Affects a single bone. It accounts for about 70-80% of cases and is often asymptomatic until discovered incidentally on an X-ray.
Fibrous dysplasia is categorized by how many bones it affects: fibrous dysplasia of bone
Osteoblasts (bone-forming cells) fail to mature, producing disorganized "woven bone" instead of strong "lamellar bone". Affects a single bone
The mutation leads to continuous activation of the Gsα protein, increasing cAMP levels. fibrous dysplasia of bone
Affects multiple bones. This form typically presents earlier in childhood and is more severe.