2. Consisting of or resembling fibers.
3. Full of sinews; tough; especially, impossible to chew.
Only one bone may be involved (fibrous dysplasia, monostotic) or several (fibrous dysplasia, polyostotic).
When associated with melanotic pigmentation of the skin and endocrine disorders, it is known as Albright's syndrome; which is a condition of cystic bone growth that results from abnormal bone development. It may occur with bone lesions, skin pigmentation, and endocrine abnormalities.
In adults, these joints or sutures, do not allow any movement; while in new-born babies and very young children, some fibrous joints, or fontanelles known as "soft spots", are movable before they have solidified.
These fontanelles on a baby’s head enable the soft bony plates of the skull to flex during the second stage of labor making it possible for the head to pass through the birth canal.
As the baby matures, the sutures close and the fontanelles gradually harden and are usually completely hardened by the child's second birthday.