Fibrous Joints - Sutures
Suture joints are one type of fibrous joint. They are the type of joint that connect the flat bones of the skull which meet in a tooth-like pattern. The fibrous tissue of these joints is continuous with the periosteum, and the joints are synarthroses (immovable). Suture joints undergo changes throughout childhood and into early adulthood. At birth, the sutures have broad spaces of fibrous tissue called fontanelles. These joints close down and undergo ossification (becoming fused with bone) beginning in childhood and continuing into a person's 20's. A joint that has ossified over time is called a synostosis.