Generally cranial growth occurs as the brain actively grows and pushes outward on the bony cranial vault. For this to occur, the junctions between the thin, gently curved bones of the skull must be soft and expandable. These junctions are called cranial "sutures," and they – as well as the larger "fontanelles" or soft spots of the head – allow the head to expand over the growing brain.
Of course, the skull eventually becomes solid. This occurs as the fontanelles are over-grown with bone and as adjacent bones slowly fuse across the sutures. This process occurs on a fairly regular schedule in the first 12-15 months of life.
When a suture fuses too soon, a process called "craniosynostosis," an abnormal head shape develops. The head is prevented from growing in the region of the fused suture, and the brain continues to grow outward into the other soft, expandable regions of the skull. The particular head shape that results depends on which suture is fused. If more than one suture is fused, not only will the head shape become abnormal, the brain will not be allowed to grow and develop, causing headaches and increasing pressure sed inside the head and brain.
Signs of craniosynostosis may include:
The signs of craniosynostosis may not be noticeable at birth, but can become apparent during the first few months of your baby's life. Thankfully, these distressing problems can be corrected. A fused suture can be opened and the cranial vault can be reshaped. Head growth is corrected and pressure is relieved. The operation sounds dramatic, but in most cases, it is very well tolerated. Under general anesthesia, the bones of the skull are exposed, and the affected region is reshaped and repositioned with plates that are absorbed by the body over time. Infants usually spend a few days in the hospital where they are monitored closely and pain is controlled.