Normal growth of the sutures of the skull

The processes of sutures and synchondroses formation, interdigitation and closure set the normal skull growth. Sutures and synchondroses represent growth sites in normal skull development. These articulations have distinctive characteristics due to their different embryological origins and histologies; sutural fusion occurs by either intramembranous ossification or chondroid bone formation whereas synchondrosis fusion occurs by endochondral ossification. The suture patterns are the result of both the closure and interdigitation processes and each suture may be coded according to its degree of sutural closure and interdigitation. Suture patterns are plastic during the juvenile stage and they undergo significant remodeling during physiological growth until adulthood. Different patterns can be observed not only between different sutures, but also within the same suture and it might depend on the time course of sutural closure. During the physiological growth, cranial sutures/synchondroses exhibit morphological changes ranging from straight lines to an interdigitated and beveled pattern and finally they are replaced by bone marrow and blood vessels.