Purpose: When linear lucency is present in the occipital bone on radiographs throughout childhood, differential diagnosis becomes important because some primary sutures are similar to fractures. The authors here chronicled the normal development of ossification centers, sutures, and synchondroses in the chondrocranium by radiographic examination.
Methods: One hundred and twenty-seven children, aged from newborns to 6 years and without any skull base deformities, were referred to for radiographs of Towne's projection.
Results: In the occipital bone at birth, three primary sutures could be identified. At the age of 0-3 years, occipital and innominate sutures started to fuse, this being complete by 4 years, whereas mendosal sutures persisted until 6 years of age, after which no primary sutures could be seen.
Conclusion: The complex process of skull base development features a step-wise process sutural closure for which radiographic standards allow differential diagnosis from fractures with judgment of the timing.