Scaphocephaly involves fusion of the sagittal suture. This sutures runs from front to back starting at the fontanel, at the top of the head, and extends backwards along the middle of the skull to the back of the head. Often the fontanel, or soft spot, is absent or closed. A ridge can be seen, or felt, running along the top of the head in between the right and left half of the skull. When viewed from above, the skull is wider near the forehead and gets narrower towards the back of the skull (which is the opposite of what is normal: that is, the back of the skull should be wider than the front). When looking straight on at the child's face, the forehead seems quite big, or prominent, and the sides of the skull look narrow.

The incidence of scaphocephaly is one in 2,000 births. It is the most common form of craniosynostosis. Almost all children affected with scaphocephaly require surgical treatment. The treatment for this condition is discussed in the treatment section.