[citation needed] The sagittal suture is formed from the fibrous connective tissue joint between the two parietal bones of the skull.

[1] The gap that remains, which is approximately 5 mm wide, allows for the brain to continue to grow normally after birth.

[1] If certain bones of the skull grow too fast before birth, then "premature closure" of the sutures may occur.

[2] If the sagittal suture closes early the skull becomes long, narrow, and wedge-shaped, a condition called 'scaphocephaly'.

This means that when inspecting a human skull, if the suture is still open, one can assume an age of less than twenty nine.