Sagittal suture


The sagittal suture is a dense, fibrous connective tissue joint between the two parietal bones of the skull. The term is derived from the Latin word sagitta, meaning arrow. The derivation of this term may be demonstrated by observing how the sagittal suture is notched posteriorly, like an arrow, by the lambdoid suture. The sagittal suture is also known as the interparietal suture, the sutura interparietalis.
In forensic anthropology, the sagittal suture is one method used to date human remains. The suture begins to close at age twenty-nine, starting at where it intersects at the lambdoid suture and working forward. By age thirty-five, the suture is completely closed. This means that when inspecting a human skull, if the suture is still open, one can assume an age of less than twenty-nine. Conversely, if the suture is completely formed, one can assume an age of greater than thirty-five.
Two anatomical landmarks are found on the sagittal suture: the bregma, and the vertex of the skull. The bregma is formed by the intersection of the sagittal and coronal sutures. The vertex is the highest point on the skull and is often near the midpoint of the sagittal suture.
At birth, the bones of the skull do not meet. If certain bones of the skull grow too fast then "premature closure" of the sutures may occur. This can result in skull deformities. If the sagittal suture closes early the skull becomes long, narrow, and wedge-shaped, a condition called scaphocephaly.

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