The sagittal suture, also known as the interparietal suture and the ''sutura interparietalis'', is a dense, fibrous

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

joint between the two parietal bones of the skull. The term is derived from the Latin word ''sagitta'', meaning

arrow An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers c ...

Structure

The sagittal suture is formed from the fibrous

joint between the two parietal bones of the skull. It has a varied and irregular shape which arises during development. The pattern is different between the inside and the outside. Two

anatomical landmarks Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors. Anatomical terminology uses many unique terms, suffixes, and prefixes deriving from Ancient Greek and Latin. T ...

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.

Development

At birth, the bones of the skull do not meet. The gap that remains, which is approximately 5 mm wide, allows for the brain to continue to grow normally after birth. The inner parts of the parietal bones fuse before the outer parts.

Clinical significance

If certain bones of the skull grow too fast before birth, then "premature closure" of the sutures may occur. This can cause

craniosynostosis Craniosynostosis is a condition in which one or more of the fibrous sutures in a young infant's skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpe ...

, which results in skull deformities. Sagittal craniosynostosis is the most common form. If the sagittal suture closes early the skull becomes long, narrow, and wedge-shaped, a condition called ' scaphocephaly'.

Society and culture

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.

History

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''.

Additional images

File:Sagittal suture - animation03.gif, Animation. Sagittal suture shown in red. File:Sagittal suture - animation05.gif, Left and right parietal bone. File:Sobo 1909 47 - sagittal suture.png, Sagittal suture seen from inside. File:Sobo 1909 105.png, Sagittal suture of a new-born child, seen from above. File:Sagittal suture.jpg, Sagittal suture of a new-born child. File:Wormian bones.jpg, Sagittal suture with wormian bones.

References

Bibliography

Sagittal suture
, ''Stedman's Medical Dictionary'', 27th ed. (2000). *Moore, Keith L., and T.V.N. Persaud. ''The Developing Human: Clinically Oriented Embryology'', 7th ed. (2003).

External links

* * {{Authority control Cranial sutures Human head and neck Joints Joints of the head and neck Skeletal system