The coronal suture is the cranial suture created in the middle of the two parietal bones as well as the frontal bone.
Bregma is the point on the centerline of the skull, along the coronal suture, where both parietal bones connect with the frontal bone. It is the center of a soft spot, or fontanel in a newborn child. The size and shape of the frontal bone can be determined by the investigation of the location of the coronal suture and bregma.
Structure and Relations
- Compared to lateral part, the coronal suture is less rough in the central part.
- Sometimes there is a continuation of the suture that merges the two halves of the frontal bone; then the line of the sagittal suture is carried forward towards the frontonasal suture, and a skull showing this distinctiveness is called metopic.
- The post-coronal depression may be seen behind the coronal suture sometimes, and along the line of the sagittal suture the vault of the calvaria creates a broad and slightly raised crest within some instances.
- On either side the temporal ridges can be observed curved over the lateral and superior parts of the parietal bones.
- As the lower of these traverses the coronal suture in front it indicates a spot called the stephanion, useful as giving a fixed point from which helps in determination of the bi-stephanic diameter.
- The gap in the middle of the temporal ridges on both sides will vary in relation to the shape of the skull and the growth of the temporal muscle.
At the junction of coronal, sagittal and frontal sutures, the anterior fontanelle is located which opens at birth and usually merges around 18-24 months later the birth.
The coronal suture fusion happens around age of 24 years. Premature merging causes malformations like oxycephaly and plagiocephaly. The coronal suture extends from just behind and above the temple area, upward to bregma.