Sutures of the Skull

• Are the immovable fibrous joints between the bones of the skull.

A. Coronal suture : lies between the frontal bone and the two parietal bones.
B. Sagittal suture : lies between the two parietal bones.
C. Squamous (squamoparietal) suture : lies between the parietal bone and the squamous part of the temporal bone.
D. Lambdoid suture : lies between the two parietal bones and the occipital bone.

• Lambda : intersection of the lambdoid and sagittal sutures.
• Bregma : intersection of the sagittal and coronal sutures.
• Pterion : a craniometric point at the junction of the frontal, parietal, and temporal bones and the great wing of the sphenoid bone.
• Asterion : a craniometric point at the junction of the parietal, occipital, and temporal (mastoid part) bones.
• Nasion : a point on the middle of the nasofrontal suture (intersection of the frontal and two nasal bones).
• Inion : most prominent point of the external occipital protuberance, which is used as a fixed point in craniometry.