The brain is located within the cranial vault, a space made up of the bones of the skull and the base of the head.
The bones of the skull and the head base (frontal, parietal, occipital, ethmoidal, sphenoid, and temporal) ossify separately and gradually.
Sutures join these bones of the skull.
Sutures are joints between the bones of the skull; they are fibrous joints composed of a thin layer of dense fibrous connective tissues called Sharpey’s fibers.
Cranial sutures are syndesmosis between the cranial bones (a syndesmosis is a fibrous joint located between two bones).
The interlocking ragged edges of the bones held together by these sutures help provide the overall strength of the joints and therefore reduce the risk of fracture due to impacts or some other possible damage.
Some of the sutures extend to the front, others to the sides, and the back of the skull.
They also act as a joint that allows the bones to widen as the brain grows and the skull expands.
This allows the skull to develop symmetrically. The sutures of the bone plates allow certain flexibility that decreases until it becomes ossified with advanced age.
But some of the sutures might close too soon, fusing prematurely, and there may be no growth in that brain area.
A quick closing of this suture on one side often gives the skull a warped or twisted appearance.
This situation can cause growth in another area or in another direction, which causes this atypical form of the brain.
The primary sutures of the skull include the following:
Side view sutures
The coronal suture joins the frontal bone with the parietal bones, extending from one ear. Each frontal bone plate meets a parietal bone plate at the coronal suture.
This suture joins the parietal bones with the occipital bone. This suture runs across the back of the head.
This suture is the continuation of the lambdoid suture and is located between the mastoid portion of the temporal bone and the occipital bone.
It is located between the parietal bone and the mastoid process.
The squamous portion of the temporal bone joins the squamous suture with the parietal bones.
Other lateral view sutures
- Sphenofrontal suture.
- Sphenoparietal suture.
- Sphenosquamous suture.
- Sphenozygomatic suture.
- Temporzygomatic suture.
- Frontocygomatic suture.
Superior frontal view sutures
The metopic suture joins the two frontal bones. This extends from the top of the head down the middle of the forehead to the nose. The two front plates of bone meet at the metopic suture.
This suture is located in the upper central part of the skull, between the two plates of the sagittal bones.
Interior view sutures
- Fronto-ethmoidal suture.
- Petro-squamous suture.
- Sphenopetrosal suture.
- Maxillolacrimal suture
- nasomaxillary suture
The lambdoid suture is one of several »sutures, «a type of immobile joint that exists only between the bones of the skull.
Its name is derived from the Greek letter lambda. From a dorsal point of view, the future is shaped like the Greek letter “Lambda.”
The lambdoid suture is a structure created by the parietals and the interparietal portion of the occiput. It widens from asterion to asterion.
The lambdoid suture is located at the back of the skull and runs from the midline to an area behind the ears.
The lambdoid suture refers to a simple, thick, and fibrous joint of the connective tissue that is found in the posterior area of the skull and that connects the parietal bones with the occipital bone and is continued below with the occipitomastoid suture between the interparietal portion of the occipital. And mastoid of the temporal bones.
Lambdoid suture complications
Cranial sutures give way during the delivery process, allowing the baby’s skull bones to move to facilitate labor.
At the time of birth, the bones involved in the formation of the lambda seam are not yet in direct contact to allow further cranial growth.
Premature ossification (synostosis) of the interface leads to malformations of the skull (craniostenosis). A proper early ossification of the lambdoid suture is rare.
Lambdoid suture synostosis is the least common type of single suture synostosis, accounting for only 1 to 3% of all cases.
Lambdoid suture synostosis can cause marked changes at the base of the baby’s skull.
Lambdoid suture synostosis can easily be confused with positional plagiocephaly caused by the baby sleeping preferentially on one side. Both can cause uneven flattening of the back of the head.
Signs of lambdoid suture synostosis
Patients with lambdoid suture craniosynostosis have to flatten the back of the head and a downward bulge of the skull behind the ear on the side of the closed suture.
There is also a downward tilt of the skull base to the affected side that can cause the hairline to appear sloping.
The effects on the appearance of the face can range from no impact to significant asymmetries.
The ear on the closed suture side may be uneven in position on the head compared to the other ear.
Most patients with this form of craniosynostosis have larger heads in the middle and posterior thirds of the skull on the side opposite the closed suture.