Lambdoid Suture: Definition, Types of Sutures, Characteristics and Associated Complications

The brain is located within the cranial vault, a space made up of the bones of the skull and the base of the skull.

The bones of the skull and the base of the skull (frontal, parietal, occipital, ethmoidal, sphenoid, and temporal) ossify separately and gradually.

These bones of the skull are joined by sutures.

The sutures

Sutures are joints between the bones of the skull, they are a type of fibrous joint, composed of a thin layer of dense fibrous connective tissues called Sharpey’s fibers .

Cranial sutures are a syndesmosis between the cranial bones (a syndesmosis is a fibrous joint located between two bones).

The interlocking ragged edges of the bones and held together by these sutures help to 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 also to the back of the skull.

They also act as a joint that allows the bones to widen evenly as the brain grows and the skull expands.

This allows the skull to develop symmetrically. The sutures of the bone plates allow a certain flexibility that decreases until it becomes ossified with advanced age.

But it could happen that some of the sutures close too soon, fusing prematurely, and it is possible that there is no growth in that area of ​​the brain.

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 main sutures of the skull include the following:

Side view sutures

Coronal suture

The coronal suture joins the frontal bone with the parietal bones, extending from one ear to the other. Each frontal bone plate meets a parietal bone plate at the coronal suture.

Sutura lambdoidea

This suture joins the parietal bones with the occipital bone. This suture runs across the back of the head.

Occipitomastoid suture

This suture is the continuation of the lambdoid suture, and is located between the mastoid portion of the temporal bone and the occipital bone.

Parietomastoid suture

Located between the parietal bone and the mastoid process.

Squamous suture

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

Metopic suture

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.

Sagittal 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.

Viscerocranial sutures

  • Maxillolacrimal suture
  • nasomaxillary suture

Sutura lambdoidea

The lambdoid suture is one of several »sutures«, which are 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 suture 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.

features

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 with each other to allow further cranial growth.

Premature ossification (synostosis) of the interface leads to malformations of the skull (craniostenosis). A true 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 as both can cause uneven flattening of the back of the head.

Signs of lambdoid suture synostosis

Patients with lambdoid suture craniosynostosis have flattening of 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 base of the skull to the affected side that can cause the hairline to appear sloping.
The effects on the appearance of the face can range from no effects 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.

This is because the sutures on the opposite side make room to compensate for the closed suture opposite them. These patients require open cranial vault remodeling.