What is Metopic Craniosynostosis?

First how is the human skull composed?

Anatomy of the Newborn Skull - Standford Children's Health

A baby's skull is made up of several major bones all connected together including two frontal, two parietal, and one occipital bone. These bones are held together by sutures which are fibrous material to give the appearance of one large bone (as we imagine the skull).

Sutures extend to the forehead, sides, and back of the skull. Sutures is what allows the bones to move during the birthing process (think tectonic plates from middle school science) and then expand to enlarge the skull as the brain begins to grow.  The major sutures of the skull include the following:

Metopic suture. This extends from the top of the head down the middle of the forehead, toward the nose. The 2 frontal bone plates meet at the metopic suture.

Coronal suture. This extends from ear to ear. Each frontal bone plate meets with a parietal bone plate at the coronal suture.

Sagittal suture. This extends from the front of the head to the back, down the middle of the top of the head. The 2 parietal bone plates meet at the sagittal suture.

Lambdoid suture. This extends across the back of the head. Each parietal bone plate meets the occipital bone plate at the lambdoid suture.

The human skull also has "soft spots" or fontanelles (the space between the bones of an infant's skull where the sutures intersect) that are covered by tough membranes that protect the underlying soft tissues and brain. The fontanelles include:

Anterior fontanelle (also called soft spot). This is the junction where the frontal and parietal bones meet. The anterior fontanelle remains soft until about 18 months to 2 years of age.

Posterior fontanelle. This is the junction of the parietal bones and the occipital bone. The posterior fontanelle usually closes first, before the anterior fontanelle, during the first several months of an infant's life.

However, if any of the sutures close too early (fuse prematurely), there may be no growth in that area. This may force growth to occur in another area or direction, resulting in an abnormal head shape.



"Anatomy of the Newborn Skull." Anatomy of the Newborn Skull. Stanford Children's Health, n.d. Web. 06 Jan. 2016.

What is Craniosynostosis?

Types of Craniosynostosis - Boston Children's Hospital

Craniosynostosis - (from cranio, cranium; + syn, together; + ostosis relating to bone)

Craniosynostosis (kray-nee-o-sin-os-TOE-sis) is a birth brain defect from the premature closing of one or more of the sutures before brain growth is complete. Closure of just one suture is most common compared to normal skull growth which the skull would expand to accommodate the growth of the brain prior to closing. When the sutures close this restricts growth in that area of the skull and promotes abnormal growth in other parts of the skull where the sutures remain open. The brain continues to expand in its normal volume but it does not allow the skull to expand to accommodate the growing brain. This leads to increased pressure within the skull and impaired development of the brain. When a baby has Craniosynostosis, the brain can't grow in its natural shape and the head is misshapen.


"NINDS Craniosynostosis Information Page." Craniosynostosis Information Page: National Institute of Neurological Disorders and Stroke (NINDS). National Institute of Neurological Disorders and Stroke, 30 June 2015. Web. 06 Jan. 2016.

What is Metopic Craniosynostosis?

This figure shows the position of the closed metopic suture indicated by the red arrow. Note the narrow forehead, the midline vertical ridge in the position of the closed metopic suture and decreased space between the eye sockets. - http://www.drderderian.com

Of the four types of Craniosynostosis, one of them is called Metopic Craniosynostosis or Trigonocephaly. This is a prominent ridge along the forehead is normal but a baby with Metopic Craniosynostosis has a triangular shape to their forehead and a noticeable ridge along the forehead. They will also have a pointed, almost triangular shape to the front and top of their skulls and eyes that appear too close together. The metopic suture runs from your baby's nose to the sagittal suture. Premature fusion gives the scalp a triangular appearance.

Metopic Craniosynostosis is one of the rarest forms of Craniosynostosis. Metopic synostosis can be quite mild in some children and fairly serious in others. There is no single proven cause for metopic synostosis. It is often noticeable at birth, but can also become apparent over time in older infants. Metopic and  other types of Craniosynostosis should not be confused with plagiocephaly—a different condition that is associated with the baby’s position during sleep.  Children with more serious instances of Metopic Synostosis can experience problems with vision, or learning and behavior. Some children with just a ridge or mild Metopic Synostosis don’t need any medical treatment. For those who do, surgery has proven to be a successful approach.



"Craniosynostosis." Symptoms. Mayo Clinic Staff, n.d. Web. 06 Jan. 2016.

Proctor, Mark R., MD. "Metopic Synostosis (Trigonocephaly) in Children." Metopic Synostosis (Trigonocephaly). Boston Children's Hospital, 2012. Web. 06 Jan. 2016.