What Is Craniosynostosis?

A baby’s skull is formed by seven separate bones. They’re connected by joints called cranial sutures that are made of fibrous tissue. These flexible joints give your child’s brain room to grow. These joints will fuse with each other around the 24-month mark.

Craniosynostosis is a birth defect caused by a disorder in one or more of these joints that causes them to fuse together prematurely. As the brain continues to grow, the fused portion of the child’s skull do not grow with it.

Typically, only one cranial suture will fuse in cases of craniosynostosis. However, in some cases multiple cranial sutures can fuse together.

What Causes Craniosynostosis?

The cause for craniosynostosis in a child is often undetermined. Doctors have linked some cases to genetic disorders. Craniosynostosis diagnoses are categorized into two main groups: nonsyndromic and syndromic craniosynostosis.

Non-syndromic craniosynostosis is the most common type of the disorder. Cases where doctors are unable to determine the specific cause of craniosynostosis in a child fall into this category. Its causes are generally believed to be a combination of environmental factors during pregnancy and genetics.

Syndromic craniosynostosis refers to cases where a specific genetic syndrome has been linked. Disorders such as Crouzon syndrome, Pfeiffer syndrome and Apert syndrome all affect a baby’s skull development.

What Are the Symptoms of Craniosynostosis?

The most common symptom of craniosynostosis is a misshapen skull. Although this often apparent at birth, it may also become gradually apparent in the first few months after birth.

The shape of the skull in a baby with craniosynostosis will often depend on which of the cranial sutures are affected by the condition. The specific term given to a type of craniosynostosis depends on which sutures it affects.

Sagittal craniosynostosis occurs when the cranial suture that runs from the front to the back of the skull fuses prematurely and causes a baby’s head to grow long and narrow. This is the most common type of craniosynostosis.

Coronal craniosynostosis is caused by the premature fusion of one of the coronal sutures that run from the ear to the top of the child’s skull. This can cause the affected side to flatten, while the unaffected side bulges outward. When both sutures are prematurely fused, the baby’s head can take on a short and wide appearance with a bulging forehead.

Metopic craniosynostosis involves the metopic suture which runs from a baby’s nose and forehead to their soft spot. When this suture fuses prematurely, it gives the head a triangular appearance with a bulging back.

Lambdoid craniosynostosis is the premature fusion of the lambdoid suture at the back of a baby’s head. This can cause a baby’s head to appear flat on one side, with one ear tilting higher on the head than the other.

Babies’ heads are very flexible by nature. If a baby’s head appears misshapen, it does not necessarily indicate they have craniosynostosis. Sometimes temporary changes in head shape can occur from the baby spending too much time in one position, such as laying on their back.

What Are the Treatments for Craniosynostosis?

In very mild cases of craniosynostosis, or in cases where a baby’s head appears misshapen, treatment may not be needed. In these cases, a doctor may create a molded helmet for the baby to wear to help their brain and skull develop normally.

For babies with severe craniosynostosis, surgery is considered the primary treatment. Which surgery a child receives and when they receive it will depend on the type of craniosynostosis they are experiencing. The isolation of an underlying genetic disorder also plays a part in determining the best way to surgically treat the condition.