What Is the Metopic Ridge?

Your baby’s skull is made up of bony plates that are connected by flexible joints called sutures. A metopic ridge is a ridge of bone that forms on an infant’s forehead along the suture line between the two frontal bones.

Usually, these joints remain open and flexible until an infant's second birthday. This allows the baby's head to fit through the birth canal during delivery, and it also allows the brain to grow normally. The metopic ridge can form at the metopic suture line when the bones fuse, and does not resolve on its own. 

A possible cause of metopic ridge is craniosynostosis, a common birth defect that causes premature fusing of one or more sutures. A metopic ridge may be a symptom of craniosynostosis or simply a benign (not harmful) finding. 

Structure

An infant’s skull is made up of five bony plates connected by four sutures. The metopic suture runs from the fontanelle, or “soft spot,” on the top of the head down to the forehead. It is the first suture in the skull to close, which sometimes happens as early as 3 months old. It is usually completely fused by the time your child is 9 months old.

Causes

It is normal for a metopic ridge to form when a child’s metopic suture fuses. It is unknown why some children develop a benign metopic ridge when others do not. 

When the metopic ridge is part of craniosynostosis, it is caused by a birth defect. Craniosynostosis is believed to be due to a combination of genetic and environmental factors. 

Location

The metopic ridge is a palpable (able to be touched or felt), bony ridge running down the middle of a child’s forehead. The metopic suture line runs from the top of the head down to the center of the forehead. 

Significance

A metopic ridge without other symptoms is not serious and does not require treatment. However, when other symptoms occur with it, a metopic ridge may be a sign of craniosynostosis.

Craniosynostosis vs. Metopic Ridge 

While having a metopic ridge on its own is not harmful, a metopic ridge may be a sign of craniosynostosis.  

Craniosynostosis is a serious condition because when one of the sutures in the skull fuses prematurely, the brain does not have enough room to continue to grow. This can lead to increased intracranial pressure that may affect development as the brain grows and pushes against the fused skull. 

Research has found that it is normal for a ridge to form when a child’s metopic suture fuses normally. This can make it difficult to distinguish a benign metopic ridge from metopic craniosynostosis.

Metopic Craniosynostosis Symptoms

In addition to a metopic ridge, metopic craniosynostosis usually causes a child to have a triangular-shaped head, in which the forehead is very narrow, and the back of the head is the long side of the triangle. 

Metopic craniosynostosis occurs when the metopic suture that runs from the top of the head down the forehead fuses prematurely. Craniosynostosis is treated with surgery to reshape the skull into a more circular form and to allow sufficient room for the brain to grow naturally. 

The classic signs of metopic craniosynostosis include:

• Narrow forehead
• Widening of the back of the head
• Eyes that are close together

Infants with a metopic ridge only do not develop a triangular-shaped head, known as trigonocephaly. A benign metopic ridge is different from craniosynostosis and does not need surgical treatment. It should be noted that ridging is not normal with any other suture lines.

Testing Relevance

Metopic ridge can usually be diagnosed with a physical exam. Your doctor will closely examine your child’s forehead and feel along the ridge. To confirm the diagnosis, your pediatrician may recommend a computed tomography (CT) scan of the head or a skull X-ray. 

Summary

A metopic ridge is a prominent ridge running down your child's forehead. It is where suture lines meet between the two bony plates. A birth defect called craniosynostosis, in which one or more sutures fuse prematurely, can cause a metopic ridge.

However, a metopic ridge also can be benign if it presents without other symptoms such as a narrow forehead, widening of the back of the head, and eyes that are close together.

A Word From Verywell

The metopic ridge is a bony ridge that forms along your child’s metopic suture line in the forehead once the suture fuses. It is a benign finding and does not require treatment. If your child has symptoms in addition to the metopic ridge, it is important to see your pediatrician. Signs to look for include a narrow forehead, widening back of the head, and close-set eyes. These signs could indicate that your child has metopic craniosynostosis, a birth defect that requires surgery. 

Children with a benign metopic ridge do not have any other symptoms. Noticing a change in your baby’s head shape is concerning. It’s helpful to remember that a metopic ridge is a harmless condition and does not affect your child’s brain growth. See your pediatrician any time you have questions or concerns about your child’s head shape. 

Frequently Asked Questions

When should you worry about the metopic ridge?

Metopic ridge is a benign condition that describes a bony ridge along your child’s metopic suture line. Metopic ridge does not require surgery. 

If your child exhibits additional symptoms such as a triangular-shaped head and close-set eyes, talk with your doctor to find out if your child has metopic craniosynostosis. 

What is a prominent metopic ridge?

A prominent metopic ridge refers to a noticeable bony ridge running down your child’s forehead. A prominent metopic ridge is usually benign. If it occurs with other symptoms, it may be a sign of the birth defect metopic craniosynostosis. 

What is craniosynostosis?

Craniosynostosis is a birth defect that affects the flexible joints in an infant’s head called sutures. These sutures usually remain open and flexible until a child is 2 years old. Craniosynostosis is the name of the condition in which a suture fuses prematurely. 

When sutures fuse early,  your baby’s head becomes misshapen and does not have enough room to grow. The increased pressure on the brain can cause problems with brain and skull development.  

What causes craniosynostosis?

Craniosynostosis is a relatively common birth defect that affects one in every 2,500 live births. It is believed to be caused by a combination of genetic and environmental factors.