What Is Frontal Bossing?

Frontal bossing is a skeletal deformity that causes a baby to have a protruding forehead. The forehead appears large and prominent. Your child may have a heavy brow ridge as well. Frontal bossing is usually a symptom that indicates a rare condition, such as a genetic disorder or birth defect. 

Frontal bossing is usually diagnosed when your little one is a baby or toddler. There is no known treatment for frontal bossing. However, the underlying condition causing the protruding forehead can usually be treated. 

Frontal Bossing Symptoms

The symptoms of frontal bossing include a prominent forehead and possibly a heavy brow ridge. Depending on which condition is causing the change in forehead shape, your child may have other symptoms as well. 

Causes

Frontal bossing is a sign of an underlying syndrome. The following conditions can cause frontal bossing:

• Acromegaly is a rare condition that occurs when the pituitary gland makes too much growth hormone. It leads to several symptoms that include larger facial bones, weakness, fatigue, joint pain, and sleep apnea.
• Basal cell nevus syndrome, also known as Gorlin syndrome, is a genetic disorder that causes skeletal abnormalities, basal cell carcinomas, and jaw cysts. 
• Congenital syphilis occurs when a mother with syphilis gives birth and passes it on to the baby. Babies with congenital syphilis are often born with deformed bones, anemia, brain and nerve problems, and jaundice. 
• Cleidocranial dysostosis is a rare birth defect that causes incomplete skull formation and underdeveloped or absent collar bones.
• Crouzon syndrome is a genetic disorder that causes premature fusing of the skull bones, also known as craniosynostosis. 
• Hurler syndrome is a disease that causes abnormal facial features, short stature, corneal clouding, and hearing problems. It is caused by an abnormal enzyme. 
• Pfeiffer syndrome is a rare genetic disorder that causes the bones in the skull to fuse prematurely.
• Rickets is a condition caused by a severe deficiency of vitamin D. It leads to bone deformities, stunted growth, and easily breakable bones.
• Rubinstein-Taybi syndrome is a birth defect that causes thick eyebrows with a prominent arch, short stature, intellectual disability, and other health problems. 
• Russell-Silver syndrome is a growth disorder that causes facial abnormalities, asymmetric limbs, difficulty feeding, and other health problems. 

The use of antiseizure drugs such as trimethadione during pregnancy can also lead to birth defects that cause a prominent forehead.

Diagnosis

Your doctor will be able to diagnose your child with frontal bossing by examining them during a physical exam. Because frontal bossing is a sign of another condition, your doctor will begin the process of identifying which condition your child has. This process usually involves taking a detailed health history and a family history.

Your doctor will likely ask several questions about when you first noticed your child’s prominent forehead, as well as any other symptoms the child is experiencing. From there, your doctor may order lab tests to help with the diagnosis. If doctors suspect a genetic disorder, they may recommend genetic testing for the whole family.

It is also possible to detect frontal bossing before your child is born during a prenatal ultrasound. A three-dimensional (3D) ultrasound may be helpful in showing a more detailed view of frontal bossing. It is helpful to remember that this condition is not always seen on ultrasounds, though.

To determine your child's diagnosis, it's likely that your doctor will order several medical tests. Possible tests may include:

• Blood tests
• Brain magnetic resonance imaging (MRI)
• Echocardiogram (ultrasound images of the heart)
• Spinal X-ray 

Treatment

Because there is no treatment for frontal bossing itself, your child’s treatment plan will depend on any other symptoms and the type of syndrome causing them. Treatment of the underlying condition will likely not reverse your child's frontal bossing, but treatment may keep it from worsening.

Prognosis 

Frontal bossing cannot be reversed because the skull malformation is due to an underlying condition. Talk with your doctor about identifying the syndrome that your child has and how to treat it. Early diagnosis of your child's underlying syndrome is an important part of treatment.

Coping

Noticing a change in your baby’s head shape is scary, especially when you do not know what condition is causing it. Frontal bossing refers to a prominent forehead and is usually a sign of an underlying syndrome. Your medical team will work closely with you to learn your child’s diagnosis and begin a treatment plan.

During this process, it is vital to find ways to care for yourself as well. Having a child with a skull deformity is stressful for parents, especially when the malformation is noticeable to others. Ask your medical team about a local support group or online community where you can seek support and learn coping skills. 

Frequently Asked Questions 

Can frontal bossing be corrected?  

There is no treatment for frontal bossing. While the bone malformation cannot be addressed, the underlying condition causing frontal bossing may be able to be treated. 

What is rickets?

Rickets is a disorder caused by vitamin D deficiency. It leads to bone deformities, stunted growth, and easily breakable bones. Rickets is a rare condition in the United States, but is more common in other parts of the world.

Can an ultrasound show frontal bossing? 

Yes, it is possible to see frontal bossing on a prenatal ultrasound. Studies have shown that a 3D ultrasound may show frontal bossing too. It's important to remember that a prenatal ultrasound does not always detect frontal bossing. It is also possible for frontal bossing to develop after birth.

Summary

Frontal bossing occurs when a baby has a protruding forehead. A child with frontal bossing may also have a heavy brow ridge. This condition usually is a sign of an underlying genetic disorder or birth defect.

While frontal bossing cannot be treated, the underlying condition that causes it can usually be managed. If you notice frontal bossing in your child, it's important to talk to your pediatrician as soon as possible. Early diagnosis and treatment can help your child get the best outcome.

A Word From Verywell  

Frontal bossing refers to a large, prominent forehead and sometimes also a protruding brow. Frontal bossing is usually a sign of an underlying genetic disorder or birth defect. This diagnosis is scary for any parent to hear and carries several unknowns.

While working closely with your medical team to learn your child’s diagnosis and carry out the treatment plan, aim to find small ways to cope. A local support group or online community of parents who have dealt with the same condition may help.