Frontal bossing is a medical term used to describe a prominent, protruding forehead. This symptom is the main marker of many conditions, including many issues that affect a person’s hormones, bones, and/or stature. It is typically identified in infancy or early childhood.
Treatments will address the underlying condition that is causing the frontal bossing. However, since frontal bossing causes a change in the way the bone and tissues of the face and skull are formed, the protruding forehead cannot be corrected.
Frontal bossing causes your child to have an enlarged or protruding forehead or an enlarged eyebrow ridge. This symptom may be mild in the early months and years of your child’s life. As he or she ages, it may become more noticeable.
Frontal bossing is a symptom of a genetic disorder or congenital defect, meaning a problem that is present at birth. The underlying cause of the bossing may result in other symptoms, such as physical deformities.
Frontal bossing is usually caused by conditions that affect your child’s growth hormones.
The most common underlying cause is acromegaly—a chronic disorder that leads to an overproduction of growth hormone. People with acromegaly have larger-than-normal hands, feet, jaws, and bones of the skull.
Other potential causes of frontal bossing include:
- use of the anti-seizure drug trimethadione during pregnancy
- basal cell nevus syndrome
- congenital syphilis
- cleidocranial dysostosis
- Russel-Silver syndrome
- Rubinstein Taybi syndrome
- Pfeiffer syndrome
- Hurler syndrome
- Cruzon syndrome
- abnormal growths in the forehead or skull
Deformities in an infant’s PEX1, PEX13, and PEX26 genes can also cause frontal bossing.
Frontal bossing can easily be diagnosed by examining a child’s forehead and brow ridge. However, the cause of the condition may not be so clear. Since frontal bossing often signals a rare disorder, other symptoms or deformities may offer clues as to its underlying cause.
Your doctor will physically inspect your child’s forehead and take down his or her medical history. You should be prepared to answer questions about when you first noticed the frontal bossing and about any other unusual characteristics or symptoms your child might have.
The doctor may order blood tests to check your child’s hormone levels and to look for genetic abnormalities. The doctor may also employ imaging scans to help determine the cause of frontal bossing. Imaging scans commonly used for this purpose include X-rays and magnetic resonance imaging (MRI) scans.
An X-ray can reveal deformities in the skull that may be causing the forehead or brow region to protrude. A more detailed MRI scan can show deformities or abnormalities in the surrounding bones and tissues. Abnormal growths may be to blame for the forehead protrusion. Imaging scans are the only way to rule out this potential cause.
There is no treatment to reverse frontal bossing. The only available treatments focus on lessening symptoms of the underlying condition and reducing any pain. Frontal bossing does not usually improve with age. However, in most cases, it does not worsen either.
Cosmetic surgery can be helpful in treating many facial deformities. However, there is no evidence that cosmetic surgery can improve the appearance of frontal bossing.
There are no known ways to prevent your child from developing frontal bossing. However, genetic counseling may help you determine if your child is likely to be born with one of the rare conditions that cause this symptom.
Genetic counseling may include blood and urine tests for both parents. If you are a known carrier of a genetic disease, your doctor may recommend certain fertility medications or treatments. Your doctor will discuss which treatment option is right for you.
Always avoid the anti-seizure medication trimethadione during pregnancy to reduce the risk of your child being born with frontal bossing.