Craniosynostosis vs Flat Head Syndrome

Medical Disclaimer This article is for educational purposes only and does not replace medical advice, diagnosis, or treatment. Parents can notice helpful clues, but craniosynostosis and positional head-shape changes should be evaluated by a qualified healthcare professional. Always talk with your child’s pediatrician, craniofacial team, pediatric neurosurgeon, craniofacial plastic surgeon, or healthcare provider about your child’s individual situation.

One of the most common questions parents ask after noticing an unusual baby head shape is:

• “Is this craniosynostosis, or is it just flat head?”
• That question can feel terrifying.

Parents may notice a flat spot on the back of the head, one ear that seems shifted, a ridge on the forehead, a head that looks long and narrow, or a forehead that seems uneven. Then they search online and find two very different possibilities:

Flat head syndrome , which is common and often improves with repositioning, tummy time, physical therapy, or helmet therapy in selected cases.

Craniosynostosis , which means one or more skull sutures closed too early and may require surgery.

Parents often wonder:

• How can I tell the difference?
• Can a flat spot be craniosynostosis?
• Can craniosynostosis look like plagiocephaly?
• Does a ridge always mean a fused suture?
• Will tummy time fix this?
• Does my baby need a helmet?
• When should we ask for a specialist referral?

The short answer is:

Flat head syndrome is usually a molding problem caused by pressure on a baby’s soft skull. Craniosynostosis is a growth problem caused by early fusion of one or more skull sutures. They can look similar, especially when the back of the head is flat, but the pattern of head shape, ear position, forehead shape, suture ridges, head growth, and timing can help doctors tell them apart.

Parents can learn the clues, but they should not have to diagnose this alone.

The American Academy of Pediatrics emphasizes that pediatric clinicians should be able to recognize head-shape abnormalities caused by both deformational, positional processes and synostotic processes, meaning fused sutures. The goal is to distinguish common non-surgical head-shape changes from craniosynostosis, which may require referral and surgical evaluation. (American Academy of Pediatrics)

This guide explains the difference in parent-friendly language.

Quick Answer: Craniosynostosis vs Flat Head Syndrome

Flat head syndrome , also called positional plagiocephaly or deformational plagiocephaly, happens when repeated pressure on one part of a baby’s skull causes flattening or asymmetry. The skull sutures are usually open. HealthyChildren.org explains that positional skull deformity can happen when a baby spends a lot of time in one position, especially during the first months of life when babies cannot yet move their heads and bodies as freely. (HealthyChildren.org)

Craniosynostosis happens when one or more skull sutures close too early. The skull cannot grow normally across the fused suture, so growth is redirected to other areas. Mayo Clinic explains that craniosynostosis is early closure of one or more joints between skull bones before the brain is fully formed, and that the head shape depends on which sutures are closed. (Mayo Clinic)

The easiest parent-friendly distinction is:

Question

Flat head syndrome / positional plagiocephaly

Craniosynostosis

What causes it?

External pressure or positioning

Early fusion of one or more skull sutures

Are the sutures fused?

Usually no

Yes, one or more sutures are fused

Is surgery usually needed?

Usually no

Often yes, depending on type and severity

Can repositioning help?

Often, especially when started early

No, repositioning does not reopen a fused suture

Can helmet therapy help?

Sometimes, for moderate or severe positional flattening

Sometimes after endoscopic surgery; helmet alone does not usually treat a fused suture

Does it affect brain growth?

Common positional skull deformities do not affect brain growth or intellectual development

Craniosynostosis can restrict skull growth and, in some cases, raise pressure concerns

Who should evaluate it?

Pediatrician; physical therapy or helmet specialist if needed

Craniofacial team, pediatric neurosurgery, or craniofacial plastic surgery

The key takeaway:

A flat spot is more often positional, but not always. Craniosynostosis is less common, but important to recognize early.

What Is Flat Head Syndrome?

Flat head syndrome is a general parent-friendly term for a baby head-shape change caused by external pressure.

The medical terms include:

Positional plagiocephaly Uneven flattening, usually on one side of the back of the head.

Deformational plagiocephaly Another term for positional flattening caused by molding forces.

Deformational brachycephaly Symmetric flattening across the back of the head, making the head look wider from side to side.

HealthyChildren.org explains that a positional skull deformity happens when a baby spends a lot of time in one position. It may happen in the womb, during birth, or more commonly during the first 4 to 12 weeks of life. (HealthyChildren.org)

Common contributors include:

• A preferred head position
• A baby always turning to the same side
• Torticollis, or tight neck muscles
• Not enough awake, supervised tummy time
• Prematurity
• Time in the NICU
• Repeated pressure from lying on the same area
• Time in car seats, swings, bouncy seats, or carriers when not needed

The important point:

In flat head syndrome, the skull is being molded by pressure. The sutures are not usually fused.

What Is Craniosynostosis?

Craniosynostosis is different.

A baby’s skull is made of several plates of bone connected by flexible seams called sutures. These sutures allow the skull to expand as the brain grows.

In craniosynostosis, one or more sutures close too early. When that happens, the skull cannot grow normally in that direction. The brain still grows, so the skull grows more in other directions, creating a head shape that often follows a recognizable pattern.

The CDC explains that when a suture closes, the baby’s head stops growing only in that part of the skull, while areas with open sutures continue to grow. The first sign is often an abnormally shaped skull, and healthcare providers may feel for hard edges along sutures, unusual soft spots, slow head growth, or facial-shape changes. (CDC)

Mayo Clinic lists common symptoms as an atypical skull shape, imbalance of facial features or ears, and a raised hard ridge along the closed suture. (Mayo Clinic)

The important point:

In craniosynostosis, the head shape is not just molded by position. It is shaped by a closed growth seam.

Why Parents Confuse the Two

Parents confuse craniosynostosis and flat head syndrome because both can cause a baby’s head to look uneven.

Both may involve:

• Flattening
• Asymmetry
• Ear position changes
• Forehead changes
• A head shape that looks different from photos of other babies
• Concern from family members
• Concern during a well-baby visit
• Internet searches that make everything feel worse

Mayo Clinic notes that a head shape that is not typical does not always mean craniosynostosis; for example, flattening at the back of the head can result from spending too much time lying on the back and may improve with position changes or helmet therapy in more significant cases. (Mayo Clinic)

The patient-friendly message:

The same word — “flat” — can describe different problems. Doctors look at the full pattern, not just one flat area.

The Biggest Difference: Molding vs Fused Suture

The simplest way to understand the difference is:

• Flat head syndrome = molding from pressure.
• Craniosynostosis = growth restriction from a fused suture.

In positional plagiocephaly, the baby’s skull is still flexible and the sutures are usually open. Pressure on the same area causes flattening.

In craniosynostosis, one or more sutures are closed too early. The skull cannot expand normally across that suture, so growth happens elsewhere.

Nationwide Children’s explains that in positional plagiocephaly, the skull sutures are not fused and the head-shape change is typically caused by repeated pressure to the same area. In craniosynostosis, one or more sutures close early, and the skull grows parallel to the fused suture rather than perpendicular to it, causing an abnormal head shape.

The practical message:

Repositioning can help molding. Repositioning cannot reopen a fused suture.

Timing Clues: When Did the Head Shape Change?

Timing can give useful clues.

More consistent with positional flat head

Flat head syndrome often becomes noticeable after birth, especially during the first few weeks or months, when babies spend a lot of time lying down and cannot reposition themselves easily.

HealthyChildren.org says positional skull deformity more often happens in the first 4 to 12 weeks of life and that by around 6 months many babies become more mobile and can turn their heads more regularly. (HealthyChildren.org)

Parents may say:

• “My baby’s head looked normal at birth, but now one side is flat.”
• “She always sleeps with her head turned to the right.”
• “He has a flat spot where he lies.”
• “It got more noticeable over the first couple months.”

More concerning for craniosynostosis

Craniosynostosis may be visible at birth or become more obvious during the first few months as the baby grows.

Mayo Clinic notes that symptoms can often be seen at birth and become easier to see during the first few months of life. (Mayo Clinic)

Parents may say:

• “The head shape looked unusual from birth.”
• “It never really improved after newborn molding.”
• “The shape is becoming more distinct.”
• “There is a hard ridge along a suture.”
• “The head looks long and narrow, triangular, or very asymmetric.”

The practical takeaway:

A head shape that develops from repeated position may be positional. A head shape present from birth, not improving, or following a classic fused-suture pattern should be checked carefully.

Head Shape Clues From the Top View

One helpful way doctors assess head shape is by looking from above.

Parents can sometimes notice these patterns after bath time when the hair is wet, but this is not a substitute for medical evaluation.

Positional plagiocephaly often looks like a parallelogram

In positional plagiocephaly, one side of the back of the head is flat. The forehead on that same side may look more prominent, and the ear on the flat side may shift forward. From above, the head may look like a parallelogram.

HealthyChildren.org explains that deformational plagiocephaly can make the head look like a parallelogram, with the forehead more prominent and the ear shifted forward on the flat side. (HealthyChildren.org)

Lambdoid craniosynostosis may look more trapezoid-like

Lambdoid craniosynostosis is a rare type of craniosynostosis that can also cause flattening at the back of the head. This is one reason parents and clinicians can confuse it with positional plagiocephaly.

Nationwide Children’s explains that lambdoid craniosynostosis is very rare but can cause posterior flattening similar to positional plagiocephaly. In lambdoid craniosynostosis, the ear and possibly forehead on the flat side are displaced backward, creating a more trapezoid-like shape; in positional plagiocephaly, the ear and forehead displacement is forward. (Nationwide Children's Hospital)

The parent-friendly summary:

Forward ear shift tends to fit positional plagiocephaly. Backward or downward ear shift with a trapezoid-like head shape raises more concern for lambdoid craniosynostosis.

Ear Position: Why Doctors Look at the Ears

Ear position can be an important clue.

In positional plagiocephaly, the ear on the flat side often shifts forward.

In lambdoid craniosynostosis, the ear on the flat side may shift backward or sometimes downward.

This distinction is not always easy for parents to judge. Babies wiggle, photos distort angles, and ears are naturally not perfectly identical. Still, it is one reason clinicians examine the head from above and behind.

HealthyChildren.org describes the ear shifting forward on the flat side in deformational plagiocephaly. Nationwide Children’s contrasts that with lambdoid craniosynostosis, where the ear and possibly forehead may be displaced posteriorly and the ear or mastoid may be displaced inferiorly. (HealthyChildren.org)

The practical message:

Ear position is a clue, not a diagnosis. But it can help doctors decide whether the pattern looks positional or synostotic.

Forehead Shape: Flat Head Can Affect the Forehead Too

Parents often think flat head syndrome only affects the back of the head.

But positional plagiocephaly can also make the forehead look more prominent on the same side as the flat spot. This can make the head look twisted or slanted from above.

HealthyChildren.org explains that with deformational plagiocephaly, the forehead may be more prominent and the ear may shift forward on the flat side. (HealthyChildren.org)

Craniosynostosis can also affect the forehead, but in different patterns:

Sagittal craniosynostosis may cause forehead and back-of-head bossing.

Unicoronal craniosynostosis may cause one side of the forehead and brow to look flat, with the opposite side appearing more prominent.

Metopic craniosynostosis may cause a triangular forehead.

Bicoronal craniosynostosis may cause a short, wide head and flatter forehead.

Johns Hopkins describes the head-shape patterns associated with different fused sutures, including long narrow head shape in sagittal synostosis, forehead and brow flattening in unicoronal synostosis, triangular forehead in metopic synostosis, and short wide head shape in bicoronal synostosis. (Hopkins Medicine)

The takeaway:

Forehead changes can happen in both conditions, but the pattern matters.

Back-of-Head Flattening: Usually Positional, Rarely Lambdoid Craniosynostosis

Most back-of-head flattening in babies is positional.

That does not mean parents should ignore it. It means the first step is usually a careful pediatric evaluation to decide whether the pattern fits positional flattening or something less common.

Mayo Clinic notes that flattening at the back of a baby’s head can be caused by spending too much time lying on the back and can be treated with regular position changes, with helmet therapy sometimes used for more significant flattening. (Mayo Clinic)

But lambdoid craniosynostosis can also flatten the back of the head. It is rare, but important to recognize because it is caused by early suture fusion.

Nationwide Children’s specifically notes that lambdoid craniosynostosis is very rare and is the craniosynostosis type that can cause back-of-head flattening similar to positional plagiocephaly. (Nationwide Children's Hospital)

The practical message:

Back flattening is usually positional, but if the head shape looks unusual, severe, worsening, or does not fit the typical positional pattern, ask about craniosynostosis.

Long, Narrow Head Shape: Think Beyond Flat Head

A long, narrow head shape is less typical for simple positional plagiocephaly and may raise concern for sagittal craniosynostosis, especially if it is persistent and noticeable.

Sagittal craniosynostosis occurs when the sagittal suture closes too early. This suture runs from front to back along the top middle of the skull.

Mayo Clinic states that early closure of the sagittal suture forces the head to grow long and narrow, and that sagittal craniosynostosis is the most common type. (Mayo Clinic)

Johns Hopkins explains that sagittal synostosis causes the skull to become long from front to back and narrow from ear to ear, a head shape called scaphocephaly. (Hopkins Medicine)

Parents may describe:

• “My baby’s head is very long front to back.”
• “The head looks narrow from the front.”
• “The forehead or back of the head seems prominent.”
• “People keep saying the head looks like a boat shape.”

The practical takeaway:

A long, narrow head shape should be evaluated for sagittal craniosynostosis, especially if it does not look like temporary newborn molding.

Triangular Forehead: Metopic Ridge vs Metopic Craniosynostosis

The metopic suture runs from the top of the nose up the middle of the forehead.

This suture is unique because it normally closes earlier than many other sutures. Some babies develop a visible or feelable ridge along the middle of the forehead without having true metopic craniosynostosis.

That distinction matters.

A simple metopic ridge may be a normal variant.

Metopic craniosynostosis is more concerning when the forehead has a triangular shape, the temples look narrow, and the eyes may appear closer together.

Johns Hopkins notes that a forehead ridge is not always suspicious and that the metopic suture is one of the earliest to close in healthy babies, making it important for a craniofacial surgeon or neurosurgeon to distinguish a normal ridge from craniosynostosis. (Hopkins Medicine)

Nationwide Children’s similarly states that metopic craniosynostosis causes a triangular forehead shape when viewed from above, while metopic ridging without the triangular shape is a normal variant and does not require surgical correction. (Nationwide Children's Hospital)

The parent-friendly message:

A forehead ridge alone does not automatically mean craniosynostosis. The bigger question is whether the forehead shape is triangular and whether the eyes, temples, and skull shape fit metopic synostosis.

One-Sided Forehead or Eye Asymmetry: Coronal Craniosynostosis Clues

Unicoronal craniosynostosis happens when one coronal suture closes too early.

This can create asymmetry in the forehead, brow, eye socket, and sometimes the nose. Parents may notice that one eye looks more open, higher, or differently shaped, or that one side of the forehead looks flatter.

Mayo Clinic explains that when only one coronal suture closes early, the forehead may flatten on that side and bulge on the other side; the nose may turn and the eye socket may rise on the affected side. (Mayo Clinic)

Nationwide Children’s describes unilateral coronal craniosynostosis as causing a rotated facial appearance, forehead flattening, elevation of the orbital roof on the affected side, and rotation of the nose. (Nationwide Children's Hospital)

The practical takeaway:

If the concern is mainly one-sided forehead, brow, eye, or facial asymmetry, ask whether coronal craniosynostosis should be ruled out.

Symmetric Flatness Across the Back: Positional Brachycephaly vs Bicoronal Craniosynostosis

Sometimes a baby’s head looks flat across the back and wide from side to side. This may be positional brachycephaly, especially if the baby spends a lot of time lying on the back.

HealthyChildren.org describes deformational brachycephaly as a head that is symmetrically flat in the back and wide from side to side. (HealthyChildren.org)

But a short, wide head shape can also be seen in bicoronal craniosynostosis, where both coronal sutures close early. The CDC describes bicoronal synostosis as causing the head to grow broad and short. (CDC)

The practical message:

Symmetric back flattening is often positional, but if the forehead, face, or skull growth pattern seems unusual, a specialist may need to rule out craniosynostosis.

Does a Ridge Mean Craniosynostosis?

Not always.

A ridge can be one of the signs doctors look for, but a ridge by itself is not enough to diagnose craniosynostosis.

Mayo Clinic lists a raised hard ridge along a closed cranial suture as one possible symptom of craniosynostosis. (Mayo Clinic)

But some ridges may occur because of:

• Normal skull anatomy
• Newborn molding
• A normal metopic ridge
• Overlapping skull plates after birth
• A ridge that feels prominent because the baby has little hair or thin soft tissue
• The key question is not just “Is there a ridge?”

Better questions include:

• Is the ridge along a suture?
• Is the head shape also abnormal?
• Is the head shape worsening?
• Is head growth normal?
• Are facial features or ears asymmetric?
• Does the pattern match a known craniosynostosis type?

The patient-friendly takeaway:

A ridge should be checked, but a ridge alone does not always mean surgery or craniosynostosis.

Does a Small or Closed Soft Spot Mean Craniosynostosis?

Not by itself.

Parents often worry when they cannot feel the soft spot or when someone says the soft spot seems small. The soft spot, or fontanelle, can vary widely in size and timing of closure.

A small or hard-to-feel soft spot can be normal, especially if head shape and head growth are normal.

The CDC includes no soft spot and slow or absent head-size growth among signs clinicians may consider in craniosynostosis, but these signs are interpreted along with the full exam, head shape, and growth pattern. (CDC)

The practical message:

Soft spot findings matter most when they appear with abnormal head shape, ridging, slow head growth, or other concerning signs.

Does Flat Head Syndrome Affect Brain Growth?

Common positional skull deformities are usually cosmetic and do not affect brain growth or intellectual development.

HealthyChildren.org states that positional skull deformities do not affect brain growth or intellectual development, are purely cosmetic, and most do not require surgery. (HealthyChildren.org)

That said, babies with positional flattening may also have torticollis, motor delay, prematurity, or other factors that deserve attention. HealthyChildren.org notes that an estimated 85% of babies with torticollis have a positional skull deformity and that infants with torticollis need physical therapy. (HealthyChildren.org)

The balanced message:

Flat head syndrome itself is usually not a brain-growth problem, but the baby should still be evaluated for neck tightness, movement preference, development, and severity of head shape.

Can Repositioning Fix Craniosynostosis?

No.

Repositioning can help positional flattening because the problem is pressure on a soft, moldable skull.

Repositioning cannot reopen a fused suture.

If a baby has true craniosynostosis, the care team may discuss monitoring, surgery, helmet therapy after certain surgeries, or other treatment depending on the type and severity.

Mayo Clinic states that craniosynostosis treatment is often surgery to reshape the head, lessen or prevent pressure on the brain, and create room for proper brain growth. Mild craniosynostosis may not need surgery, but for most babies surgery is the main treatment. (Mayo Clinic)

The practical takeaway:

If the head shape is positional, repositioning may help. If a suture is fused, repositioning alone is not the treatment.

Can a Helmet Fix Craniosynostosis?

Usually, a helmet alone does not treat the fused suture in craniosynostosis.

Helmet therapy has two different roles that parents often confuse.

Helmet therapy for positional flat head

For some babies with moderate or severe positional plagiocephaly, helmet therapy may help reshape the head, especially when repositioning and physical therapy are not enough.

Mayo Clinic notes that if the back of a baby’s head is very flat on one side from positioning, helmet therapy can help reshape the head to a more balanced look. (Mayo Clinic)

Helmet therapy after craniosynostosis surgery

For babies who have minimally invasive or endoscopic craniosynostosis surgery, helmet therapy is often used afterward to guide skull growth.

Mayo Clinic states that after minimally invasive surgery, babies have regular visits to fit helmets that help shape the skull, and that open surgery usually does not require a helmet afterward. (Mayo Clinic)

Johns Hopkins similarly explains that after endoscopic strip craniectomy, a child needs a cranial orthotic helmet for several months to help mold the head into a more symmetrical shape as it grows. (Hopkins Medicine)

The key message:

A helmet may help mold skull growth, but it does not magically open a fused suture. In craniosynostosis, helmet use depends on the diagnosis and surgical plan.

What Parents Can Check at Home

Parents cannot diagnose craniosynostosis at home, but they can gather useful information.

A good time to look is after bath time when the baby’s hair is wet. HealthyChildren.org suggests checking whether the back of the head is evenly round, the ears are even, and the width of the head and forehead are balanced. (HealthyChildren.org)

You can gently observe:

Top view of the head

Back of the head

Forehead shape

Ear position

Eye and eyebrow symmetry

Whether one side is flatter

Whether the baby always turns one way

Whether the shape is improving or worsening

Whether there is a persistent ridge

Whether head circumference is following the growth curve

You do not need to press hard on the skull or repeatedly feel the soft spot.

The practical message:

Take photos from consistent angles and bring them to your pediatrician. Patterns over time can help.

Photos That Can Help the Doctor

Photos are not a substitute for an exam, but they can help show change over time.

Helpful angles include:

• Top of the head
• Back of the head
• Front of the face
• Both side profiles
• Three-quarter views

Take photos:

• In similar lighting
• From similar distance
• With the hair wet or flattened if possible
• Every 2 to 4 weeks if tracking a concern
• Before and after repositioning or physical therapy efforts

Bring the photos to the appointment and ask:

“Does this look positional, or are you concerned about craniosynostosis?”

When Positional Flat Head Is More Likely

Positional flat head may be more likely when:

• The head looked more typical at birth
• Flattening developed during the first weeks or months
• The baby prefers turning the head one direction
• There is known torticollis or neck tightness
• The flatness is on the back or one back side of the head
• The ear on the flat side seems shifted forward
• The forehead on the flat side is more prominent
• The head looks like a parallelogram from above
• The head shape improves with repositioning, tummy time, or therapy
• Head circumference is growing as expected
• Development is otherwise on track

HealthyChildren.org describes deformational plagiocephaly as uneven flattening in the back of the head, often with forehead prominence and the ear shifted forward on the flat side. It also notes that positional skull deformities often relate to the position in which a baby spends the most time. (HealthyChildren.org)

The parent-friendly takeaway:

If the shape matches where the baby rests and the baby strongly prefers one side, positional flattening becomes more likely.

When Craniosynostosis Is More Concerning

Craniosynostosis may be more concerning when:

• The head shape looked unusual at birth
• The shape does not improve over time
• The shape becomes more pronounced as the baby grows
• There is a hard ridge along a suture
• The head is very long and narrow
• The forehead is triangular
• One forehead or brow is flatter than the other
• One eye looks higher, wider, or differently shaped
• The nose or face seems rotated
• The ear shift looks backward or downward rather than forward
• The head shape looks trapezoid-like from above
• The baby’s head circumference is not growing as expected
• More than one area of the skull seems restricted
• The pediatrician is concerned after examining the sutures

The CDC says craniosynostosis is often first identified by an abnormally shaped skull, and providers may feel for hard suture edges, unusual soft spots, slow head growth, and facial-shape problems. (CDC)

The practical message:

If the head shape fits a fused-suture pattern, ask for specialist evaluation rather than waiting only on repositioning.

When to Ask for a Craniofacial Referral

Ask your pediatrician whether a craniofacial referral is appropriate if:

• Craniosynostosis is suspected
• The diagnosis is unclear
• Head shape is worsening
• There is a persistent suture ridge
• The head is long and narrow, triangular, short and wide, or markedly asymmetric
• The forehead, eyes, brow, ears, or face look asymmetric
• The head shape is not improving with repositioning
• There is concern for lambdoid, sagittal, metopic, coronal, or multisuture craniosynostosis
• Head growth is slowing or crossing percentiles
• You are being told to “wait and see” but feel the pattern is getting more obvious
• You want a specialist opinion before imaging or helmet treatment

Mayo Clinic states that craniosynostosis is usually diagnosed by specialists such as pediatric neurosurgeons or specialists in plastic and reconstructive surgery, using physical exam, imaging when needed, and genetic testing if a syndrome is suspected. (Mayo Clinic)

The patient-friendly takeaway:

A referral does not mean your baby definitely needs surgery. It means the right team can clarify the diagnosis and timing.

Does My Baby Need Imaging?

Maybe, but not always right away.

Some babies can be diagnosed clinically by an experienced specialist. Others may need imaging, such as ultrasound, X-ray, CT scan, 3D CT, or MRI depending on the question and the care team’s approach.

Mayo Clinic explains that imaging studies such as CT, MRI, or cranial ultrasound can show whether sutures have fused, and that imaging, laser scans, and photographs may be used to measure skull shape and plan surgery. (Mayo Clinic)

For families, the practical question is:

• “Should we see the craniofacial team first, and let them decide what imaging is needed?”
• This matters because not every baby with a flat spot needs a CT scan.

The practical takeaway:

Imaging can be very helpful when needed, but the first step is often a careful exam and referral decision.

What Parents Should Not Do

When parents are scared, it is easy to try anything that claims to fix head shape. Some products are not safe.

Do not use infant sleep positioners or head-shaping pillows to try to correct a flat spot. HealthyChildren.org states that infant head-shaping pillows are not safe, can create an unsafe sleep environment, may contribute to suffocation risk, and are not proven effective for positional skull deformities, craniosynostosis, or other medical purposes. (HealthyChildren.org)

Do not stop safe sleep practices because of a flat spot. Babies should still sleep on their backs unless your healthcare professional gives different instructions for a specific medical reason.

Do not assume a helmet is the answer before the diagnosis is clear.

Do not assume a flat spot is harmless if the pattern is unusual, worsening, or not improving.

Do not blame yourself.

The patient-friendly message:

Safe sleep still matters. Head-shape concerns should be handled through pediatric guidance, supervised awake positioning, physical therapy when needed, helmet referral when appropriate, and craniofacial evaluation when craniosynostosis is possible.

What Treatment Looks Like for Positional Flat Head

Treatment depends on age, severity, and whether torticollis is present.

Common approaches include:

• More supervised tummy time while awake
• Changing the direction the baby faces in the crib
• Encouraging the baby to turn toward the non-preferred side while awake
• Alternating feeding positions
• Limiting unnecessary time in car seats, swings, and bouncy seats
• Physical therapy for torticollis
• Helmet therapy in selected moderate or severe cases

HealthyChildren.org recommends increasing tummy time while the baby is awake and watched, reducing unnecessary pressure from carriers and seats, and using physical therapy when torticollis is present. (HealthyChildren.org)

The practical takeaway:

For positional flat head, early action can help because the skull is still growing and moldable.

What Treatment Looks Like for Craniosynostosis

Treatment depends on:

• Which suture is fused
• How severe the head-shape change is
• Whether one or multiple sutures are involved
• The baby’s age
• Whether the condition appears isolated or syndromic
• Whether there are pressure, eye, airway, or developmental concerns
• The craniofacial team’s recommendation

Mayo Clinic states that mild craniosynostosis may not require surgery, but for most babies surgery is the main treatment. The purpose is to reshape the head, lessen or prevent pressure on the brain, and create room for brain growth. (Mayo Clinic)

Surgery may be:

Endoscopic surgery Usually considered for younger babies in selected cases and often followed by helmet therapy.

Open cranial vault remodeling A larger surgery often used for older babies, more significant reshaping, or cases where endoscopic surgery is not the best option.

Johns Hopkins explains that the surgical approach depends on the child’s age, severity, and other factors, and describes both open cranial vault remodeling and endoscopic strip craniectomy as common approaches. (Hopkins Medicine)

The practical message:

Craniosynostosis treatment is individualized. The same head-shape concern does not lead to the same plan for every baby.

Common Parent Scenarios

“My baby has a flat spot on one side of the back of the head.”

This is often positional plagiocephaly, especially if your baby prefers turning one direction. Ask the pediatrician to check for torticollis, ear position, forehead shift, and whether the pattern looks like a parallelogram.

“My baby’s head is long and narrow.”

Ask whether sagittal craniosynostosis should be ruled out, especially if the shape was present early, is not improving, or there is a ridge along the top of the head.

“My baby has a ridge down the forehead.”

Ask whether it looks like a normal metopic ridge or metopic craniosynostosis. The key distinction is often whether the forehead is triangular and whether the eyes or temples appear affected.

“One eye looks higher or different.”

Ask whether coronal craniosynostosis should be considered, especially if there is forehead flattening, brow asymmetry, or facial rotation.

“The back of the head is flat, but the ear looks shifted backward.”

Ask specifically about lambdoid craniosynostosis. It is rare, but this is one of the patterns clinicians look for.

“The pediatrician says it is positional, but it is getting worse.”

Ask whether physical therapy, helmet referral, or craniofacial referral is appropriate. It is reasonable to ask for reassessment if the pattern is not improving.

Bring these questions to your appointment:

• Does this look more like positional plagiocephaly or craniosynostosis?
• Which head-shape features make you think that?
• Is my baby’s head circumference growing normally?
• Do you feel any hard ridges along the sutures?
• Is the flat side associated with forward or backward ear shift?
• Does the head look like a parallelogram or trapezoid from above?
• Is there forehead, eye, brow, or facial asymmetry?
• Does my baby have torticollis or a head-turning preference?
• Should we start physical therapy?
• Should we try repositioning first?
• How long should we watch before reassessing?
• Is helmet therapy appropriate?
• Should we be referred to a craniofacial team?
• Do we need imaging, or should a specialist decide?
• What symptoms would make this more urgent?

If you are referred, ask:

• Does my baby have craniosynostosis?
• Which suture is involved?
• Is this positional plagiocephaly, craniosynostosis, or both?
• Is the diagnosis clear from exam, or is imaging needed?
• If imaging is needed, what type and why?
• Does this look like isolated single-suture craniosynostosis?
• Is there any concern for multisuture or syndromic craniosynostosis?
• Does my baby need genetic testing?
• Is surgery recommended?
• What happens if we monitor instead?
• Is endoscopic surgery an option?
• Is open surgery recommended?
• Would helmet therapy be needed?
• How does my baby’s age affect treatment options?
• How urgent is the decision?
• What follow-up is needed?

Red Flags: When to Call a Doctor Promptly

Call your child’s healthcare professional promptly if your baby has:

A head shape that is rapidly worsening

A hard ridge along a suture with abnormal head shape

Head circumference that is not growing as expected

A persistently bulging soft spot

Repeated or projectile vomiting

Poor feeding

Unusual sleepiness or decreased alertness

Extreme irritability

High-pitched cry

Very noticeable scalp veins

Developmental delays or loss of skills

New eye movement concerns

Breathing problems

Seizure-like activity

Johns Hopkins lists signs that may be associated with elevated intracranial pressure in craniosynostosis, including a full or bulging fontanelle, decreased alertness, visible scalp veins, irritability, high-pitched cry, poor feeding, projectile vomiting, increasing head circumference, and developmental delays. (Hopkins Medicine)

Seek urgent medical care if your baby is difficult to wake, has trouble breathing, has seizure-like activity, has repeated vomiting, or seems seriously ill.

How to Explain the Difference to Family

Here is a simple explanation:

“Flat head syndrome usually means the baby’s soft skull has been molded by pressure from lying in the same position. Craniosynostosis means one of the skull growth seams closed too early. They can both change head shape, but the patterns are different. The pediatrician or craniofacial team looks at the whole head shape, ear position, forehead, ridges, head growth, and sometimes imaging to tell the difference.”

This can help family members understand why you may be doing tummy time and repositioning — but also why you may still need a specialist opinion.

Flat head syndrome and craniosynostosis are not the same.

Flat head syndrome is usually caused by repeated pressure on a soft, moldable skull.

Craniosynostosis is caused by early fusion of one or more skull sutures.

Positional plagiocephaly often creates a parallelogram-like head shape from above, with the ear and forehead shifted forward on the flat side.

Lambdoid craniosynostosis is rare but can also flatten the back of the head; it may create a trapezoid-like shape with the ear shifted backward or downward.

• A long, narrow head may suggest sagittal craniosynostosis.
• A triangular forehead may suggest metopic craniosynostosis, but a metopic ridge alone can be normal.
• One-sided forehead, brow, eye, or facial asymmetry may raise concern for coronal craniosynostosis.
• A ridge or small soft spot alone does not automatically mean craniosynostosis.
• Repositioning, tummy time, and physical therapy can help positional flattening.
• Repositioning does not reopen a fused suture.

Helmet therapy can help selected positional cases and is also used after some craniosynostosis surgeries, but helmet use depends on the diagnosis.

The most important next step is a calm, timely evaluation.

The simplest parent-friendly summary is:

If the head shape follows where the baby rests, positional flat head is more likely. If the head shape follows a fused-suture pattern, does not improve, includes a hard ridge, or affects the forehead, eyes, ears, or head growth, craniosynostosis should be ruled out.

Frequently Asked Questions About Craniosynostosis vs Flat Head Syndrome

Is flat head syndrome the same as craniosynostosis?

No. Flat head syndrome is usually caused by repeated pressure on a baby’s skull, while craniosynostosis is caused by one or more skull sutures closing too early. Nationwide Children’s explains that positional plagiocephaly differs from craniosynostosis because the skull sutures are not fused in positional plagiocephaly. (Nationwide Children's Hospital)

Can craniosynostosis look like flat head syndrome?

Yes, especially lambdoid craniosynostosis, which can flatten the back of the head. Lambdoid craniosynostosis is rare, but it can be confused with positional plagiocephaly. Nationwide Children’s notes that lambdoid craniosynostosis is very rare and can create posterior flattening similar to positional plagiocephaly. (Nationwide Children's Hospital)

What is the biggest difference between positional plagiocephaly and craniosynostosis?

The biggest difference is the cause. Positional plagiocephaly is caused by external pressure or positioning. Craniosynostosis is caused by early fusion of a skull suture. In positional plagiocephaly, the sutures are usually open. In craniosynostosis, one or more sutures are fused.

How can parents tell if a flat spot is positional?

Positional flattening often develops after birth, is related to a baby’s preferred head position, appears on the back or one back side of the head, and may be associated with torticollis. HealthyChildren.org explains that deformational plagiocephaly often includes uneven flattening in the back of the head, forehead prominence, and forward ear shift on the flat side. (HealthyChildren.org)

What head shape suggests sagittal craniosynostosis?

Sagittal craniosynostosis often causes a long, narrow head shape. Mayo Clinic states that early closure of the sagittal suture forces the head to grow long and narrow. (Mayo Clinic)

Does a forehead ridge mean metopic craniosynostosis?

Not always. A metopic ridge can be a normal variant. Johns Hopkins explains that a forehead ridge is not always suspicious and that the metopic suture closes early in healthy babies. A craniofacial surgeon or neurosurgeon can help distinguish a normal ridge from metopic craniosynostosis. (Hopkins Medicine)

Can repositioning fix craniosynostosis?

No. Repositioning can help positional flattening because that problem is caused by pressure. Repositioning cannot reopen a fused skull suture. Craniosynostosis treatment may involve monitoring or surgery depending on type and severity.

Can tummy time help flat head syndrome?

Yes, supervised tummy time while the baby is awake can help reduce pressure on the back of the head and support motor development. HealthyChildren.org recommends increasing tummy time while babies are awake and watched. (HealthyChildren.org)

Should I stop putting my baby on their back to sleep because of a flat spot?

No. Back sleeping remains important for safe sleep. Use tummy time only when your baby is awake and supervised, and talk with your pediatrician about safe ways to reduce pressure on the flat area.

Can a helmet fix flat head syndrome?

Sometimes. Helmet therapy may be considered for moderate or severe positional flattening, especially when repositioning and physical therapy are not enough. Mayo Clinic notes that helmet therapy can help reshape a very flat area to a more balanced look in positional flattening. (Mayo Clinic)

Can a helmet fix craniosynostosis?

A helmet alone usually does not treat the fused suture. Helmets are often used after minimally invasive craniosynostosis surgery to guide skull growth. Mayo Clinic states that after minimally invasive surgery, babies may wear helmets to help shape the skull, while open surgery usually does not require a helmet afterward. (Mayo Clinic)

Does flat head syndrome affect brain development?

Common positional skull deformities do not affect brain growth or intellectual development. HealthyChildren.org states that positional skull deformities are purely cosmetic and most do not require surgery. (HealthyChildren.org)

Does craniosynostosis affect brain development?

It can in some cases, especially if multiple sutures are involved or pressure inside the skull increases. The CDC explains that when more than one suture closes early, the brain may not have enough room to grow, which can lead to pressure inside the skull. (CDC)

When should I ask for a craniofacial referral?

Ask for referral if craniosynostosis is suspected, the diagnosis is unclear, the head shape is worsening, there is a hard suture ridge, the head is long and narrow or triangular, the forehead or eyes are asymmetric, the ear shift looks unusual, or the head shape does not improve with repositioning.

Does my baby need a CT scan?

Not always. Some babies are diagnosed clinically, and others need imaging. Mayo Clinic explains that CT, MRI, or cranial ultrasound can show whether sutures have fused. Ask whether a craniofacial specialist should evaluate your baby before imaging is ordered. (Mayo Clinic)

Are head-shaping pillows safe?

No. HealthyChildren.org states that infant head-shaping pillows are not safe, may create an unsafe sleep environment, may increase suffocation risk, and are not proven effective for positional skull deformities or craniosynostosis. (HealthyChildren.org)

Suggested External Sources for the Published Blog

Use these at the bottom of the published article as a “Sources” section:

American Academy of Pediatrics — Identifying the Misshapen Head: Craniosynostosis and Related DisordersBest for: distinguishing craniosynostosis from deformational head-shape changes, recognizing head-shape patterns, and guiding referral decisions. (American Academy of Pediatrics)

HealthyChildren.org / American Academy of Pediatrics — When a Baby’s Head Is Misshapen: Positional Skull DeformitiesBest for: positional plagiocephaly, deformational brachycephaly, torticollis, tummy time, forward ear shift, parallelogram shape, and parent-safe prevention steps. (HealthyChildren.org)

CDC — Craniosynostosis Best for: basic definition, suture closure, signs of craniosynostosis, diagnosis, and treatment overview. (CDC)

Mayo Clinic — Craniosynostosis: Symptoms, Causes, Diagnosis, and TreatmentBest for: craniosynostosis symptoms, types, head-shape patterns, diagnosis, imaging, surgery goals, and helmet therapy after minimally invasive surgery. (Mayo Clinic)

Johns Hopkins Medicine — Craniosynostosis and Craniosynostosis Surgery Best for: suture-specific head-shape patterns, intracranial pressure symptoms, endoscopic surgery, open cranial vault remodeling, and post-surgery helmet therapy. (Hopkins Medicine)

Nationwide Children’s Hospital — Differentiating Craniosynostosis From Positional PlagiocephalyBest for: practical comparison of positional plagiocephaly and craniosynostosis, ear shift differences, lambdoid synostosis clues, metopic ridge versus metopic synostosis, and top-view head-shape patterns. (Nationwide Children's Hospital)