Craniosynostosis, or simply synostosis, is the early growing together (or fusion) of two or more bones of the skull.
The types of craniosynostosis are based on how many bones are fused together:
- Single-Suture Synostosis (Primary)
- Sagittal synostosis (scaphocephaly)
- Unilateral coronal synostosis (anterior plagiocephaly)
- Lambdoid (posterior plagiocephaly)
- Metopic (trigonocephaly)
- Double-Suture Synostosis
- Bicoronal (brachycephaly)
- Sagittal plus metopic
- Complex Multisuture Synostosis
- Bicoronal, sagittal, metopic
- Cloverleaf skull (Kleeblattschädel)
A newborn's skull is made up of many separate bones that are not yet fused together. The brain grows quickly in the first two years of life. It’s important that the skull bones remain open, so the brain has enough room to grow. Complete fusion of the bones normally occurs late in the teen years. Synostosis interferes with normal growth of the brain and skull.
A suture is the seam between two skull bones. The different skull sutures naturally close throughout a human’s life. Some of these sutures close at a young age. Others may close later in life.
At birth, the open sutures allow a lot of flexibility in the face and skull bones. This flexibility allows the newborn to pass through the birth canal. The bones will settle into a typical shape within one to two weeks after birth.
Shape of the Head
The main symptom of craniosynostosis is an abnormal head shape. An abnormal head shape (plagiocephaly) can happen when forces push on the skull before or after birth. This can happen before birth:
- When the baby descends into the pelvis
- If the mom has an abnormally shaped uterus
- If the fetus is in an odd position
- If the mom is having more than one baby (like twins or triplets)
After birth, abnormal head shape is most commonly a result of gravity. This can happen when the baby lies in one position for long periods of time.
Most head shape problems will fix themselves within the first few weeks after birth. The fix is usually rapid brain growth or frequent repositioning of the baby. Repositioning involves moving the baby (usually onto the stomach) to make sure they are not sleeping or lying on one side of the head for too long.
Molding helmets may be used for newborns who are not showing improvement in head shape with repositioning techniques. It is important to recognize positional plagiocephaly (a non-surgical condition) from craniosynostosis, which requires surgery to correct the problem.
Craniosynostosis causes a change in the normal shape of the head. If a suture − the seam between two skull bones − is fused, it cannot grow. This causes the bones with open sutures to grow more than usual to allow enough room for brain growth. In many children, the only symptom may be an irregularly shaped head.
Some children will experience unusually high pressure on the brain, initially causing headaches. If left untreated, some children may develop learning disabilities or problems with their eyesight. Early in life the brain avoids damage from this pressure as other bones grow to accommodate the growing brain. Doctors cannot predict which children will develop this pressure problem. With more than one suture fused, the chance of increased pressure is higher.
Children who have multiple suture craniosynostosis, have a higher risk of increased brain pressure. They can experience head pain, damage to the eyes, and developmental delays because of this.
There may be reasons other than synostosis that your child's head is misshapen, so your child's doctor may order X-rays or a CT scan to screen for this condition. The doctor may refer your child to a neurosurgeon or plastic surgeon to obtain an opinion regarding the problem.
Craniosynostosis can happen on its own without other related abnormalities (non-syndromic). It may stem from an underlying genetic condition (syndromic). The type of craniosynostosis a child has depends on which skull sutures fuse. The child’s head shape looks different based on which sutures fuse.
Types of synostosis can include:
- Single-suture synostosis (primary)
- Double-suture synostosis
- Complex multisuture synostosis
Single-Suture Synostosis (Primary)
If one skull suture fuses, the condition is called single-suture synostosis. Examples of single-suture synostosis include:
- Sagittal synostosis (scaphocephaly): This is the most common type of synostosis. It happens when the sagittal suture fuses. Sagittal synostosis produces a boat-shaped head that is longer than it is wide. This type of synostosis creates a prominent forehead. The child will have a ridge on the top of the head along the closed suture.
- Unilateral coronal synostosis (anterior plagiocephaly): In unilateral coronal synostosis, one side of the coronal suture fuses. This causes the head shape to be uneven. One side of the forehead looks flat. It also creates an almond-shaped eye socket on one side of the head.
- Lambdoid (posterior plagiocephaly): Lambdoid synostosis is a rare type of craniosynostosis that happens when part of the lambdoid suture fuses. Since this suture is at the back of the head, the back of the skull will look flat. One ear may look higher than the other.
- Metopic (trigonocephaly): This form of synostosis is uncommon (less than 10% of cases). It happens when the metopic suture fuses. The metopic suture is at the front of the skull. Metopic synostosis can cause a triangle-shaped head. The child will have a narrow forehead and eyes that are close together.
If two skull sutures fuse, the condition is called double-suture synostosis. Examples of double-suture synostosis include:
- Bicoronal (brachycephaly): This form of synostosis happens when both sides of the coronal suture fuse. It can cause a short and wide skull. It also causes vertical growth in the skull (turribrachycephaly). Bicoronal synostosis is often diagnosed in children with Apert's syndrome and Crouzon's syndrome. It is also found in children without these syndromes.
- Bilambdoid: In bilambdoid synostosis, both sides of the lambdoid suture fuse. This condition causes the skull to look wider than normal (posterior brachycephaly).
- Sagittal plus metopic: This type of double-suture synostosis occurs when both the sagittal and metopic sutures fuse. Because both sutures run lengthwise down the middle of the head, this type of synostosis creates a head shape that is long and narrow (scaphocephaly).
Complex Multisuture Synostosis
In some cases, more than two skull sutures will fuse. These conditions are called complex multisuture synostosis. Examples of complex multisuture synostosis include:
- Bicoronal, sagittal, metopic: This condition happens when the sagittal, metopic and both sides of the coronal suture fuse. As a result, the head will look short and wide. The head may also appear pointed at the top (turribrachycephaly).
- Cloverleaf skull (Kleeblattschädel): This is a very rare form of craniosynostosis where the coronal, sagittal and lambdoid sutures all fuse. It is often found in children with severe Apert’s syndrome, Crouzon’s syndrome and Carpenter’s syndrome.
- Pancraniosynostosis: This is another rare form of craniosynostosis where all of the large sutures in the skull fuse.
Sometimes craniosynostosis is associated with an underlying genetic condition. These conditions can include:/p>
This is the most common syndrome related to craniosynostosis. It is associated with bilateral coronal craniosynostosis, midfacial abnormalities, forward protrusion of the eyes and airway obstruction. About 30% of patients will have fluid buildup in the brain (hydrocephalus). There generally are no limb abnormalities. Intelligence is often normal. This syndrome occurs in one out of 25,000 births. A mutation that may be responsible for Crouzon's syndrome has been found in the FGFR2 gene. However up to one-third of the cases occur spontaneously.
This syndrome is also related to bilateral coronal craniosynostosis, with a tall and shortened head. Other forms of synostosis may also be seen with this condition. The skull base is frequently fused as well. Hand, elbow, hip and knee abnormalities may also be present. Like Crouzon's syndrome, the face has a classical appearance with protrusion and wide spacing of the eyes, beaked nose and down-slanting eyelids. It occurs in about one in 100,000 births. This is usually an inherited pattern. Developmental delay is common. Intellectual disabilities are seen in 50-85% of cases.
This syndrome is commonly associated with lambdoid and sagittal synostosis. The child may also have limb abnormalities that may include extra digits on the feet. It is also associated with abnormalities of the heart. A genetic location for this syndrome has not yet been identified.
This syndrome is also characterized by craniosynostosis and limb abnormalities. Unicoronal craniosynostosis is common as well as mid-facial deformities, protruding eyes and hearing loss. Fluid buildup in the brain (hydrocephalus) is common. Three types have been described, with types 2 and 3 being the more severe forms.
This is a congenital syndrome that’s often associated with craniosynostosis and limb abnormalities. The genetic location of this syndrome is different than the other syndromes. Characteristic features include coronal synostosis (usually unilateral) with limited growth in the anterior cranial base. Children may also have a low set hairline, eyelid abnormalities, facial asymmetry and mild to moderate developmental delay.
Craniosynostosis is treated by surgery that opens the fused sutures. This creates space for brain growth. A variety of surgeries may be used. The surgeon will discuss the craniosynostosis treatment options available for your child. They will work with you to choose the most appropriate procedure depending on the sutures involved and your child's age when they are diagnosed. A neurosurgeon and a plastic surgeon work together for more complex types of craniosynostosis.
Minimally Invasive Craniosynostosis Surgery
Minimally invasive surgery can be used to treat patients with various types of craniosynostosis. It is reserved only for young infants (younger than 4 months of age).
Patients who have minimally invasive surgery will wear a custom-made helmet for a few months after surgery. The helmet will gently mold the child’s head into a more natural shape as the brain grows.
Endoscopic Craniectomy or Strip Craniectomy: One of the most common types of minimally invasive surgery is an endoscopic craniectomy or strip craniectomy. The surgeon will remove the suture by making small incisions (cuts) on the scalp. A small camera (endoscope) is used alongside the CT imaging to work in exactly the right spot. When used to treat sagittal synostosis, this procedure is called an endoscopic strip sagittal craniectomy.
Cranial Springs: This surgery starts with a strip craniectomy, where the surgeon will remove the fused suture. After that, the surgeon places stainless steel springs in the newly opened suture. This gives the brain room to grow. The surgeon will remove the springs a few months later. This procedure is typically used to treat sagittal synostosis.
Open Craniosynostosis Surgery
Cranial Vault Reconstruction (CVR): The surgeon will remove pieces of the skull near the fused suture and re-shape it to allow room for the brain to grow. A CVR may be done on the entire skull or in individual sections. It is also called cranial vault reconstruction, cranial vault remodeling or cranial reconstruction.
Cranioplasty: A cranioplasty repairs skull anomalies or holes. A surgeon may repair the skull with the child’s original bone (autologous cranioplasty). They may use artificial bone (skull allograft implant) as well.
Distraction (Cranial Vault Distraction or Cranial Distraction): This surgery is used to expand part of the skull, usually the back of the skull (posterior vault distraction or PVR). During the operation, the surgeon will remove a piece of skull. They will put in a medical device that’s secured by screws. The device allows the skull to increase in size. Once enough bone grows back, the surgeon will take out the screws and device.
Frontal-Orbital Advancement (FOA): An FOA removes and reshapes the skull bone around the forehead. It is often used to treat older infants who have a severe metopic synostosis or coronal synostosis.
Before surgery, your child will be scheduled for an appointment with the Craniosynostosis and Cranial Reconstruction Center. This will include neurosurgery and plastic surgery. To help us prepare for a successful surgery, please share your child's full medical history, including any:
- Bleeding disorders within the family
- Medications your child is currently taking
- Any allergies to medication, foods, latex (rubber) or the environment
Let us know of any unexplained problems with surgery. Watery eyes, sneezing or wheezing while playing with balloons may be due to a latex allergy. Anyone who has had multiple surgical procedures might have this allergy.
If your child needs a helmet after surgery, we will schedule a helmet fitting appointment at the Hanger Clinic. They specialize in creating orthotics and prosthetics. This appointment will happen a week or two before your child’s surgery. We’ll notify you once your child’s helmet is ready. You can pick it up right before or after your child’s surgery.
Day of Surgery
On the day of the procedure, a doctor called an anesthesiologist will talk to you about methods of pain control that are appropriate to your child's size and age.
The anesthesiologist will get a thorough history of your child's past anesthetics. They will also need to know any family reactions to general anesthesia. On the day of the surgery, please be prepared with this information. It is very important in preventing possible reactions to anesthetics that may be used during the surgery.
Before coming to the hospital, please read the pre-operation checklist below. If your child is old enough to understand, please explain what will happen before, during and after surgery using familiar terms.
- Mark your calendar clearly with the date, time and arrival time for your child's surgery. Surgery for patients who arrive late may have to be rescheduled. Please make arrangements for reliable transportation.
- Be sure you understand the eating and drinking instructions. If you don't follow these directions, surgery may be postponed.
- Inform us as soon as possible if your child develops a rash, fever, flu, cold, diarrhea, vomiting or has been exposed to any communicable diseases like COVID-19, chicken pox, measles, mumps. Surgery may have to be postponed if exposure was recent.
- To avoid potential bleeding complications, do not give your child aspirin, Motrin, Advil or ibuprofen for five days prior to surgery, except as prescribed by your child's surgeon. If, by mistake, your child does take any of the medications listed, please let us know. These medicines interfere with the blood's ability to clot. Your child's surgery may have to be rescheduled. Your child may take Tylenol, an aspirin-free medicine, for pain or fever reduction.
- Once your child's surgery has been scheduled, schedule a preoperative physical with your pediatrician or family doctor prior to surgery. This ensures that your child has no illnesses that may complicate surgery or anesthesia. It also allows your child's doctor to know when your child is having surgery. The doctor must complete the preoperative history and physical form that you received when you and your child last visited us in neurosurgery. Bring this completed form with you on the day of your child's surgery.
- Before surgery, a nurse or technologist will take a sample of your child's blood. Your child’s pre-operative labs can be done at any Cincinnati Children’s outpatient lab location. Appointments are not necessary. Arrangements can be made for families that live out of town to have the testing done closer to their home.
- Blood transfusions are often needed for children who have surgery for craniosynostosis. If your child's neurosurgeon has told you that your child will need a blood transfusion for surgery, you have the option of using the blood provided through Hoxworth Blood Center or of donating through Hoxworth's Directed Donor Program. Hoxworth believes that the blood obtained through regular donations is as safe as blood secured through directed donors. This is especially true if the directed donor is not the parent or immediate relative. Women who have given birth within the past six months cannot donate blood. If you are interested in the Directed Donor program, please call Hoxworth at 513-451-0910 or 800-830-1091.
- Please follow the bathing instructions that were reviewed with you by your nurse.
- Arrive at the hospital an two hours before the scheduled time of surgery. Bring your child's overnight bag, the form completed by your child's pediatrician and your insurance card. If you plan on spending the night with your child while they recover with us, remember your own overnight bag.
- For patients having minimal access craniosynostosis surgery, your child will see a helmet specialist to be fitted prior to surgery.
Preparing Your Child for Surgery
Children Younger than 12 Months
- Stop solid baby foods, cereal and formula five hours before arriving at the hospital. Limit your child's diet to clear liquids.
- Stop clear liquids and breastfeeding three hours before arriving at the hospital.
Children Older than 12 Months
- Stop solid foods, milk, juices, candy and gum seven hours before arriving at the hospital.
- Stop clear liquids three hours before arriving at the hospital. Clear liquids are fluids you can see through:
- Clear broth
- Breast milk (but not formula)
If your child takes daily medication for the heart, asthma or seizures, they need to take the medication the morning of surgery. Your child should take medicine with a small sip of clear liquid. Do not give antibiotics the morning of the surgery as they can cause nausea and vomiting.
If you have questions about your child's medication, please call the neurosurgery office at 513-636-4726.
Depending on the type of surgery, your child may go to our pediatric intensive care unit (PICU) right after surgery. Your child's head will be fully wrapped with a turban dressing. Their head will be elevated. Sticky pads on your child's chest give readings to monitor the heart. A red light on your child's finger or toe tells us if the blood is getting enough oxygen. Your child will get needed fluids and medications through their IV. A blood sample will be taken to make sure your child is recovering as well as expected. This will happen about every six hours for a few days.
Your child will be sleepy the first day. They will be able to take a bottle the evening of the surgery. Two days after surgery the head dressing will be removed.
When their blood counts are stable, your child will move from the PICU into a regular room. At this point, you'll be able to hold your child. Their head and face will be swollen. The worst swelling occurs two to three days after surgery. Often their eyes swell shut. This may frighten your child. Parents' voices and familiar music and sounds help comfort your child.
You can take your child home on the fourth or fifth day after surgery if they had cranial vault reconstruction. Most children undergoing minimally invasive craniosynostosis surgery leave the hospital in one to two days after surgery. Head and face swelling will be improved. The swelling around the eyes will come and go for two to three more weeks.
If your child sleeps face down, they will awaken with the eyes swollen shut. After one or two hours, this swelling will go away. To decrease swelling, we recommend that you put your child to sleep on their back for several weeks after surgery. If they roll over, reposition the child onto their back. Keep their head up.
Once home, your child may have the days and nights confused. To lessen the effects of this adjustment, provide periods of play during the day in a bright room.
- Pain: Your child will be sent home with pain medication. When they are discharged, you will be given instructions on how and when to give these medications.
- Diet: Once your child is home, go back to a regular diet. There are some restrictions right after surgery. Since your child will be spending several nights with us, we will restrict the diet as needed during that time.
- Wound Care: You should wash your child's incision (cut) each day with a mild shampoo (see home care instructions for a child with cranial incision lines). Do not use cream rinse or any lotions on the head until the skin heals completely. Cover your child's head when going outside. The incision gets sunburned very easily.
- Activity: Your child may return to usual activity levels when you go home. Remove low-lying furniture with sharp edges such as coffee tables to prevent possible head injuries. Your child should stay home from school and daycare until the first follow up visit.
- Bathing: Your child should shower with mild baby soap or shampoo daily. A sponge bath with mild soap followed by rinsing with clean water is fine for smaller children. Do not allow the wound to soak in the bath tub.
If your child needs to wear a helmet after minimally invasive surgery, they can start wearing the helmet approximately 72 hours after the procedure. Your child’s doctor and helmet specialist will give specific instructions of when to start the helmet therapy. They will tell you how long your child should wear the helmet each day.
Follow-up appointments are typically two weeks after the surgery. This appointment will either be with an advance practice provider or your child’s surgeon. Three months after surgery your child will have a follow-up appointment with the surgical team.
These appointments should be scheduled before you take your child home from Cincinnati Children's.
If your child has a helmet, follow up will be determined by the helmet specialist. Most children will go to their first helmet follow-up appointment seven to ten days after surgery.
Call Your Child's Doctor If:
Call the neurosurgery care team at 513-636-4726 if you are concerned with your child's progress after surgery.
Please call if your child has:
- Temperature greater than 100.4 degrees Fahrenheit
- Bleeding or drainage from the incision
- Redness, swelling, or pain at the incision
- Confusion or excessive sleepiness
- Severe headache
- Excessive vomiting (when nothing stays down)
Our office hours are 8 a.m. to 4:30 p.m. Monday-Friday. On evenings and weekends, please call the main hospital line at 513-636-4200 and ask to have neurosurgery on-call doctor paged.