What Are the Common Types of Craniosynostosis?

Patient Presentation
A 4-month-old male came to clinic for his well child appointment. He was doing well, was breastfeeding, smiling and had good head control during tummy time. The past medical history showed a term delivery without complications. The parents were concerned about his head shape as they thought that his forehead seemed more pointed.

The pertinent physical exam showed a well-appearing male with all three growth parameters growing normally at approximately 50%. His posterior fontanelle was closed but his anterior fontanelle was open, was 1-2 cm in size and was in a normal position without pulsations. His metopic suture appeared and felt more ridged than expected but his other sutures appeared patent without ridging or abnormal head shape. The rest of his examination was normal.

The diagnosis of possible metopic craniosynostosis was made and the patient was referred to the neurosurgeon who ordered computed tomography of the head. The radiologic evaluation showed a normally open metopic suture and all other sutures were also open. The patient was referred back to the pediatrician for continued monitoring.

Figure 135 – Craniosynostosis Types. From Dr. Sandi Lam at Texas Children’s Hospital, https://www.texaschildrens.org/blog/2014/08/craniosynostosis-101-commonly-asked-questions

Discussion
Usually when an infant is born the fontanelles and sutures remain open allowing the cranial bones the ability to move and undergo molding. This assists in delivery and molding from delivery usually resolves within hours to a few days.

Positional plagiocephaly (also called deformational plagiocephaly) usually occurs after birth (usually in the first few weeks) due to mechanical factors including positioning of the infant’s head such that little repositioning occurs (i.e. bottle feeding only on same side, placement in crib on same side, placement always on infant’s back with no prone placement, etc.). The cranial sutures all remain open but the cranium is deformed. There usually is a parallelogram skull shape when observed from above caused by flattening of the affected occiput and anterior displacement of the ipsilateral ear and facial structures.

Artificial molding of infants’ heads has been occurring within different global cultures for thousands of years. Archeologists believe that the practice may occur for multiple reasons including protection of the infant’s head possibly increasing survival, as social status symbol, and/or to differentiate in-group members from non-members. Various methods were used including wrapping the head in cloth or other binding material or using a cradleboard (a protective baby carrier) or another similar device. Pressure is exerted on the infant’s head from a few weeks of age, then continued for several months, during the time of maximum malleability of the cranial bones.

Learning Point
Craniosynostosis is the premature fusion of the cranial sutures. As the sutures cannot have bone growth and they therefore are fixed. The non-fixed cranial bones will continue to grow perpendicular to the craniosynostosis. The result of the fixation of different sutures causes characteristic head shapes. Signs and symptoms of craniosynostosis include abnormal head shape, suture line ridging, abnormal head circumference measurements, or premature fontanelle closure. Untreated craniosynostosis not only can cause cosmetic and psychosocial problems, but could also cause intracranial hypertension and developmental delays. Those patients with syndromes may have additional morbidities.

Craniosynostosis is usually divided into non-syndromic and syndromic types.

Non-syndromic craniosynostosis usually has one suture affected (but could be multiple) and the patient does not have other associated anomalies. The entire suture, part of it or only one side may be affected as well.
• Sagittal – 45% of cases, has elongated anterior-posterior diameter (i.e. scaphocephaly)
• Coronal – 25% of cases, often unilateral (i.e. anterior plagiocephaly), if unilateral there is flattening of the face on the synostotic side and bossing on the contralateral. The face may appear twisted.
  Bilateral craniosynostosis produces a brachycephaly shape.

• Metopic – 20% of cases, has a triagonal forehead (i.e. trigonocephaly)
• Lambdoid – 5% of cases, usually unilateral (i.e. posterior plagiocephaly), appears to have downward displacement of the cranial case and appears as a head tilt.

Syndromic craniosynostosis usually has more than one suture affected and the patient has other associated anomalies. Many have associated genetic mutations.
The most common are:

• Crouzon syndrome – (FGFR2 gene) – midface anomalies, normal hands and intelligence
• Apert syndrome – (FGFR2 gene) – midface and syndactly anomalies, developmental delay
• Pfeiffer syndrome – (FGFR2 and FGFR1 genes) – hand and feet anomalies and cardiac anomalies
• Saethre-Chotzen syndrome – (TWIST1 gene) – midface and hand anomalies, and cardiac anomalies
• Muenke syndrome (FGFR3 gene) – hand anomalies, deafness and intellectual disability

Common radiographic imaging examples can be reviewed here.

Questions for Further Discussion
1. When do the fontanelles usually close? A review can be found here
2. What are some reasons for using cranial banding for positional plagiocephaly? A review can be found here
3. What specialities are usually involved with syndromic craniosynostosis?

Related Cases

Disease: Craniosynostosis | Head and Brain Malformations

Symptom/Presentation: Mass or Swelling

Specialty: Neurology / Neurosurgery | Genetics | Radiology / Nuclear Medicine / Radiation Oncology

Age: Infant

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Craniofacial Abnormalities.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Dempsey RF, Monson LA, Maricevich RS, et al. Nonsyndromic Craniosynostosis. Clin Plast Surg. 2019;46(2):123-139. doi:10.1016/j.cps.2018.11.001

Sawh-Martinez R, Steinbacher DM. Syndromic Craniosynostosis. Clin Plast Surg. 2019;46(2):141-155. doi:10.1016/j.cps.2018.11.009

Parents Have Been Reshaping Their Kids’ Skulls for 45,000 Years. Smithsonian Magazine. Accessed August 7, 2023. https://www.smithsonianmag.com/smart-news/parents-have-been-reshaping-their-kids-skulls-45000-years-180957343/

Head Space: Behind 10,000 Years of Artificial Cranial Modification. Atlas Obscura. Published 15:00 400AD. Accessed August 7, 2023. http://www.atlasobscura.com/articles/head-space-artificial-cranial-deformation

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, Unive