craniofacial

Unicoronal Craniosynostosis

What is Unicoronal Craniosynostosis?

Unicoronal craniosynostosis is a type of craniosynostosis where one of the coronal sutures in a baby’s skull closes prematurely. The coronal sutures run from ear to ear over the top of the skull. When one side fuses early, it leads to an asymmetric head shape, known as anterior plagiocephaly. This causes flattening of the forehead and brow on the affected side, with compensatory bulging on the opposite side. The eye socket on the affected side may appear elevated, and the nose can deviate away from the fused suture.

The Procedure

How Diagnosed

Unicoronal craniosynostosis is typically diagnosed within the first few months of life, often based on the visible asymmetry of the baby’s head and face. A clinician may detect ridging along the fused suture and observe the uneven appearance of the forehead and orbits. Diagnosis is confirmed through imaging, such as a CT scan or 3D reconstruction, which shows the early fusion of the coronal suture and any associated skull deformation.

What Are the Causes?

Most cases of unicoronal craniosynostosis are non-syndromic and occur sporadically, meaning they are not inherited and have no known cause. However, in some instances, it can be associated with genetic syndromes such as Muenke syndrome, Saethre-Chotzen syndrome, or Apert syndrome. These syndromic forms often present with additional features like limb abnormalities or other craniofacial differences. Genetic testing may be offered to identify these underlying conditions.

What Are the Implications?

The primary concern in unicoronal craniosynostosis is the noticeable facial asymmetry, which can impact appearance and self-esteem. Functionally, the condition can affect eye alignment, leading to strabismus (squint), amblyopia (lazy eye), or other visual impairments. In rare cases, increased intracranial pressure can develop, potentially affecting brain development if untreated.

What Are the Treatment Options?

Treatment focuses on correcting the skull and facial asymmetry and addressing any associated complications. Not all children with unicoronal synostosis need surgery. Surgical options include:

Fronto-Orbital Advancement (FOA): This is the standard surgical treatment for unicoronal craniosynostosis, usually performed between 12 and 18 months of age. It involves reshaping and repositioning the forehead and eye socket bones to achieve a more symmetrical appearance.
Endoscopic-Assisted Surgery: This less invasive option can be performed earlier (before 6 months of age). It involves removing the fused suture through small incisions, followed by helmet therapy to guide skull growth and shape.

Additional treatments may include vision therapy, glasses, or eye muscle surgery to correct strabismus.

What Are the Possible Complications?

Surgical treatment is generally safe and effective, but complications can include:

Infection or bleeding
Scarring and risks associated with anesthesia
Persistent or recurrent asymmetry, possibly requiring additional surgery
Visual problems, including continued strabismus
In rare cases, increased intracranial pressure postoperatively

With timely diagnosis and appropriate surgical intervention, most children with unicoronal craniosynostosis have favorable outcomes in terms of both appearance and development.