1. Health
You can opt-out at any time. Please refer to our privacy policy for contact information.

Coronal Synostosis


Updated November 13, 2011

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

left unilateral coronal synostosis repair

Photo © Millicent Odunze, M.D., M.P.H.

Left unilateral coronal synostosis repair.

Coronal synostosis occurs when the coronal suture has closed prematurely. There are two coronal sutures, and they can affect one or both sides. If one side is affected, it is known as unilateral coronal synostosis. The involvement of both coronal sutures is known as bilateral coronal synostosis.

Unilateral Coronal Synostosis

Unilateral coronal synostosis is also known as an anterior plagiocephaly. It is different from deformational/positional plagiocephaly, which is caused by external forces. In unilateral coronal craniosynostosis, one of the coronal sutures has fused prematurely. It is the second most common of the craniosynostoses, comprising 20 percent of cases. How can you tell if your baby has a unilateral coronal synostosis? Some of the signs of this type of synostosis are:

  • Ear on the side of the closed suture is more anterior than the other ear
  • Top of the nose is on the side of the closed suture
  • Bottom of the nose is pointed to the side opposite of the closed suture
  • Forehead on the side of the closed suture is flattened
  • Forehead on the side opposite of the closed sutue is bulging
  • Eye/eyebrow on the side of the closed suture is higher than the opposite eye/eyebrow

Bilateral Coronal Synostosis

Bilateral coronal synostosis is also known as brachycephaly. Since both coronal sutures have fused prematurely, there is symmetry. It is tied for second place with unilateral coronal synostosis with an incidence of 20 percent. Brachycephaly is manifested by:

  • Head is shortened from front-to-back but widened from side-to-side
  • Bulging forehead
  • Eyes are spaced widely apart
  • Head height is increased

Next page: Metopic Synostosis

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.