Craniosynostosis (kray-nee-o-sin-os-TOE-sis) is a bih defect in which one or more of the fibrous joints between the bones of your baby&;s skull (cranial sutures) close prematurely (fuse), before your baby&;s brain is fully formed. Brain growth continues, giving the head a misshapen appearance Craniosynostosis usually involves fusion of a single cranial suture, but can involve more than one of the sutures in your baby&;s skull (complex craniosynostosis). In rare cases, craniosynostosis is caused by ceain genetic syndromes (syndromic craniosynostosis). Treating craniosynostosis involves surgery to correct the shape of the head and allow for normal brain growth. Early diagnosis and treatment allow your baby&;s brain adequate space to grow and develop. Although neurological damage can occur in severe cases, most children have normal cognitive development and achieve good cosmetic results after surgery. Early diagnosis and treatment are key. Types of Craniosynostosis The types of craniosynostosis depend on what sutures join together early. Sagittal synostosis- The sagittal suture runs along the top of the head, from the baby's soft spot near the front of the head to the back of the head. When this suture closes too early, the baby's head will grow long and narrow (scaphocephaly). It is the most common type of craniosynostosis. Coronal synostosis - The right and left coronal sutures run from each ear to the sagittal suture at the top of the head. When one of these sutures closes too early, the baby may have a flattened forehead on the side of the skull that closed early (anterior plagiocephaly). The baby's eye socket on that side might also be raised up and his or her nose could be pulled toward that side. This is the second most common type of craniosynostosis. Bicoronal synostosis - This type of craniosynostosis occurs when the coronal sutures on both sides of the baby's head close too early. In this case, the baby's head will grow broad and sho (brachycephaly). Lambdoid synostosis - The lambdoid suture runs along the backside of the head. If this suture closes too early, the baby's head may be flattened on the back side (posterior plagiocephaly). This is one of the rarest types of craniosynostosis. Metopic synostosis - The metopic suture runs from the baby's nose to the sagittal suture at the top of the head. If this suture closes too early, the top of the baby's head shape may look triangular, meaning narrow in the front and broad in the back (trigonocephaly). This is one of the rarest types of craniosynostosis. Reference: GHAI Essential pediatrics, 8th edition