In simple words: Craniosynostosis is a birth defect where the bones in a baby's skull close too early, before the brain is fully formed. This can make the baby's head have an unusual shape.The soft spots on the baby's head might feel hard or be missing.Because the brain keeps growing, it might not have enough space in the skull, which can sometimes cause problems.

Craniosynostosis is a condition present at birth where one or more of the fibrous joints between the bones of a baby's skull (cranial sutures) close prematurely, before the baby's brain is fully formed.Continued brain growth causes the head to have an abnormal shape. The specific type depends on which sutures are affected.Sagittal synostosis (scaphocephaly) involves the sagittal suture, causing a long, narrow head. Coronal synostosis (anterior plagiocephaly if one side is affected, brachycephaly if both sides are affected) involves the coronal suture(s), causing the forehead to flatten or the head to become short and wide. Metopic synostosis (trigonocephaly) involves the metopic suture, resulting in a triangular forehead. Lambdoid synostosis involves the lambdoid suture at the back of the head.

Example 1: A newborn is examined and found to have a long, narrow head shape. Upon further examination, the sagittal suture is determined to be fused. This is diagnosed as sagittal synostosis (scaphocephaly)., An infant presents with a flattened forehead on one side and bulging on the other.The physician diagnoses unilateral coronal synostosis (anterior plagiocephaly)., A baby is born with a triangular-shaped forehead.Imaging confirms premature fusion of the metopic suture, leading to a diagnosis of metopic synostosis (trigonocephaly).