Which condition is characterized by the premature fusion of the sagittal suture?

The condition characterized by the premature fusion of the sagittal suture is sagittal synostosis. This specific type of craniosynostosis occurs when the sagittal suture, which runs from the front to the back of the skull, fuses too early. As a result, the growth of the skull is affected; typically, the skull will become elongated in shape, often referred to as a "scaphocephalic" head shape. This can lead to increased intracranial pressure and potential developmental delays if not addressed.

Other options detail different conditions unrelated to the fusion of the sagittal suture. Cephalohematoma refers to the accumulation of blood between the skull and the periosteum, often due to birth trauma. Erythema toxicum neonatorum is a benign skin condition that occurs in newborns, involving red, blotchy spots. Ankyloglossia, commonly known as tongue-tie, is a condition where the strip of tissue connecting the tongue to the floor of the mouth is shorter than usual, impacting tongue mobility but not directly related to cranial sutures.