What is the primary characteristic of sagittal synostosis?

The primary characteristic of sagittal synostosis is the fusion of the sagittal suture, which runs from the front to the back of the skull. This fusion restricts the normal growth of the skull in the area where the suture is located. As a result, the head takes on a long and narrow shape, often referred to as "scaphocephaly." This occurs because, without the ability to expand in width, the skull compensates by growing longer in the anteroposterior direction. This condition is important to identify, as it may require surgical intervention to correct the shape of the head and prevent potential complications associated with cranial pressure or development.

Other options reference conditions that are not directly related to sagittal synostosis. For instance, the blockage of cerebrospinal fluid is more indicative of conditions such as hydrocephalus, while bleeding between the skull and periosteum relates to cephalohematomas or other trauma-related injuries. Odema due to impaired venous return may lead to different scalp issues but is not characteristic of sagittal synostosis itself. Understanding these distinct characteristics helps in accurately diagnosing and managing cranial deformities in infants.