What describes the growth of the head when sagittal synostosis occurs?

When sagittal synostosis occurs, the growth of the head is characterized by it becoming long and narrow. This condition results from the premature fusion of the sagittal suture, which runs from the front of the skull to the back. As the brain continues to grow, this fusion limits lateral expansion; therefore, the skull compensates by elongating in the anterior-posterior dimension, leading to a head shape that is elongated and narrow rather than round or wide.

In contrast, other options describe different growth patterns that do not occur with sagittal synostosis. For example, a head that grows large in all dimensions would imply a uniform expansion, which is not seen in this condition due to the restrictive nature of the premature suture fusion. Similarly, a head showing no significant changes contradicts the physical manifestation of sagittal synostosis, as the condition is characterized by noticeable alterations in head shape. Finally, a head that becomes round and wide suggests an even distribution of growth across the skull, which again does not apply in the case of sagittal synostosis where the restriction in width leads to the observed elongated shape.