What do we call the soft spots in an infant's skull where the cranial bones have not yet fused?

The term for the soft spots in an infant's skull where the cranial bones have not yet fused is "fontanel." These areas are crucial for allowing the baby's head to change shape during birth and for accommodating rapid brain growth in the early months of life. There are several fontanels, with the most well-known being the anterior fontanel located at the top of the head and the posterior fontanel located at the back.

In contrast, cranial sutures refer to the fibrous joints that connect the various bones of the skull and are not the soft spots themselves but rather the seams where the bones meet. The epicranial aponeurosis is a layer of tissue extending over the top of the skull, functioning primarily as a tendinous expansion for muscle attachment, while the calvaria refers to the upper part of the skull, which includes several bones but does not directly address the soft spots in infants. Recognizing the significance of fontanels aids in understanding infant anatomy and development, particularly in how these areas evolve as the child matures.