Fontanelles

Fontanelles are gaps found between the individual bones of a newborn's skull. These gaps, also referred to as "soft spots," exist because the skull bones are not fused together at the time of birth. To fill these gaps, membranous connective tissue develops. Fontanelles are vital in facilitating the movement and molding of the skull during labor, and they also enable the brain to grow as it develops after birth.

Some examples of fontanelles in the infant’s skull include the anterior and posterior fontanelle, sphenoid fontanelle, and mastoid fontanelle. Usually, these fontanelles are flat and firm. However, certain conditions such as dehydration or infection can cause changes in their appearance of, resulting in them being sunken or bulging.