Fontanels are the fibrous, membrane-covered gaps created when more than two cranial bones are juxtaposed, as opposed to sutures, which are narrow seams of fibrous connective tissue that separate the flat bones of the skull. At birth, an infant has six fontanels (the anterior and posterior, two mastoid, and two sphenoid). The anterior fontanel is the largest and most important for clinical evaluation. The average size of the anterior fontanel is 2.1 cm, and the median time of closure is 13.8 months.

http://purl.obolibrary.org/obo/HP_0000235

Fontanels are the fibrous, membrane-covered gaps created when more than two cranial bones are juxtaposed, as opposed to sutures, which are narrow seams of fibrous connective tissue that separate the flat bones of the skull. At birth, an infant has six fontanels (the anterior and posterior, two mastoid, and two sphenoid). The anterior fontanel is the largest and most important for clinical evaluation. The average size of the anterior fontanel is 2.1 cm, and the median time of closure is 13.8 months.

Abnormal cranial suture/fontanelle morphology

HP:0000235

Abnormal cranial suture/fontanelle morphology

http://purl.obolibrary.org/obo/HP_0000929