Fontanelle

The term Fontanelle ( Old-French " small source " ) is now used primarily as a medical- anatomical term. Fontanelle denotes the not yet covered by bony or cartilaginous structures area of ​​the skull of newborns or infants, or more generally of newborn vertebrates. It is one continuous unit of inner and outer membranous layers on the skull where there is no bony or cartilaginous layers. There are points at which at least three cover plates of the skull are not completely contiguous.

Anatomy

The newborn individual has two unpaired Hauptfontanellen, referred to as large and small fontanelle fontanelle, as well as four other smaller fontanelles (each paired front and rear Seitenfontanellen ).

The diamond-shaped anterior fontanelle ( frontal fontanel or fontanelle anterior) lies centrally on the skull. At this point, each of the right and left frontal bones (ossa frontalia ) and the parietal bones meet ( parietal ) and coronal suture ( coronal suture ), sagittal suture ( sagittal suture ) and frontal suture ( frontal suture ) to each other ( see also suture ).

The triangular small fontanelle ( fontanel or occipital fontanelle posterior) is located at the back of the head, at the point where the parietal bones ( occipital bone ) with the occipital bone and the sagittal suture to the lambdoid suture ( lambdoid suture ).

The rear Seitenfontanellen ( mastoid fontanelle ) located on either side of the head between the temporal, the parietal and the occipital bone.

The front Seitenfontanellen ( sphenoid fontanelle ) are also on both sides of the head, between the frontal and parietal bone and the great wing of the sphenoid.

The fontanelles have an important task especially at birth. Together with the cartilaginous lining of the skull they allow by overlaying pushing the bone plates of the skull deformation during childbirth and thus facilitate the passage through the birth canal. The final closure occurs at the fontanel, after about two months, with the large fontanelle after two years. The Seitenfontanellen close after about a year. In various deficiencies, such as rickets, the closure will take much longer. The premature ossification is called craniosynostosis ( premature or Nahtsynostose ).

In some children with Down syndrome ( trisomy 21) results in the formation of another opening on the seam ( sagittal suture ) between the large and the small fontanelle, which is also referred to as third fontanelle.