Fontanelles are the areas on the skull of a newborn or infant that are not covered by bone or cartilage. they consist of robust connective tissue and bridge the places where the skull plates have not yet grown together. There are a total of six fontanelles that close at different times. As a rule, however, all fontanelles close during the first two years of life.
The skull of a newborn consists of several skull plates of different sizes, which pass through shortly after birth Fontanelles and Sutures ("Skull sutures") are connected. Fontanelles are bounded by at least three skull plates and connect them to one another. They are related to those that are not yet ossified in the newborn Sutures, which are each located between two skull plates. Fontanelles and sutures together ensure the initial deformability of the child's skull, which is indispensable during birth and later growth of the brain.
The six fontanelles of the child's skull are divided into the large fontanel, the small fontanel and four side fountain. The large fontanel is located on the forehead on the roof of the skull and is surrounded by four skull plates (the two front and two parietal bones). It is characterized by theirs diamond shapewhich it occupies through the adjacent skull plates. The large fontanel usually closes between the ages of 9 and 18 months. In rare cases, it can close earlier or only in the 27th month of life. The small fontanel lies between three skull plates (between the two parietal bones and the occiput) on the occiput. she is triangular and much smaller than the anterior fontanel. It often closes from the sixth week of life and is usually completely closed at the end of the child's first year.
The small fontanel is usually the lowest point of the child in the birth canal at birth. This position of the head is also the best position for an uncomplicated birth. The two anterior lateral fontanelles lie on both sides between the frontal bone, the parietal bone and the large wing of the sphenoid bone. They often have a rectangular shape and are the two smaller of the four side fontanels. Similar to the small fontanel, they have completely disappeared within the first year of life. The two rear side fontanels are very variable in size and shape. They lie between the temporal, parietal and occipital bones and close by the age of 18 months. The closure of the individual fontanelles can be caused by various deficiency symptoms, such as rickets (Calcium deficiency), can be greatly delayed.
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Fontanelles play in the birth an important role. Since the child's skull is pressed through a narrow birth canal, it must be able to deform a little. Since the skull plates are not grown together, but through the connective tissue fontanelles and Sutures are connected to each other, they can shift against each other or above each other at birth. This allows a short-term when passing through the birth canal Decrease in head circumference. After birth, the skull returns to its original shape.
In addition, especially the large and small fontanels are for the doctor and the midwife This is important during childbirth, as by feeling these two fontanelles you can assess the position of the head. Both fontanelles can be distinguished from one another by their shape and size. As already mentioned, the position of the head, in which the small fontanel is the lowest point of the skull, is the best position for an uncomplicated birth.
Fontanelles play a decisive role not only during childbirth. Since the child's brain is subject to rapid growth, the skull must grow with it. The fontanelles are flexible areas between the skull plates in the newborn, which are the brain unhindered growth enable. As the brain slowly grows, the fontanelles begin to close.
More information can be found here: Development of the child
Since the fontanelles represent a transition between the skull plates consisting of connective tissue, the Pulse of the newborn sometimes feel or recognize at these points. Since there is no bone in these areas to shield the brain from the outside, you can see the pulsation of the blood vessels under the fontanelles on the scalp, which supply the brain. The heartbeat of the child pumps the blood from the heart into the vessels of the whole body and thus also into the brain. The pressure required for this can be felt as a pulse at several points on the body. Since babies, unlike adults, still have fontanelles, the pulse can be seen in these areas on the child's head or felt with the fingers. Thus is the pulsation of the fontanelles perfectly normal and in most cases is not a warning sign of illness.
Fontanel is bulging / swollen outward
Since, in contrast to the skull plates, a fontanel is not a bony structure, its arching or indentation can provide information about the Pressure conditions inside the head be made. A normal fontanel should be either flat or slightly sunken in an upright infant. In a lying position, the fontanel should be flat or slightly curved outward in a healthy baby. It should also feel soft when you lightly stroke it.
If the fontanel is slightly curved outwards when the baby is lying down, this is perfectly normal. If a fontanel is strongly curved outward in a lying position or when the child is sitting upright, this can be an indication of a increased intracranial pressure, for example due to an impaired drainage of the cerebral fluid, or an inflammation. Bruising in the brain, for example after an accident, can also be the cause of an arched fontanel. A tight fontanel that does not give in to pressure can be a sign of inflammation. If such a bulge or tense fontanel is observed, one should definitely be observed Pediatrician be visited to clarify what it is. If a fontanel has clearly sunk in when the infant is lying down, this can be a sign of a disturbed water balance, either by strong water balance Loss or lack of fluids, be.
More information can be found here: Symptoms of a water head, Cerebral haemorrhage, purulent meningitis