Bregma, also known as the bregmatic suture or bregmatic fontanelle, is a specific anatomic structure located on the top of the head. It is the point where the two parietal bones and the frontal bone meet, forming a small gap or opening.
Structure of Bregma
The bregma is a junction point between three bones in the skull: the two parietal bones and the frontal bone. The parietal bones are a pair of large, flat bones that form the sides and top of the cranium. They are located behind the frontal bone and above the temporal bones. The frontal bone, on the other hand, is a single bone that forms the forehead and the roof of the eye sockets.
The bregma is formed by the union of the parietal bones and the frontal bone along the coronal suture, which is a fibrous joint that allows some movement between these bones. The coronal suture extends from the bregma to the back of the head, dividing the skull into two halves.
At birth, the bones of the skull are not fully fused together and there are several gaps or openings called fontanelles. The bregmatic fontanelle, also known as the anterior fontanelle, is the largest and most important of these openings. It is located at the bregma and is shaped like a diamond. The size of the bregmatic fontanelle varies depending on the size and shape of the head, but it is usually about 2.5 cm long and 1.5 cm wide.
Where is Bregma Located?
The bregma is located on the top of the head, approximately at the midline. It is situated between the two parietal bones and the frontal bone, just above the root of the nose. The location of the bregma is important because it serves as a reference point for identifying other structures on the head and performing certain medical procedures.
Function
The main function of the bregma is to allow the bones of the skull to grow and expand during the first few months of life. This is especially important because the brain is still developing and needs room to grow. The fontanelles, including the bregmatic fontanelle, act as pressure relief valves that allow the bones of the skull to flex and expand as the brain grows.
As the baby grows and the brain reaches its full size, the fontanelles begin to close and the bones of the skull fuse together. This process is complete by the age of two or three, at which point the fontanelles are no longer visible.
In addition to its role in brain development, the bregma also serves as a reference point for identifying other structures on the head. For example, the location of the bregma is used to identify the midline of the head and to locate the parietal bones and the frontal bone.
Clinical Significance
The bregma is clinically significant for several reasons. First, it is an important landmark for performing certain medical procedures, such as administering medication or performing a lumbar puncture. The location of the bregma can also be used to identify abnormal head shape or skull deformities, such as a bulging fontanelle or a misshapen head.
In addition, the size and shape of the bregmatic fontanelle can provide important clues about the health of a baby. A fontanelle that is excessively large or bulging may indicate increased intracranial pressure, which can be a sign of a serious medical condition such as hydrocephalus or meningitis. On the other hand, a fontanelle that is sunken or very small may indicate dehydration or malnutrition.
It is important for healthcare professionals to regularly check the size and shape of the fontanelles in infants and young children. This can help to identify any potential health concerns early on and allow for timely treatment.
In adults, the bregma is still an important reference point for certain medical procedures, such as brain surgery. It is also used as a reference point for measuring head circumference, which can provide important information about brain size and development.
