The brow bone, scientifically known as the supracebral arch or superciliary arch, is a prominent bony protuberance located on the roof of the orbit, above the eyesockets, in primates and some other animals. In humans, the brow bones are often not well expressed and can be most easily seen in profile, forming the separation between the forehead (the squama frontalis) and the roof of the eye sockets (the orbitale).
Structure
The brow bone is a nodule or crest of bone that rises from the frontal bone of the skull. It sits atop the superciliary sulci, which are shallow grooves, separating it from the supraciliary eminences, which are the areas where the brow ridges meet at the top of the head. The ridges arch over each eyesocket, providing mechanical protection. The arches are most prominent medially and are connected by a smooth elevation called the glabella.
In other primates, the brow ridge is usually continuous and often straight rather than arched. It is separated from the frontal eminences by a shallow groove. The ridges are most prominent medially and are joined to one another by a smooth elevation named the glabella.
The brow bone is a crucial part of the face's structure and plays an essential role in maintaining balance and support of the head. It also contributes to the overall shape of the face and can vary in size and prominence between different species.
Evolutionary Advantage
The brow bone likely evolved to serve various functions, including providing mechanical protection for the eyes and orbital bones, aiding in the extension of the face towards the brain, and contributing to facial expression and communication.
In Paleolithic humans, pronounced brow ridges were a common feature, and their presence suggests that the brow bone may have had significant adaptive values for early hominins, such as increased hunting abilities, communication, and cognitive functions. Over time, the size and shape of the brow ridges may have shifted due to changes in environmental pressures and selective pressures.
Modernity and brow bone reduction
In modern times, the presence of prominent brow ridges may not be socially acceptable or may be indicative of an unhealthy lifestyle in some cultures. As a result, many individuals seek to reduce or remove their brow bones through aesthetic procedures, such as brow reductions, brow lifts, or facelifting.
These procedures are performed under general anesthesia and can include the reshaping of the bone and the removal of excess skin and fat from the forehead area. While there is minimal risk associated with brow bone reduction procedures, recovery time may vary depending on the individual and the techniques used.
In summary, the brow bone is a foundational element of the face's anatomy, serving various functions throughout human evolution. Today, there are numerous procedures available to alter the size and shape of the brow bone, reflecting changing norms and societal perceptions of beauty.
