Forehead of cranium

The forehead of cranium is the area of the face stretching from the hairline at the front, down to the eyebrows. It forms the upper section of the facial skeleton and is predominantly made up of the frontal bone. Below, the forehead connects to the eye sockets and the nose area. Key features of the forehead's frontal bone include two prominent bumps on the upper sides, known as frontal eminences, and slightly raised ridges above the rim of each eye socket, called superciliary arches, which are usually more distinct in men. Between these ridges lies a small dip called the glabella. Near the top edge of each eye socket, there's a hole known as the supraorbital foramen, through which supraorbital nerve and vessels pass. The frontal bone also extends down on both sides of each orbit to form parts of the eye socket’s inner and outer rims.

The skin is the outermost layer of the forehead of cranium, followed by a dense layer of connective tissue containing blood vessels and nerves. Beneath this is the frontal belly of the occipitofrontalis muscle, which starts in the forehead skin, blends with the fibers of orbicularis oculi and corrugator supercilii muscles, and attaches to the aponeurosis in the center of the scalp. Further deep is a layer of loose areolar connective tissue that is continuous with the loose areolar tissue in the scalp. Since the frontalis muscle is only attached to the skin and not to the frontal bone, inflammatory fluid from the scalp can easily spread down, causing swelling around the eyes, known as periorbital edema. The deepest layer is the pericranium (or the periosteum) which is tightly adhered to the underlying frontal bone itself.