The forehead skin is the thickest facial skin and is rich in sebaceous glands and sweat glands. Richly vascularized, subcutaneous tissue contains a homogenous layer of adipose tissue. Within this layer in the forehead are found numerous transverse fibrous septa from the frontalis muscle to the dermis. These septa are partially responsible for the deep transverse forehead rhytids. The paired frontalis muscles are the primary elevators of the brow.
Innervation is by the frontal branch of the facial nerve.
The galeal aponeurosis encloses the frontalis muscle with a thin superficial layer over the muscle, and a deeper well-defined layer beneath the muscle. This deeper layer is firmly attached to the supraorbital margin, contributing to the arcus marginalis. Laterally, the galea conceptually continues as the superficial temporal fascia. Posteriorly, the galea continues as the occipitalis muscle. The 2 bellies of the occipitalis take their origin from the periosteum and bone of the superior nuchal line of the mastoid portion of the temporal bone and insert into the galea aponeurosis.