Reconstruction of the Scalp and Forehead

The pertinent anatomy of the scalp that has clinical relevance can be divided into the specific regions as well as the cross-sectional components. The cross-section anatomy is summed in the acronym SCALP, the skin containing hair follicles, sebaceous and sweat glands, a thin layer of subcutaneous fat, the galeal aponeurosis, a zone of subgaleal loose areolar tissue, and lastly, periosteum or pericranium. Skin, in contrast to the subgaleal space, is tightly adherent to the underlying galea. The galea has an interesting teleological history since the aponeurosis may represent a vestige of the panniculus carnosus, a layer of immediate subdermal striated muscle seen in non-primate mammals that enable twitching of isolated areas of skin. In that vein, the galea is a fusion sheet between the frontalis of the forehead and the occipitalis posteriorly, two other structures that represent vestigial remnants of the panniculus carnosus. Laterally, the galea is contiguous with the temporoparietal fascia.