Occipitofrontalis Muscle

Description

Spanning the cranial vault, the occipitofrontalis (epicranius) is presented as two muscle bellies separated by the galea aponeurotica. The frontal belly lies anteriorly in the forehead, superficial to the frontal bone and blending inferiorly with the soft tissues of the brow, while the occipital belly sits posteriorly over the occipital squama near the superior nuchal line. Between them, the galea forms a broad tendinous sheet that rides over the pericranium and continues laterally into the temporoparietal fascia. Clear boundaries. Functionally, the split architecture matters because forehead movement is transmitted across the scalp through the galea rather than by a continuous muscle mass. Clinicians encounter this anatomy in scalp lacerations, where wounds that violate the galea tend to gape and bleed more due to separation under frontalis and occipitalis tension, and in coronal or pretrichial approaches where staying in the subgaleal plane helps protect the superficial temporal vessels and the temporal branch of the facial nerve as it courses over the zygomatic arch toward the frontalis. The frontalis also becomes an easy proxy for facial nerve function in neurologic exam, since inability to elevate the eyebrow suggests peripheral facial palsy, while forehead sparing points away from it. Use this asset for head and neck anatomy teaching in gross anatomy and surgical anatomy courses, for plastic surgery and dermatologic surgery atlases discussing scalp flaps and coronal incisions, or for clinical education pieces on facial nerve examination and scalp trauma management. It also supports clear labeling in publisher workflows when epicranial aponeurosis, temporoparietal fascia, and frontalis need to be distinguished without clutter. Anatomical accuracy verified by SciePro's Medical Advisory Board.