Anatomy, Head and Neck; Frontalis Muscle

Excerpt

The frontalis muscle plays a significant role in our day-to-day social interactions. As the only muscle that raises the eyebrows, its function goes beyond simply keeping the brows out of one’s visual field; it is also necessary for conveying emotions and nonverbal communication. The antagonist muscles to the frontalis muscle are the procerus muscle, the corrugator supercilii muscle, and the orbicularis oculi muscle. (Fig 1) The frontalis, corrugator, procerus, and orbicularis muscles all have cutaneous insertions and have a confluence at the glabella, and the orbital rim, where their respective movements and forces extended to the skin may cause cutaneous rhytids (frown lines, smile lines, forehead lines, horizontal nasal lines). The balance between these muscles determines the eyebrow position and shape.