Frontalis

Frontalis, or the frontal part of the occipitofrontalis muscle, is a muscle of the scalp that covers the forehead. It forms the front portion of the occipitofrontalis (epicranius) and lies over the forehead and upper part of the orbital region. The frontalis originates from the galea aponeurotica (epicranial aponeurosis) and inserts into the skin of the eyebrows and forehead. It is innervated by the temporal branches of the facial nerve (cranial nerve VII) and receives vascular supply from the superficial temporal artery as well as from the frontal branches of the supraorbital and supratrochlear arteries.

Functionally, the frontalis elevates the eyebrows and stretches the skin of the forehead, producing horizontal forehead wrinkles. It contributes to facial expressions such as surprise and alertness and can work with the corrugator supercilii to create a frown. It is paired and continuous with the occipitalis muscle across the scalp, connected by the epicranial aponeurosis.

Clinical significance is centered on its role in facial movement. Dysfunction or paralysis of the frontalis, as seen in Bell’s palsy, reduces the ability to raise the eyebrows. Conversely, botulinum toxin injections to the frontalis are commonly used to reduce horizontal forehead wrinkles, and surgical brow lifts aim to reposition the frontalis to improve brow position and forehead contour.