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. Innervation is by the posterior auricular branch of the facial nerve. The paired corrugator superciliaris muscles arise from the frontal bone near the superomedial orbital rim, anteriorly and slightly cephalad to the trochlea. The muscle runs superolaterally through the fibers of orbicularis oculi and frontalis before inserting into the medial eyebrow skin. The corrugator muscle is a brow depressor, pulling the brow medially and inferiorly, producing vertical glabellar folds.
Innervation is from terminal branches of the frontal branch of the facial nerve.
The flat, thin procerus muscle takes origin from the nasal bone and inserts into the glabella and lower mid forehead. It lies between the paired frontalis muscles. The procerus is a brow depressor, forming horizontal nasal root creases. It has a curved origin from the medial orbital margin, being attached to the superomedial orbital margin, maxillary process of the frontal bone, the medial palpebral ligament, the frontal process of the maxilla, and the inferomedial orbital margin. Fibers from the medial origin sweep around the orbital margin in a horseshoe fashion.