Orbital group of facial muscles
This muscle consists of three parts:
- Orbital part - encircles the orbital opening;
- Palpebral part - situated in the upper and lower eyelids;
- Lacrimal (deep palpebral) part - lies the most profoundly.
This muscle originates from the medial part of the superciliary arch, penetrates the frontalis and orbicularis oculi muscles and inserts into the skin over the middle of the eyebrow.
Upon contraction, the corrugator supercilii pulls the skin of the eyebrow downward and medially and produces vertical wrinkles of the forehead.