Corrugator supercilii

At a glance

English

Corrugator supercilii

Latin (TA2)

Musculus corrugator supercilii

System

Muscle

Region

Head

Side

Paired, left and right

About the corrugator supercilii

The corrugator supercilii is a short, slender, roughly pyramidal muscle lying deep under the inner end of the brow. It sits under the frontalis and the orbital part of orbicularis oculi, so it cannot be seen on the surface, but its effect is plain whenever someone knits the brows. Its Latin name means the wrinkler of the eyebrow.

It arises from bone at the inner tip of the frontal bone's superciliary arch, close to the root of the nose. From there its fibres run upwards and outwards, threading between the palpebral and orbital parts of orbicularis oculi, and end in the underside of the eyebrow skin, roughly above the middle of the upper orbital margin. It is one of the few facial muscles with a bony origin and a purely skin insertion over such a short distance.

When it contracts it draws the eyebrow medially and downwards. This gathers the skin between the brows into vertical furrows, the familiar frown lines above the root of the nose. It is the chief muscle of expressions of concern, effort and pain, and it also works when we squint against bright light, pulling the brows together to shade the inner corner of the eyes. The procerus, which pulls the skin between the brows downwards, and the depressor supercilii act with it, while the frontalis opposes it by lifting the brows.

The supratrochlear nerve and vessels pass close by, between the corrugator and the frontalis, and in some people irritation of this nerve at that point is thought to provoke headaches. For that reason the muscle may be weakened with botulinum toxin or partly removed surgically to treat some forms of migraine, and the same injection is widely used to soften frown lines for cosmetic reasons.

Attachments, action and supply

Origin

Inner tip of the frontal bone's superciliary arch.

Insertion

Underside of the eyebrow skin, over the middle of the supraorbital margin.

Action

Draws the eyebrow downwards and medially, producing vertical frown lines between the brows.

Nerve supply

Temporal branches of the facial nerve (cranial nerve VII).

Blood supply

Supratrochlear and supraorbital arteries from the ophthalmic artery, with branches of the superficial temporal artery.