Head and neck muscles (chewing, facial, and throat muscles)

Orbital part of orbicularis oculi

Musculus orbicularis oculi, pars orbitalis

Origin

Medial orbital margin: frontal process of the maxilla, the frontal bone and the medial palpebral ligament

Insertion

Forms a closed elliptical ring around the orbit and returns to its origin (partly via the lateral orbital margin toward the zygomatic bone)

Function

Forceful, voluntary closing of the eye (e.g. against bright light or during coughing/sneezing); pulls the eyebrow and forehead down

Innervation

Facial nerve (CN VII), temporal and zygomatic branches

Movement & chain

Works together with the palpebral part (reflexive, gentle blinking) but itself provides the forceful, voluntary closure of the eyelid, unlike the palpebral part.

Palpation

Felt around the orbital margin during forceful eye closure.

Clinical

In CN VII palsy (peripheral facial paralysis), forced eye closure is impaired or impossible, risking corneal drying (lagophthalmos).

Segmental innervation

Facial nerve (VII), motor.

In clinical practice

A commonly used injection site for botulinum toxin in treating 'crow's feet' (wrinkles lateral to the eye).

Region in the model

Head and neck muscles (chewing, facial, and throat muscles)