Musculus malaris
Thin muscle below the eye that depresses the lower eyelid. In horses, assists in exposing the sclera (eye white), an important fear/pain body language signal.
Origin: Fascia over zygomatic arch and malar region
Insertion: Lower eyelid and skin of the cheek
Action: Depresses the lower eyelid, exposing the sclera
Innervation: Auriculopalpebral and buccal branches of facial nerve (CN VII)
Increased sclera exposure is a validated behavioral indicator of stress, fear, or pain in horses.
Increased sclera exposure is a validated behavioral indicator of stress, fear, or pain in horses. Signs include: Visible white of the eye at rest; wide-eyed alarmed expression; combined with tense ears and elevated head carriage.
See the Malar Muscle on our interactive 3D horse model. Open 3D Model