Zygomaticus Minor

Facial Expression · Head & Neck

Zygomaticus Minor belongs to the Facial Expression group of the Head & Neck. Originating at Zygomatic bone, near the zygomaticomaxillary suture, it inserts at Skin and muscle of the upper lip, lateral to levator labii superioris. It is responsible for several movements: Elevates the upper lip; deepens the nasolabial furrow. Innervation is provided by the Buccal and zygomatic branches of facial nerve (CN VII).

Origin, Insertion, Action & Nerve

Origin

Zygomatic bone, near the zygomaticomaxillary suture

Insertion

Skin and muscle of the upper lip, lateral to levator labii superioris

Action

Elevates the upper lip; deepens the nasolabial furrow

Nerve

Buccal and zygomatic branches of facial nerve (CN VII)

Attachments explained

The Zygomaticus Minor is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.

Origin

Zygomatic bone, near the zygomaticomaxillary suture

Insertion

Skin and muscle of the upper lip, lateral to levator labii superioris

Action & function

When the Zygomaticus Minor contracts, it produces the following movements: Elevates the upper lip; deepens the nasolabial furrow.

As part of the Facial Expression group of the Head & Neck, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.

Nerve supply & clinical relevance

The Zygomaticus Minor receives its nerve supply from the Buccal and zygomatic branches of facial nerve (CN VII).

Because a muscle can only contract when its nerve is intact, injury to the Buccal and zygomatic branches of facial nerve can weaken or paralyse the Zygomaticus Minor, impairing the movements it normally produces (elevates the upper lip). This is why knowing the innervation is central to localising nerve lesions in clinical practice.

How to study the Zygomaticus Minor (the OIANS method)

OIANS stands for Origin, Insertion, Action and Nerve, the four facts that uniquely define every skeletal muscle. To learn the Zygomaticus Minor, work through them in order: picture its origin, trace the muscle to its insertion, reason out the action that shortening between those two points must create, then add the nerve that drives it.

Most students remember the Zygomaticus Minor fastest by linking its action back to its attachments rather than memorising each fact in isolation. Once the origin and insertion make sense, the action usually follows logically.