From Surf Wiki (app.surf) — the open knowledge base

Zygomaticus major muscle

Facial muscle that raises the corner of the mouth and moves it posteriorly during smiling

Field	Value
Name	Zygomaticus major
Latin	musculus zygomaticus major
Image	Sobo 1909 260 - Zygomaticus major muscle.png
Caption	Muscles of the head, face, and neck. Zygomaticus major shown in red.
Origin	Anterior of zygomatic
Insertion	Modiolus of the mouth
Action	Draws the angle of the mouth upward laterally
Blood	Facial artery
Nerve	Zygomatic and buccal branches of the facial nerve

The zygomaticus major muscle is a muscle of the face. It arises from either zygomatic arch (cheekbone); it inserts at the corner of the mouth. It is innervated by branches of the facial nerve (cranial nerve VII).

It is a muscle of facial expression, which draws the angle of the mouth superiorly and posteriorly to allow one to smile. Bifid zygomaticus major muscle is a notable variant, and may cause cheek dimples.

Structure

Origin

The zygomaticus major muscle originates from the superior margin of the lateral surface of the temporal process of zygomatic bone, just anterior to the zygomaticotemporal suture.

Insertion

It inserts at the corner of the mouth by blending with the levator anguli oris muscle, the orbicularis oris muscle, and the deeper muscular structures.

Nerve supply

The muscle receives motor innervation from the buccal branch and zygomatic branch of the facial nerve (CN VII).

Vasculature

The muscle receives arterial supply from the superior labial artery.

Variation

The zygomaticus major muscle may occur in a bifid form, with two fascicles that are partially or completely separate from each other but adjacent. It is thought that cheek dimples are caused by bifid zygomaticus major muscle.

Function

The zygomaticus major muscle raises the upper lip to bare the upper teeth. It additionally deepens and raises the nasolabial furrow. Acting in conjunction with other muslces of facial expression that elevate the lip, it curls the upper lip to produce facial expressions such as smiling, disdain, contempt, or smugness.

Physiology

The average muscle can contract with a force of 200 g.

Clinical significance

The zygomaticus major muscle may be used in reconstructive surgery to replace lost tissue, such as with injuries to the lips.

Additional images

File:Zygomaticus major muscle animation small.gif|Position of zygomaticus major muscle. Animation. File:Zygomaticus.png|Muscles of the head, face, and neck. Zygomaticus major shown in red.

References

(February 2021). "Zygomaticus major muscle bony attachment site: a Thiel-embalmed cadaver study". Morphologie.
Standring, Susan. (2020). "Gray's Anatomy: The Anatomical Basis of Clinical Practice".
(1998). "Double or bifid zygomaticus major muscle: Anatomy, incidence, and clinical correlation". Clinical Anatomy.
(October 2009). "Application of isometric load on a facial muscle – The zygomaticus major". Clinical Biomechanics.
(January 2021). "Split zygomaticus major muscle sling reconstruction for significant lower lip defects". British Journal of Oral and Maxillofacial Surgery.

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

muscles-of-the-head-and-neck

Want to explore this topic further?

Ask Mako anything about Zygomaticus major muscle — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report