Zygomaticus major muscle

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Zygomaticus major
Sobo 1909 260 - Zygomaticus major muscle.png
Muscles of the head, face, and neck. Zygomaticus major shown in red.
Details
Origin anterior of zygomatic
Insertion modiolus of the mouth
Artery facial artery
Nerve zygomatic and buccal branches of the facial nerve
Actions draws the angle of the mouth upward laterally
Identifiers
Latin musculus zygomaticus major
TA98 A04.1.03.029
TA2 2079
FMA 46810
Anatomical terms of muscle

The zygomaticus major muscle is a muscle of the human body. It extends from each zygomatic arch (cheekbone) to the corners of the mouth. 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.

Contents

Structure

The zygomaticus major muscle originates from the upper margin of the temporal process, part of the lateral surface of the zygomatic bone. [1] [2] It inserts into tissue at the corner of the mouth. [2]

Nerve supply

The zygomaticus major muscle is supplied by a buccal branch and a zygomatic branch of the facial nerve (VII).

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. [1] [3] Usually a single unit, dimples are caused by variations in form. [4] [5] It is thought that cheek dimples are caused by bifid zygomaticus major muscle. [3]

Function

The zygomaticus major muscle raises the corners of the mouth and draws them posteriorly when a person smiles. [6] The average muscle can contract with a force of 200 g. [2]

Clinical significance

The zygomaticus major muscle may be used in reconstructive surgery to replace lost tissue, such as with injuries to the lips. [7]

Image

See also

Related Research Articles

Face Part of the body at the front of the head

The face is the front of an animal's head that features three of the head's sense organs, the eyes, nose, and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities affects the psyche adversely.

Smile Conscious or subconscious facial muscular movement conveying smile or pleasure

A smile is formed primarily by flexing the muscles at the sides of the mouth. Some smiles include a contraction of the muscles at the corner of the eyes, an action known as a Duchenne smile. Among humans, a smile expresses delight, sociability, happiness, joy or amusement. It is distinct from a similar but usually involuntary expression of anxiety known as a grimace. Although cross-cultural studies have shown that smiling is a means of communication throughout the world, there are large differences among different cultures, religions and societies, with some using smiles to convey confusion or embarrassment.

Dimple Small natural indentation in the flesh

A dimple is a small natural indentation in the flesh on a part of the human body, most notably in the cheek. Numerous cultures believe that cheek dimples are a good luck charm that entices people who think they are physically attractive, but they are also associated with heroism and innocence, which has been included in literature for many centuries.

Lip Visible body part at the mouth

Lips are a visible body part at the mouth of many animals, including humans.

Platysma muscle Human neck muscle

The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effect on either side of the neck.

Zygomaticus minor muscle Facial muscle that draws the upper lip upwards and backwards during smiling

The zygomaticus minor muscle is a muscle of facial expression. It originates from the zygomatic bone, lateral to the rest of the levator labii superioris muscle, and inserts into the outer part of the upper lip. It draws the upper lip backward, upward, and outward and is used in smiling. It is innervated by the facial nerve (VII).

Mentalis Muscle that raises the central portion of the lower lip

The mentalis muscle is a paired central muscle of the lower lip, situated at the tip of the chin. It originates from the mentum of the mandible, and inserts into the soft tissue of the chin. It is sometimes referred to as the "pouting muscle" due to it raising the lower lip and causing chin wrinkles.

Depressor anguli oris muscle Facial muscle that depresses the corner of the mouth during frowning

The depressor anguli oris muscle is a facial muscle. It originates from the mandible and inserts into the angle of the mouth. It is associated with frowning, as it depresses the corner of the mouth.

Risorius

The risorius is a muscle of facial expression which arises in the fascia over the parotid gland and, passing horizontally forward, superficial to the platysma, inserts onto the skin at the angle of the mouth. It is a narrow bundle of fibers, broadest at its origin, but varies much in its size and form.

Facial artery

The facial artery is a branch of the external carotid artery that supplies structures of the superficial face.

Marginal mandibular branch of the facial nerve

The marginal mandibular branch of the facial nerve passes forward beneath the platysma and depressor anguli oris, supplying the muscles of the lower lip and chin, and communicating with the mental branch of the inferior alveolar nerve.

Buccal space

The buccal space is a fascial space of the head and neck. It is a potential space in the cheek, and is paired on each side. The buccal space is superficial to the buccinator muscle and deep to the platysma muscle and the skin. The buccal space is part of the subcutaneous space, which is continuous from head to toe.

Human nose Feature of the face

The human nose is the most protruding part of the face. It bears the nostrils and is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum which separates the nostrils and divides the nasal cavity into two. On average the nose of a male is larger than that of a female.

Buccal fat pad

The buccal fat pad, is one of several encapsulated fat masses in the cheek. It is a deep fat pad located on either side of the face between the buccinator muscle and several more superficial muscles. The inferior portion of the buccal fat pad is contained within the buccal space. It should not be confused with the malar fat pad, which is directly below the skin of the cheek. It should also not be confused with jowl fat pads. It is implicated in the formation of hollow cheeks and the nasolabial fold, but not in the formation of jowls.

Nasolabial fold

The nasolabial folds, commonly known as "smile lines" or "laugh lines", are facial features. They are the two skin folds that run from each side of the nose to the corners of the mouth. They are defined by facial structures that support the buccal fat pad. They separate the cheeks from the upper lip. The term derives from Latin nasus for "nose" and labium for "lip". Nasolabial fold is a misnomer, however. The proper anatomical term is melolabial fold, meaning the fold between the cheek and lip.

Inferior alveolar nerve block is a nerve block technique which induces anesthesia (numbness) in the areas of the mouth and face innervated by one of the inferior alveolar nerves which are paired on the left and right side. These areas are the skin and mucous membranes of the lower lip, the skin of the chin, the lower teeth and the labial gingiva of the anterior teeth, all unilaterally to the midline of the side on which the block is administered. However, depending on technique, the long buccal nerve may not be anesthetized by an IANB and therefore an area of buccal gingiva adjacent to the lower posterior teeth will retain normal sensation unless that nerve is anesthetized separately, via a (long) buccal nerve block. The inferior alveolar nerve is a branch of the mandibular nerve, the third division of the trigeminal nerve. This procedure attempts to anaesthetise the inferior alveolar nerve prior to it entering the mandibular foramen on the medial surface of the mandibular ramus.

A jaw abnormality is a disorder in the formation, shape and/or size of the jaw. In general abnormalities arise within the jaw when there is a disturbance or fault in the fusion of the mandibular processes. The mandible in particular has the most differential typical growth anomalies than any other bone in the human skeleton. This is due to variants in the complex symmetrical growth pattern which formulates the mandible.

Zygoma reduction, also known as cheekbone reduction surgery, is a surgery used to reduce the facial width by excising part of the zygomatic bone and arch. Wide cheekbones are a characteristic facial trait of Asians, whose skull shapes tend to be more brachycephalic in comparison with Caucasian counterparts, whose skull shapes tend to be more dolichocephalic .This surgery is popular among Asians due to their inherent wide cheekbones. Due to the advanced surgical skills of Korean surgeons who perform facial contouring surgeries, the number of Asian people undergoing this surgery is increasing.

The cheek constitutes the facial periphery, plays a key role in the maintenance of oral competence and mastication, is involved in the facial manifestation of human emotion, and supports neighboring primary structures.

Human mouth Part of human anatomy

In human anatomy, the mouth is the first portion of the alimentary canal that receives food and produces saliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth.

References

  1. 1 2 "Zygomaticus major muscle bony attachment site: a Thiel-embalmed cadaver study". Morphologie. 105 (348): 24–28. 2021-02-01. doi:10.1016/j.morpho.2020.06.009. ISSN   1286-0115.
  2. 1 2 3 Kim, Kyoung-Eun; Oh, Seung Ha; Lee, Shi-Uk; Chung, Sun G. (2009-10-01). "Application of isometric load on a facial muscle – The zygomaticus major". Clinical Biomechanics. 24 (8): 606–612. doi:10.1016/j.clinbiomech.2009.06.008. ISSN   0268-0033 via ScienceDirect.
  3. 1 2 Pessa, Joel E.; Zadoo, Vikram P.; Garza, Peter A.; Adrian, Erle K.; Dewitt, Adriane I.; Garza, Jaime R. (1998). "Double or bifid zygomaticus major muscle: Anatomy, incidence, and clinical correlation". Clinical Anatomy. 11 (5): 310–313. doi:10.1002/(SICI)1098-2353(1998)11:5<310::AID-CA3>3.0.CO;2-T. PMID   9725574.
  4. "Dimple Creation – Cute as a button, who pays for a deformity?".
  5. "Zygomaticus Major Muscle Function, Origin & Anatomy".
  6. Stel, Mariëlle; van Dijk, Eric; Olivier, Einav (2009). "You Want to Know the Truth? Then Don't Mimic!". Psychological Science. 20 (6): 694. doi:10.1111/j.1467-9280.2009.02350.x. PMID   19422628.
  7. Lidhar, T.; Sharma, S.; Ethunandan, M. (2021-01-01). "Split zygomaticus major muscle sling reconstruction for significant lower lip defects". British Journal of Oral and Maxillofacial Surgery. 59 (1): 106–108. doi:10.1016/j.bjoms.2020.06.031. ISSN   0266-4356 via ScienceDirect.