ANATOMY

Zygomaticus Major Muscle is one of the 36 facial muscles. The muscle originates from each Zygomatic Arch (Cheek bone or Malar Bone) and ends by blending with the fibers of Levator Anguli Oris (facial muscle of mouth) and Orbicularis Oris (complex of muscles in lips encircling the mouth) at Modiolus (conical shaped central axis in Cochlea).

INNERVATION

Facial Nerves innervates the Zygomaticus Major Muscle. To be more specific Buccal and Zygomatic branches of the Facial Nerve (Cranial Nerve VII) innervates the muscle.

BLOOD SUPPLY

Zygomaticus Major Muscle is supplied blood from the Facial Artery and Transverse Facial Artery which is the branch of External Carotid Artery also known as Anaesthetist’s Artery.

FUNCTION

Zygomaticus Major Muscle raises the corner of mouth while smiling. The muscle stretches to pull the mouth upward and sideways that results in forming a smile expression. It also stretches the skin of cheek bone at the top. Variation in the muscle causes the formation of Dimples.

CLINICAL SIGNIFICANCE

The frequent use of this muscle can cause Crow’s Feet (laugh line or character line) or wrinkles around eyes. Inability to form Facial expressions may be the first symptom for the damage of these Facial Muscles due to the nerve damage. Damage to facial nerve causes in Facial Paralysis. This type of damage occurs due to some reasons given below.

• Stroke

• Bell’s Palsy

• Parotid Salivary Gland Cancer

• Infectious Myositis

• Myopathy