Levator Anguli Oris - Function, Action, Origin & Insertion, Pain

Levator Anguli Oris:

• What is Levator Anguli Oris?
• Function & Action
• Origin & Insertion
• Pain

What is Levator Anguli Oris?

The levator anguli oris is a small but important facial muscle located in the upper cheek region. It belongs to the group of muscles responsible for facial expression and plays a major role in elevating the corners of the mouth. This muscle helps create natural facial expressions such as smiling, smirking, and expressing happiness or confidence.

Anatomically, it lies beneath the levator labii superioris and zygomaticus muscles. Because of its deep placement, the levator anguli oris is not easily seen on the surface, but its contribution can be observed when the mouth corners lift upward. Understanding this muscle is helpful in fields like dentistry, facial aesthetics, speech therapy, and Botox treatment planning.

Function & Action

The primary function of the levator anguli oris is to elevate the angle (corner) of the mouth. When it contracts, it pulls the mouth corner upward and slightly inward. This action is essential for producing a natural smile and other positive facial expressions. It works in coordination with muscles like the zygomaticus major, risorius, and orbicularis oris.

In addition to lifting the mouth corners, it helps deepen the nasolabial fold and contributes to facial symmetry. Since facial muscles often work together, dysfunction or weakness in the levator anguli oris can alter smile patterns. Treatments such as facial exercises, trigger point therapy, or cosmetic procedures may target this muscle to improve expression or symmetry.

Origin & Insertion

The origin of the levator anguli oris is the canine fossa of the maxilla, a small depression just below the infraorbital foramen. This location on the upper jaw bone gives the muscle an ideal angle to elevate the mouth corner during contraction.

The muscle inserts into the modiolus at the angle of the mouth, blending with fibers of the orbicularis oris and zygomaticus muscles. Because the modiolus is a hub where many facial muscles intersect, the levator anguli oris plays a coordinated role in fine-tuning mouth movement and expression. Its anatomical path explains why it contributes to both elevation and slight medial pull of the lips.

Pain

Pain involving the levator anguli oris is often related to muscle tension, overuse, dental issues, or referred pain from surrounding facial muscles. Trigger points may develop in the region, leading to aching sensations near the upper lip, cheek, or nasolabial fold. Some people experience discomfort when smiling, chewing, or speaking if this muscle is strained.

Causes of pain may include bruxism (teeth grinding), TMJ dysfunction, facial nerve irritation, sinus issues, or cosmetic procedures such as fillers or Botox. Treatment typically involves warm compresses, facial massage, stretching, trigger point therapy, and addressing underlying dental or TMJ problems. If pain persists, a healthcare professional can evaluate for nerve-related or structural causes.