The zygomaticus major muscle is primarily responsible for creating a smile.
The Smiling Muscle: Zygomaticus Major
According to research, the zygomaticus major muscle is often referred to as the "smiling muscle" because its main function is to draw the corners of the mouth up and outwards, which is the fundamental action of a smile. While it's the primary muscle, smiling isn't a solo act.
A Team Effort: Facial Muscles and Smiling
It's important to understand that smiling is a complex facial expression that involves numerous muscles working together. The reference states that up to 43 other facial muscles contribute to the variety and nuance of smiles we can produce.
Muscles Involved in Smiling
Here's a quick overview of the key players:
- Zygomaticus Major: As mentioned, this is the main muscle.
- Zygomaticus Minor: This muscle assists in raising the upper lip.
- Orbicularis Oculi: This muscle surrounds the eye and is responsible for creating "crow's feet," often associated with genuine smiles (Duchenne smiles).
- Levator Labii Superioris: Helps raise the upper lip and can contribute to a more intense or expressive smile.
Types of Smiles and Muscle Involvement
The specific muscles involved can vary based on the type of smile:
- Duchenne Smile (Genuine Smile): Involves both the zygomaticus major and the orbicularis oculi, creating a more authentic and heartfelt expression. These muscles are often involuntary.
- Social Smile (Polite Smile): Primarily involves the zygomaticus major, without significant contraction of the orbicularis oculi. This smile is often voluntary and used in social situations.
