Dimples are caused by a variation in the zygomaticus major muscle, a muscle involved in facial expression. Specifically, a split or division in this muscle creates a small indentation or dimple in the cheek when smiling.
The Role of the Zygomaticus Major Muscle
The zygomaticus major muscle typically runs from the zygomatic bone (cheekbone) to the corner of the mouth. In individuals with dimples, this muscle is often divided into two distinct bundles:
- One bundle connects below the corner of the mouth.
- The other bundle connects at the corner of the mouth.
How the Split Causes Dimples
This division of the zygomaticus major muscle affects how the skin moves when smiling. The skin is pulled inward at the point where these muscle bundles attach, creating a visible indentation, or dimple. Essentially, it's the tethering of the skin to the underlying divided muscle that produces the characteristic dimple. Without this division, the muscle would contract smoothly, without causing the skin to indent.
Are Dimples Genetic?
While the precise genetics are complex and not fully understood, dimples are often considered to be hereditary. It is believed that they are passed down through families, though the exact inheritance pattern can vary.
Summary
In summary, dimples are a facial feature caused by a split in the zygomaticus major muscle, leading to a small indentation in the cheek when smiling. This unique muscle structure pulls the skin inward, creating the characteristic dimple appearance.
