A dimple is a small, visible indentation in the skin that appears when certain underlying structures pull the surface inward. Cheek dimples, the most recognized type, are caused by a variation in a facial muscle that tethers the skin from beneath. They’re often called a genetic trait, but the full picture is more interesting than the simple explanation most people have heard.
What Causes Cheek Dimples
Cheek dimples come down to one specific muscle: the zygomaticus major, which runs from your cheekbone down to the corner of your mouth. In most people, this muscle is a single band. In people with dimples, it splits into two bundles as it travels across the cheek. The upper bundle inserts above the corner of the mouth as usual, while the lower bundle dips below it.
That lower bundle is the key. Along its middle portion, it attaches directly to the inner surface of the skin. When you smile, both bundles contract and pull. The spot where the lower bundle is anchored to the skin gets tugged inward, creating that characteristic dip. This is why dimples only appear (or deepen) during a smile and flatten out when the face is relaxed.
Not all dimples sit in the same spot. A study of over 1,400 people found that about 61% of cheek dimples appeared at a specific anatomical point, roughly where a vertical line down from the outer corner of the eye meets a horizontal line from the corner of the mouth. The remaining 39% fell elsewhere on the cheek, which explains the variety in dimple placement from person to person.
Are Dimples Genetic?
Dimples are widely described as a dominant genetic trait, meaning you’d only need to inherit one copy of the responsible gene to have them. But according to MedlinePlus, there is actually no solid proof that dimples follow a straightforward inheritance pattern, and researchers haven’t identified which gene or genes are involved. The “dominant trait” label likely became popular because dimples tend to run in families, but the genetics appear more complicated than a simple one-gene model would predict.
One reason the genetics are murky: dimples can change over a person’s lifetime. Some children are born with dimples that fade as they grow into adulthood. Others develop dimples later in childhood despite not having them at birth. If dimples were controlled by a single dominant gene, you’d expect them to be stable from birth. The fact that they shift suggests that factors like facial fat distribution, muscle development, and skin elasticity all play a role in whether a dimple is visible at any given age.
How Common Are Dimples
Dimples are less common than many people assume. In a screening study of 1,462 people, only 121 (about 8%) had naturally occurring facial dimples. Among those with dimples, women outnumbered men roughly nine to one. Unilateral dimples, appearing on just one cheek, were far more common than bilateral dimples, showing up in about 73% of cases compared to 27% with dimples on both sides.
A small number of people in that study had chin dimples, either alone or alongside cheek dimples, but cheek dimples accounted for the vast majority.
Chin Dimples
Chin dimples (sometimes called cleft chins) have an entirely different origin than cheek dimples. They aren’t caused by a muscle pulling on the skin. Instead, they form during fetal development when the two halves of the lower jaw don’t fully fuse together at the midline. This leaves a small notch in the bone of the chin. A chin dimple can also result from the paired muscles that cover the chin failing to come together completely during development, leaving a gap where the skin dips inward.
Unlike cheek dimples, chin dimples are typically visible all the time, not just when smiling, because the underlying cause is structural rather than muscular.
Back Dimples (Dimples of Venus)
The two small indentations on the lower back, just above the buttocks, are called dimples of Venus (or fossae lumbales laterales, in anatomical terms). These are created by a short ligament that runs between a bony prominence on each side of the pelvis and the skin directly above it. The ligament pulls the skin inward at that point, creating a visible dip on each side.
These dimples are considered hereditary and sit symmetrically on either side of the spine. An imaginary line connecting the two dimples passes directly over the second sacral vertebra, which makes them useful landmarks in spinal surgery. Whether or not they’re visible depends partly on body composition: fat accumulation in the lower back can obscure them, and people with certain pelvic angles are more likely to have prominent ones.
Sacral Dimples in Newborns
A sacral dimple is a small indentation at the base of a newborn’s spine, near the tailbone. Most are completely harmless. However, certain characteristics prompt further evaluation because they can occasionally signal an underlying issue with the spinal cord. Dimples considered higher risk are those that are deep, larger than 5 millimeters, located higher up on the back (more than 2.5 centimeters from the anal opening), or accompanied by other skin markings like tufts of hair or discoloration. A shallow dimple sitting low and close to the tailbone, with no other unusual features, is almost always benign.
Dimpleplasty: Surgical Dimple Creation
For people who want dimples but weren’t born with them, a cosmetic procedure called dimpleplasty can create them. It’s done under local anesthesia as an outpatient procedure. The surgeon works from inside the mouth, using a small circular tool to remove a core of tissue (mucosa, fat, and muscle) from the inner cheek while leaving the outer skin intact. A suture then connects the cheek muscle on both sides of the gap to the inner surface of the skin, pulling it inward to mimic a natural dimple.
The procedure is generally considered low risk. Bleeding during or after surgery is uncommon, and nerve injury is rare. Infection is the more notable concern. One documented case involved a patient who developed abscesses in both cheeks after the surgery and took three weeks to recover, with visible scarring. Proper oral hygiene after the procedure helps minimize infection risk, but complications, while uncommon, can leave lasting marks.
Surgically created dimples initially appear as a constant indentation, visible even without smiling. Over time, as the internal suture softens and scar tissue matures, the dimple typically becomes more natural-looking, appearing mainly when the person smiles or moves their face.