A dimple is an anomaly of the muscle that causes a dent in the cheek, especially when the individual smiles. Some people have dimples in both cheeks, others in just one cheek. Babies are likely to have dimples caused by baby fat in their cheeks. When they lose their baby fat as they get older, their dimples disappear. Other children do not have them at birth, but may develop them later in childhood. In some people, dimples last only until adolescence or young adulthood, while in others they are a lifetime trait.

Dimples can be passed through multiple generations. The frequency with which a heritable trait is carried forth through genes is called penetrance.

Sometimes a variation in penetrance may also occur. Some individuals may carry a particular gene, but they do not manifest the traits associated with it. Nonetheless, they pass the traits to their successive generations.

Apart from that, sometimes the dimples may also be caused from spontaneous mutations that result in a dent in the cheek or a cleft chin that leads to dimples.

From my observation with my third daughter, her cheek dimple only started to appear (or perhaps much more visible to me) when she was about 7 or 8 years old. She’s got quite a deep chin dimple though.

With my two older daughters, they are fortunate to be blessed with deep dimples on both sides of their cheeks since birth. Their assets are inherited as my hubby has dimples and everyone else from his side of the family has dimples on their cheeks.  With my eldest daughter, her dimples used to appear prominently whenever she smiled. When she was about 8 or 9 years old, the dimples don’t quite appear anymore when she smiles. However, they are still there and deep as ever.

Dimples that have a similar appearance can occur in successive generations of a family. For example, in one family, it was observed that the siblings, their father, uncles, grandfather, and great-grandfather all had similar-looking dimples in both cheeks. In other families, dimples may occur in a child but are not seen in more than one generation.