a dominant trait. It is believed that cheek dimple genes occur on the 16th chromosome, whereas cleft chin genes occur on the 5th. However, the University of Utah considers dimples an "irregular" dominant trait that is probably controlled mostly by one gene but is influenced by other genes. Characteristics Having bilateral dimples (dimples in both cheeks) is the most common form of cheek dimples. In a 2018 study of 216 people aged 18–42 with both unilateral (one dimple) and bilateral, 120 (55.6%) had dimples in both of their cheeks. It was originally concluded that 60% of people with one dimple likely have it in their left cheek, but later research concluded that 53% were on the right, however, this may be due to differing cultures. Dimples are analogous and how they form in cheeks varies from person to person. Dimple depth and size can also vary; unilateral dimples are usually large, and a possible 12.8% of bilateral people have dimples positioned asymmetrically. They are not linked with a dimpled chin: a study from 2010 by the University of Ilorin examined 500 Yoruban Nigerians with both uni- and bilateral cheek dimples, discovering that only 36 (7.2%) had a cleft chin as well. The shape of a person's face can affect the look and form as well: leptoprosopic (long and narrow) faces have long and narrow dimples, and euryprosopic (short and broad) faces have short, circular dimples. People with a mesoprosopic face are more likely to have dimples in their cheeks than any other face shape. Singaporean plastic surgeon Khoo Boo-Chai (1929–2012) determined that a cheek dimple occurs on the intersecting line between the corner of the mouth and the outer canthi of the eye, (nicknamed the "KBC point" in dimple surgery) but people with natural dimples do not always have their dimples on the KBC point. The other common type of facial dimple form near the mouth in three types: lower para-angle (underneath the mouth and lips), para-angle ("around the mouth angle"), and upper para-angle (above the mouth and lips). Society and culture Cheek dimples are often associated with youth and beauty and are seen as an attractive quality in a person's face, accentuating smiles and making the smile look more cheerful and memorable. Throughout numerous cultures and history, there have been superstitions based on dimples: Chinese culture believes that cheek dimples are a good luck charm (particularly, children born with