It is called Carabelli cusps. A Carabelli cusp is a
condition in which a person has an extra cusp on her molar. This usually seen
on the first molar of our teeth and rarely on the second and third molar.
Sometimes it also occurs on the other part of the teeth. This condition is
heritable, meaning it’s in your family genes; it can be passed through
families. This kind of condition is common for Europeans for about 75 out of
85% chances. Carabelli cusps comes with different sizes, it can be very large
or small.