An extra small cusp on the tooth may be a supernumerary tooth. A supernumerary tooth is an extra tooth within the normal range of teeth and may be found in many positions on the tooth, but the most common is the maxillary median supernumerary tooth, which may be distributed symmetrically or unilaterally. The crowns of the teeth are usually small and tapered, and the roots are short. Multiple teeth are usually due to genetic factors, but may also be related to embryonic nutrition and other factors, resulting in the development of multiple teeth that affect the face of the jaw and teeth. Clinically, the presence of a supernumerary tooth usually requires extraction. When there is an extra small cusp on the teeth need to go to the hospital, under the guidance of professional doctors for scientific treatment.