Hyperdontia is the condition of having supernumerary teeth, or teeth that appear in addition to the regular number of teeth (32 in the average adult). Affected patients often demonstrate teeth that are larger in size with a more complex anatomy. The additional teeth may be single or multiple; unilateral or bilateral; and in one or both jaws. The most common supernumerary tooth arises in the midline of the anterior maxilla and is known as a mesiodens. There are many numbers of theories about the development of the etiology of hyperdontia even though it's not fully explained. Hyperactivity of the dental lamina or dichotomy of the tooth bud, the molecular mechanism during the early phase of tooth development can be a ground for single supernumerary teeth. Eruption failure, rotation or displacement of the adjacent teeth, dilacerations, root resorption, crowding, malocclusion, fistulas and cystic formation, nasal cavity eruption, and delayed or abnormal root development of permanent teeth are common clinical complications linked with supernumerary teeth.
I was thinking same, but I would have thought it would be two rows, non-crossing