Abstract
Supernumerary deciduous teeth was found in a girl of 3 years and 2 months. Teeth erupted in both sides of lower incisor region. As to the frequency of supernumerary appearance deciduous tooth, Okamoto (1941) reported that it occurred once in tens of thousands, Ikuta (1925) reported 2 cases in 23, 600 and Fukada (1957) failed to see any in 10, 149 subjects examined. It shoud be noted that all these supernumerary tooth, as they appeard in so few instances, occurred in the upper frontal teeth, except that which was reported by Tochihara (1956) to have ocurred in the lower frontal teeth. Two theories have been advanced as to possible origin of the supernumerary tooth in the deciduous dentition, of which the one is based on the ontogenetic dysplasia and the other based on the phylogenetic atavism. In view of our findings on the position of the tooth erupted and the shape and size of the tooth itself, we would like to favor the theory advanced by Fujita (1958) for the origin of the supernumerary tooth as being the result of a morphological disturbance that occurred in the dental lamina.
