We investigated the case of an infant presenting natal teeth at AA and swellings on the gingiva in the lower central deciduous incisor region. As swellings had still remained in the area after months the extraction of the natal teeth and a part of the hard tissues were exposed, we excised, the swellings and examined them histopathologically.
A radiograph showed defined hard tissue similar to the radiopaque areas of a rice grain and having the size of a pea.
Histopathological examination showed that the swellings were vascular fibrous tissues with large number of acute inflammatory cell infiltration and in the hard tissues such as osteodentin there were found stratified structures, entrapped cells and tublar dentine structures.
We considered in this case that the differentiation of odontoblasts occured in the dentine papillae or that the lower tissue in connection with pulp had remained after the extraction of the natal teeth, and thereafter osteodentin was formed.