Unusual multiple natal teeth: case report.

An 18-month-old Japanese boy with multiple natal teeth was examined. Fourteen hard structures were reported to have been present at birth at the regions of the anterior teeth and first primary molars in both jaws. The structures were excessively mobile and 11 of the structures had exfoliated successively since 5 months of age. The three structures remaining at the regions of the first primary molars had bonelike appearance and color, and were smaller in overall dimension than the corresponding primary teeth. Radiographic examinations showed that the structures had neither roots nor pulp chambers and their radiopacity corresponded to that of mandibular bone. Furthermore, there were no permanent successors except for the upper central incisors and left lateral incisor at the regions where the structures were situated. Histological examinations revealed that the specimens consisted of dentin with tubular structure, osteodentin-like structure, and cementumlike structure.