A Case of Autotransplantation of an Incomplete Root Formation Tooth in a Patient with Congenitally Missing Teeth

<p> Purpose: Several strategies exist for treating congenital defects of permanent teeth. One treatment strategy for children is tooth autotransplantation. Because the tooth roots of children are still developing and have wide apical foramens, endodontic treatment may be unnecessary following tooth autotransplantation. In addition, root growth can be expected if intact Hertwig’s epithelial root sheath is attached to the transplanted teeth. We report a case of congenital defects of permanent teeth, which were treated by autotransplantation of a tooth with incomplete root formation from a region lacking eruption space.</p><p> Case: A 2-year-old girl was brought to the Takatsu Dental Clinic with the chief complaint of class Ⅲ malocclusion. A panoramic radiograph at the age of 5 revealed a congenital defect of four permanent teeth: 15, 24, 25, and 45. By the age of 7, her permanent teeth had begun to replace her deciduous molars. The root of 65 was resorbed, but there was no succedaneous permanent tooth. Coincidentally, there was insufficient eruption space for 34 and 35. Therefore, we planned to transplant 34 into the extraction socket of 65.</p><p> Results: The deciduous molar 65 was extracted and the recipient socket was carefully prepared to avoid penetration into the maxillary sinus. Tooth 34 was then carefully extracted to avoid damaging the growing root and periodontal ligaments. Donor tooth 34 was positioned into the recipient socket and fixed with nylon thread. The root of tooth 34 was short and the pulp cavity was wide open at the time of transplantation. Three years after transplantation, the tooth root had developed into its regular length and the root apex had completed its development. The transplanted tooth was vital and had no percussion pain or discoloration.</p><p> Conclusion: After transplantation of tooth 34 to extraction socket 65, the number of teeth in the upper and lower jaws filled in the left side, which solved the esthetic and functional problems of the patient. The tooth root developed into its regular length three years after the transplantation without any discomfort. This case shows that autotransplantation of a tooth with an incomplete root in the mixed dentition stage is an option for effectively treating congenital defects of permanent teeth.</p>