Heterotopic Formation of Dentine and Enamel by Transplantation of Epithelium and Pulp Tissue

Epithelium surrounding the base of the permanent cuspid teeth, and pulp tissue in 18 young dogs were transplanted to the fascia of the abdominal wall as an autogenous graft, and after 9 to 31 days there was found newly formed enamel, dentine, cementum and bone.

Method. The epithelium was obtained in the following way: Under ether anesthesia a cuneiform osteotomy of the mandible, including the deciduous cuspid tooth was made in dogs of between 3 and 6 weeks of age and this allowed access to the permanent cuspid tooth, which was removed. A circular incision was made equatorially allowing the dental epithelium and pulp to be removed en masse from the calcified tooth shell. The tooth shell itself was always discarded. The soft tissues were gently wiped with moist gauze, were X-rayed, and a section was removed for histological control. The calcium-free material was then transplanted to a pocket between the lateral abdominal muscles, with aseptic pre cautions, and the incision closed with silk.

It was found easy to separate (a) the sheet of ameloblasts with the subjacent vascular connective tissue parietes, hereafter called the ameloblast layer from (b) the odontoblasts and their underlying pulp cells, in this paper called the odontoblast layer. In some experiments the ameloblast and odontoblast layers were separately transplanted, and in others they were transplanted together.

Results. In all cases calcified tissue was found in the transplant after 9 days. When the ameloblast and odontoblast layers were transplanted together in a nearly normal relationship, enamel and dentine were found between the 2 layers and the ameloblasts were present in a normal cylindrical form, as in the original tissue.