Root morphogenesis in ectopically transplanted pleurodont teeth of the iguana

Abstract

A study was made to determine the behavior and fate of transplanted reptilian teeth with a pleurodont type of attachment. The purpose was to compare this attachment with the behavior of other types of attachments, when they are transplanted, and to determine which portions of the ankylosed tooth are controlled by intrinsic factors. 50 small green iguanas were used. Autologous transplants of both individual buds of a known stage of development and small blocks of the entire upper or lower jaw were placed in the gular region or anterior chamber of the eye. The transplants and the jaws were examined at intervals from 0 to 180 days. Tooth buds transplanted with or without the jaw were capable of growth to normal size and shape. New bud formation also began after transplant acceptance, and buds were more protected from epithelial injury than previously reported amphibian tooth transplants. The ankylosed adult tooth began the process of shedding almost immediately. While lack of normal environment and lack of underlying bone did not prevent formation of a normal root shaft with dentin, there was little evidence of induction of the ‘bone of attachment’ and underlying jaw bone by the growing buds. The root shaft size and shape were, therefore, intrinsic features of the pleurodont tooth.