A histological study of tooth grafts in an inbred strain of mice

Abstract

Abstract. Male adult mice of the C57B1 strain were grafted subcutaneously with two maxillary molar teeth extracted from 10‐day‐old mice of the same strain. The grafts were removed at intervals of 2 to 50 days after transplantation and examined histologically. The cellular components of the grafts degenerated rapidly until by four days only a narrow strip of viable tissue remained at the cervix. Blood vessels entered the cervix at five days and spread throughout the pulp during the following week. At the same time, the pulp was repopulated. Cellular dentin was deposited at the cervix at five days, and condensations of cells were visible adjacent to these deposits. These cells differentiated into odontoblasts which gradually formed a continuous layer in the transplants and secreted varying amounts of secondary dentin. The derivatives of the dental papilla thus recovered their function after a time, whereas the enamel organ derivatives formed epithelial cysts around the crowns of the transplanted teeth. No root growth occurred in any of the grafts. It is thought that the initial loss of blood supply and subsequent establishment of vascular connections between host and graft influenced the pattern and type of degeneration and repair.