ELECTRON MICROSCOPY OF DEVELOPING ENAMEL MATRIX IN THE SYRIAN HAMSTER

¹ University of Alabama Medical Center, Birmingham, Ala.

Electron micrographs of developing teeth of hamsters show that:

1. Enamel matrix develops intracellularly and in two phases.

2. The first formed matrix is the interrod material.

3. The rods develop from extensions of the ameloblasts and at first exist as cytoplasm enclosed by the interrod substance. The transformation of the cytoplasm into fibrillar material starts on one side of the rod. The fiber direction is well organized. Those of the rod run in its long axis while those of the interrod material are at right angles to the rod.

4. No rod sheath is found during developmental stages.