High resolution electron microscopic technique applied to the detection of distortions in apatite crystallites during amelogenesis.

Distortions in the crystal structure of developing tooth enamel from human fetuses and newborn cats were studied by high resolution electron microscopy. Undecalcified sections were observed in a JEOL 100B transmission electron microscope. Two kinds of crystal sections were observed. In one, the diffraction images corresponded to the (10.0) and (00.2) lattice planes, and in the other they corresponded to the (01.0) and (10.1) planes. The unit cell distortion in naturally bent crystals showed a linear correlation with the inverse of the radius of curvature for both the [00.2] and the [10.1] axes. along the [00.2] axis of crystallites from both cat and human enamel, the distortion per unit cell was linearly correlated with the inverse of the length of the crystallite segment under consideration.