Developmental Studies on the Three-Dimensional Arrangement of Enamel Prism; Approach on the Crystallographic Aspects.

本文用计算机图形模拟技术研究了牙釉质Tomes突的形态与牙釉质微晶排列的关系，特别是微晶长度对牙釉质棱柱（棱柱体）中微晶排列的影响。本文的研究旨在证实Wakita等人最近提出的理论基础，现有的研究表明，在Tomes过程的S面上析出的微晶的长度是有限的。这种局限性与Tomes突S面的表面结构有关。也就是说，当在给定的S面上引出的微晶的长度超过某些方面时，它会穿过相邻的微晶。这意味着这种现象只能在CRT上，而在棱镜中不可能是二维和三维的。因为实际棱柱中的每个微晶不仅有长度，而且有宽度和厚度，相邻微晶之间的交叉是由它们所引出的Tomes过程的S面的状态与微晶长度的密切关系造成的。也就是说，在曲率较小的S面上引出的微晶与相邻的微晶发生交叉，尽管它们的长度比同一S面上其他区域引出的微晶短。

The relationship between the shape of the Tomes' process and the arrangement of enamel crystallites was examined by use of the computer graphic simulation technique, especially on the effects of length of crystallites to the arrangement of crystallites in the enamel prism (prism body). This studies aimed to confirm the theoretical bases recently given by Wakita and his coworkers.Present studies revealed that there was limit in the length of crystallites, when they educe on the S-face of the Tomes' process. This limitation was related to the surface structure of S-face of Tomes' process. That is, when the length of crystallite which educes on the given S-face came over the certain aspects, it crosses over the neighboring crystallites. It means that this phenomenon is capable only be on the CRT and it is impossible to be two-dimensionally as well as three-dimensionally in the prism. Because each of crystallites in actual prism have not only its length but also its width and thickness.These cross over between neighboring crystallites is resulted by the close relationship between the condition of the S-face of the Tomes' process on which they educe, and the crystallite length. That is, the crystallites educed on the S-face with small curvature occur cross over with neighboring ones, although their length are shorter than that educed on other area of the same S-surface.