Takahashi M, Mori K, Miyata K, Asami Y, Sasagawa I, Kato J, Kobayashi K
Shigaku. 1989 Oct;77(3):996-1005.
The purpose of this study is to investigate features and histological structures of the microdontic wisdom tooth. Materials investigated in this study deal with a very small upper right microdontic wisdom tooth of a male patient aged thirty-six. It was observed with binocular microscopy and under X-ray. Horizontal ground sections of it were prepared and observed with polarizing microscopy, phase microscopy, microradiograph, and scanning electron microscopy. Total length of this specimen was about 1/2 of the average measurement in Japanese upper third molars, breadth of the crown about 1/3, thickness of the crown about 1/4. It had one cusp and one root. It is considered that one cusp was formed by fusing of the mesiolingual cusp and mesiobuccal one because fundamental features of the buccal and lingual surfaces of upper molars were preserved in this specimen. It is thought that dental tubules in this specimen were formed more densely than those in the common wisdom tooth because the space of retreating odontoblasts of this specimen was limited but that enamel rods in this specimen were formed more thickly than those in the common wisdom tooth because the space of retreating ameloblasts of this specimen was wide. It is considered that the degeneration in this specimen came up to not only the dental form, but also the histological structure of the enamel because the surface layer of the enamel of this specimen was composed of the laminal structure.
本研究的目的是调查过小智齿的特征和组织结构。本研究中所研究的材料是一名36岁男性患者右上颌一颗非常小的过小智齿。通过双目显微镜和X射线对其进行观察。制备其水平磨片，并通过偏光显微镜、相差显微镜、显微放射摄影和扫描电子显微镜进行观察。该标本的总长度约为日本上颌第三磨牙平均长度的1/2，牙冠宽度约为1/3，牙冠厚度约为1/4。它有一个牙尖和一个牙根。据认为，由于该标本保留了上颌磨牙颊面和舌面的基本特征，所以一个牙尖是由近中舌尖和近中颊尖融合形成的。据认为，该标本中的牙本质小管比普通智齿中的形成得更密集，因为该标本中退缩成牙本质细胞的空间有限，但该标本中的釉柱比普通智齿中的形成得更粗，因为该标本中退缩成釉细胞的空间较宽。据认为，该标本中的退化不仅表现在牙齿形态上，还表现在釉质的组织结构上，因为该标本釉质的表层由板层结构组成。
