March 24, 2022
Keio University School of Medicine
Japan Agency for Medical Research and Development
Professor Yoshiaki Kubota of the Department of Anatomy, Keio University School of Medicine, in a joint study with the university's Department of Physiology, Department of Biochemistry, and Division of Cardiology, as well as Jichi Medical University, Nagasaki University, Shiga University of Medical Science, and the University of Connecticut in the United States, has developed a new imaging technology for the three-dimensional structure of blood vessels in teeth. This research has revealed that blood vessels are deeply involved in the process of tooth hardening.
Teeth are the hardest structures in the human body, and their hardness is essential, especially for eating. In the center of these hard teeth is a soft tissue called the dental pulp. The blood vessels within the dental pulp are important for maintaining tooth health, and it has been suggested that they also play some role in the process of tooth hardening. However, unlike other soft tissues, the task of "slicing sections" of teeth for detailed observation was nearly impossible due to their hardness. Therefore, it remained unclear how blood vessels enter the teeth and how they contribute to tooth hardness.
In this study, we first made various improvements to conventional experimental methods to visualize the blood vessels in teeth, and succeeded in cleanly slicing sections of mouse teeth. We then successfully established a technology to visualize the three-dimensional structure of dental blood vessels at the single-cell level.
Using this technology to observe the course of blood vessels in detail, we discovered a unique population of vascular cells that cluster around odontoblasts, which are responsible for tooth hardening. These cells promote the maturation of odontoblasts and supply components necessary for hardening, such as phosphorus. Furthermore, when we created genetically modified mice in which only these specific vascular cells were removed, we found that the teeth did not harden.
This study is the first in the world to establish a high-precision imaging technology for teeth and to use this technology to elucidate the mechanism of tooth hardening. In the future, it is expected to be applied to technologies for regenerating teeth lost to cavities and periodontal disease, especially for creating hard teeth.
The results of this research were published in the online edition of the "Journal of Experimental Medicine" on March 23, 2022 (US Eastern Time).
For the full press release, please see below.