Preface

These are the Proceedings of the ACBTE4, a record of the studies read at the 5th Meeting of the Association for Comparative Biology of Tooth Enamel(also abbreviated ACBTE), held from 24 to 26 September 1994, at the Karuizawa Seminar House of Nihon University.
The study of the comparative biology of tooth enamel is, unfortunately, not a research theme where many people compete to be the leader. So it is not often that we find an excellent compendium of newly presented reports in this research field. Most of what we see are just the newest part of studies that investigators have worked hard on for a long time, or some part of a major study, which we expect to grow and become outstanding work in the future.
It is not surprising that in a long study an investigator may hit a wall that it seems impossible to get through. In such a case, he/she works hard to break through this wall in various ways. Some change materials, others change the method of research. It is also not rare to apply new methods of analysis during experiments.
Studies of tooth enamel have a long history. It is well known that enamel is a very important subjects in the field of paleontology and comparative animal biology because of its unique characteristics. On the other hand, its high mineral content and hardness often stand in the way of investigators and act as the obstacle in performing work. It seems that this is one of reason why the study of tooth enamel has been left behind that of other tissue.
However, the slowness of advances the in research, Gott sei Dank, has meant that investigators of enamel were exempted from the hard work of developing new methods for their own studies, alone by trial and error. If one has the courage to introduce new methods into the research field, investigations, will be able to advance enamel studies borrowing from other areas, especially developmental biology which less need to struggle directly with the hardness of enamel
At the ACBTE 4 meeting, many reports from the traditional field of comparative biology of tooth enamel attracted participants by their interesting themes. At the same time, a number of studies showed that some new methods have already been introduced into enamel studies and that they have contributed to advances of the field. Each of these presentations were followed by much exciting discussion.
The pages of these Proceedings record the excitements at that time. So that after reading each article readers will be able to feel the atmosphere of excitement, and it will not be difficult to remember for readers who were fortunate to be there. This makes the Proceedings especially valuable, we believe. To hold this Meeting and to publish this Proceeding provides a focus for the enthusiasm of enamel investigators in Japan, who are daily making effort to advance this field.
Many reason, including requests for revisions and delay of contributions have made it necessary to postpone the publication of these Proceedings. We apologize to all authors, as it may have weakened its function as news like this kind of publication always needs to fulfill.
The 5th Meeting of the Association for Comparative Biology of Tooth Enamel was successfully held with invaluable support of the staff of the Department of Oral Anatomy II, the Nihon University School of Dentistry at Matsudo. We, the organizers, wish to express our heartfelt thanks to them.

July, 1995
WAKITA, Minoru : Editor in Chief