Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

FRIS Interviews #13

FRIS Interviews#13

  • 波田野 悠夏Yuka Hatano

    Assistant Professor

    Humans and Society

    Research Fields

    Biological Anthropology, Forensic Medicine, Human Anatomy

    Main Research Topics

    Three-dimensional analysis of human face and its application to facial approximation, Tracing the populational history of the Japanese using morphological analysis of tooth crown of skeletal remains

波田野 悠夏

“Does it excite me?”
That’s the criteria for deciding whether to work on something

“I was fascinated by anatomy.”
Applying knowledge and skills learned as a dentist to facial reconstruction

You graduated from the Nippon Dental University School of Life Dentistry at Niigata. Was your original aim to become a dentist?


I had orthodontic treatment in junior high school, which interested me in teeth and jaw. I saw a dentistry career as one of my options for the future. It was also at my father's recommendation. I enrolled in Nippon Dental University School of Life Dentistry at Niigata, a school to which I could commute from home and offered a substantial tuition exemption system. Medical and dental universities in Japan have anatomy classes in the second year. In such a class, I laid eyes on a corpse for the first time (outside of a relative's funeral). The shock of that left a vivid impression on me. Strangely, however, it did not feel scary, and I became fascinated by anatomy, which allowed me to study by coming into contact with human bodies. I started to visit the anatomy lab after classes and to attend anatomy seminars that were presented during extended vacation periods. I became particularly indebted to Dr. Takashi Nara, an anthropologist whose research specializes in ancient skeletal remains, such as those of Neanderthals. Old human skeletal remains excavated from archaeological sites are often in fragments. To analyze their morphology, you first must put the fragmented pieces back together into their original, complete shape.

While still in my third year of undergrad, I worked part-time on bone restoration under Dr. Nara. Something caught my attention one day when I was restoring some children’s bones: a dental dysplasia called enamel hypoplasia. I had been under the impression this does not typically occur in deciduous teeth. When I spoke to Dr. Nara about it, he recommended I do a presentation at an academic conference in Japan. I was still an undergrad student, but here I was, making my debut at an academic conference! It was my first encounter with research and became a turning point in my life.

I started my clinical internship at a hospital while in my fifth year (*medical and dental schools are six-year courses in Japan), surrounded by students working hard to become clinicians. Meanwhile, I suffered an unexpected accident and was forced to take time off from studying. My clinical training ended up taking two years due to curriculum-related issues. It was twice as long as other students, so I could sink deeply into my dental studies. At the same time, my narrow escape from death gave me time to re-think what I truly wanted to do with my life in the future. A large number of graduates become clinical dentists. But, personally, I felt that I’d be able to live in a way that is true to self, even if I was in the minority if I took the dental science I had studied up to that point and applied it to research in biological anthropology working with archaeological human remains.

A large number of graduates become clinical dentists. But, personally, I felt that I’d be able to live in a way that is true to self, even if I was in the minority if I took the dental science I had studied up to that point and applied it to research in biological anthropology working with archaeological human remains.

Graduating dental school in March 2016, I became a dental intern at Tohoku University Hospital the following month. In my undergrad years, my research supervisor was Dr. Toshihiko Suzuki, and this same Dr. Suzuki ran a dental forensic laboratory at Tohoku University Hospital. The significant decisive factor for me was that I was able to continue my research after finishing my duties as an intern.

The education in Japanese schools of dentistry is strongly vocational. It focuses on national exams, and unlike other faculties, it does not offer opportunities for thesis research, writing papers, or for presenting at academic conferences. In addition, biological anthropology is an academic field where it is common for researchers to have undergone a specialized science education during their undergrad years and then also at graduate school. People such as myself, who are graduates of dental departments , make their start in the field with a significant handicap in terms of their research background. As someone trying to make their way in this kind of research field, I was fortunate to have been given research opportunities while still an undergrad student and to have been able to receive direction from multiple faculty members at various universities. It was a rare and precious opportunity.

During my internship, Dr. Nara asked me to restore the face of a samurai of the late Edo period name Kobayashi Torasaburo. As a result of the Boshin War, the civil war that marked the end of the Edo and the start of the Meiji periods in Japan, his domain, the Echigo–Nagaoka Domain, was suffering great hardship. It was given 100 bags of rice by way of relief, but Kobayashi Torasaburo refused to use the rice for food, saying this would only relieve a temporary hunger. Instead, proceeds from the sale of the 100 bags of rice were used to build the Kokkan Gakko school. Kobayashi Torasaburo was working from a long-term perspective—building the foundations of modern education for the reconstruction of Nagaoka. I happen to come from the same hometown as this great man.

This historical incident, known as One Hundred Bags of Rice, is also quite well known from a policy speech that then Prime Minister Junichiro Koizumi gave in May 2002, when he referred to the spirit of the event. Kobayashi Torasaburo was an advocate for the importance of education, and I’ve felt admiration for him ever since I was in elementary school. Incidentally, I graduated from Nagaoka High School, which traces its history back to the Kokkan Gakko school, and my birthday is the same as that of Kobayashi Torasaburo! Never in my life did I think that I’d be working on his facial reconstruction. I will never forget the excitement and uncanny sense of connection I felt when I first laid eyes on his skeletal remains.

How was your experience working on the facial reconstruction of Kobayashi Torasaburo, with whom you share such a close connection?


Kobayashi Torasaburo's skull was marked by a distinctive facial expression, with a clear difference in the left and right sides of his mandible. Records show that he lost sight in his right left eye when he was about three years old. People whose visual field is compromised on one side try to compensate for this by tilting their heads when looking at objects in front of them. Distinctive lifestyle habits during bone development cause a distortion in the mandible and maxilla, biasing its growth to either the left or right side.

Of course, other causes, such as genetic influences, are also possible, but I would guess that Kobayashi Torasaburo’s loss of eyesight had a big impact on his skull morphology. As illustrated by Kobayashi Torasaburo’s story, the great pleasure of researching old human skeletal remains is in connecting records of their lives that remain in documents with the actual shapes of real people’s bodies, and conversely, in inferring aspects of their lives from the shapes of their skeletal remains. This is also where the realm of interdisciplinary research, a fusion of the humanities and the sciences, comes into its own.

To do facial reconstruction, we make a precise reproduction model of the skull and apply layers of clay to build up a thickness that equates to the soft tissue—basically muscles and skin. Back when I was working on Kobayashi Torasaburo, data on the thickness of the soft tissue required for facial reconstruction was inadequate, and there was no data focusing on the occlusal relationship between the upper and lower teeth, which determines facial features, nor was there any biological data. So in my doctoral program, I worked on analyzing the thickness of the soft tissue of living bodies using digital data obtained from medical CT and 3D scanners.

You have also been involved in the facial reconstruction of members of the Makino family, a family that served as the rulers of the Echigo–Nagaoka Domain.


The facial reconstruction work I did on members of the Makino family was also a factor in my sense of connection with my hometown, Nagaoka. I am in charge of the facial reconstruction of the females. It’s a known fact that the morphology of facial features of people of the Edo period depended on the class to which they belonged, be they farmers, commoners, samurai, or aristocrats. In particular, the characteristics we recognize in members of the ruling class—feudal lords, in other words—are referred to as “aristocratic traits.” Even if members of the first generation might have had round faces, changes took place with each generation, with the faces in aristocratic lineages changing to become excessively long and slim. The period of a few hundred years from Japan’s Middle Ages to the present day is not a long time when looked at from the perspective of human history overall. Various studies have been done to try and discover why such dramatic changes in skull morphology took place over such a short period. Going from what we know from previous research, women who became legal wives (rather than concubines) of feudal lords were chosen from select family lineages, and the reason for the facial features I’m describing is thought to lie in the atrophy of the masticatory organ, the result of a diet of extremely soft foods. It is not often that we dig up human skeletal remains where it is clear that the buried person was of a high social class, so there are almost no comprehensive anthropological studies that take into account feudal lords and kinship relationships, which leaves a lot still open for investigation.

That is all sitting in the background as context. With the Makino family, which ruled over the Echigo–Nagaoka Domain, the remains of the lords from the 4th to the 11th generations and of the 8th- and 10th-generation legal wives are in a good state of preservation. Furthermore, the current head of the Makino family has permitted the family’s remains to be studied to contribute to the development of science and provide insights into how such aristocratic traits changed. At the present moment, we can say that we have no skeletal material other than that of this particular family that can be directly accessed for research purposes and where we can trace the process of change in aristocratic traits over a long period.

In addition to all this, you are involved in verifying the identity of missing persons from the Great East Japan Earthquake or of missing persons daily.


Bones and teeth remain for a long time, and we can use them to gain a variety of information.

In forensic anthropology, the remains allow us to infer things such as the gender, age, and life history of a person. An example might be: this person was male, about 50 years old, and suffered an injury in this location in the past. I am involved in forensic autopsies, verifying the identity of unidentified persons from the morphological characteristics of their teeth and evidence of treatments they have had during their lifetimes.

We know many dentists were involved in identity verification after the Great East Japan Earthquake. I was still a student at the time, so I have no experience in verifying identities at the site of the disaster, but even now, about once a year, I am asked to take part in the identity verification of remains of persons thought to have died during the 2011 disaster. It is a job with a heavy social responsibility, but as a dentist at Tohoku University, which went through the earthquake experience, I hold that responsibility and coordinate with forensic doctors and people in charge of the prefectural police with the aim of returning the entire body to the family.

Some may say that it is not a good idea to pick up on research, but now that I am allowed to do so, I am researching with my antennae of interest and sensibility wide open.

Please describe your current research.


I am working on multiple themes at the same time. My central interest is facial reconstruction, where I work with a skull to restore the facial features that the person used to have. This is used in biological anthropology to understand how the shape of our faces has changed and what people used to look like in the past. Until now, most of the data used in facial reconstruction research has been collected from corpses (donated bodies), but to be able to do this work more accurately, it is my job to bring together data that can be used for facial reconstruction. I do this by collecting CT information from contemporary people, taking 3D scanned images of facial morphology, and measuring the thickness of detailed soft tissue, while also taking into account information about the bite, which affects the facial morphology. In the future, I plan to automate facial reconstruction using AI.

What would you say is the appeal of doing research?


The process of traversing seemingly unrelated, disparate fields and connecting them to understand a single phenomenon is exciting. Isotope analysis had made possible the accurate dating of excavated artifacts. We are getting a clearer picture of the genetic information of past people through whole-genome analysis obtained from ancient human skeletal remains. Together with skeletal remains provided by archaeological experts, unearthed remains and information on relics are useful in bringing people of the past “back to life” and in recreating how they stood and walked. Integrating information from various related fields with the morphological analysis of human skeletal remains and getting a closer look at the people of the past and their life histories is thrilling as a research process.

What do you see as the most rewarding part of your research?


Working muscles under the skin play a major role in forming human facial features. Muscles function by moving with the bones as their fulcrum, and their use over a long period of time comes to impact the morphology of the skull. In other words, to get an accurate picture of what a face once looked like, one must first have an accurate understanding of the bones of the skull.

Research into the face has taken place across various fields, but for the most part, it has only looked at the shape of the skin's surface. As my research has involved handling bones of the skull, I have a great advantage in being able to work with the shape of the skeletal remains themselves. In addition to that, I work in a way where I think of the morphology of teeth and the oral cavity to be the entrance point for food into the body.

It’s also my unique research style to apply my know-how from dentistry to sample problem points and then to be able to proceed with the analysis as digital data. Someone like myself standing in a lab working with a skull may strike others as odd. However, when I think about what I do as bringing the people of olden times—the types of people I learned about back in school—back to life, I lose all sense of time and become completely absorbed in my research.

What benefits do you see your research providing to society in the future?


This research can be used to identify victims of disasters whose bodies have decayed to a skeletal state. At present, it is possible to reconstruct the face to some extent with DNA, and in the US, this is being put to use in criminal investigations; however, DNA analysis cannot reveal the changes resulting from one’s lifestyle habits. Therefore, speaking from a morphological point of view, I would like to create a technology that can restore facial features.

There are also ways that my research can be applied in archeology. DNA analysis results are difficult for the general public to understand. However, we can present them in a way that is easy to comprehend, thus making this will be an excellent outreach technique. Excavations are necessary to obtain ancient human skeletal remains, and this demands the cooperation of local people and municipalities. It is imperative to return research results to the local community. With the use of 3D scanners and other tools to gather morphological information, the work of facial reconstruction will become even more accurate.

In addition to research, I believe that it is extremely important to preserve the data that we already have in a digital form, so I’ve taken the initiative to do this. In biological anthropology, there are many cases which are difficult to access, even if their location is known. I think that the best we can do going forward is to digitalize the data and make it accessible to everyone. There are many issues that need to be cleared, of course, such as the issue of rights with such data. A high level of accessibility naturally facilitates the ease of collaboration with other researchers and research, and one would anticipate a big positive difference in the results too. The Makino family, who were the lords of the Echigo-Nagaoka Domain that I was speaking about earlier, are one such example. We know that the remains of members of the family were in good condition during the excavation of the burial ground in 1983. After that, the researcher who was leading the excavation and the then-head of the Makino family made a mutual decision for the future. It was one of foresight and wisdom. Speculating that science and technology will have advanced further in 50 years time, they decided to take measures to preserve the information in such a way before re-bury the remains, so that it would not be lost. Several decades have now passed, and this story from the past crosses over to the present, with my teacher, who was a student of the researcher in charge at the time, re-opening the investigation in accordance with the last wishes of the two people I just mentioned. In addition to that, I have myself in charge of processing the digital data and the facial reconstruction.

Through the collaborative efforts of Japanese researchers, including myself, the faces of successive feudal lords have been reconstructed, and we have also digitalized the information, allowing us to carry on with our research without the fear of damaging the skull.

AI is going to keep developing from now on, and we must handle the information we gain from it with great care, but I feel it’s important to promote digitalization. At first, it might only be useful for research purposes, but I think it will also serve social needs in a roundabout way, as it will also help protect Japan's heritage. This is an issue I've been thinking about since joining the Frontier Research Institute for Interdisciplinary Sciences (FRIS) at Tohoku University.

What is your personal definition of “research”?


To me, research means getting involved in anything that interests you. When you research something, you do make a thorough investigation of one question; however, my style is to push and extend the boundaries of my knowledge outwards rather than keeping myself tucked away in a bubble. In Japanese, we have a proverb: “It’s better to regret something that you do rather than something that you do not do.” Even though I am trying to make a very thorough investigation of one area, I do give in to my curiosity, and I take on research themes in fields in which I am a complete amateur. This is what research means for me, and I believe that these expanded boundaries will one day merge and become a larger frame.

Anthropology is basically an interdisciplinary field of study that tries to understand humankind from a range of angles. Since the old days, it has created a ground in which different researchers can come together and pool their wisdom, transcending the frameworks of academic disciplines such as medicine, dentistry, or biology. I believe that the interdisciplinary research promoted by FRIS has a high level of affinity with anthropology.

The ability to collaborate immediately is the most interesting aspect of FRIS.

Please tell us about your encounter with FRIS.


I first became clearly aware of FRIS after my appointment at the Division for Interdisciplinary Advanced Research and Education (DIARE) at Tohoku University in 2018. DIARE regularly presents seminars and workshops, and I was able to interact with academics from FRIS at these events. I learned that at FRIS, it was possible to conduct research at one’s own discretion and enjoy horizontal connections. When I attended seminars at DIARE, it was stimulating to listen to presentations by students who were my peers, but with whom I did not usually interact. So FRIS felt appealing because it offered a very similar environment. I saw firsthand that cross-disciplinary collaborations were taking place, so after successfully completing my doctoral program, I felt that FRIS was where I wanted to continue my research and I put in an application.

Although I did apply, I never expected to be hired, however. I had heard that this post was intended for the Japan Society for the Promotion of Science Postdoctoral Fellows (PDs) and researchers with world-class achievements, such as research experience at overseas universities. So I was surprised to be hired as I had only just completed my doctoral program and did not really have any achievements yet. It’s sobering for me to think that I have to produce results each day without wasting this opportunity that has fallen into my hands.

Ms. Hatano, what are the unique features and appeal of working at FRIS?


The moments of strongest appeal for me are those when I can apply my skills to a completely different field. It's wonderful to be able to get ideas when I'm stuck with something, but it's also an exciting experience to be involved and collaborate in research in fields that are totally unfamiliar to me. To be more specific, last month, Dr. Yuji Saito, who is researching rocket fuel at FRIS, came to me with a request saying that he “wants to compare fuel morphology before and after combustion.” I responded by saying that “given the size, I would suggest using a medical CT.” In forensic autopsies, a CT scan is taken before the autopsy to ensure that the cause of death is not overlooked and to investigate the cause of death more efficiently. I wouldn’t think that rocket fuel researchers normally have access to CT equipment. While studying for my doctorate, I was working on 3D analysis. So I have the skills to take images obtained by CT to create stereoscopic images, to measure the volume and area, and to investigate where changes such as cracks have occurred.

Within a few weeks of Dr. Saito approaching me, I am at the stage where I have been able to photograph and analyze the materials. I think that a major factor in why I was able to carry these out so smoothly after receiving the request is that we were acquaintances, both working at FRIS. I can see that what we have here is a truly interdisciplinary process taking place as we speak.

The CT imaging of fuel is, in and of itself, not quite novel enough, and it may still be some time before my research yields any significant results, but I have a feeling that the results will be interesting.

I also feel that the connections I have with various academics right now will grow into something significant in the future. I currently take a deep interest in a range of different fields, and I'd like to form teams with academics with whom I've made connections within these areas and take on a major research theme.

Bringing together different skills and approaches is sure to give the research a dramatic boost, and it will make it fun, over and above anything else.

What do you think are the benefits of being at FRIS?


One benefit is relative freedom. Doctors working at university hospitals have to do clinical work, so it is difficult for them to go on long work-related trips. In contrast, with my primary affiliation being with FRIS, I am in a position to act relatively freely. My mentor, Dr. Suzuki, readily sends me on extended work-related trips.

I recently participated in an excavation project on Miyakojima island in Okinawa Prefecture, thanks to a researcher whom I have known for a long time.

While on Miyakojima, I met an academic named Kaishi Yamagiwa, who is a full-time lecturer at the Research Institute for Islands and Sustainability at the University of the Ryukyus. Dr. Yamagiwa specializes in archaeology and is researching prehistoric shell hatchets, which are tools that were used for cutting and digging.

These shell hatchets exist in large and small sizes, and their shape varies depending on the period they belong to.

I was asked about analysis methods for restoring and comparing the purpose and ways these hatchets were used, working with evidence remaining on the object. I proposed a method using a silicone rubber impression material that we use in dental practice. In dentistry, it’s pretty common research practice to make a surface replica of a specimen using an impression material that reproduces details with a high level of precision and then to observe minute structural changes and cracks using a scanning microscope (SEM). A pilot study applying this method to shell hatchets has been carried out, and good results have been obtained.

When it comes down to it, if technologies, information, and knowledge that we already have been to be shared widely, you would expect there to be a lot of research that would make dramatic progress. In Japanese, we have an expression: “mochi wa mochiya,” which literally means that if you are after mochi, or rice cakes, you should go to a mochi shop. Nevertheless, things that a mochi shop might see as matter-of-fact, everyday knowledge might be pretty unfamiliar to other kinds of people. Since coming to FRIS, I have come to feel even more strongly how beneficial it is to be aware of such things. In addition to this awareness, we are also valued for connecting people, for being someone you can consult on issues, and for the expansiveness range of what we are able to offer in terms of coming up with relevant ideas from information that we have been given.

How do you envision your future as a researcher?


While I care about numerical indicators such as track records and impact factors to some extent, I don't want to put the brakes on my curiosity and my interests. In the future, when I am in a position to accept students, I’d like to be the kind of researcher who does not say “no” to their interests and pursue their research themes together with them. On the other hand, this also makes demands of one’s broadmindedness and skills, and one also needs management skills such as the ability to make general improvements and to raise funds for the management of the laboratory. I want to work hard on my research each day while also keeping effective time management in mind so that I can be efficient in handling the huge amount of work that is required to run a lab.

As a female researcher, it’s only natural that I have concerns, such as child-bearing. At this stage, I do not have any set ideas. Marriage itself is not something that I take for granted, and even if I do find a partner, giving birth to a child is a matter of timing and personal values. In today's diversified world, we are able to make decisions more freely than in the past, but I think that there are still people who will waver on this issue. It is dead clear to me that trying to raise a child on your own is something that brings you to your limits, both physically and mentally. I think a real solution would be to make innovative use of babysitters and public services while trying to gain an understanding of your workplace and the people around you.

On the other hand, I have senior researchers around me who are thinking about quitting because they cannot carry out their research as they would like. It’s not good for research to become painful work. Personally, I want to work out strategies that will allow me to survive as a researcher, and continue my research in ways that are enjoyable. I want to be a role model who can convey the pleasures of research to younger researchers that come after me.

The future comes into view when you step out and do things. I want first to take action, then keep going if I get good results. If things don’t go well, I want to change gears emotionally as I reflect on the reasons things went wrong. This is how I want to move forward.

What does your 2020 ASN Young Scientist Oral Presentation Award mean to you?


I received the award based on my facial reconstruction presentation, which was a profoundly moving experience. I applied for the young scientist award for the first time as a 21-year-old undergrad student. I was feeling very nervous and unprepared for the world of presentations at academic conferences.

I was not able to answer the questions well, and this got me down. I received positive feedback, though, and this made me carry on presenting at the anthropological society annual meetings almost every year after that. The University of Tokyo and Kyoto University have labs specializing in anthropology, so presentations by students from these universities are always high-level. Meanwhile, I was a student from a school of dentistry, and as I presented, I was always worried about my suitability as a researcher—that I could not compare to these students who were taking anthropology as their area of specialty. So when I heard that had won the award, I was so surprised that I almost fell to pieces. It took ten years for me to receive that award, and it turned into a good way to commemorate the culmination of my degree research.

You were not affiliated with FRIS in 2020, but did FRIS have any influence on your award, even if indirectly?


Yes, it did, to a large extent. The support I received while a student at DIARE was quite substantial. Research funds that you are free to use at your discretion expand the range of your research to include things like documentary research. I took part in exchange meetings held each month, and they were an excellent opportunity for me to build up my communication skills in talking about what I was researching. Unless they take the initiative themselves, postgraduate students don’t even get the chance to learn about what’s being researched in the lab next door.

There are no lectures either.

I am saying that there are zero opportunities to hear about what’s going on in fields other than your own or explain the research you are doing to people in other fields. The exchange meetings, where I had regular opportunities to listen to presentations by frontline researchers and by outstanding students studying in other areas, were rich opportunities to learn about everything from design to speaking styles. At first, I was paying so much attention to the kind of words that could attract the audience’s attention, and even now, I prepare my presentations thinking about impactful design and catchy phrases.

How do you see FRIS developing in the future?


First and foremost, I believe that FRIS’s most valuable asset is its environment, one in which researchers from different fields become colleagues. Because of the Covid-19 pandemic, it took a year after being hired to finally meet a fellow academic who had graduated at the same time as me. From this single meeting, it led to the collaboration research about rocket fuel mentioned above and I was able to get involved in research outside my field. In the spring of 2022, many academics moved on from FRIS. During the five years of service, there are always some who “graduate” in this way each year. These ex-FRIS academics then form other relationships in the new workplaces they have chosen, thus widening the network around FRIS.

I find it very reassuring to have so many ex-FRIS academics that have come before me working outside FRIS. Sometimes big obstacles are involved when considering using experimental equipment that is unavailable in the laboratory. In such cases, it may be able to have occasions to use the equipment in a stress-free way by going through someone who used to work at FRIS. In any case, the circle of people nurtured by FRIS is bound to give birth to even more significant projects across universities and other countries. I believe that FRIS’s development lies in the cycle's limitless chain of connections.

(Interview conducted in May 2022)