Dentistry and SDH: Dentists are on the front lines of the 'Social Determinants of Health' [Series 6]
I am Takaya, an MBA dentist. (Click here for my self-introduction)
Just as the organizational turmoil I wrote about in previous installments was finally beginning to settle down, I started to venture outside the clinic.
Many people often ask me how I had the energy to go outside when things were so difficult inside.
To be honest, it wasn't that I had energy to spare. I just felt that if I didn't step outside the clinic, I wouldn't be able to move forward myself. The origin of why I began to feel this way lies in a boy I met a long time ago.
The boy who was a high school student at the time
I still haven't forgotten the boy who came in for his first visit shortly after I returned to the family practice; he was still a high school student at the time.
Both of his parents were heavy smokers. He wasn't attending school. I was told he hardly ever left the house. His mother brought him in, and he kept his head down and would barely open his mouth.
When I finally got him to sit in the chair and looked inside his mouth, I was speechless. Almost all of his teeth had caries (cavities/tooth decay), and some had reached the nerves. His gums were red and swollen, and the bleeding wouldn't stop. It was a condition I wouldn't expect to see in a high school student's mouth.
As a dentist, the first thing I think about is a 'treatment plan.' How many teeth can be saved, and how many must be given up? What order should I proceed in? But that day, I couldn't get into that mode.
The cause of this child's oral collapse was not in his mouth. It was in his home, in his life, and in society. It wasn't a situation where I could just say, 'Let's brush your teeth.' It wasn't a situation where I could say, 'Let's eat proper meals,' either.
At that moment, I realized clearly: this is something that can no longer be solved just inside a dental clinic.
The fact that 'preventable diseases' are not being prevented
Let me step away from his personal story for a moment and talk about the data. This is because what was happening in that boy's mouth was by no means a unique tragedy.
Caries and periodontal disease are among the few diseases for which prevention methods are scientifically established. Professor Roy C. Page of the University of Washington says that these are diseases that should essentially rarely occur. Yet, they are rampant all over the world.
Looking at the Global Burden of Disease study, untreated permanent tooth caries is the most prevalent disease on the planet [1]. About one in three people on Earth has it. It's not the common cold or headaches; tooth decay is number one in the world.
Even looking at Japan, about 30% of people over the age of 20 have untreated tooth decay [2]. Despite so many people having it, social awareness does not match its scale.
Diseases that should be preventable are not being prevented. This is not a problem of technology or knowledge. It is a problem of society.
When I arrived at this realization, the term SDH was in my mind.
I encountered the term SDH
SDH (Social Determinants of Health). This is a concept proposed by the WHO (World Health Organization), and it is a simple yet shocking assertion that health is not determined by medical care alone.
To what extent is it 'not just medical care'? There is a famous diagram published by the Canadian Medical Association. It is an infographic titled 'WHAT MAKES CANADIANS SICK?', which shows the breakdown of factors that determine health as follows [3].
YOUR LIFE — 50%: Income, early childhood development, education, employment/working conditions, social isolation, safe and nutritious food, living environment, etc.
YOUR HEALTH CARE — 25%
YOUR BIOLOGY — 15%
YOUR ENVIRONMENT — 10%
The impact of medical care on health is only 25%. The majority of the rest is determined by social conditions such as income, education, employment, living environment, and human connections.
Furthermore, these social factors are almost impossible to control through one's own efforts. The home one is born into, the community one grows up in, the school one attends. Under these conditions, health disparities accumulate quietly but surely.
It is known that these disparities appear in stages according to income and educational background. In the world of public health, this is a phenomenon called the Social Gradient. The lower the income bracket, the more likely one is to develop cancer, have a stroke, develop diabetes, and lose teeth.
That boy's oral collapse was not the result of his personal lack of tooth brushing. It was the most visible manifestation of the social environment he was placed in.
British public health scholar Michael Marmot expressed this with the phrase 'Closing the gap in a generation' [4]. It is a declaration that health disparities are not destiny, but can be narrowed depending on how society is designed.
Why dentistry is on the front lines of SDH
This is the part I most want to convey.
'I understand that SDH is important. But isn't that a matter for public health and government, a world far removed from dentists?' I think many people feel this way. In fact, it is the exact opposite. Dentistry stands on the front lines of SDH. Please let me explain the reasons in order.
Reason 1: Because the mouth is a 'cumulative record' of life and society
In a domestic survey investigating the causes of tooth loss (8020 Promotion Foundation's 'Survey on Causes of Permanent Tooth Extraction'), the primary cause of extraction is periodontal disease at approximately 37%, followed by dental caries at approximately 29%, and fractures at approximately 18% [5].
In other words, the primary reason people lose teeth is not an unforeseen accident, but a chronic disease that progresses over a long period of time. Periodontal pocket depth, bleeding, the progression of dental caries, and tooth loss. None of these happen suddenly one day. The cumulative results of years and decades of lifestyle habits and social environments remain in the oral cavity as physical traces.
Blood pressure and blood sugar levels fluctuate with the day's physical condition. But tooth loss does not disappear. The mouth is the place where the eating habits a person has had and the environment they have lived in are most honestly engraved.
That is why dental clinics are in a rare position to grasp the accumulation of systemic diseases at an 'early stage and in a visible form'.
Reason 2: Because oral diseases and systemic diseases grow from the same root
This is where the Common Risk Factor Approach, proposed by Sheiham & Watt in the UK in 2000, comes into play [6].
Simply put, it is a theory that the major chronic diseases plaguing humanity—caries, periodontal disease, cardiovascular disease, diabetes, obesity, and some cancers—all share the same risk factors.
Look at this table. The 'parents who are heavy smokers,' 'irregular diet,' and 'social isolation' found in that boy's home are not only risk factors for dental caries and periodontal disease, but also risk factors for future diabetes, heart disease, and cancer.
The collapse of the oral cavity is a precursor to the collapse of the entire body.
This is illustrated in a single image known as the famous 'Metabolic Domino' diagram [7]. A disruption in lifestyle habits knocks over the first domino—obesity and hyperglycemia—which then triggers a chain reaction leading to arteriosclerosis, myocardial infarction, and stroke. Periodontal disease is a phenomenon that occurs quite far upstream in this domino effect. Dentistry can be the first to observe the domino before it falls.
Reason 3: Because dental caries are made not just by 'bacteria' but by 'society'
When explaining the development of dental caries, we used to teach it using four circles: 'bacteria, food, teeth, and time.' That is not wrong. However, in 1990, Fejerskov and Manji showed that those four circles are surrounded by a much larger circle (this diagram is also cited in the 2007 Lancet review on dental caries) [8].
The outer circle represents social environment, income, education level, lifestyle, health knowledge, and oral health literacy.
In other words, dental caries is a phenomenon of the oral cavity, but at the same time, it is a phenomenon of the society in which that person is placed. Bacteria and sugar are merely the 'results' at the very center. At the true upstream lie life and society.
This is the core of why 'dentistry and SDH are related.' When a dentist drills a cavity, we are filling a scar formed at the most downstream point of the social determinants. We keep drilling while leaving the upstream causes of the wound untouched.
There are two ways to approach public health
Having reached this point, the question becomes, 'So, what do we do?'
There are broadly two types of public health approaches.
One is the high-risk approach. This is a method of providing pinpoint, intensive care to people who already have a disease or are at high risk. In dentistry, this means providing the best treatment and prevention to each patient who comes to see us. Clinical practice is almost entirely driven by this.
The other is the population approach. This is a method of lowering the risk level of the entire community from the bottom up. This includes school-based fluoride mouth rinsing and community-wide nutrition education.
The relationship between these two was organized by Watt in the UK in 2007 using the metaphor of a 'river' [10]. He lined up oral health measures from the upstream to the downstream of the river.
Treating patients in the clinic is at the very downstream of the river. We are pulling people who have been washed down onto the shore one by one. It is important work. However, just waiting downstream cannot stop people from being washed down from upstream.
If we only operate with a high-risk approach, no matter how many high-risk individuals we save, new high-risk individuals will continue to be born from behind forever.
This was what I felt intuitively on the day I met that boy. Even if his treatment went well, his younger brother, sister, and other children in the neighborhood living in the same environment would come to the clinic with the same oral collapse. Just waiting downstream will never bring an end to it.
Therefore, we head upstream of the river and go outside.
Children's cafeterias and non-standard vegetables
One of our initiatives outside the clinic is the children's cafeteria.
We partner with a local NPO, Grow Up, and hold it about once every three months at a community space called JUJU. For ingredients, we make use of non-standard vegetables from nearby farmers.
Why would a dental clinic run a children's cafeteria? At first, many local residents were puzzled by this.
The reason is clear. The collapse of oral health in children is directly linked to the family dining table. Habits such as snacking on sugary foods, not being able to have dinner at a set time, and having little time to eat together as a family are closely related to the incidence of dental caries. Furthermore, chewing and swallowing ability—the development of oral function—is determined by what and how one eats.
A children's cafeteria is not just a place to provide meals. It is a place where children can experience eating properly and eating with others outside of their home. The dining table is the primary site for the development of oral function and is also the smallest unit of community where people connect with one another.
The story of non-standard vegetables has a similar structure. Every day, farmers have large quantities of vegetables that cannot be sold on the market because they are misshapen, uneven in size, or have uneven coloring. We buy these and use them in the children's cafeteria. The farmers' income increases slightly, the food costs for the children's cafeteria decrease slightly, and the children get to eat nutritious vegetables. A small cycle begins to turn within the community.
In the language of public health, this is a population approach that raises the food environment of the entire region by one level—it is truly a step upstream.
Work experience and internships with local high schools
Another area we are focusing on is accepting students for work experience.
We are creating opportunities for children to see the professions of dental hygienist and dentist, mainly through local nursery schools and kindergartens. We are also planning to start full-scale internships in partnership with Sonobe High School.
Why work experience? This also connects directly to the 'education' factor of SDH.
People with more years of education are more likely to engage in healthy behaviors, have longer lifespans, and have lower rates of chronic disease. This is an extremely robust correlation that has been repeatedly demonstrated in epidemiological studies around the world.
The 'education' referred to here is not just classroom learning at school. It includes knowing that there are options for one's career path and believing that one can work in a job that is useful to someone else. It is education in a broad sense that encompasses all of these things.
In rural areas, there are physically fewer career options. The jobs that children can see directly are limited, and medical professions are among them. Coming to a dental clinic, trying on a white coat, talking to a dental hygienist, and seeing a patient say 'thank you' as they leave—just that alone adds a new point to their career map.
This is an act of intervening directly from the clinic into the upstream factor of 'education' in SDH.
Dental Hygienist Scholarship
One initiative that is already underway is the dental hygienist scholarship program. We have put up a sign and also posted it on our clinic's website.
The biggest constraint on regional dental care is no longer the number of dentists. It is securing dental hygienists. Most students attending dental hygienist schools find employment at dental clinics in urban areas after graduation. The number of students returning to rural areas is decreasing year by year. As a result, regional dental clinics are unable to secure qualified personnel, forcing them to scale back home-visit dental care and preventive services.
There are actually areas in the central and northern parts of Kyoto Prefecture that are called 'dentist-less villages.' In areas without dental clinics, there is no one to implement either high-risk approaches or population approaches in the first place.
The dental hygienist scholarship is a system where the clinic supports part of the tuition fees when students from the local area aim to become dental hygienists. It is designed so that repayment is waived if they work at our clinic or a local dental clinic for a certain period after graduation.
This is an investment in what economics calls 'Health Capital.' We are cultivating the human resources who will support regional medical care within the region itself. Without this, no matter how excellent a medical system you build, there will be no one to operate it. I consider it infrastructure investment, just like roads and water supply.
If you take SDH seriously, it inevitably leads to regional revitalization
The initiatives I have written about so far may seem like separate stories: children's cafeterias, non-standard vegetables, vocational experience, and dental hygienist scholarships.
However, they all connect to a single argument.
The essence of the term 'regional revitalization' is not about measures against population decline. It is about creating a society where being born and raised in a certain region is not a disadvantage. This is the exact same problem setting as what Marmot calls 'closing the health gap in a generation.'
Moreover, even from the perspective of this country's finances, investment in the upstream cannot be avoided. Taxes and debt used to cover social security benefits have expanded approximately 3.1 times, from about 16 trillion yen in fiscal 1990 to about 50 trillion yen in fiscal 2017 [11]. The cost of continuing to treat diseases downstream is no longer at a sustainable level.
The health disparity that Nantan City faces—where oral decay is severe despite being only 30km from Kyoto City—has the same roots as Nantan City's regional issues: population outflow, aging, and economic contraction.
The declining birthrate is particularly troublesome. A vicious cycle of: number of births decreases -> child-rearing related market shrinks -> need for administrative services decreases -> more people leave, and COVID-19 has accelerated this. To reverse this rotation, we cannot just wait downstream in the river. Therefore, seriously intervening in SDH structurally becomes regional revitalization.
I now feel that my role as the fourth-generation director lies here.
The meaning of a '100-year clinic' is also changing little by little for me. It is not about 'the clinic lasting 100 years,' but about 'the region lasting 100 years because the clinic exists.' The subject shifts from the clinic to the region.
From a management perspective, this also makes sense
Just to be sure, I will also write this in management terms. Activities that go out into the community are neither volunteer work nor one-off CSR. They are investments positioned at the core of business strategy.
It is very effective for recruitment. The positioning of 'earning money at a high-unit-price, self-pay-centered clinic in an urban area' versus 'participating in solving SDH issues in a rural area' can reach completely different candidate pools. Talent motivated by a sense of purpose, those oriented toward regional medical care, and those with experience in international cooperation. These groups choose their workplace based on significance rather than salary competition.
Furthermore, it is effective for regional branding. For local residents, the positioning of Takaya Dental Clinic changes from 'a place that treats me' to 'a place that supports the region.' In rural areas where word-of-mouth is strong, this becomes a stronger competitive advantage than anything else.
And it is effective for administrative collaboration. When talking with the health and medical departments of Kyoto Prefecture, Nantan City, Kyotamba Town, and Kameoka City, the quality of the cooperative relationship changes when you enter from the context of SDH. Subsidies, utilization of public land, and partnership agreements. Resources that cannot be obtained through pure commercial development open up.
In short, addressing SDH is a management strategy for a dental clinic as a social venture.
What I want to tell that boy now
Having written this far, I would like to return to that boy one last time.
His treatment was, in the end, one of the most frustrating cases in my career. He stopped coming to the clinic midway through, and I lost contact with him. I don't know how he is doing now.
However, the feeling I had when I was speechless in front of him that day became the starting point for everything that followed. The sentence I wrote in the mission statement of my business plan, 'Creating a society where no one is left behind through dental care,' is not an abstract ideal. It is a promise to myself to never let a child like him slip through the cracks in the same way again.
What was happening in his mouth was not just tooth decay. It was a social problem that took the form of tooth decay. It was he who made me realize that.
Whether I am treating patients in the clinic, preparing for a children's cafeteria, or explaining a scholarship for dental hygienists, I am living the continuation of that day.
When thinking about the next 100 years for a clinic with a 100-year history, the path I chose was one that did not stop within the clinic. I still don't know if this is the right answer. Even so, for now, I feel that the direction I am heading is not wrong.
Sources and References
[1] Marcenes W, Kassebaum NJ, Bernabé E, et al. Global Burden of Oral Conditions in 1990–2010: A Systematic Analysis. Journal of Dental Research. 2013;92(7):592–597. (Of the 291 diseases and injuries evaluated in GBD 2010, untreated permanent tooth caries is the most prevalent condition in the world. The prevalence across all ages is approximately 35%)
[2] Ministry of Health, Labour and Welfare 'e-Health Net' Characteristics and Prevalence of Adult Tooth Decay (Approximately 30% of people aged 20 and over have untreated tooth decay / Written by Jun Aida).
[3] Canadian Medical Association 'What Makes Us Sick?' 2013. (Breakdown of factors determining health: Lifestyle 50% / Medical care 25% / Biological factors 15% / Physical environment 10%)
[4] Marmot M, Friel S, Bell R, Houweling TAJ, Taylor S. Closing the gap in a generation: health equity through action on the social determinants of health. WHO Commission on Social Determinants of Health, Final Report, 2008. (Also published in The Lancet. 2008;372:1661–1669)
[5] 8020 Promotion Foundation 'Second Survey Report on Reasons for Permanent Tooth Extraction' 2018. (Main reasons for extraction: Periodontal disease 37.1%, Caries 29.2%, Fracture 17.8%, Other 7.6%, Impacted teeth 5.0%, Orthodontics 1.9%)
[6] Sheiham A, Watt RG. The Common Risk Factor Approach: a rational basis for promoting oral health. Community Dentistry and Oral Epidemiology. 2000;28(6):399–406.
[7] Hiroshi Ito 'Metabolic Domino' (Proposed in 2003) / Hiroshi Ito 'Metabolic Domino and CKD' Journal of the Japanese Society of Internal Medicine, Vol. 100, No. 1, 2011. (In the dental field, caries and periodontal disease are positioned at the very upstream = starting point of the domino)
[8] Fejerskov O, Manji F. Multifactorial model of caries (1990). The same figure is reprinted in Selwitz RH, Ismail AI, Pitts NB. Dental caries. The Lancet. 2007;369(9555):51–59.
[9] Ministry of Health, Labour and Welfare 'Survey of Dental Diseases' (Trends in the average number of remaining teeth per person by age group from 1973 to 2013).
[10] Watt RG. From victim blaming to upstream action: tackling the social determinants of oral health inequalities. Community Dentistry and Oral Epidemiology. 2007;35(1):1–11.
[11] National Institute of Population and Social Security Research 'FY2017 Social Security Cost Statistics'. (Taxes and debt covering social security benefits increased from approximately 16 trillion yen in FY1990 to approximately 50 trillion yen in FY2017, an increase of about 3.1 times)