Bridging the Dental Gap: Unequal Access to Oral Care Across Japan
A nationwide look into Japan’s dental divide
Japan is known for its universal health coverage, which includes dental care for nearly everyone. Yet, a new study published in The Lancet Regional Health Western Pacific reveals that where you live and how much you earn still determines how well you can care for your teeth.
Researchers from the University of Tsukuba analyzed an astounding 216 million dental insurance claims collected between April 2017 and March 2018. This was the first time scientists used the National Database of Health Insurance Claims to map dental care utilization across Japan’s 47 prefectures.
Their goal was simple but important: to uncover whether all Japanese citizens enjoy equal access to dental services and if not, what socioeconomic factors might be driving the gap.
What the researchers examined
The study looked at nine key dental treatments, including cavity fillings, tooth extractions, periodontal (gum) surgeries, dentures, and outreach dental services (home or nursing-home visits for people unable to travel).
To fairly compare regions, the researchers calculated a Standardized Claim Ratio (SCR)—an index that adjusts for age and sex to measure how often people in each prefecture received dental care relative to the national average.
They also compared these patterns with three regional factors:
The number of dental clinics per population
The average income per person
The proportion of residents enrolled in universities (a proxy for educational level)
The hidden inequalities behind the smiles
The results were striking. While some treatments, like fillings and extractions, were fairly uniform across Japan, others varied dramatically:
Outreach services (home-based dental care) showed a 19 fold difference between prefectures.
Periodontal surgeries, used to treat severe gum disease, differed 17 times from one region to another.
In wealthier, better-educated areas, preventive treatments such as dental cleaning and calculus removal were far more common. In contrast, lower-income regions saw higher rates of tooth extractions, pulpectomies (root treatments), and dentures procedures typically needed when oral disease has already progressed.
This pattern suggests that people in more disadvantaged areas seek dental care later, when problems become urgent or painful, rather than early for prevention.
Why supply and education make a difference
The number of dental clinics also mattered. Prefectures with more clinics had higher rates of preventive and periodontal treatments, showing that a robust dental infrastructure improves access to early care.
Education played a similar role. Regions with more university students saw higher preventive care rates, indicating that awareness and knowledge about oral health strongly influence dental habits.
However, urgent treatments like tooth extractions or dentures appeared less affected by clinic density, suggesting that Japan’s healthcare system successfully delivers essential care even in underserved areas.
What this means for Japan’s future
The findings highlight a crucial challenge for Japan’s health system: universal coverage does not automatically guarantee equal access.
The researchers suggest that policies should focus on expanding preventive dental programs especially in lower-income regions and addressing the shortage of specialists for complex treatments such as periodontal surgery. They also recommend community-based oral health education to encourage early dental visits.
As Japan’s population continues to age, ensuring equal access to oral care isn’t just about preserving smiles it’s about preserving overall health and quality of life.
Reference
Taira K., Mori T., Ishimaru M., Iwagami M., Sakata N., Watanabe T., Takahashi H., & Tamiya N. (2021). Regional Inequality in Dental Care Utilization in Japan: An Ecological Study Using the National Database of Health Insurance Claims. The Lancet Regional Health – Western Pacific, 12, 100170.