The Blind Spot in Health Checkups. The Latest Dental-Medical Collaboration Model that Predicts Lifestyle Disease Risk Not by the Number of Teeth, but by 'Occlusal Pairs (FTU)'

In Japanese health checkups, “dental health status” has long been neglected. Even if checks for cavities and periodontal disease are performed, there is almost no system in most medical institutions to evaluate how this links to systemic health, especially “lifestyle-related diseases” such as diabetes, obesity, and hypertension.

What dentists have emphasized so far, as represented by the “8020 movement,” has been the metric of “how many teeth are left in the mouth (number of present teeth).” However, in recent years, at the forefront of preventive medicine, a litmus test that is more precise than just the mere number of teeth is attracting attention.

That is the concept of “Functional Tooth Units (FTU).” Without knowing FTU, we cannot talk about future reductions in medical expenses or fundamental anti-aging.

”Missing Matches” Don’t Count. What is FTU (Functional Tooth Unit)?

The fatal flaw of the number of present teeth (the number of teeth just growing there) is that it ignores the physical fact: “Even if there are 10 teeth left in the upper jaw and 10 in the lower jaw, if they do not occlude at all from top to bottom (missing occlusion), the ability to crush things (masticatory efficiency) is equal to zero.”

FTU was devised to correct this. FTU counts a “pair of teeth that are functionally and firmly occluding from top to bottom” as one unit.

• For example, if the upper and lower first molars (back teeth) are firmly occluding, that alone becomes a powerful score that guarantees a large area of mastication.
• Conversely, a state where “only the front teeth are occluding” means that no matter how many teeth there are, the FTU score is hopelessly low.

”Metabolism and Circulation Risks” Directly Linked to FTU Decline

Why does the FTU score function as a predictive model for lifestyle-related diseases? (Endpoint evaluation related to E07)

1. Dependence on Carbohydrates (Soft Sugars): When FTU declines (back teeth are lost and no longer occlude), ingredients with hard cell walls like meat and root vegetables (proteins and dietary fiber) physically cannot be bitten off. As a result, patients unconsciously shift to a diet excessively high in carbohydrates, such as “udon, bread, and soft sweets that can be swallowed without chewing.” When this continues for months to years, a chain reaction of chronic protein deficiency and blood sugar spikes is triggered, and HbA1c (a diabetes marker) worsens in the blink of an eye (related to E06).
2. Dysfunction of the Cerebral Blood Flow Pump and Endocrine Abnormalities: A decline in FTU drastically reduces the activity level (exercise volume) of the jaw muscles for “clenching and grinding with strong force.” The weakening of the blood flow pump to the head not only increases the risk of cognitive decline but also significantly delays the advance warning to the gastrointestinal tract, “amount of saliva secretion,” and the secretion timing of “satiety hormones (incretins, etc.)” that should be induced by chewing stimulation (E14), causing constant overeating.

The Paradigm of “Systemic Intervention” Through Dental-Medical Collaboration

When a physician is treating a patient’s metabolic syndrome and instructs them, “Reduce the calories in your meals. Please exercise,” but no results are produced, the high probability is not that the cause is “because the patient lacks willpower,” but rather “because the patient’s FTU has already collapsed, and the physical equipment (infrastructure) to consume a healthy diet (hard vegetables and meat) does not exist in their mouth.”

What is needed in future medicine (especially care for the elderly and those with pre-diabetes) is complete collaboration between internal medicine and dentistry. Before looking at blood test values, first have them open their mouths and measure their “FTU score.” If the score is low, before diet guidance, “rebuilding the upper and lower occlusal pairs (FTU) through dentures, implants, or chewing training” is precisely the most reliable and cost-effective “first step in systemic treatment.”