2018 Volume 33 Issue 1 Pages 3-16
The 8020 Campaign has been in effect since 1989, and the percentage of Japanese people aged 80 and older with 20 or more present teeth exceeded 50％ in 2016. However, primary prevention based on the “population strategy” alone is insufficient to promote the maintenance of satisfactory chewing ability throughout life. Rather, the “high-risk strategy” advocated by the WHO must be implemented.
The reason this strategy has not yet become established is that it means dentists would recommend interventions to prevent high-risk patients from developing the condition they are at risk for, but it has been difficult to develop effective screening indicators. With this in mind, impending bite collapse was adopted as a surrogate endpoint for 404 middle-aged and elderly patients with 20 or more present teeth at the time of their first visit to a dental clinic.
The initial stage of bite collapse was determined using a combination of number of present teeth（＜20）, estimated number of occlusal teeth（＜20）and occlusal support assessed on a six-level scale（＜level 4）, and patients were followed up for a maximum of 6.5 years. Statistical analyses were performed using Cox proportional hazard analysis. The analyses revealed significant high risks, even for patients receiving continuing dental care, linked to：（1）increasing age,（2）improper patient guidance such as interdental brush use,（3）quantity and quality of periodontal pocket countermeasures,（4）factors related to both dental and medical care such as smoking cessation guidance and diabetes management, and（5）factors not yet known to be risk factors, such as a difference in the number of molars on the left and right sides.
The authors conclude that long-term prognostic evaluation in dental clinics of patientsʼ risk of bite collapse is important.
