Number of remaining teeth and health-related quality of life: The Korean National Health and Nutrition Examination Survey 2010-2012

Objectives/aims: With the Euro-Qol-5 dimension (EQ-5D) system, we investigated the relationship between the number of remaining teeth and QoL using data from the Korean National Health and Nutrition Examination Survey (KNHANES), 2010-2012. A total of 17,417 participants, more than 19 years old, were finally included in this study (men = 7394 and women = 10,023). Through this study, we have discovered that the remaining teeth affect overall health and that the fewer number of them may indicate a lower quality of life, as well. The quality of life according to the number of remaining teeth was assessed among Koreans using the Euro-Qol-5 dimension (EQ-5D) system. Method: The Euro-Qol-5 dimension (EQ-5D) system was used to measure the health-related QoL. Its five dimensions included mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The respondents were asked to choose one of the followings: G 1, no problems; G 2, some problems; and G 3, problematic, to best describe their health status for the five dimensions. Then, we assigned low QoL to G2 + G3 and high QoL to G1. We used age, gender, economic income, educational level, residence, and marital status for the demographic variables and, drinking, smoking, exercise, BMI, and metabolic syndrome for health behaviors. Multiple logistic regression analysis was performed to examine the odds ratios (ORs) and confidence intervals (CIs) for the high QoL (G1) on the five categories of EQ-5D according to the number of remaining teeth. On the basis of the 0-15 remaining teeth group, we drew a comparison of the QoL between the 16-20 and 21-28 remaining teeth groups. Results: Subjects with 21-28 remaining teeth had higher QoL scores and had higher ORs of high QoL, especially for mobility (OR = 1.256, 95% CI = 1.056-1.495), self-care (OR = 1.441, 95% CI = 1.096-1.894), and usual activities (OR = 1.241, 95% CI = 1.022-1.508, respectively), than those with 0-15 remaining teeth after adjusting for age, sex, body mass index, smoking, drinking, exercise, income, education, and metabolic syndrome. ORs from the high QoL had the tendency to increase as the number of remaining teeth increased (all p for trend < 0.05). However, there was no relationship between the number of remaining teeth and QoL in the pain/discomfort and anxiety/depression dimensions. Conclusion: The number of remaining teeth was associated with QoL, and subjects who had more teeth obtained higher QoL scores. The subjects in the high QoL group were especially associated with the components of EQ-5D such as mobility, self-care, and daily living.