Logistic regression analysis of factors affecting survival of permanent second molars in Korean adults

Abstract

Objectives: The purpose of this study was to analyze the factors affecting the survival of permanent second molars in Korean adults using logistic regression analysis. Methods: This National survey was conducted in 2006 and was performed in 3 stages comprising stratified sampling, age, sex, and region. This study included 15,777 persons, aged 2-95 years. The raw data was analyzed using SPSS software v12.0 and the relationship between the 9 variables and the tooth survival rate was analyzed by frequency and cross-tabulation. Logistic regression analysis using the functional weightage of the age, sex, regions of the Korean population was also performed. Entry was at level of 5%, while removal was at a 10% level during logistic regression analysis. The nine variables used for analysis were age, socio-economic level, monthly family income, sex, frequency of toothbrushing per day, diabetes, educational level, smoking, and frequency of snack intake per day. Results & Conclusions:The most significant explanatory variables, in increasing order of significance, were age, socioeconomic status, and diabetes. As age increased by 10 years, the survival rate of second molars decreased at a slow rate 7.5% to 9.5%. The survival rate of the second molar of an individual engaged in activities, such as farming, stock breeding, and fishing decreased from 64.4% to 78.8% as compared to people at high positions in various companies and in society.