Five-year cohort study on risk predictors for toothloss in elderly

Objectives:The aim of this cohort study was to identify the predictors associated with tooth loss over a five-year period in an elderly population. Methods: Among all 4542 inhabitants aged 70 years according to a registry of resident,600 people were selected randomly. 378 dentate subjects who could participate in both the baseline and the follow-up examinations after five-years were included in the analysis. In order to identify risk predictors of tooth loss with a different degree of robustness, three multiple logistic regression analyses (model -1, -2 and -3) where the dependent variables were one, two and three or more tooth loss were performed. The following dependent variables were used in the model -1, -2 and -3 ; the Eichner index (class A,B1-B4,C1,C2,dummy)which based on existing natural tooth contacts between maxilla and mandible in the bilateral premolar and molar regions, gender (0:Female, 1:Male), number of decayed root tooth (0:0, 1:1+), number of crown (0-4,5-8,9+,dummy), LB level(0:10³ -10⁵, 1:10⁶+CFU/ml), mean clinical attachment level, serum albumin concentration, chewing ability using 15 kinds of different foods (0:the ability to chew 15 foods, 1:1-14 foods), visit dentist regularly (0:Yes, 1:No), and smoking habit (0:No, 1:Yes). Results: Overall, 17.7 % of subjects lost three or more teeth over a five-year period. The mean number of missing teeth per year was 1.36±1.99. Logistic regression analysis indicated that Eichner index class B (OR: 2.09-3.42) and mean clinical attachment level (OR: 1.41-1.86) were the most robust risk predictors. Furthermore, one or more decayed root teeth (OR: 2.04-2.45) and nine or more crown restorations (OR: 2.57-2.94) and 10⁶ or more CFU/ml lactobacilli level (OR: 2.53-2.65) were moderately robust risk predictors. Conclusion: The findings in the cohort study suggest that oral local factors such as periodontal disease and occlusal conditions contributes to tooth loss in elderly people.