Evaluation of dental caries (DMFT) and associated factors in the elderly based on data from the Azar cohort study

Abstract

Introduction: Due to the growing population of the elderly in the world, it is necessary to pay attention to their oral and dental health. Examining the factors related to dental caries in old age such as demographic factors, chronic diseases, smoking and alcohol consumption can play a significant role in maintaining and improving the oral and dental health of the elderly. The present study describes the state of tooth decay in the elderly based on the DMFT (Decayed, Missing, Filled Teeth) index and analyzes its relationship with various factors. Methods and Materials: The data collected in the basic phase of the Azar cohort study related to the caries index based on DMFT and possible related factors for the elderly 60 years and older in the Azar cohort population were extracted and subjected to statistical analysis. The Azar cohort study was started in 2013 in Shabestar city between about 15,000 adults aged 35 to 70, of which 2,629 are elderly. Most of the data has been completed based on questionnaires and interviews. Oral examination to measure the DMFT index was also performed by a trained person according to the national protocol of the Persian cohort. In the present study, data related to the DMFT index and its relationship with oral hygiene habits (number of brushing times), gender, age, marital status, level of education, socio-economic status, chronic diseases, smoking, alcohol consumption and the body mass index was analyzed. In the descriptive part, mean and standard deviation were used for quantitative variables, and frequency and percentage were used for qualitative variables. Mann-Whitney U and Kruskal-Wallis analysis were used to compare DMFT index based on the studied variables. In the final analysis, negative binomial with loglink was used to check the relationship between the DMFT index of the elderly and the studied variables in different regression models. Three regression models were performed for the entire elderly population and two regression models were performed for the elderly with natural teeth by entering the brushing variable into the model. Results: For all 2629 elderly people of Azar cohort, the average age was 64.15±2.91. About half of the elderly were women and 85% were married. The average DMFT index was 28.42±6 (with a range of 1 to 32), the average number of decayed teeth was 1.28±3.42, and the average number of extracted teeth was 26.58±8.36, the average number of filled teeth was equal to 0.55±2.13. About 71% of the elderly were completely edentulous and about 29% had some natural teeth. 40% of people with natural teeth brushed at least once a day. About 44% of the elderly were illiterate and only about 20.7% of the elderly had a high socio-economic status. Diabetes was observed in 87% and high blood pressure in 72% of the elderly. About 12% of the elderly were smokers and 2.5% were alcohol drinkers, and about 76% had a body mass index higher than normal. In the Kruskal-Wallis analysis, there was a significant relationship between DMFT index and the variables of age (P < 0.001), gender (P = 0.003), education level (P < 0.001), economic and social status (P < 0.001), body mass index (P=0.04), smoking (P<0.001) and brushing frequency were observed in people with natural teeth (P<0.001). In different regression models, no significant relationship was found between the DMFT index and the studied variables. Conclusion: The high prevalence of complete edentulous and the high rate of extracted teeth in the elderly population of Azar cohort indicate the unfavorable oral health status of the elderly and show the necessity of developing programs to improve oral and dental health in an integrated manner with other health areas.