HOOTH LOSS AND RISK FACTORS AMONG ELDERLY VIETNAMESE
2 . Methodology 2.1 . Study sample This cross-sectional study involved elderly people aged 65 – 74 years old , living in Danang , Vietnam . The participants were selected according to a multistage stratified random sampling method based on demographic characteristics . Danang is subdivided into six urban districts and two rural districts . In the first stage of the current study , three urban districts and one rural district were randomly selected including Hai Chau , Thanh Khe , Cam Le , and Hoa Vang . The second stage , the lists of the elderly aged 65-74 were obtained from the community unions for elderly adults into which include all the citizens over 60 years of age . Fortyfive participants from each of the selected urban districts and 135 participants from the rural district were randomly sampled and stratified into groups by gender and age ( male : female ratio 1:1 , and 65- 69:70-74 years old 1:1 ). After factoring in 10 % of compensation for the possible decline of survey participants , the total sample consisted of 300 participants ; however , 42 participants withdrew during the study . Thus , the final sample was 258 participants including 128 females and 130 males . A written informed consent was obtained from each participant . Selected participants were mentally healthy persons who were able to answer questionnaires about their oral health status . The examination was performed at the local health centre or the dental clinic of the Danang University of Medical Technology and Pharmacy . Two dental students were trained to ask the questions and record the answers on an assessment form . The first author conducted all clinical oral examinations . Ten percent of the participants were re-examined to test the reliability of the collected data . The intrarater reliability between studies was above 0.9 . 2.2 . Evaluation of tooth loss Each absent tooth regardless of the circumstances would be registered as a tooth loss . In the case of at least one existing third molar , the other third molar loss was recorded . Recording all third molars would be excluded if all of them were not present during the dental examination . The number of lost teeth was classified into categories : 1 ) No tooth loss ; 2 ) 1-3 lost teeth ; 3 ) 4-6 lost teeth ; 4 ) 7-16 lost teeth ; 5 ) > 16 lost teeth . The number of lost teeth was also dichotomized into ≤6 lost teeth or > 6 lost teeth . The position of any lost tooth based on tooth functional groups , such as incisors , canines , premolars , and molars was also determined for both upper and lower jaws . 2.3 . Evaluation of risk factors The assessment of tooth loss risk factors was based on the Oral Health Questionnaire for adults ( WHO , 2013 ). Personal interviews were conducted before the dental examination , and data from the questionnaires were categorised into the bivariate classes : Sociodemographic factors : gender ( female , male ); age group ( 65 – 69 , 70 – 74 ); place of residence ( rural , urban ); time in education ( ≤5 years , > 5 years ).
Oral health behaviours : Participants were asked the following questions : “ How often do you clean your teeth ?” ( Categorised as : ≥ 2 times / day or ≤ 1 time / day ); “ How long is it since you last visited a dentist ?” ( ≤1 year or > 1 year ); “ Do you smoke tobacco , consume alcohol or have any chronic disease ?” ( Yes or no ). This study was registered and approved by the Human Research Ethics Committee of the Da Nang University of Medical Technology & Pharmacy and performed according to the World Medical Association Declaration of Helsinki . 2.4 . Statistical methods Data entry and statistical analyses were performed in version 17.0 of the Statistical Package for Social Sciences ( SPSS ). The Student ’ s t-test , Chi-square test were used to analyse correlations between tooth loss status and risk factors . Binomial logistic regression was used to determine the odds of having > 6 lost teeth . A confidence level of 95 % and a two-tailed p-value of 0.05 were used to determine any significant difference .
3 . Results Among the 258 elderly Vietnamese , the prevalence of missing , at least , one incisor , canine , premolar or molar were 42.2 %, 20.9 %, 50.4 % and 89.1 % respectively . The prevalence of tooth loss ( canines , premolars , and molars ) in the upper jaw was statistically higher than in the lower jaw , except for incisors ( p < 0.01 ) ( Table 1 and Figure 1 ).
Figure 1 . The distribution of tooth loss among elderly Vietnamese ( red -Residual teeth ; grey - Missing teeth )
Table 2 shows that the mean tooth loss for the sample was 7.6 (± 7.0 ). Within each category of predictors , a statistically higher number of lost teeth was found for : the 70-74 age group
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