TOOTH LOSS AND RISK FACTORS AMONG ELDERLY VIETNAMESE
2. Materials and Methods
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 years old were obtained from the community unions for older adults into which all the citizens over 60 years old are incorporated. Forty-five 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 encompassing 10 % amount 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. Written informed consent was obtained from each participant. Selected participants were mentally healthy persons who were able to answer questionnaires about oral health status. Examination procedure 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 participants were reexamined for testing the reliability of the collected data. The intra-rater 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. The recording of all third molars would be excluded if all of them did not present during the dental examination. The number of lost teeth were 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 had been 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 lower jaw, except for incisors( p < 0.01)( Table 1 and Figure 1).
Figure 1. The distribution of tooth loss among elderly Vietnamese
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