A cross-sectional study was carried over a period from April 2018 to July 2019 with the approval of the institutional review committee of BPKIHS, Dharan (IRC/0959/017). The principles of the Declaration of Helsinki were followed during this study. The study obtained written consent from each participant after explaining the objectives, and use of the study. The population involved in this study were inhabitants from the rural area of Sunsari district, in the eastern region of Nepal. Sunsari district comprises of twelve, both rural and urban municipalities. Dental health camps were organized in different wards of six rural municipalities (Koshi, Gadhi, Barju, Bhokraha, Harinagara, Dewanganj) by Department of Public Health Dentistry. The study selected one ward, in each of the six rural municipalities, based on a lottery method. The total eligible population of these wards was approximately 16,120 (estimated population between the age of 20 years to 65 years) [19]. Approximately 1578 inhabitants, who attended the dental health camps were registered in the camp register list, and two out of every seven registered participants were selected in a random manner and examined. Among them a total of 440 participants who met the inclusion criteria were interviewed and enrolled in the study. (Fig. 1).
Criteria for selection: Inclusion Criteria: Patients between 20 and 65 years old, tobacco users who were currently consuming tobacco in the form of smoking or smokeless tobacco, non-tobacco users who had never used tobacco in any form (smoke or smokeless tobacco), and patient who consented for clinical examination and answered the comprehensive questionnaire. Exclusion Criteria: Former smokers, patients who actively consume alcohol, patients suffering from known systemic illness, pregnant and lactating females.
Method of data collection: A set of standardized pre-tested semi- structured questionnaire was used for all selected participants. Face-to-face interviews were used to record all basic information and social demographics. Age groups were categorized into three categories, as “20-34”, “35-44”, “45-65” years and Body Mass Index (BMI) was calculated as body weight (kg) divided by height (m2). Socio-economic status was assessed and categorized into upper, lower middle and lower class [20]. To ensure objectivity, direct questions were asked to all the participants regarding their use of tobacco. Current smokers were defined as subjects smoking more than five cigarettes per day for the past 2 years or more, and subjects consuming smokeless tobacco on a daily basis for the past 2 years or more [21].
The SLT users were dichotomized as participants who consumed khaini and those who chewed SLT (gutkha, betel quid with tobacco, zarda). Intraorally, Plaque Index (PLI) was recorded as the presence or absence of visible plaque [22]. Bleeding Point Index (BPI) was used to examine presence or absence of bleeding on probing [23]. Simplified Oral Hygiene Index (OHI-S) was recorded according to Greene and Vermillion, 1964 [24]. A periodontal probe, UNC-15 (University of North Carolina-15, Hu-Friedy, Chicago, IL) was used for all periodontal recordings. To avoid inter-observer variation, a single experienced periodontist (K.G) examined all subjects and the dental hygienist (K.T) was trained by the researcher to fill the questionnaire form. The kappa statistics was used to assess the intra-examiner reliability among the forty-four participants who were not enrolled in the study. The participants were re-examined after one week of first examination. The kappa value for single examiner was 0.8 which showed good agreement between the two examinations. The estimation of periodontal disease in this study was based on the case- definition given by CDC- AAP in 2012 [25]. No periodontitis was defined as, no evidence of mild, moderate, or severe periodontitis. Mild periodontitis as ≥2 interproximal sites with AL ≥3 mm, and ≥2 interproximal sites with PD ≥4 mm (not on same tooth) or one site with PD ≥5 mm. Moderate periodontitis as ≥2 interproximal sites with AL ≥4 mm (not on same tooth), or ≥2 interproximal sites with PD ≥5 mm (not on same tooth). Severe periodontitis as ≥2 interproximal sites with AL ≥6 mm (not on same tooth) and ≥1 interproximal site with PD ≥5 mm. Probing depth was measured to the nearest millimeter as the distance from the gingival margin to the bottom of the periodontal sulcus/pocket (cut-offs at ≥4 mm and ≥5mm). Clinical attachment level (CAL) was computed from the cemento-enamel junction (CEJ) to the base of pocket/sulcus (cut-offs at ≥3mm, ≥4 and ≥ 6mm). Presence of caries was examined with a dental explorer, teeth loss and the reason for each tooth loss as self-reported by the participants were recorded.
Statistical Analysis: Descriptive statistics, mean, standard deviation, percentage and frequency were calculated for all the variables along with tabular presentations. Univariate and forward conditional method for multivariate logistic regression was done to assess the crude and adjusted odds ratio with 95% CI to find out the association between tobacco use and other factors with periodontitis. Level of significance was set at p<0.05. Those variables that fell under p<0.2 at univariate analysis, were considered for multivariate logistic regression. All the data collected data was entered into Microsoft Excel 2007 and converted using the statistical software package SPSS 11.5 (SPSS, Chicago, IL, USA) for further analysis.