Periodontal diseases are one of the two most prevalent dental disease worldwide. It has been concluded that subjects with Asian ethnicity have the third-highest prevalence of periodontitis . The overall prevalence of periodontitis based on attachment level in this study was found to be 71.6%. The general trend observed was for a higher loss of attachment than probing pocket depths. Tobacco habits, brushing frequency and technique could have contributed to an increase in attachment loss. In countries like the United States and Europe, the prevalence rates reported were 47% to 76% in an age range of 30-74 years [25,26]. Shaju J et al in 2011 in an Indian population reported a prevalence of 89.6% to 79.9% in the age group of 12-74 years . In the middle age population of south-east Asian countries such as India, Nepal, and Vietnam, reported nearly one- third to half the population were affected with periodontitis . A direct comparison of prevalence rates may not be made as the case definition used differs in most studies and therefore, heterogenicity in the results are observed. Despite this, periodontitis is still prevalent with no gender differentials observed in the studied population. Important factors responsible could be poor oral hygiene with high plaque score along with tobacco consumption rather than gender, geography or economic status.
Periodontitis is a multifactorial disease with various factors affecting it that may be modifiable or non-modifiable . Factors associated with periodontitis do not necessarily imply the cause and effect relation, but identifying them may have a significant impact on prevention, treatment, and progression of the disease . This study showed a significant strength of association between periodontitis and tobacco users (smokers, khaini users), along with age, high plaque score and teeth loss as significant factors associated to periodontitis in this specific population. The results of our study are in agreement to study done by Bhat et al in 2018 that concluded a high prevalence of periodontitis, with sociodemographic factors, plaque, and tobacco as the main risk indicators to periodontitis . Age has been described as a non-modifiable predisposing factor, and there is ample epidemiological evidence suggesting progressive worsening of periodontal status with increasing age [32,33]. In this study an increasing age was a significant risk to periodontitis and the study adds to evidence that the disease tends to cumulate for life . Both factors, high plaque score levels and tobacco consumption are preventable and can be modified. Corbet et al in 1993  mentioned that supragingival plaque is related to progressive periodontal disease and the association between them are available from studies conducted on Sri Lankans and South Pacific island populations . Plaque is considered the primary etiological factor for periodontitis, and it’s also noted that controlling it may form the basis for management of periodontitis. In this study, over 90% of the population answered that they use toothbrushes for cleaning their teeth at least one time in frequency. However, the population assessed had a significantly high plaque score percentage. This signifies the need for proper brushing techniques and oral hygiene awareness programmes to be reinforced at community level.
In the present study, an association between tobacco consumption and periodontitis was established, supporting previous research data [37,38]. The prevalence of tobacco smoking was 20.7% in our study and the results are in accordance with the STEPS survey done in 2012-13 in the Nepalese population . Effect of tobacco smoking has been implicated as one of the important risk factors for periodontitis and this study also showed that smokers to have a significant impact and had an odd of 3.149 for periodontitis. Comparing the results with the global population, studies have shown an overall increased risk with odds ratio of 2.82  in sweedish population, 1.18  in portugese population and 1.6  in an Indian population. A research done in other South-East Asian population reported a higher odd of 3.5 for chronic periodontitis among smokers . The ill effect of tobacco smoke on periodontal status is seen principally by the nicotine, that exerts its harmful effects on the tissues and its healing. The impact results in reduced migration of neutrophils into the oral tissues  with inhibition of phagocytosis and oxidative killing . There are increased levels of pro-inflammatory cytokines such as TNF-α  and a decrease in levels of antibodies to putative periodontal pathogens .
However, tobacco smoking has been on the decline  and the rate of SLT users has surpassed to that of tobacco smoke. The reason may be an increase in cigarette taxation and smoke-free policies implemented at a vast scale. Another strong reason may be the perception that SLT use is relatively safer than cigarette smoking and may be an alternate to tobacco consumption . This is a question to be raised as a staggering 83.8% of population using SLT in both the forms had periodontitis and were almost two times more likely to have the disease than non-users. The results are in agreement with the studies that have reported an odds ratio of 2.1 in a US study  and 1.7 in an Indian population . In the current study, 66.4% of individuals consumed khaini, also known as surti in the local language followed by 33.6 % individuals who were SLT chewers. Nepal STEPS survey reveals khaini (77.6%) to be the most common SLT product used followed by chewing tobacco . The results of this study are in agreement to a hospital-based study done in India by Katuri et al in 2016  showed the most commonly used SLT product was khaini (51.3%) and concluded SLT users to have greater attachment loss. Study done by Kulkarni et al in 2016  reported gutkha (69.47%) to be the most commonly used, and concluded SLT use to have similar impact on periodontium as tobacco smoke. Research in other South-East Asian populations reports a strong association between chewing quid with tobacco and periodontal diseases , however, the current study fails to show a significant association of periodontitis with SLT chewers. The reason may be SLT chewers either spitted the products after chewing or swallowed them. In many countries in South East Asia, including India and Nepal, over 90% of SLT users use tobacco as the main constituent or often betel quid, slaked lime, catechu is added to tobacco . Therefore, nicotine exposure may be supposed to exert its wide range of effects on the periodontal tissues. Traditional khaini and zarda available in south east Asian countries are supposed to contain the highest levels of carcinogenic substances. In addition, the product available also have high pH and nicotine content that may facilitate rapid absorption of chemicals through oral mucosa making the population more susceptible to periodontitis . Therefore, differences in the effects of SLT products in relation to periodontium exists across the globe and, the results should be interpreted based in population studied. However, it would be fair to predict that due to pervasive use of SLT, periodontitis will be higher than projected and this study indicates that SLT users have similar impact as smokers on the periodontium. Based on these evidences and result of the current study, policy makers in the developing countries should address strongly the differential harms of SLT use on the oral health and encourage its cessation.
Teeth loss can be a consequence of caries, periodontitis, trauma, accidents, and previous root canal treatments. In this study, individuals who lost their teeth, 52.7% was due to caries and 26.1% due to periodontitis. The results are in accordance to study done by Papapanou PN in 1996 , who reported 50% of teeth lost due to caries and 30-35% due to periodontitis. This study showed that patient’s with teeth loss had an odd of 2.02 for periodontitis. The reasons for tooth loss may be high plaque score, loss of attachment, dental caries and widespread tobacco use in the population. The results are in agreement with the studies that refer to the combination of age, modifiable factors such as smoking, smokeless tobacco as the strongest predictor of tooth loss [55,56,57]. The number of lost teeth in adults has also been used as a marker of periodontitis in epidemiologic literature. The dentists should counsel their patients about the impact of modified factors on tooth loss.