start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=1 article-no= start-page=324 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210105 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Living with Family Is Directly Associated with Regular Dental Checkup and Indirectly Associated with Gingival Status among Japanese University Students: A 3-Year Cohort Study en-subtitle= kn-subtitle= en-abstract= kn-abstract=Although some studies showed that lifestyle was associated with oral health behavior, few studies investigated the association between household type and oral health behavior. The aim of this prospective cohort study was to investigate the association between household type, oral health behavior, and periodontal status among Japanese university students. Data were obtained from 377 students who received oral examinations and self-questionnaires in 2016 and 2019. We assessed periodontal status using the percentage of bleeding on probing (%BOP), probing pocket depth, oral hygiene status, oral health behaviors, and related factors. We used structural equation modeling to determine the association between household type, oral health behaviors, gingivitis, and periodontitis. At follow-up, 252 students did not live with their families. The mean +/- standard deviation of %BOP was 35.5 +/- 24.7 at baseline and 32.1 +/- 25.3 at follow-up. In the final model, students living with their families were significantly more likely to receive regular dental checkup than those living alone. Regular checkup affected the decrease in calculus. The decrease in calculus affected the decrease in %BOP over 3 years. Living with family was directly associated with regular dental checkups and indirectly contributed to gingival status among Japanese university students. en-copyright= kn-copyright= en-aut-name=NakaharaMomoko en-aut-sei=Nakahara en-aut-mei=Momoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=EkuniDaisuke en-aut-sei=Ekuni en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KataokaKota en-aut-sei=Kataoka en-aut-mei=Kota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YokoiAya en-aut-sei=Yokoi en-aut-mei=Aya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Uchida-FukuharaYoko en-aut-sei=Uchida-Fukuhara en-aut-mei=Yoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=FukuharaDaiki en-aut-sei=Fukuhara en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KobayashiTerumasa en-aut-sei=Kobayashi en-aut-mei=Terumasa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=ToyamaNaoki en-aut-sei=Toyama en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=SahoHikari en-aut-sei=Saho en-aut-mei=Hikari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=IslamMd Monirul en-aut-sei=Islam en-aut-mei=Md Monirul kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=IwasakiYoshiaki en-aut-sei=Iwasaki en-aut-mei=Yoshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=MoritaManabu en-aut-sei=Morita en-aut-mei=Manabu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= affil-num=1 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=6 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=7 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=8 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=9 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=10 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=11 en-affil=Health Service Center, Okayama University kn-affil= affil-num=12 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=lifestyle kn-keyword=lifestyle en-keyword=dental health behavior kn-keyword=dental health behavior en-keyword=oral health kn-keyword=oral health en-keyword=oral hygiene kn-keyword=oral hygiene en-keyword=gingivitis kn-keyword=gingivitis en-keyword=behavioral sciences kn-keyword=behavioral sciences END start-ver=1.4 cd-journal=joma no-vol=17 cd-vols= no-issue=22 article-no= start-page=8623 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20201120 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Association between Household Exposure to Secondhand Smoke and Dental Caries among Japanese Young Adults: A Cross-Sectional Study en-subtitle= kn-subtitle= en-abstract= kn-abstract=The long-term effects of secondhand smoke (SHS) on dental caries among Japanese young adults remain unclear. The purpose of this cross-sectional study was to evaluate whether household exposure to SHS is associated with dental caries in permanent dentition among Japanese young adults. The study sample included 1905 first-year university students (age range: 18-19 years) who answered a questionnaire and participated in oral examinations. The degree of household exposure to SHS was categorized into four levels according to the SHS duration: no experience (-), past, current SHS < 10 years, and current SHS >= 10 years. Dental caries are expressed as the total number of decayed, missing, and filled teeth (DMFT) score. The relationships between SHS and dental caries were determined by logistic regression analysis. DMFT scores (median (25th percentile, 75th percentile)) were significantly higher in the current SHS >= 10 years (median: 1.0 (0.0, 3.0)) than in the SHS-(median: 0.0 (0.0, 2.0)); p = 0.001). DMFT >= 1 was significantly associated with SHS >= 10 years (adjusted odds ratio: 1.50, 95% confidence interval: 1.20-1.87, p < 0.001). Long-term exposure to SHS (>= 10 years) was associated with dental caries in permanent dentition among Japanese young adults. en-copyright= kn-copyright= en-aut-name=SahoHikari en-aut-sei=Saho en-aut-mei=Hikari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=Taniguchi-TabataAyano en-aut-sei=Taniguchi-Tabata en-aut-mei=Ayano kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=EkuniDaisuke en-aut-sei=Ekuni en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YokoiAya en-aut-sei=Yokoi en-aut-mei=Aya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KataokaKouta en-aut-sei=Kataoka en-aut-mei=Kouta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=FukuharaDaiki en-aut-sei=Fukuhara en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=ToyamaNaoki en-aut-sei=Toyama en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=IslamMd Monirul en-aut-sei=Islam en-aut-mei=Md Monirul kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=SawadaNanami en-aut-sei=Sawada en-aut-mei=Nanami kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=NakashimaYukiho en-aut-sei=Nakashima en-aut-mei=Yukiho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=NakaharaMomoko en-aut-sei=Nakahara en-aut-mei=Momoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=DeguchiJunya en-aut-sei=Deguchi en-aut-mei=Junya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=Uchida-FukuharaYoko en-aut-sei=Uchida-Fukuhara en-aut-mei=Yoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=YonedaToshiki en-aut-sei=Yoneda en-aut-mei=Toshiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=IwasakiYoshiaki en-aut-sei=Iwasaki en-aut-mei=Yoshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=MoritaManabu en-aut-sei=Morita en-aut-mei=Manabu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= affil-num=1 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=3 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=7 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=8 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=9 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=10 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=11 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=12 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=13 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=14 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=15 en-affil=Health Service Center, Okayama University kn-affil= affil-num=16 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=secondhand smoke kn-keyword=secondhand smoke en-keyword=dental caries kn-keyword=dental caries en-keyword=permanent dentition kn-keyword=permanent dentition en-keyword=young adult kn-keyword=young adult END start-ver=1.4 cd-journal=joma no-vol=15 cd-vols= no-issue=7 article-no= start-page=e0236259 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200723 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Relationship between oral hygiene knowledge, source of oral hygiene knowledge and oral hygiene behavior in Japanese university students: A prospective cohort study en-subtitle= kn-subtitle= en-abstract= kn-abstract=The aim of this prospective cohort study was to examine whether oral hygiene knowledge, and the source of that knowledge, affect oral hygiene behavior in university students in Japan. An oral exam and questionnaire survey developed to evaluate oral hygiene knowledge, the source of that knowledge, and oral hygiene behavior, such as the frequency of tooth brushing and regular dental checkups and the use of dental floss, was conducted on university student volunteers. In total, 310 students with poor tooth brushing behavior (frequency of tooth brushing per day [<= once]), 1,963 who did not use dental floss, and 1,882 who did not receive regular dental checkup during the past year were selected. Among these students, 50, 364, and 343 in each respective category were analyzed in over the 3-year study period (follow-up rates: 16.1%, 18.5%, and 18.2%, respectively). The odds ratios (ORs) and 95% confidence intervals (CIs) for oral hygiene behavior were calculated based on oral hygiene knowledge and the source of that knowledge using logistic regression models. The results showed that dental clinics were the most common (> 50%) source of oral hygiene knowledge, and that a more frequent use of dental floss was significantly associated with dental clinics being a source of oral hygiene knowledge (OR, 4.11; 95%CI, 1.871-9.029; p < 0.001). In addition, a significant association was seen between dental clinics being a source of oral hygiene knowledge and more frequent regular dental checkups (OR, 13.626; 95%CI, 5.971-31.095; p < 0.001). These findings suggest the existence of a relationship between dental clinics being the most common source of oral hygiene knowledge and improved oral hygiene behavior in Japanese university students. en-copyright= kn-copyright= en-aut-name=FukuharaDaiki en-aut-sei=Fukuhara en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=EkuniDaisuke en-aut-sei=Ekuni en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KataokaKota en-aut-sei=Kataoka en-aut-mei=Kota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=Taniguchi-TabataAyano en-aut-sei=Taniguchi-Tabata en-aut-mei=Ayano kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Uchida-FukuharaYoko en-aut-sei=Uchida-Fukuhara en-aut-mei=Yoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ToyamaNaoki en-aut-sei=Toyama en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YonedaToshiki en-aut-sei=Yoneda en-aut-mei=Toshiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=SugiuraYoshio en-aut-sei=Sugiura en-aut-mei=Yoshio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=IslamMonirul en-aut-sei=Islam en-aut-mei=Monirul kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=SahoHikari en-aut-sei=Saho en-aut-mei=Hikari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=IwasakiYoshiaki en-aut-sei=Iwasaki en-aut-mei=Yoshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=MoritaManabu en-aut-sei=Morita en-aut-mei=Manabu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= affil-num=1 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=2 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=6 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=7 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=8 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=9 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=10 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=11 en-affil=Health Service Center, Okayama University kn-affil= affil-num=12 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= END start-ver=1.4 cd-journal=joma no-vol=17 cd-vols= no-issue=9 article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200427 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Association between Sleep Quality and Duration and Periodontal Disease among University Students: A Cross-Sectional Study en-subtitle= kn-subtitle= en-abstract= kn-abstract=The purpose of this cross-sectional study was to investigate the association between sleep quality and duration, and periodontal disease among a group of young Japanese university students. First-year students (n = 1934) at Okayama University who voluntarily underwent oral health examinations were included in the analysis. Sleep quality and duration were assessed by the Japanese version of the Pittsburgh Sleep Quality Index. Dentists examined Oral Hygiene Index-Simplified (OHI-S), probing pocket depth (PPD), and percentage of sites with bleeding on probing (BOP). Periodontal disease was defined as presence of PPD >= 4 mm and BOP >= 30%. Overall, 283 (14.6%) students had periodontal disease. Poor sleep quality was observed among 372 (19.2%) students. Mean (+/- standard deviation) sleep duration was 7.1 +/- 1.1 (hours/night). In the logistic regression analysis, periodontal disease was significantly associated with OHI-S (odds ratio [OR]: 2.30, 95% confident interval [CI]: 1.83-2.90; p < 0.001), but not sleep quality (OR: 1.09, 95% CI: 0.79-1.53; p = 0.577) or sleep duration (OR: 0.98, CI: 0.87-1.10; p = 0.717). In conclusion, sleep quality and duration were not associated with periodontal disease among this group of young Japanese university students. en-copyright= kn-copyright= en-aut-name=IslamMd Monirul en-aut-sei=Islam en-aut-mei=Md Monirul kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=EkuniDaisuke en-aut-sei=Ekuni en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ToyamaNaoki en-aut-sei=Toyama en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=Taniguchi-TabataAyano en-aut-sei=Taniguchi-Tabata en-aut-mei=Ayano kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KataokaKota en-aut-sei=Kataoka en-aut-mei=Kota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=Uchida-FukuharaYoko en-aut-sei=Uchida-Fukuhara en-aut-mei=Yoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=FukuharaDaiki en-aut-sei=Fukuhara en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=SahoHikari en-aut-sei=Saho en-aut-mei=Hikari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=SawadaNanami en-aut-sei=Sawada en-aut-mei=Nanami kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=NakashimaYukiho en-aut-sei=Nakashima en-aut-mei=Yukiho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=IwasakiYoshiaki en-aut-sei=Iwasaki en-aut-mei=Yoshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=MoritaManabu en-aut-sei=Morita en-aut-mei=Manabu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= affil-num=1 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=7 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=8 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=9 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=10 en-affil=Department of Preventive Dentistry, Okayama University Hospital kn-affil= affil-num=11 en-affil=Health Service Center, Okayama University kn-affil= affil-num=12 en-affil=Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=sleep quality kn-keyword=sleep quality en-keyword=sleep duration kn-keyword=sleep duration en-keyword=periodontal disease kn-keyword=periodontal disease en-keyword=university students kn-keyword=university students END