MDPI AG Acta Medica Okayama 2304-6767 13 12 2025 Effects of miR-128-3p on Renal Inflammation in a Rat Periodontitis Model 577 EN Mohammad Nurhamim Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yixuan Zhang Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Momoko Nakahara Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Yosei Nagashima Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takayuki Maruyama Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Manabu Morita Department of Oral Health, Takarazuka University of Medical and Health Care Daisuke Ekuni Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objectives: The study aim was to investigate the effects of extracellular vesicles (EVs) derived miR-128-3p on renal inflammation using a rat periodontitis model. Methods: Ten-week-old male Wistar rats were divided into two groups: a control (n = 8) and a lipopolysaccharides (LPS) group (n = 8). The LPS group received LPS (Porphyromonas gingivalis) injection in the gingiva for 7 days. At the end of the experiment, plasma, gingival tissue, and kidney samples were collected. Hematoxylin and eosin staining was performed to evaluate the glomerular tissue injury score. Bioinformatic analysis was conducted to identify potential target genes of miR-128-3p. The reverse transcription-quantitative polymerase chain reaction was performed to evaluate miR-128-3p, inflammatory, pro-inflammatory cytokine, chemokine and predicting gene’s expression. The control and LPS groups were compared using Welch’s t-test. p-values < 0.05 were considered to indicate statistical significance. Results: The kidney glomerular tissue injury score was significantly higher in the LPS than in the control group. miR-128-3p expression in the LPS group was significantly higher in the gingival tissue and plasma. mRNAs (interleukin [IL]-1β, tumor necrosis factor [TNF]-α, C-X3-C motif chemokine ligand 1 [CX3CL1], and C-X-C motif chemokine ligand 7 [CXCL7]) expression was higher in the kidney of the LPS group. The potential target genes of activin A receptor type I (Acvr1), ribosomal protein S6 kinase B1 (Rps6kb1), and transforming growth factor beta receptor type 1 (Tgfbr1) were significantly lower in the kidneys of the LPS group. Conclusions: EVs-derived miR-128-3p in LPS induced periodontitis may cause kidney inflammation which may be mediated by, Rps6kb1, Tgfbr1, and Acvr1. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2077-0383 12 7 2023 Nutrients Associated with Sleep Bruxism 2623 EN Naoki Toyama Department of Preventive Dentistry, Academic Field of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daisuke Ekuni Department of Preventive Dentistry, Academic Field of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Nanami Sawada Department of Preventive Dentistry, Academic Field of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Miho Yamashita Department of Foods and Human Nutrition, Notre Dame Seishin University Momoe Komiyama Department of Foods and Human Nutrition, Notre Dame Seishin University Takahiko Nagahama Department of Foods and Human Nutrition, Notre Dame Seishin University Manabu Morita Department of Preventive Dentistry, Academic Field of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background: The purpose of the present research was to identify nutrients related to sleep bruxism and to establish a hypothesis regarding the relationship between sleep bruxism and nutrients. Methods: We recruited 143 Japanese university students in 2021 and assigned them to sleep bruxism (n = 58) and non-sleep bruxism groups (n = 85), using an identical single-channel wearable electromyography device. To investigate nutrient intakes, participants answered a food frequency questionnaire based on food groups. We assessed differences in nutrient intakes between the sleep bruxism and non-sleep bruxism groups. Results: Logistic regression modeling showed that sleep bruxism tended to be associated with dietary fiber (odds ratio, 0.91; 95% confidence interval, 0.83-1.00; p = 0.059). In addition, a subgroup analysis selecting students in the top and bottom quartiles of dietary fiber intake showed that students with sleep bruxism had a significantly lower dietary fiber intake (10.4 +/- 4.6 g) than those without sleep bruxism (13.4 +/- 6.1 g; p = 0.022). Conclusion: The present research showed that dietary fiber intake may be related to sleep bruxism. Therefore, we hypothesized that dietary fiber would improve sleep bruxism in young adults. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 19 21 2022 The Impact of Oral Health Behaviors, Health Belief Model, and Absolute Risk Aversion on the Willingness of Japanese University Students to Undergo Regular Dental Check-Ups: A Cross-Sectional Study 13920 EN Ichiro Sumita Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Naoki Toyama Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daisuke Ekuni Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takayuki Maruyama Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Aya Yokoi Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daiki Fukuhara Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yoko Uchida-Fukuhara Department of Oral Morphology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Momoko Nakahara Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Manabu Morita Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Oral health behaviors, risk aversion, and the health belief model are associated with health behaviors. However, there have been few studies that investigated the association between these factors and the willingness to undergo regular dental check-ups. The purpose of this cross-sectional study was to investigate the associations between the willingness of Japanese university students to undergo regular dental check-ups and oral health behaviors, the health belief model, and absolute risk aversion. An analysis was conducted with the cooperation of questionnaire respondents (n = 748) who underwent dental check-ups at Okayama University. The students answered questionnaires on oral health behaviors, the health belief model, absolute risk aversion, and willingness to undergo regular dental check-ups. The logistic regression analysis showed significant positive associations (p < 0.05) between oral health behaviors (use of the inter-dental brush and the dental floss) and the health belief model with the willingness to undergo regular dental check-ups. However, there was no significant association with absolute risk aversion (p > 0.05). These results suggest that willingness to undergo regular dental check-ups was associated with oral health behaviors and the health belief model, but not with absolute risk aversion. No potential conflict of interest relevant to this article was reported.

Frontiers Media SA Acta Medica Okayama 2235-2988 12 2022 Features of the oral microbiome in Japanese elderly people with 20 or more teeth and a non-severe periodontal condition during periodontal maintenance treatment: A cross-sectional study 957890 EN Naoki Toyama Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daisuke Ekuni Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Aya Yokoi Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Md Monirul Islam Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Nanami Sawada Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yukiho Nakashima Department of Preventive Dentistry, Okayama University Hospital Momoko Nakahara Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ichiro Sumita Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Manabu Morita Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Introduction The aim of the present study was to characterize the profile and diversity of the oral microbiome of a periodontally non-severe group with >= 20 teeth in comparison with a severe periodontitis group of elderly Japanese people. Methods A total of 50 patients who had >= 20 teeth and aged >= 60 years were recruited, and 34 participants (13 non-severe participants) were analyzed. After oral rinse (saliva after rinsing) sample collection, the V3-V4 regions of the 16S rRNA gene were sequenced to investigate microbiome composition, alpha diversity (Shannon index, Simpson index, richness, and evenness), and beta diversity using principal coordinate analysis (PCoA) based on weighted and unweighted UniFrac distances. A linear discriminant analysis effect size was calculated to identify bacterial species in the periodontally non-severe group. Results The periodontally non-severe group showed lower alpha diversity than that of the severe periodontitis group (p <0.05); however, the beta diversities were not significantly different. A higher relative abundance of four bacterial species (Prevotella nanceiensis, Gemella sanguinis, Fusobacterium periodonticum, and Haemophilus parainfluenzae) was observed in the non-severe group than that in the severe periodontitis group. Conclusion The oral microbiome in elderly Japanese people with >= 20 teeth and a non-severe periodontal condition was characterized by low alpha diversity and the presence of four bacterial species. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2076-2607 10 5 2022 Maternal Gut Microbiome Decelerates Fetal Endochondral Bone Formation by Inducing Inflammatory Reaction 1000 EN Yoko Uchida-Fukuhara Department of Oral Morphology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takako Hattori Department of Biochemistry and Molecular Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shanqi Fu Department of Biochemistry and Molecular Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Sei Kondo Department of Biochemistry and Molecular Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Miho Kuwahara Department of Biochemistry and Molecular Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Md Monirul Islam Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kota Kataoka Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daisuke Ekuni Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Satoshi Kubota Department of Biochemistry and Molecular Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Manabu Morita Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Mika Iikegame Department of Oral Morphology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hirohiko Okamura Department of Oral Morphology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University To investigate the effect of the maternal gut microbiome on fetal endochondral bone formation, fetuses at embryonic day 18 were obtained from germ-free (GF) and specific-pathogen-free (SPF) pregnant mothers. Skeletal preparation of the fetuses' whole bodies did not show significant morphological alterations; however, micro-CT analysis of the tibiae showed a lower bone volume fraction in the SPF tibia. Primary cultured chondrocytes from fetal SPF rib cages showed a lower cell proliferation and lower accumulation of the extracellular matrix. RNA-sequencing analysis showed the induction of inflammation-associated genes such as the interleukin (IL) 17 receptor, IL 6, and immune-response genes in SPF chondrocytes. These data indicate that the maternal gut microbiome in SPF mice affects fetal embryonic endochondral ossification, possibly by changing the expression of genes related to inflammation and the immune response in fetal cartilage. The gut microbiome may modify endochondral ossification in the fetal chondrocytes passing through the placenta. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 18 1 2021 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 324 EN Momoko Nakahara Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Daisuke Ekuni Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kota Kataoka Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Aya Yokoi Department of Preventive Dentistry, Okayama University Hospital Yoko Uchida-Fukuhara Department of Preventive Dentistry, Okayama University Hospital Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Terumasa Kobayashi Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Naoki Toyama Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hikari Saho Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Md Monirul Islam Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiaki Iwasaki Health Service Center, Okayama University Manabu Morita Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences 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. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 17 22 2020 Association between Household Exposure to Secondhand Smoke and Dental Caries among Japanese Young Adults: A Cross-Sectional Study 8623 EN Hikari Saho Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ayano Taniguchi-Tabata Department of Preventive Dentistry, Okayama University Hospital Daisuke Ekuni Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Aya Yokoi Department of Preventive Dentistry, Okayama University Hospital Kouta Kataoka Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Naoki Toyama Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Md Monirul Islam Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nanami Sawada Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yukiho Nakashima Department of Preventive Dentistry, Okayama University Hospital Momoko Nakahara Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Junya Deguchi Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoko Uchida-Fukuhara Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshiki Yoneda Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiaki Iwasaki Health Service Center, Okayama University Manabu Morita Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences 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. No potential conflict of interest relevant to this article was reported.

Public Library of Science Acta Medica Okayama 1932-6203 15 7 2020 Relationship between oral hygiene knowledge, source of oral hygiene knowledge and oral hygiene behavior in Japanese university students: A prospective cohort study e0236259 EN Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Daisuke Ekuni Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kota Kataoka Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ayano Taniguchi-Tabata Department of Preventive Dentistry, Okayama University Hospital Yoko Uchida-Fukuhara Department of Preventive Dentistry, Okayama University Hospital Naoki Toyama Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshiki Yoneda Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshio Sugiura Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Monirul Islam Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hikari Saho Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiaki Iwasaki Health Service Center, Okayama University Manabu Morita Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences 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. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 17 10 2020 Caries Increment and Salivary Microbiome during University Life: A Prospective Cohort Study 3713 EN Yoko Uchida-Fukuhara Department of Preventive Dentistry, Okayama University Hospital Daisuke Ekuni Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Md Monirul Islam Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kota Kataoka Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School Ayano Taniguchi-Tabata Department of Preventive Dentistry, Okayama University Hospital Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Naoki Toyama Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Terumasa Kobayashi Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kohei Fujimori Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nanami Sawada Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiaki Iwasaki Health Service Center, Okayama University Manabu Morita Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences The purpose of this 3-year prospective cohort study was to explore the relationship between an increase in dental caries and oral microbiome among Japanese university students. We analyzed 487 students who volunteered to receive oral examinations and answer baseline (2013) and follow-up (2016) questionnaires. Of these students, salivary samples were randomly collected from 55 students at follow-up and analyzed using next-generation sequencing. Students were divided into two groups: increased group (Delta decayed, missing, and filled teeth (Delta DMFT) score increased during the 3-year period) and non-increased group (Delta DMFT did not increase). Thirteen phyla, 21 classes, 32 orders, 48 families, 72 genera, and 156 species were identified. Microbial diversity in the increased group (n = 14) was similar to that in the non-increased group (n = 41). Relative abundances of the family Prevotellaceae (p = 0.007) and genera Alloprevotella (p = 0.007) and Dialister (p = 0.039) were enriched in the increased group compared with the non-increased group. Some bacterial taxonomic clades were differentially present between the two groups. These results may contribute to the development of new dental caries prevention strategies, including the development of detection kits and enlightenment activities for these bacteria. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 17 9 2020 Association between Sleep Quality and Duration and Periodontal Disease among University Students: A Cross-Sectional Study EN Md Monirul Islam Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Daisuke Ekuni Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Naoki Toyama Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ayano Taniguchi-Tabata Department of Preventive Dentistry, Okayama University Hospital Kota Kataoka Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoko Uchida-Fukuhara Department of Preventive Dentistry, Okayama University Hospital Daiki Fukuhara Department of Preventive Dentistry, Okayama University Hospital Hikari Saho Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nanami Sawada Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yukiho Nakashima Department of Preventive Dentistry, Okayama University Hospital Yoshiaki Iwasaki Health Service Center, Okayama University Manabu Morita Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences 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. No potential conflict of interest relevant to this article was reported.