Details of the Researcher

PHOTO

Hazem Abbas Farouk Abbas
Section
Graduate School of Dentistry
Job title
Assistant Professor

Research History 3

  • 2023/04 - Present
    Tohoku University　Assistant professor

  • 2013/02 - 2016/08
    Egyptian Ministry of Health and private practice　Dentist

  • 2011/11 - 2012/10
    Resident dentist

Education 3

  • Tohoku University　Graduate School of Dentistry　PhD

    2019/10 - 2023/03

  • Tohoku University　Graduate School of Dentistry　MSc

    2016/09 - 2019/03

  • School of Dentistry - Cairo University　School of Dentistry

    2006/09 - 2011/06

Committee Memberships 5

  • International Association for Dental Research (IADR) - member

    2017/01 - Present

  • IADR Fellowships Committee member - International Association for Dental Research (IADR)

    2025/06 - 2028/06

  • JDR Clinical & Translational Research Journal - Scientific Advisory Board member

    2025/01 - 2028/01

  • International Director of the Behavioral, Epidemiologic and Health Services Research Group (BEHSR) of the IADR

    2023/06 - 2025/06

  • Executive Committee Member of the Behavioral, Epidemiologic and Health Services Research Group (BEHSR) of the IADR

    2022/06 - 2023/06

Professional Memberships 1

  • International Association for Dental Research (IADR)

    - Present

Research Interests 7

  • Aging

  • Dental Public Health

  • Social Epidemiology

  • Global Oral Health

  • Oral health services utilization

  • Oral health policies' research

  • Structural determinants of Health

Research Areas 1

  • Life sciences / Community dentistry / Dental Public Health and Oral Epidemiology

Awards 4

  1. Tohoku University Graduate School of Dentistry’s Certificate of Excellent Research Award for the “Outstanding Research Achievements” during the PhD course - 2023

    2023/03　Tohoku University　“Outstanding Research Achievements” during the PhD course

  2. JADR/GC Young investigator Award 2022

    2022/06　International Association for Dental Research - Japan Division（JADR）　The Association Between Toothbrushing Habits and COVID-19 Symptoms

  3. Lion Dental Research Award

    2021/07　International Association for Dental Research (IADR)　Does Remaining Teeth And Dental Prosthesis Associate With Social Isolation? A prospective cohort study from Japan gerontological Evaluation study (JAGES).

  4. WILEY - COMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY (CDOE) Top 10 cited article

    2024/04　WILEY - COMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY (CDOE)

Papers 24

  1. Multiple Tobacco Product Use and Dental Pain: A Cross-sectional Study

    T. Yamamoto, H. Abbas, M. Sato, M. Iwasaki, T. Tabuchi

    JDR Clinical & Translational Research　2026/08/06

    Publisher: SAGE Publications

    DOI： 10.1177/23800844261467716 　

    ISSN： 2380-0844

    eISSN： 2380-0852

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    Introduction: Although individual tobacco products, including new tobacco products, have been associated with adverse oral health outcomes, few studies have examined the association between multiple tobacco product (MTP) use and dental pain as an indicator of current oral health status. Methods: We conducted a cross-sectional study using data from a nationwide internet survey in Japan. The 2023 survey included the outcome variable, current tobacco product use, and most covariates; however, it did not include the number of remaining teeth, an oral health–related covariate relevant to interpreting dental pain. Therefore, we included participants who responded to the 2023 survey and for whom information on remaining teeth was available from the 2022 survey. Current tobacco product use was assessed for 6 product types: cigarettes, heated tobacco products, electronic cigarettes, cigars, pipe/water pipes, and smokeless tobacco. Participants were categorized as having no current product use, single-product use, or MTP use. The outcome was self-reported dental pain within the past week. Covariates were sex, age, education, household income, living alone, marital status, drinking, self-rated health, psychological distress, number of remaining teeth, and daily toothbrushing. We used multivariable modified Poisson regression to estimate adjusted prevalence ratios (aPRs) and 95% CIs. Results: We analyzed 19,703 participants; the mean age was 50.2 y (SD, 16.9) and 10,165 (51.6%) were men. Overall, 2518 participants (12.8%) reported dental pain within the past week, 2463 (12.5%) used a single tobacco product, and 1040 (5.3%) used MTPs. After adjustment for all covariates, MTP use was associated with a higher prevalence of dental pain (single-product use: aPR, 1.03 [95% CI, 0.92–1.15]; MTP use: aPR, 1.39 [95% CI, 1.25–1.54]). Conclusions: MTP use was associated with dental pain. Longitudinal studies are needed to clarify the temporal and causal relationships between MTP use and oral health. Knowledge Transfer Statement: The findings of this study suggest that collaboration between policy makers in dental and oral health and those in tobacco control may be important for addressing oral health disparities between tobacco users and nonusers.

  2. Adverse and positive childhood experiences and dental pain in adulthood: a cross-sectional study

    Takafumi Yamamoto, Hazem Abbas, Misuzu Sato, Masanori Iwasaki, Takahiro Tabuchi

    Scientific Reports　2026/07/10

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-026-60490-1 　

    eISSN： 2045-2322

  3. Oral Frailty, Social Frailty, and 6-Year Risk of Long-term Care Onset

    I. Susanti, H. Abbas, K. Takeuchi, J. Aida, K. Osaka

    JDR Clinical & Translational Research　2026/07/03

    Publisher: SAGE Publications

    DOI： 10.1177/23800844261452968 　

    ISSN： 2380-0844

    eISSN： 2380-0852

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    Objectives: This 6-y longitudinal study examined the relationship between oral frailty measured in 2016 and the onset of long-term care (LTC) measured in 2022 and investigated whether social frailty (SF) measured in 2019 mediates the association among community-dwelling older adults aged ≥65 y in Japan. Methods: Four waves (2013–2022) of data from the Japan Gerontological Evaluation Study (JAGES) were analyzed. Oral frailty was classified into robust, pre–oral frail, and oral frail categories. LTC onset was identified through official certification records. Logistic regression models estimated odds ratios (ORs) for LTC onset after adjusting for sociodemographic, behavioral, and health-related confounders measured in 2013. Causal mediation analysis using parametric logistic regression models was used to assess social frailty (robust and social frail) as a mediating pathway. Results: During 6 y of follow-up among 3,559 participants (48.7% males, mean [SD] age 71.9 [4.8]), 6.1% developed LTC dependency. Overall, a clear gradient relationship was observed. The oral frail group had a 47% likelihood of enrolling in LTC compared with the robust group (adjusted OR = 1.47; 95% confidence interval [CI], 1.01–2.17), while the pre–oral frail group was 39% more likely to enroll in LTC (adjusted OR = 1.39; 95% CI, 0.96–2.02) than the robust group. Furthermore, SF mediated approximately 7% to 19% of the association between oral frailty and LTC onset, indicating that declining oral function contributes to social vulnerability, which in turn accelerates the dependency. Moreover, sensitivity analysis restricted to a complete data scenario attenuated the relationship, likely due to reduced power and missing data. Conclusion: These findings suggest that oral frailty may be an important predictor of long-term care onset, with part of the association potentially explained by social frailty. Maintaining oral health and promoting social participation may be important components of strategies aimed at supporting healthy aging and potentially reducing the risk of care dependency. Knowledge Transfer Statement: This longitudinal cohort study shows that oral frailty increased the risk of long-term care dependency among older adults after 6 years, partly through social frailty. For patients and clinicians, maintaining natural dentition and oral function might help preserve social engagement and delay care dependency. For policymakers, these findings could guide the provision of oral health initiatives, such as integrating oral health promotion and social participation strategies into healthy aging and long-term care prevention policies.

  4. Dental prosthesis use and subsequent functional capacity decline among older adults: a three-year cohort study based on self-reported measures from the JAGES

    Mari Nakagawa, Kenji Takeuchi, Taro Kusama, Hazem Abbas, Katsunori Kondo, Hiroshi Egusa, Ken Osaka

    Frontiers in Oral Health　7　2026/05/07

    Publisher: Frontiers Media SA

    DOI： 10.3389/froh.2026.1784871 　

    eISSN： 2673-4842

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    Background Functional capacity (FC) is a key determinant of healthy aging. Oral health deterioration, particularly tooth loss, has been associated with FC decline among older adults. Although dental prostheses may mitigate functional deterioration by restoring oral function, longitudinal evidence on their protective effects on FC, especially across specific domains, remains limited. This study investigated the association between dental prosthesis use and the decline in overall and domain-specific FC among older Japanese adults experiencing tooth loss. Methods We conducted a 3-year prospective cohort study using data from the Japan Gerontological Evaluation Study (JAGES). Participants were living independently older adults aged ≥65 years with <20 teeth at baseline (2016), followed up in 2019. Dental prosthesis use (removable dentures, fixed prostheses, and/or implants) was assessed by self-report at baseline and dichotomized as use vs. non-use. FC was measured using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), including total score and subdomains: instrumental activities of daily living (IADL), intellectual activity, and social role. FC decline was defined as a decrease of ≥1 point in the TMIG-IC score during follow-up. Modified Poisson regression with robust variance was used to estimate the relative risks (RRs) and 95% confidence intervals (CIs), adjusting for sociodemographic factors, health behaviors, comorbidities, and number of remaining teeth. Results Among 22,632 eligible participants (mean age at baseline: 74.0 years, SD = 5.7; 51.4% male), 7,573 participants (33.5%) experienced a decline in total FC. Dental prosthesis use was significantly associated with a lower risk of decline in the total TMIG-IC score [RR = 0.91 (95% CI: 0.86–0.97)] compared with no use. For the TMIG-IC subdomain, we observed a significant association between dental prosthesis use and a lower risk of decline in intellectual activity [RR = 0.87 (95% CI: 0.80–0.96)]. Conclusions This large-scale cohort study demonstrated that the use of dental prostheses was associated with a reduced risk of FC decline in older adults, particularly in the intellectual activity domain. Because prosthesis use and FC were assessed by self-reported and residual confounding may remain, further studies are warranted to clarify the potential role of prosthodontic rehabilitation in maintaining FC in later life.

  5. Oral Frailty and Social Frailty Among Older Japanese

    Isi Susanti, Hazem Abbas, Kenji Takeuchi, Jun Aida, Ken Osaka

    Gerodontology　2026/02/17

    Publisher: Wiley

    DOI： 10.1111/ger.70056 　

    ISSN： 0734-0664

    eISSN： 1741-2358

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    ABSTRACT Objective To examine the association between oral frailty (OF) and social frailty (SF) among independent community‐dwelling older adults in Japan. Methods A cross‐sectional study was conducted using data from the 2022 wave of the Japan Gerontological Evaluation Study (JAGES) including 19,319 functionally independent older adults aged ≥ 65 years. Oral frailty was used as an exposure variable in four ways: (1) a categorical variable (robust = 0, pre‐frail = 1, frail ≥ 2), (2) count score (sum of 5 OF components), (3) individual OF components and (4) a combined variable for the four oral functions. SF was measured using the 5‐item index (SF‐5; robust = 0, pre‐frail = 1, frail ≥ 2). Missing data were handled via multiple imputation. Ordered logistic regression models were used after adjusting for sociodemographic and health‐related covariates. Results Participants were 48.4% males and aged 65–104 years. SF prevalence was 28.3% ( n  = 5466). In the adjusted models, oral frail individuals had higher odds of being socially frail (OR 1.35; 95% CI 1.26–1.45) than the robust group and the highest oral frailty score (score 5) showed the highest odds (OR 2.53; 95% CI 1.50–4.27) for SF. In addition, among OF components, dry mouth had the strongest association (OR 1.29; 95% CI 1.20–1.38), and those with four diminished oral functions were more likely to be socially frail (OR 2.42; 95% CI 1.53–3.82). Overall, a clear gradient‐like pattern was observed with more oral frailty linked to higher odds of social frailty. Conclusion OF and its components were associated with SF among older adults in Japan. These findings might suggest the need for integrated screening and preventive strategies to mitigate social vulnerability linked to oral functional decline.

  6. With the Rise of Right‐Wing Governments, Why a One‐Time “50% Health Tax” Will Be a Hard Sell and How It Could Be Implemented

    Hazem Abbas, Maha El Tantawi, Manami Hoshi‐Harada, Kenji Takeuchi, Ken Osaka, Carol C. Guarnizo‐Herreño, Marco A. Peres

    Community Dentistry and Oral Epidemiology　2025/12/30

    Publisher: Wiley

    DOI： 10.1111/cdoe.70051 　

    ISSN： 0301-5661

    eISSN： 1600-0528

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    ABSTRACT Recent calls from the World Health Organization (WHO) to globally impose a one‐time tax, labelled as “Health tax”, on tobacco, alcohol and sugar sweetened beverages (SSBs) aim to achieve a 50% retail price increase to reduce consumption and improve health outcomes. However, with the rise of right‐wing governments globally, this substantial intervention might be a hard sell. Right‐wing governments usually lean towards tax reductions to stimulate economic growth, job creation and encourage investments. In addition, they support free‐market capitalism, deregulation and minimum government interventions. Furthermore, some of such governments share a sentiment of distrust in science and cut health and research spending. Moreover, regardless of political orientations, path dependence (the institutional resistance to change) is another hurdle. In addition, the expected restrictions on the availability and affordability of these products in case of implementing such tax may lead to public rebuttal. All these structural, political and commercial determinants of health raise concerns about the applicability of such intervention and its sustainability if implemented. This commentary argues that the implementation of this substantial one‐time tax would be a hard sell and could backlash among most of the right‐wing policy makers due to their inherent tax aversion stance and other factors. It suggests that advocacy using a more negotiable approach could be a way forward. For example, “a gradual phased implementation” could offer a viable alternative following two successful case studies from the Philippines and Egypt under their right‐wing governments. The Philippines implemented the “Sin Tax Reform” an annual excise tax increase on (tobacco, alcohol, and SSBs) from 2012 onwards, while Egypt imposed annual tax increases on tobacco products since 2010 onwards. These phased approaches seemed to have gained more favourable consideration from right‐wing policy makers and contributed to smoking reduction in the Philippines but not in Egypt. In addition, some alternatives such as marketing restrictions on these products among other interventions could be considered. Context specific variations as well as the variations in readiness to adopt such fiscal policies for the health cause among the right‐wing political spectrum are acknowledged.

  7. Oral health and happiness after 3-years with causal mediation of oral functions

    Hazem Abbas, Kenji Takeuchi, Taro Kusama, Sakura Kiuchi, Katsunori Kondo, Ken Osaka

    Journal of Dentistry　162　106036-106036　2025/11

    Publisher: Elsevier BV

    DOI： 10.1016/j.jdent.2025.106036 　

    ISSN： 0300-5712

  8. Oral Health and Social Isolation After 6 Years: Mediation of Oral Functions

    Hazem Abbas, Kenji Takeuchi, Taro Kusama, Sakura Kiuchi, Ken Osaka

    Community Dentistry and Oral Epidemiology　2025/10/26

    Publisher: Wiley

    DOI： 10.1111/cdoe.70035 　

    ISSN： 0301-5661

    eISSN： 1600-0528

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    ABSTRACT Objectives Tooth loss was longitudinally associated with social isolation. The absence of dental prosthesis use was an additional risk factor. However, the mediating pathways for this association are unknown. The aim of this cohort study was to estimate the mediating effect of three oral functions: speaking, smiling and chewing observed at baseline on the association between oral health at baseline and social isolation after 6 years of follow‐up. Methods The 2010–2016 panel data from 6103 functionally independent participants aged ≥ 65 years who were not socially isolated at baseline was used from the Japan Gerontological Evaluation Study (JAGES). Causal mediation analysis using parametric logistic regression models was used to calculate the natural direct effect (NDE), the natural indirect effect (NIE), and the total effect. Social isolation was derived from a 5‐point index and dichotomised (0/3 = not isolated, 4/5 = isolated). The confounders observed at baseline were age, sex, educational attainment, income, activities of daily living, living area, and having depressive symptoms assessed using the geriatric depression scale (GDS‐15). Results The mean age of the participants was 72.4 years (SD = ±5.1), and 44.7% were males. Social isolation was observed at follow‐up among 3.6% of participants ( n  = 220). The cumulative incidence rate of socially isolated participants among those with ≥ 20 teeth was 2.9% increasing gradually to 3.2%, 3.5%, 3.7% and 7.2% among those with 10–19 teeth and used dental prosthesis, 10–19 teeth and did not use the dental prosthesis, 0–9 teeth and used dental prosthesis, and 0–9 teeth and did not use the dental prosthesis respectively. Compared with those with ≥ 20 teeth, having difficulty in speaking [NIE odds ratio (OR) = 1.02, 95% confidence interval (CI) = 0.93–1.11], problems in smiling (NIE OR = 1.02, 95% CI = 0.93–1.10) and difficulty in chewing (NIE OR = 1.04, 95% CI = 0.94–1.14) might have mediated the association for those with 10–19 teeth and used dental prosthesis as well as for those with 10–19 teeth without dental prosthesis (NIE OR = 1.02, 95% CI = 0.94–1.10), (NIE OR = 1.02, 95% CI = 0.93–1.11) and (NIE OR = 1.02, 95% CI = 0.93–1.11) respectively. While they might not have mediated the association for those with 0–9 teeth with and without dental prosthesis use. Conclusion With low precision and uncertain estimates, limited oral function might have mediated the association between tooth loss (10–19 with and without dental prosthesis use groups) and social isolation over 6 years. It was uncertain whether a mediation effect of oral functions was observed for those with 0–9 teeth with and without dental prosthesis use.

  9. AI-driven innovations for dental implant treatment planning: A systematic review

    Kyaw Zaww, Hazem Abbas, Juan Ramón Vanegas Sáenz, Guang Hong

    Journal of Prosthodontic Research　2025

    Publisher: Japan Prosthodontic Society

    DOI： 10.2186/jpr.jpr_d_24_00338 　

    ISSN： 1883-1958

    eISSN： 1883-9207

  10. Childhood socioeconomic status affects dental pain in later life Peer-reviewed

    Yamamoto T, Cooray U, Kusama T, Kiuchi S, Abbas H, Kondo K, Osaka K, Aida J

    Journal of Dental Research Clinical & Translational Research　2024/06

    DOI： 10.1177/23800844241271740 　

  11. Challenges and way forward for implementation of sugar taxation in the Middle East and North Africa (<scp>MENA</scp>)

    Hazem Abbas, Carol C. Guarnizo‐Herreño, Maha El Tantawi, Georgios Tsakos, Marco A. Peres

    Community Dentistry and Oral Epidemiology　2024/04/08

    Publisher: Wiley

    DOI： 10.1111/cdoe.12955 　

    ISSN： 0301-5661

    eISSN： 1600-0528

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    Abstract Background Over consumption of added sugar beyond the World Health Organization (WHO) recommended level of 10% of daily energy intake has well‐established negative health consequences including oral diseases. However, the average consumption of added sugar in the Middle East and North Africa region (MENA—World Bank's regional classification) is 70% higher than the WHO recommended level. Imposing taxes on added sugar has been proposed by the WHO to decrease its consumption. Yet, only 21.6% of the total MENA population are covered by taxation policies targeting added sugar. Challenges Well‐recognized challenges for the implementation of sugar taxation in MENA include the tactics used by the food and beverage industry to block these type of policies. However, there are also other unfamiliar hurdles specific to MENA. Historically, there have been incidents of protest and riots partially sparked by increased price of basic commodities, including sugar, in MENA countries. This may affect the readiness of policy makers in the region to impose added sugar taxes. In addition, there are also cultural, lifestyle and consumption behavioural barriers to implementing added sugar taxation. Ultra‐processed foods and sugar‐sweetened‐beverages (SSBs) rich in added sugar are perceived by many in MENA as essential treats regardless of their health risks. Furthermore, some countries even provide subsidies for added sugar. Also, (oral) healthcare providers generally do not engage in policy advocacy mainly due to limited training on health policy. Ways forward Here, we discuss these challenges and suggest some ways forward such as (1) support from a health‐oriented political leadership, (2) raising public awareness about the health risks of over consumption of sugar, (3) transparency during the policy‐cycle development process, (4) providing a free and safe environment for a community dialogue around the proposed policy, (5) training of (oral) healthcare professionals on science communication and policy advocacy in local lay language/dialect, ideally evidence informed from local/regional studies, (6) selecting the appropriate political window of opportunity to introduce a sugar tax policy, and (7) clear and strict conflict of interest regulations to limit the influence of commercial players on health policy.

  12. Estimating the prevalence of and clarifying factors associated with multiple tobacco product use in Japan: a cross-sectional study in 2022

    Takafumi Yamamoto, Hazem Abbas, Upul Cooray, Tetsuji Yokoyama, Takahiro Tabuchi

    Journal of Epidemiology　2024

    Publisher: Japan Epidemiological Association

    DOI： 10.2188/jea.je20240153 　

    ISSN： 0917-5040

    eISSN： 1349-9092

  13. Exposure to household dysfunction at childhood and later number of teeth among older Japanese adults: A life course study from the Japan Gerontological Evaluation Study. International-journal

    Hazem Abbas, Kenji Takeuchi, Sakura Kiuchi, Katsunori Kondo, Ken Osaka

    Journal of public health dentistry　83　(3)　299-308　2023/07

    DOI： 10.1111/jphd.12582 　

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    OBJECTIVES: The aim of this retrospective cohort study was to investigate the life course association between exposure to two household dysfunctions (father violence against mother and parental divorce) at childhood (≤18 years) with later number of remaining teeth (≥65 years) in functionally independent older Japanese population. This was the first study to investigate this research question in the Asian context. METHODS: The Japan Gerontological Evaluation study (JAGES) self-reported retrospective data gathered in 2013 was used (n = 21,604). Each household dysfunction was binary variable (Yes/No), while the five categories of the number of remaining teeth were ≥20, 10-19, 5-9, 1-4, and no teeth. Sex-stratified ordered logistic regression models were used to calculate the odds ratios (OR) of having fewer teeth. The models were adjusted for age, economic adversity in childhood, educational attainment, comorbidities, and smoking status. RESULTS: Overall, 46.4% were men and a total of 1149 participants (5.3%) experienced household dysfunction at childhood [men = 642 (6.4%), women = 507 (4.4%)]. The regression models showed higher OR of having fewer teeth among men who experienced a household dysfunction [OR = 1.16; 95% Confidence interval (CI) = 1.00-1.36] than men who did not. This association was not observed among women [OR = 0.94; 95% CI = 0.79-1.13]. Similar magnitude and direction of the association was observed among men but not among women when the two components of household dysfunction were used separately and aggregately as exposure variables. CONCLUSION: An exposure to a household dysfunction at childhood was associated with having fewer teeth in later life among men but not among women.

  14. The role of science communication and academic health advocacy in improving population oral health and tackling inequalities. International-journal

    Hazem Abbas, Kenji Takeuchi, Ken Osaka, Carol C Guarnizo-Herreño, Georgios Tsakos, Richard G Watt

    Community dentistry and oral epidemiology　2023/06/06

    DOI： 10.1111/cdoe.12882 　

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    Oral conditions are a public health problem globally and stark oral health inequalities exist between and within countries. Yet, oral diseases are rarely considered as a health priority and evidence-informed policy generation is challenging. Science communication and health advocacy are critical in that respect. However, due to time limitations, research workload and other factors, academics are usually hindered from participating in such lengthy endeavours. Here, we make the case that 'science communication and health advocacy task forces' should be a priority at academic institutions. The two main duties of these task forces are knowledge transfer about the burden of oral conditions and patterns of inequalities, and their underlying social and commercial determinants, and advocacy and mediation between the stakeholders involved directly or indirectly in policy making. These interdisciplinary task forces, including both academics and non-academics, should collectively have skills that include (1) knowledge about oral health, dental public health and epidemiology, (2) ability to communicate clearly and coherently and make the case in both lay and scientific language terms, (3) familiarity with digital and social media platforms and ability to create visual aids, videos and documentaries, (4) good negotiation skills and (5) maintaining scientific transparency and avoiding getting involved in confrontation with political parties. In the current context, the role of the academic institutions should not only be the production of knowledge, but also the active transferability and application of this knowledge towards public benefit.

  15. Association Between Toothbrushing Habits and COVID-19 Symptoms. International-journal

    Hazem Abbas, Kenji Takeuchi, Shihoko Koyama, Ken Osaka, Takahiro Tabuchi

    International dental journal　73　(2)　302-310　2023/04

    DOI： 10.1016/j.identj.2022.07.011 　

    ISSN： 0020-6539

    eISSN： 1875-595X

  16. Does remaining teeth and dental prosthesis associate with social isolation? A six-year longitudinal study from the Japan Gerontological Evaluation Study (JAGES). International-journal

    Hazem Abbas, Jun Aida, Upul Cooray, Takaaki Ikeda, Shihoko Koyama, Katsunori Kondo, Ken Osaka

    Community dentistry and oral epidemiology　51　(2)　345-354　2023/04

    DOI： 10.1111/cdoe.12746 　

    ISSN： 0301-5661

    eISSN： 1600-0528

  17. Oral status and homebound status: A 6‐year bidirectional exploratory prospective cohort study International-journal

    Hazem Abbas, Jun Aida, Sakura Kiuchi, Katsunori Kondo, Ken Osaka

    Oral Diseases　29　(3)　1291-1298　2023/04

    DOI： 10.1111/odi.14039 　

    ISSN： 1354-523X

    eISSN： 1601-0825

  18. Large Contribution of Oral Status for Death Among Modifiable Risk Factors in Older Adults: The Japan Gerontological Evaluation Study (JAGES) Prospective Cohort Study. International-journal

    Noriko Nakazawa, Taro Kusama, Upul Cooray, Takafumi Yamamoto, Sakura Kiuchi, Hazem Abbas, Tatsuo Yamamoto, Katsunori Kondo, Ken Osaka, Jun Aida

    The journals of gerontology. Series A, Biological sciences and medical sciences　78　(1)　167-173　2023/01/26

    DOI： 10.1093/gerona/glac052 　

    eISSN： 1758-535X

  19. Association among the number of teeth, dental prosthesis use, and subjective happiness: A cross-sectional study from the Japan Gerontological Evaluation study (JAGES). International-journal

    Hazem Abbas, Jun Aida, Katsunori Kondo, Ken Osaka

    The Journal of prosthetic dentistry　2022/04/19

    DOI： 10.1016/j.prosdent.2022.02.014 　

    ISSN： 0022-3913

    eISSN： 1097-6841

  20. Oral Status and Dementia Onset: Mediation of Nutritional and Social Factors

    S. Kiuchi, U. Cooray, T. Kusama, T. Yamamoto, H. Abbas, N. Nakazawa, K. Kondo, K. Osaka, J. Aida

    Journal of Dental Research　101　(4)　420-427　2022/04

    DOI： 10.1177/00220345211049399 　

    ISSN： 0022-0345

    eISSN： 1544-0591

  21. Factors associated with smoking behaviour changes during the COVID-19 pandemic in Japan: A 6-month follow-up study

    Takafumi Yamamoto, Hazem Abbas, Makiko Kanai, Tetsuji Yokoyama, Takahiro Tabuchi

    Tobacco Control　2022

    DOI： 10.1136/tc-2022-057353 　

    ISSN： 0964-4563

    eISSN： 1468-3318

  22. Examining the associations between oral health and social isolation: A cross-national comparative study between Japan and England International-journal

    Shihoko Koyama, Masashige Saito, Noriko Cable, Takaaki Ikeda, Taishi Tsuji, Taiji Noguchi, Hazem Abbas, Isao Miyashiro, Ken Osaka, Katsunori Kondo, Richard G. Watt, Jun Aida

    Social Science & Medicine　277　113895-113895　2021/05

    Publisher: Elsevier {BV}

    DOI： 10.1016/j.socscimed.2021.113895 　

    ISSN： 0277-9536

    eISSN： 1873-5347

  23. 口腔の健康と全身の健康の関連の文献レビューと因果推論手法の提案 ：口腔の健康と認知症のレビュー

    相田 潤, 山本貴文, 木内 桜, Hazem Abbas

    厚生労働科学研究費補助金（循環器疾患・糖尿病等生活習慣病対策総合研究事業） 分担研究報告書　2020

    Publisher: 厚生労働省

  24. Income or education, which has a stronger association with dental implant use in elderly people in Japan? International-journal

    Hazem Abbas, Jun Aida, Masashige Saito, Georgios Tsakos, Richard G. Watt, Shigeto Koyama, Katsunori Kondo, Ken Osaka

    International Dental Journal　69　(6)　454-462　2019/12/27

    Publisher: Wiley

    DOI： 10.1111/idj.12491 　

    ISSN： 0020-6539

    eISSN： 1875-595X

Show all ︎Show first 5

Presentations 4

  1. Exposure to household dysfunction at childhood and later number of teeth among older Japanese adults: A life course study from the Japan Gerontological Evaluation Study.

    2023/06/25

  2. Association Between Toothbrushing Habits and COVID-19 Symptoms.

    2022/06/20

  3. Does remaining teeth and dental prosthesis associate with social isolation? A six-year longitudinal study from the Japan Gerontological Evaluation Study (JAGES).

    2021/07/22

  4. Income or education, which has a stronger association with dental implant use in elderly people in Japan?

    2018/07/24

Research Projects 2

  1. Research grant for international students 2022

    Institution: Futokukai foundation

    2022/08 - 2023/03

  2. Tohoku University, Graduate School of Dentistry Travel Grant (2020)

Social Activities 6

  1. 査読者 Scientific Advisory Board member

    2025/01 - Present

  2. peer reviewer

    2024/05 - Present

  3. peer reviewer

    2023/07 - Present

  4. peer reviewer

    2023/07 - Present

  5. peer reviewer

    2021/06 - Present

  6. peer reviewer

    2018/10 - Present

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Media Coverage 4

  1. 高齢者における歯の本数と閉じこもりとの関連

    株式会社THF

    2022/01

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    東北大学大学院歯学研究科国際歯科保健学分野博士課程のハゼム・アッバス氏が、 歯の本数が20本未満の高齢者は、20本以上と比べて、６年後の閉じこもりが 1.42倍多くなることを公表した。外出頻度が週１回未満の状態である閉じこもりは、 社会的孤立や身体活動量の低下を招き、要介護リスクの増加などにつながる可能性がある。 アッバス氏らは、日本の13市町村が参加した日本老年学的評価研究のデータを使い、 2010年時点で要介護状態でない65歳以上の高齢者２万6579人を対象に、6年間の 追跡研究をおこなった。歯の本数と口腔機能が将来の閉じこもりと関連するかを 検討した結果、歯の本数が20本未満だと20本以上と比べて６年後の閉じこもりは 1.42倍多く、咀嚼困難はそうでない場合に比べて1.28倍多かった。 咀嚼困難や歯の本数が20本未満であることと閉じこもりとの関連の効果は、 年齢が70歳から75歳になることと同程度だった。

  2. 歯のインプラント治療 収入が高い人ほど受けている（約5倍）

    JAGES プレスリリース

    2020/03

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    歯のインプラント治療は、歯周病やむし歯の治療などで歯を抜くことになった場合に、人工の歯を植える有用な治 療方法です。日本では国民皆保険でカバーされていないため（自費治療のため）、高価な治療費を支払うのが難し い人では利用が少ないことが予想されますが、そのことを示すデータはありませんでした。世界的にもインプラント利 用の社会格差の研究はほとんどありません。 本研究では、65 歳以上の地域在住高齢者約 18 万人を調査し、所得や学歴によりインプラント治療の経験に差 があるか調べました。その結果、年齢や性別、地域の歯科医院の多さを考慮したうえで、収入が低い群に比べて高 い群で 4.85 倍、学歴が低い群に比べて高い群で 2.13 倍、インプラントを利用していました。インプラントは自費治 療であるため、収入が低い人が受けにくいという実態が客観的なデータで示されました。歯科治療の利用が収入で 変わってしまうという格差を解消するためには、保険診療の拡大が必要かもしれません。多様な新しい医療技術が 登場する中、どの医療技術を保険でカバーするのか、質調整生存年（QALY）を用いた客観的な検討が必要でしょ う。

  3. 歯数20本未満の高齢者 補綴物で幸福感増加－医科歯科大らが解明

    日本歯科新聞社

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    歯が20本未満の場合は、歯科補綴物を使用するか否かで幸福感に違いが出る－。東京医科歯科大学大学院医歯学総合研究科の相田潤教授と東北大学大学院歯学研究科の小坂健教授、ハゼム・アッバス大学院生らの研究グループが明らかにしたもの。

  4. 歯の健康 孤立防ぐ鍵に 高齢者２万６０００人を調査

    山陰中央新法デジタル