https://doi.org/10.1177/00220345211029277 Journal of Dental Research 1–8 © International & American Associations for Dental Research 2021 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/00220345211029277 journals.sagepub.com/home/jdr Research Reports: Clinical Introduction Social mobility refers to the movement of individuals across socioeconomic strata throughout the life course. In different periods of life, individual-level socioeconomic status (SES) has been associated with oral health (Costa et al. 2012; Schwendicke et al. 2015) via multiple putative mechanisms in a complex way, including access to dental care and behavioral and psychosocial factors (Listl et al. 2012). Severe tooth loss is more common among individuals of lower SES, and it imposes an enormous burden on people’s quality of life and high eco- nomic costs to health systems (Listl et al. 2015). Life course epidemiology provides a useful framework for understanding how health inequalities develop over time and can help to develop appropriate interventions as early as possi- ble. Three main social life course hypotheses have been pro- posed to explain such health inequalities: critical/sensitive period, accumulation of risks, and social trajectories/mobility (Ben-Shlomo and Kuh 2002). The social mobility hypothesis assumes that different trajectories affect health differently, incor- porating sensitive periods and accumulation hypotheses. If there is a sensitive time window, usually described as early life/child- hood, then the strongest effect will be observed among those exposed to that period. While upward mobility is equivalent to childhood lower status (revealing a sensitive period), downward mobility reflects a lower status in adulthood (revealing another possible sensitive period; Ben-Shlomo and Kuh 2002). Finally, the persistently lower SES group indicates the accumulation of disadvantage with possibly the highest disease level. Several studies have linked social trajectories with oral health, mainly tooth loss, and they usually show that people who are persistently lower in the social hierarchy have worse oral health (Bernabé et al. 2011; Peres et al. 2011; Åström et al. 2015; Delgado-Angulo and Bernabe 2015; Broadbent et al. 2016; Han and Khang 2017; Listl et al. 2018; Vendrame et al. 1029277JDR XX X 10.1177/00220345211029277Journal of Dental ResearchSocial Mobility and Tooth Loss research-article 2021 1 Department of Preventive and Social Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil 2 Aging Research Center, Karolinska Institutet and Stockholm University, Solna, Sweden 3 Department of Dentistry–Quality and Safety of Oral Health Care, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands 4 National Dental Research Institute Singapore, National Dental Centre Singapore, Singapore 5 Oral Health ACP, Health Services and Systems Research Programme, Duke-NUS Medical School, Singapore A supplemental appendix to this article is available online. Corresponding Author: R.K. Celeste, Departamento de Odontologia Preventiva e Social, Faculdade de Odontologia, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2492, 3° andar, Porto Alegre–RS–CEP 90035-003, Brazil. Email: roger.keller@ufrgs.br Social Mobility and Tooth Loss: A Systematic Review and Meta-analysis R.K. Celeste 1 , A. Darin-Mattsson 2 , C. Lennartsson 2 , S. Listl 3 , M.A. Peres 4,5 , and J. Fritzell 2 Abstract This study systematically reviews the evidence of the association between life course social mobility and tooth loss among middle-aged and older people. PubMed, Scopus, Embase, and Web of Science were systematically searched in addition to gray literature and contact with the authors. Data on tooth loss were collated for a 4-category social mobility variable (persistently high, upward or downward mobility, and persistently low) for studies with data on socioeconomic status (SES) before age 12 y and after age 30 y. Several study characteristics were extracted to investigate heterogeneity in a random effect meta-analysis. A total of 1,384 studies were identified and assessed for eligibility by reading titles and abstracts; 21 original articles were included, of which 18 provided sufficient data for a meta- analysis with 40 analytical data sets from 26 countries. In comparison with individuals with persistently high social mobility, the pooled odds ratios (ORs) for the other categories were as follows: upwardly mobile, OR = 1.73 (95% CI, 1.53 to 1.95); downwardly mobile, OR = 2.52 (95% CI, 2.19 to 2.90); and persistently low, OR = 3.96 (95% CI, 3.13 to 5.03). A high degree of heterogeneity was found (I 2 > 78%), and subgroup analysis was performed with 17 study-level characteristics; however, none could explain heterogeneity consistently in these 3 social mobility categories. SES in childhood and adulthood is associated with tooth loss, but the high degree of heterogeneity prevented us from forming a robust conclusion on whether upwardly or downwardly mobile SES may be more detrimental. The large variability in effect size among the studies suggests that contextual factors may play an important role in explaining the difference in the effects of low SES in different life stages (PROSPERO CRD42018092427). Keywords: socioeconomic factors, prevalence, epidemiology, social mobility, meta-analysis, dental public health