Background Several studies have assessed the relationship between type 2 diabetes (T2D) and tooth loss; however, results have been inconsistent. Therefore, the present systematic review and meta-analysis of observational studies was designed to examine the association between T2D and tooth loss. Methods This systematic review and meta-analysis was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guideline. We searched all the relevant studies in international databases of Scopus, PubMed, ProQuest, Web of Science, Cochrane Library, and Google scholar search engine until February 2022. The heterogeneity of the studies was calculated using the I2 index. Measure of effect and 95% confidence interval (CI) were extracted from each study. The results of the study were analyzed using the random effects model. Results In the present study, 22 eligible studies were included. Meta-analysis of unadjusted and adjusted results showed that T2D significantly increased the risk of tooth loss, and Odds Ratio (OR) unadjusted was 1.87 (95% CI: 1.62–2.13, p < 0.001), and OR adjusted was 1.20 (95% CI: 1.10–1.30, p < 0.001), respectively. Subgroup analysis based on study design for adjusted OR indicated that in the cohort study (OR: 1.29, 95% CI: 1.07–1.51), in the cross-sectional study (OR: 1.15, 95% CI: 1.06–1.23), and in the case-control study (OR: 5.10, 95% CI: 1.01–9.18) there was a significant association between T2D and tooth loss. Other subgroups analyses showed consistent results and no publication bias existed. Conclusions The findings suggest that T2D is associated with increased risk of tooth loss. This conclusion may provide useful evidence for correlated clinical researches.

In forensic medicine, it is important to identify whole or fragmented bodies. This aim can be particularly challenging in mass disasters. Palatal rugae patterns can be used as a surrogate parameter in forensic medicine. This stems from the difficulty in falsifying these patterns, their resistance to trauma, to decomposition for several days postmortem, and to combustion under high-temperatures, as well as being distinguishable among different races. The present study aimed to analyze the differences in the palatal rugae patterns among three Iranian ethnicities (Fars, Turkmen, and Sistani). This retrospective study involved the use of archived materials. The study casts were selected from the database of patients who visited a private orthodontics clinic. A total of 309 dental casts (103 Fars, 103 Turkmen, and 103 Sistani) were assessed, which belonged to 181 females and 128 males aged between 12 and 30 years (mean: 16.86 ± 3.18 years). The difference in the mean number of palatal rugae in women between the three ethnicities was statistically significant. Also, the differences in the total number of straight rugae were significant between the three ethnic groups. The most common rugae shapes in the three ethnic groups were the straight and wavy shapes. The length of the palatal rugae in the primary and secondary rugae among the study subjects younger than 18-years-old was significantly different between the three ethnic groups. Thus, the present research highlighted the differences in palatal rugae patterns among three Iranian ethnicities. Therefore, palatal rugae can be used in forensic medicine as a complementary approach to human identification.

Background: Although dental care attendance during pregnancy has been recommended by guidelines and institutions, the demand for dental services is still low among pregnant women. The aim of this study was to examine the prevalence of not receipt dental care and also determinants of that during pregnancy. Materials and Methods: This population-based study was conducted on 4071 mothers in 10 provinces of Iran, during 2014–2015. We calculated the prevalence of not receipt of dental care, and reasons for nonreceipt of care. We used logistic regression to estimate odds of nonreceipt of care by demographics variables. In the analyses, the level of statistical significance was set at P < 0.05. Results: Overall, 54.70% of women had no dental visit during pregnancy. In mothers who had a history of stillbirth, neonatal death and live birth, the prevalence of not receipt dental care during pregnancy were 54.56%, 48.92%, and 58.76%, respectively. The logistic regression analyses showed that parity second-to-fourth birth than first birth (odds ratio [OR] 1.37 confidence interval [CI] 95% 1.17–1.59, residence in rural (OR 1.68 CI 95% 1.45–1.95), and not intended pregnancy (OR 1.32 CI 95% 1.03–1.68) associated with not received dental care during pregnancy. Conclusion: Most pregnant women in this study received insufficient dental care. The need for dental care during pregnancy must be promoted widely among women of reproductive age, and family barriers to dental care should be addressed.