Association between Maternal Smoking during Pregnancy and Missing Teeth in Adolescents

Oral health and smoking in Bandare-Kong cohort study: a cross-sectional population-based study (findings from PERSIAN cohort study)

Considering the harmful effects of smoking on oral and dental health, our aim was to investigate the oral and dental health status of people in the city of Bandare-Kong, Iran, and its relationship to smoking. This cross-sectional population-based study used baseline data from the Bandare-Kong Cohort Study. A total of 4063 participants aged 35-70 years were included in this study. Using Stata17 software, negative binomial regression was employed to identify factors related to the decayed, missing, and filled teeth (DMFT) index. The association between smoking status and DMFT was assessed by the adjusted incidence rate ratio (IRR). Of the 4063 participants, 987 (24.29%) used cigarettes, hookahs, or both. The mean ± standard error (SE) DMFT index in all subjects was 11.08 ± 0.15; it was 14.17 ± 0.53 for cigarette smokers and 12.39 ± 0.37 for hookah users (p < 0.001). After adjusting for other variables, the rate of DMFT for cigarette smokers was 0.33 (IRR: 1.33; 95% confidence interval [CI]: 1.22, 1.44), which was higher than for those who did not use cigarettes. The rate of DMFT for those who used cigarettes, hookahs, or both was 0.11 (IRR: 1.11; 95% CI: 1.05, 1.18), which was also higher than for those who did not smoke. Cigarette smoking is a risk factor for oral health complaints. Although the rate of DMFT was increased in hookah smokers, it was not a predictor of dental problems. However, we suggest that hookah use be included in educational policies to control oral and dental diseases.

Possible role of superoxide dismutase 3 in hypoxia-induced developmental defects in murine molars

OBJECTIVES

To investigate the effects of hypoxia on tooth germ development in mice and explore the underlying mechanisms.

METHODS

Tooth germs were extracted from E14.5 mouse embryos and divided into the control and hypoxia groups for organ culture. The hypoxia group was exposed to hypoxia (0% oxygen) for 3 h, followed by normoxia for 21 h. After 2 or 7 days, samples were collected for morphometric analysis, reverse transcription-quantitative polymerase chain reaction, immunohistochemistry (IHC), and immunofluorescent staining (IF). Additionally, superoxide dismutase 3 (SOD3) expression patterns in mandibular molar tooth germs from C57BL/6 mouse embryos were analyzed using IHC. The SOD inhibitor sodium N, N-diethyldithiocarbamate trihydrate (DETC; 400 μM) was applied under normoxia for 3 days, followed by morphometry, IHC, and IF.

RESULTS

After 7 days, the hypoxia group exhibited significantly smaller tooth size, fewer cusps, reduced cell proliferation, and increased apoptosis in the epithelium compared to the control group. Sod3 mRNA expression was higher than other Sod family member expressions in the control group. In the hypoxia group, Sod3 mRNA and SOD3 protein expression were significantly decreased, whereas hypoxia-inducible factor-1 expression and reactive oxygen species levels were increased. SOD3 was primarily expressed in the dental epithelium from E12.5 to E17.5. DETC impaired tooth germ development in the control group, resulting in a phenotype similar to that of the hypoxia group, and significantly reduced amelogenin and msh homeobox 2 expression in the epithelium.

CONCLUSIONS

Hypoxia impairs tooth germ development. SOD3 probably plays a protective role during this process.

Associations of Prenatal Vitamin D status with Oral Health in Offspring: A Systematic Review

PURPOSE

The aim of this work is to evaluate the impact of prenatal vitamin D levels on oral health in offspring.

MATERIALS AND METHODS

The search was carried out in three databases: MEDLINE (PubMed), ResearchGate and Wiley Online Library. The inclusion criteria were randomised controlled trials and cohort studies published between June 16, 2017 and June 16, 2022, laboratory assessment of prenatal vitamin D status and evaluation of primary or mixed dentition for observation of dental caries and developmental defects of enamel. The risk of bias for randomised controlled trials was analysed according to the Cochrane risk-of-bias tool and Newcastle-Ottawa scale was used to assess risk of bias for cohort studies.

RESULTS

A total of 177 studies were identified, 11 were included in the data synthesis. Eight out of 11 studies were considered as high quality and the other 3 studies had moderate risk of bias. The synthesis of data revealed that the impact of prenatal vitamin D status on oral health in children is quite controversial and subsequent studies are necessary to examine whether vitamin D levels affect the risk of developing dental caries and enamel defects.

CONCLUSION

The effect of prenatal vitamin D on oral health in offspring is not entirely clear. Since disturbances in dental hard tissues have a polyetiological origin, health specialists need to notify mothers about other possible risk factors and emphasise the importance of eating habits and individual oral hygiene in early childhood.

Association between Smoking during Pregnancy and Short Root Anomaly in Offspring

Short root anomaly (SRA) is a dental anomaly with short dental roots and its pathogenesis is poorly understood. This study investigated the association between maternal smoking during pregnancy and SRA in offspring. A survey was conducted on 558 children aged 8–16 years from two public schools in Ulaanbaatar, Mongolia. SRA was diagnosed using cases with a root-crown ratio of maxillary central incisors of ≤1.0. A questionnaire survey was conducted to assess maternal lifestyle habits. Multiple logistic regression was used to analyse the association between maternal smoking during pregnancy and SRA in offspring after adjusting for possible confounders. The prevalence of SRA in these children was 14.2%. Children whose mothers smoked from pregnancy to date were found to be 4.95 times (95% confidence interval [CI]: 1.65–14.79) more likely to have SRA than those whose mothers never smoked, after adjusting for possible confounders. Additionally, children whose mothers had been exposed to passive smoking during pregnancy were found to be 1.86 times (95% CI: 1.02–3.40) more likely to have SRA than those whose mothers had not been exposed to passive smoke. Our population-based study suggests that maternal and passive smoking exposure during pregnancy can affect tooth root formation in children.