Hao Zhang

Introduction and aims: Growing evidence indicates that early childhood oral health, particularly dental caries, may be associated with children’s cognitive development; however, findings remain inconsistent, especially in preschool-aged populations. This study aimed to examine the associations between early childhood caries and intelligence quotient (IQ) in four-year-old children. Method: This study used a cross-sectional design based on data from 1,099 four-year-old children in the Shanghai Birth Cohort. Oral health measurements included the decayed, missing, filled teeth (dmft) index, and caries status. Child IQ was assessed using the fourth edition of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV). Multivariable linear regression models were used to estimate the associations between oral health indicators and child IQ. Restricted cubic spline models were used to assess non-linear relationships. Results: Higher dmft index scores were significantly associated with lower full scale intelligence quotient (FSIQ) scores ( β = −0.25; 95% CI: −0.48, −0.03) and verbal comprehension index (VCI) scores ( β = −0.31; 95% CI: −0.56, −0.05) after adjusting for potential confounders. Consistently, children with caries showed significantly lower FSIQ scores than those without caries ( β = −1.59; 95% CI: −3.01, −0.18). Conclusion: Dental caries, particularly as measured by the dmft index, was associated with lower IQ scores in preschool children. These findings should be interpreted as population-level associations rather than deterministic outcomes for individual children. Longitudinal studies are needed to confirm these findings and clarify the mechanisms linking early oral health and neurocognitive development.

Background/Objectives: Current approaches to monitoring obstructive sleep apnea (OSA) risk primarily focus on structural or functional abnormalities, often neglecting systemic metabolic and physiological factors. Resource-intensive methods, such as polysomnography (PSG), limit their routine applicability. This study aimed to evaluate composite nutritional-inflammatory indices derived from routine blood markers to identify feasible indices for OSA management and explore their association with OSA risk. Methods: Data from 9622 adults in the NHANES (2015–2020) and GWAS datasets were analyzed using logistic regression, restricted cubic splines, machine learning, and Mendelian randomization (MR). These techniques were employed to identify nutritional-inflammatory indices associated with OSA risk. Random forest modeling identified body mass index (BMI) and albumin (ALB) as key components of the advanced lung cancer inflammation index (ALI). Causal relationships between ALI components and OSA were validated using MR. Results: ALI was significantly associated with OSA, with individuals in the highest ALI tertile exhibiting a 59% higher likelihood of OSA (OR = 1.59, 95% CI: 1.38–1.84; p < 0.001). BMI and ALB were identified as key contributors to ALI and confirmed as causal risk factors for OSA (BMI: OR = 1.91, 95% CI: 1.80–2.02; ALB: OR = 1.11, 95% CI: 1.04–1.19). Age, gender, and the neutrophil-to-lymphocyte ratio (NLR) were also significant predictors. Conclusions: This study identifies ALI as a potential composite index for assessing OSA risk. Integrating statistical modeling, machine learning, and causal inference techniques highlights the utility of nutritional-inflammatory indices in improving OSA monitoring and management in clinical practice.

Triclosan (2,4,4′-trichloro-2′-hydroxy-diphenyl ether, TCS) is widely used in personal care and household products. It is ubiquitous across the ecosystem nowadays. Several in vitro and in vivo studies have suggested the possible adverse effects of TCS on male reproductive health. However, little research has been done on human beings, especially in eastern countries. To assess the effects of TCS exposure on male fecundity, we recruited couples who planned to conceive and went to the preconception care clinics for physical examination in Shanghai, China. TCS was quantified in male urine samples collected at enrollment. For this study, 443 couples were included in the cohort, and 74.7% of couples (n = 331) were prospectively followed 12 months later. The outcomes of interest included the pregnancy status of their wives and time to pregnancy. Elevated male urinary TCS concentrations were found to be associated with diminished fecundability (fecundability odds ratio (FOR) 0.77; 95% CI, 0.62–0.97). The risk of infertility significantly increased (OR = 1.6; 95% CI, 1–2.6) as TCS levels elevated. Besides, we divided TCS concentration into tertiles a priori, and there tended to be a dose-response pattern in both analyses. Our findings suggest that environmental exposure to TCS may have an adverse impact on male fecundity.

Periodontal diseases and poor oral hygiene are potentially associated with decreased female fecundability. Fecundability refers to the probability of conception during a given period measured in months or menstrual cycles. This study aims to examine whether halitosis is associated with female fecundability in a large sample of Chinese women who planned to be pregnant. In 2012, a total of 6319 couples came for preconception care in eight districts in Shanghai, China and were followed by telephone contact. Three thousand nine hundred fifteen women who continued trying to be pregnant for up to 24 months remained for final statistical analyses. Halitosis was self-reported at the preconception care visit. Time to pregnancy (TTP) was reported in months and was censored at 24 months. Fecundability ratio (FR) was defined as the ratio of probability of conception among those with and without halitosis. FR and 95% confidence interval (CI) were estimated using the discrete-time Cox model. 80.1 and 86.1% of women had self-reported clinically confirmed pregnancy within 12 and 24 months, respectively. Halitosis was reported in 8.7% of the women. After controlling for potential confounders, halitosis was associated with a reduced probability of spontaneous conception (for an observation period of 12 months: adjusted FR 0.82, 95% CI 0.72–0.94; for an observation period of 24 months: adjusted FR 0.84, 95% CI 0.74–0.96). Halitosis is associated with reduced fecundability in Chinese women.

Objective: To investigate the disparity in dental caries between native and migrant children in Shanghai, China.Methods: Between 2013 and 2015, a random cluster sample of native and migrant children aged 5, 9, 12 and 15 years was collected from each district in Shanghai. Oral examination was performed following the World Health Organization (WHO) method, and findings were reported as decayed‐missing‐filled teeth of primary dentition (dmft) and permanent dentition (DMFT).Results: A total of 10 150 children were examined, and 33.6% of them were migrants. Migrant children had a higher prevalence of deciduous caries than native children (the 5‐year‐old age group, 67.8% vs 63.0%, P = 0.024; the 9‐year‐old age group, 75.9% vs 66.1%, P < 0.001), and higher dmft values were found in migrant children. But with respect to permanent teeth, no statistical differences were found between the two groups in caries prevalence or DMFT. After controlling for potential confounders by logistic regression, migrant children showed a higher risk of deciduous caries (odds ratio 1.42, 95% confidence interval 1.25‐1.61, P < 0.001) but not of permanent caries. Migrant children exhibited relatively lower deciduous Restorative Care Index (RCI). However, 9‐ and 15‐year‐old migrant children had a higher permanent RCI than their native counterparts.Conclusions: Dental caries prevalence in migrant children was higher in the deciduous teeth but not in the permanent teeth compared to that in their native counterparts. School‐based dental public health services may contribute to reducing the disparity in dental health status between migrant and native children.

The aim of the present study was to obtain the prevalence of malocclusions in preschool children in Shanghai, China. A cross-sectional survey was conducted among 2335 children aged 3–5 years from kindergartens. Several occlusal parameters were clinically assessed, including second deciduous molar terminal plane, canine relationship, degree of overjet and overbite, anterior and posterior crossbite, and the presence or absence of physiologic spaces and crowding. All parents of subjects were asked to fill in the oral health knowledge questionnaires. The prevalence of malocclusion in primary dentition in Shanghai was 83.9%, and no significant differences were found in genders. Data showed that the prevalence of deep overbite (63.7%) was the highest in children with malocclusion, followed by deep overjet (33.9%), midline deviation (26.6%), anterior crossbite (8.0%) and anterior crowding (6.5%). The results revealed a high prevalence of malocclusion in primary dentition in children aged 3–5 years old of Shanghai, especially in vertical anomalies. The need for preventive orthodontic therapy is extremely desired and oral health education about malocclusion should be strengthened.

Triclosan (2,4,4′-trichloro-2′-hydroxy-diphenyl ether, TCS) is widely used in personal care, household, veterinary and industrial products. It was considered as a potential male reproductive toxicant in previous in vitro and in vivo studies. However, evidence from human studies is scarce. Our study aims to investigate the relationship between TCS exposure and semen quality. We measured urinary TCS concentrations in 471 men recruited from a male reproductive health clinic. TCS was detected in 96.7% of urine samples, with a median concentration of 0.97 ng (mg·creatinine)⁻¹ (interquartile range, 0.41–2.95 ng (mg·creatinine)⁻¹). A multiple linear regression analysis showed a negative association between natural logarithm (Ln) transformed TCS concentration (Ln-TCS) and Ln transformed number of forward moving sperms (adjusted coefficient β = −0.17; 95% confidence interval (CI) (−0.32, −0.02). Furthermore, among those with the lowest tertile of TCS level, Ln-TCS was negatively associated with the number of forward moving sperms (β = −0.35; 95% CI (−0.68, −0.03)), percentage of sperms with normal morphology (β = −1.64; 95% CI (−3.05, −0.23)), as well as number of normal morphological sperms, sperm concentration and count. Our findings suggest that the adverse effect of TCS on semen quality is modest at the environment-relevant dose in humans. Further studies are needed to confirm our findings.