Yemeni dental and medical students have shown markedly poor oral health attitude and behavior. Further studies are required to reveal possible shortcoming in these schools' education process. Dental and medical curricula should emphasize the importance of proper oral hygiene, and further participation of medical and dental students in oral hygiene seminars is highly encouraged.

Background This systematic review of randomized clinical trials aimed to evaluate the available evidence regarding the efficacy of propolis-based mouthwash on dental plaque and gingival inflammation. Methods PubMed, Scopus, and Web of Science databases were searched up to November 2019. Clinical trials that evaluated the efficacy of propolis mouthwashes compared with chlorhexidine (CHX) were included. The primary outcomes comprised dental plaque and/or gingival inflammation. Two authors assessed the risk of bias using the Cochrane tool. Due to marked heterogeneity of the available data, studies were assessed qualitatively, and no metaanalysis was performed. Results Nine clinical trials, comprising 333 subjects, fulfilled the eligibility criteria. Most of the included studies showed high risk of bias. Overall, propolis mouthwashes showed good efficacy on plaque and gingivitis in all of the included studies. Out of the eight studies that reported on plaque index, 5 studies found equal efficacy of propolis and CHX in reducing plaque, two studies found superior efficacy in favor of CHX, while one study found superior efficacy in favor of propolis. Six studies assessed gingival inflammation outcome, four of which reported better results with propolis, while two studies reported comparable results. Conclusions The results suggest that propolis-based mouthwashes have potential benefits in reducing plaque and gingival inflammation. However, methodological limitations along with small sample sizes in some of the included studies weaken the strength of the evidence. Therefore, further well-designed clinical trials with large sample sizes and adequate follow-up period are recommended to discern the efficacy of propolis mouthwash on plaque and gingivitis.

Objectives E-cigarette use has become popular, particularly among the youth. Its use is associated with harmful general and oral health consequences. This survey aimed to assess self-reported oral hygiene practices, oral and general health events, and changes in physiological functions (including physical status, smell, taste, breathing, appetite, etc.) due to E-cigarette use among dental students. Methods This online, multicounty survey involved undergraduate dental students from 20 dental schools across 11 different countries. The questionnaire included demographic characteristics, E-cigarette practices, self-reported complaints, and associated physiological changes due to E-cigarette smoking. Data were descriptively presented as frequencies and percentages. A Chi-square test was used to assess the potential associations between the study group and sub-groups with the different factors. Statistical analysis was performed using SPSS at P < 0.05. Results Most respondents reported regular brushing of their teeth, whereas only 70% used additional oral hygiene aids. Reported frequencies of complaints ranged from as low as 3.3% for tongue inflammation to as high as 53.3% for headache, with significant differences between E-cigarette users and non-users. Compared to non-smokers, E-cigarette users reported significantly higher prevalence of dry mouth (33.1% vs. 23.4%; P < 0.001), black tongue (5.9% vs. 2.8%; P = 0.002), and heart palpitation (26.3%% vs. 22.8%; P = 0.001). Although two-thirds of the sample reported no change in their physiological functions, E-cigarette users reported significant improvement in their physiological functions compared to never smokers or tobacco users. Conclusion Dental students showed good oral hygiene practices, but E-cigarette users showed a higher prevalence of health complications.

Background: Orofacial cleft is among the most common developmental malformations in humans. This study aimed to identify the relationship between environmental factors and nonsyndromic cleft lip and/or palate (NSCL/P) in Northwest China. Methods: This case-control study was conducted in Gansu Province, China over two years (Jan. 1, 2017–Jan. 1, 2019). Overall, 600 NSCL/P cases and 660 normal control cases were finally enrolled in the current study. Data were collected by conducting face-to-face interviews with both parents of each case. Results: Univariate (χ2) analysis revealed 22 factors as being significantly associated with NSCL/P. Multivariate (stepwise logistic regression) analysis identified that 14 factors had statistically significant association with NSCL/P. Male gender (OR=0.789), paternal age at childbirth of 25-29 yr (OR=0.690), and folic acid supplement (OR=0.197) were found to be protective factors against NSCL/P. On the other hand, blood A-type, multiple births, positive family history of NSCLP (OR=6.660), parental consanguinity (OR=6.107), positive abortion history, high or low maternal childbearing age, and maternal passive smoking (OR=4.349), malnutrition (OR=4.431), infections, and drug use (OR=2.188) during early gestation were significant risk factors for NSCL/P. Conclusion: Parental age at childbirth of 25–29 yr, and folic acid supplement can reduce the risk of NSCL/P. By contrast, maternal passive smoking, infections, and drug use during early gestation period, and multiple births, parental consanguinity, positive family history, and maternal abortion history can increase the risk of NSCL/P. Identification of risk factors is essential in minimizing the incidence of NSCL/P in a particular population.

Background: Tongue examination helps considerably in diagnosing the un derlying health state of the patient, especially in the cases of chronic diseases. The aim of this study is to determine the prevalence and association of tongue lesions with risk factors among Yemeni dental patients. Materials and methods: An oral medicine specialist examined all 713 patients attending the dental polyclinics at the University of Sciences and Technology (Sana'a, Yemen). The examination sheet was designed to include information related to patient characteristics, medical history, dental history, habits, and tongue lesions. Results: The prevalence of tongue lesions among the examined participants was 76.5%. The prevalence rate was 83.4% for males and 69.2% for females. Fissured tongue was the most common condition. Logistic regression analysis indicated that older age (p<0.001), gender (p=0.007), khat chewing (p<0.001), and smoking (p=0.001) were associated with fissured tongue; gender (p<0.001), khat chewing (p<0.001), and smoking (p<0.001) were associated with hairy tongue; and older age (p<0.001), khat chewing (p=0.001), and smoking (p=.021) were associated with coated tongue. Conclusion: The prevalence of tongue lesions among this sample of Yemeni population was 76.5%; fissured tongue and hairy tongue were the most prevalent lesions. Khat chewing, smoking, and older age were the associated risk factors for many of studied lesions and anomalies.