Background Malocclusion is a common oral health problem in schoolchildren. Literature describing the prevalence of malocclusion varies substantially across China. Aim This study identified the epidemiological characteristics of malocclusion among Chinese schoolchildren from 1991 to 2018. Design Six English and Chinese electronic databases were searched through November 2018. The search was supplemented by hand searching to identify relevant surveys. The overall prevalence of malocclusion was estimated by a random‐effects meta‐analysis model, and variations in different groups were assessed by subgroup meta‐analysis. Results Thirty‐seven eligible articles describing 117 682 samples were investigated. The pooled national prevalence for malocclusion was 47.92% (95% CI: 58.6%‐71.9%). For the Angle classification, the overall prevalence rates were 30.07% (95% CI: 25.37%‐35.48%), 9.91% (95% CI: 7.41%‐13.79%), and 4.76% (95% CI: 3.85%‐6.54%) for Class I, Class II, and Class III malocclusion, respectively. A deep overbite (16.67%, 95% CI: 11.50%‐23.08%) was shown to be the most common trait of malocclusion. When stratified by sex, males had a slightly higher prevalence than females (RR = 1.04, 95% CI: 1.01‐1.06). More importantly, an ascending trend and substantial variations across the country were observed. Conclusions Our results confirmed that malocclusion has become a serious oral health problem in Chinese schoolchildren, highlighting the need for proactive interventions at an early age. Moreover, high‐quality epidemiological studies on malocclusion are still required.

Objective This study intends to assess the prevalence of temporomandibular disorders and its clinical signs in Chinese students. Materials and Methods Search strategies were performed in seven electronic databases, and the reference lists from potentially relevant studies were searched manually. Only observational studies that met the eligibility criteria were selected. A validated instrument was used to evaluate the quality of the included studies. A random‐effects model was used to calculate the pooled prevalence of temporomandibular disorders and its clinical signs. Results Twenty‐three articles that met the eligibility criteria were included in this review and meta‐analysis. The prevalence of temporomandibular disorders was 29.1% (95% confidence interval [CI], 23.7–35.1; n = 12,702), and a significant difference was observed between males and females. The most prevalent sign was temporomandibular joint sounds (17.4%; 95% CI, 13.8–20.6; n = 6,615) followed by abnormal jaw movement (12.3%; 95% CI, 9.1–16.7; n = 5,496) and pain (9.9%; 95% CI, 7.4–13; n = 4,552). Conclusions The overall prevalence of temporomandibular disorders in Chinese students was approximately 29.1%, and a statistically significant difference was observed between males and females. The most prevalent sign was temporomandibular joint sounds (17.4%), followed by abnormal jaw movement (12.3%) and pain (9.9%).

Several genetic polymorphisms have been shown to affect the activity of taxanes. The most common gene reportedly associated with these effects is ATP-binding cassette transporter B subfamily member 1 (ABCB1), also

Background Temporary anchorage devices have been used for decades in orthodontic practice for many applications. The aim of this systematic review was to assess the effectiveness of orthodontic temporary anchorage devices in canine retraction during the two-step technique. Methods A search was systematically performed for articles published prior to June 30, 2019 in five electronic databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus). The risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials (RCTs) and the risk of bias in nonrandomized studies of interventions (ROBINS-I) tool for controlled clinical trials (CCTs). The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach was used for the quality assessment. Data concerning the mean difference in mesial molar movement and extent of canine retraction were extracted for statistical analysis. The mean differences and 95% confidence intervals were analyzed for continuous data. A meta-analysis with a random-effects model for comparable outcomes was carried out. Results Three RCTs and five CCTs were finally included. Meta-analysis showed a significant increase not only in anchorage preservation in the implant anchorage group in both the maxilla (1.56 mm, 95% CI: 1.14 to 1.98, P < 0.00001) and the mandible (1.62 mm, 95% CI: 1.24 to 2.01, P < 0.00001) but also in canine retraction in the implant anchorage group in both the maxilla (0.43 mm, 95% CI: 0.16 to 0.69, P = 0.001) and the mandible (0.26 mm, 95% CI: 0.02 to 0.49, P = 0.03). Conclusions There is very low-quality evidence showing that implant anchorage is more efficient than conventional anchorage during canine retraction. Additional high-quality studies are needed.

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy, characterized by the clonal expansion of myeloid blasts in the peripheral blood, bone marrow, and/or other tissues. The new drugs used for treating AML are facing a big challenge, and the candidates include cytotoxic drugs, targeted small-molecule inhibitors, and monoclonal antibodies. In recent years, active research has focused on several new agents for including them in the large antileukemic drug family. This review aims to introduce some of these new drugs and highlights new advances made in the old drugs, mainly in the last 5 years.

Medical students' perceptions of the medical school learning environment (MSLE) have an important impact on their professional development, and physical and mental health. Few studies reported potential factors that influenced medical students' perceptions of MSLE. Thus, the main goal of this study was to identify influencing factors for medical students' perception levels of MSLE. The perception levels of MSLE were assessed by the Johns Hopkins Learning Environment Scale. The univariate and multivariate logistic regression analyses were performed to identify significant predictors for the perceptions of MSLE. The nomograms were established to predict medical students' perception levels of MSLE. In the multivariate logistic regression model, gender, university category, grade, mother education level, learning environment of schools, interests in medicine, and Kolb learning experience were significantly associated with medical students' perceptions of MSLE. Correspondently, the nomograms were built based on significant variables identified by the univariate logistic regression analysis. The validation of the nomograms showed that the model had promising predictive accuracy, discrimination, and accordance (area under the curve (AUC) = 0.751). This study identified influencing factors of medical students' perceptions of MSLE. It is essential to implement corresponding interventions to improve medical students' perceptions.

Introduction: Dexmedetomidine and midazolam have become important approaches for the sedation of dental surgery. However, the comparison of these 2 drugs for the sedation of dental surgery has not been well established. We conduct a systematic review and meta-analysis to evaluate the efficacy of dexmedetomidine versus midazolam for dental surgery. Methods: PubMed, Embase, and the Cochrane Central Register of Controlled Trials are searched. Randomized controlled trials (RCTs) assessing the influence of dexmedetomidine versus midazolam on dental surgery are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. Meta-analysis is performed using the random-effect model. Results: Five RCTs and 420 patients are included in the meta-analysis. Compared with midazolam intervention for dental surgery, dexmedetomidine intervention has similar lowest SpO 2 , lowest heart rate and lowest systolic blood pressure, duration of surgery, and total volume of local anesthetic, but is associated with stable and reduced lowest diastolic blood pressure. Conclusions: Similar benefits of dexmedetomidine and midazolam intervention are observed for the sedation of dental surgery in terms of SpO 2 , heart rate, systolic blood pressure, and the volume of local anesthetic, but dexmedetomidine may result in more stable diastolic blood pressure.

Background: To assess the effectiveness of orthodontic temporary anchorage devices in canine retraction during two-step technique. Methods: The search was systematically performed up to June 2019 in five electronic databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus). A risk of bias assessment was performed using the Cochrane Risk of Bias Tool for Randomized Controlled Trials (RCTs) and the Risk of Bias in Nonrandomized Studies - of Interventions (ROBINS-I) tool for controlled clinical trials (CCTs) . The Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach was applied for quality assessment. Data concerning the mean difference in mesial molar movement and extent of canine retraction were extracted for statistical analysis. The mean difference and 95% confidence interval were analyzed for continuous data. A meta-analysis with a random-effects model for comparable outcomes was carried out. Results: Three RCTs and five CCTs were finally included. Meta-analysis showed a significant increase not only in anchorage preservation in the implant anchorage group in both the maxilla (1. 56 mm , 95% CI: 1.14 to 1.98, P <0.00001 ) and the mandible (1.62 mm , 95% CI: 1.24 to 2.01, P <0.00001 ) but also in canine retraction in the implant anchorage group in both the maxilla (0.43 mm , 95% CI: 0.16 to 0.69, P =0.001 ) and the mandible (0.26 mm , 95% CI: 0.02 to 0.49, P =0.03 ). Conclusions: Very low-quality evidence shows that implant anchorage is more efficient than conventional anchorage during canine retraction. Further high-quality studies are needed.