Clinical application of a digital semi-rigid bridge space maintainer fabricated from polyetheretherketone for premature loss of primary molars.

BACKGROUND: Premature loss of primary molars can be treated with a band loop space maintainer (SM). However, fabricating a conventional band loop SM requires multiple clinical and laboratory procedures, which can potentially affect the accuracy of the SM. Moreover, the conventional SM is unable to fully restore masticatory function and maintain the vertical dimension of the edentulous space. In this current study, a fully digital workflow to fabricate a semi-rigid bridge SM made from polyetheretherketone (PEEK) has been described and evaluated for its clinical effectiveness. METHODS: A total of 15 children (eight males and seven females) between the ages of 4-8 years, who experienced the premature loss of a single primary molar, were included in this study. Digital impressions were taken using the CEREC CAD/CAM chair system and imported into CAD software to design the semi-rigid bridge SM, which was fabricated using PEEK block as the maintainer material. The digital SM was tried-in and bonded to the abutment with resin cement. The edentulous space was measured immediately after bonding (T0) and 1 month (T1), 3 months (T2), and 6 months (T3) after treatment. The periodontal condition and mobility of the SM and abutment were also examined. RESULTS: The use of digital impressions resulted in a decreased occurrence of the pharyngeal reflex. The digital semi-rigid bridge SM, fabricated with PEEK, was both convenient and aesthetically pleasing, and successfully restored the anatomy and masticatory function of the missing primary molar. None of the 15 semi-rigid bridge SMs or abutments became loose or fell off during the study, and only one child presented with gingivitis. Furthermore, the difference in the edentulous space at T0, T1, T2, and T3 was not statistically significant (all P > 0.05). CONCLUSIONS: The digital semi-rigid bridge SM fabricated with PEEK was clinically effective in maintaining the missing space and had advantages over the traditional band/crown loop SM.

Cross attention guided multi-scale feature fusion for false-positive reduction in pulmonary nodule detection.

False-positive reduction is a crucial step of computer-aided diagnosis (CAD) system for pulmonary nodules detection and it plays an important role in lung cancer diagnosis. In this paper, we propose a novel cross attention guided multi-scale feature fusion method for false-positive reduction in pulmonary nodule detection. Specifically, a 3D SENet50 fed with a candidate nodule cube is applied as the backbone to acquire multi-scale coarse features. Then, the coarse features are refined and fused by the multi-scale fusion part to achieve a better feature extraction result. Finally, a 3D spatial pyramid pooling module is used to enhance receptive field and a distributed aligned linear classifier is applied to get the confidence score. In addition, each of the five nodule cubes with different sizes centering on every testing nodule position is fed into the proposed framework to obtain a confidence score separately and a weighted fusion method is used to improve the generalization performance of the model. Extensive experiments are conducted to demonstrate the effectiveness of the classification performance of the proposed model. The data used in our work is from the LUNA16 pulmonary nodule detection challenge. In this data set, the number of true-positive pulmonary nodules is 1,557, while the number of false-positive ones is 753,418. The new method is evaluated on the LUNA16 dataset and achieves the score of the competitive performance metric (CPM) 84.8%.

Validity of Broselow tape for estimating the weight of children in pediatric emergency: A cross-sectional study.

Objective: To assess the validity of the Broselow tape in estimating the weight of Chinese children in pediatric emergency. Methods: A cross-sectional study was conducted in the emergency department of the Children's Hospital of Zhejiang University School of Medicine (Hangzhou, Zhejiang Province, China) in March 2022. Broselow tape was used to estimate weight and its validity was compared with the advanced child life support (APLS) method. Results: The study included 442 children (mean age: 48 months; male-to-female ratio: 1.13:1). The < 10, 10-19 and > 19-kg groups included 44, 257, and 141 children, respectively. The color concordance rates of the Broselow tape-estimated weight in the three groups were 56.8, 57.2, and 68.1%, respectively. The percentage of weight estimations within 10% of actual weight were 65.8% (59.1, 65.8, and 68.1% for the <10, 10-19 and > 19-kg groups, respectively) and 44.8% (40.9, 50.6, and 35.5% for the < 10, 10-19 and > 19-kg groups, respectively) using the Broselow tape and the APLS method, respectively. The correlation between the Broselow tape estimated weight and actual weight was r = 0.931 (P < 0.0001, 95% CI: 0.918-0.943), while the correlation between actual weight and the APLS method calculated weight was r = 0.883 (P < 0.0001, 95% CI: 0.861-0.902). The mean percentage error using the Broselow tape was 1.0 ± 12.0% (P < 0.001 vs. -7.2 ± 17.2% of the APLS method). Conclusion: The Broselow tape may be an available method for predicting the weights of Chinese children in pediatric emergency.

Spontaneous healing of complicated crown-root fractures in children: Two case reports.

BACKGROUND: Complicated crown-root fracture is considered a severe dental trauma and is unlikely to heal without treatment. Usually, dentists have to remove the loose coronal fragment of the fractured tooth and treat the remaining part with multidisciplinary approaches. However, we observed spontaneous healing of fracture in two pediatric cases with a history of complicated crown-root fractures over 4 years ago. CASE SUMMARY: In case 1, a 12-year-old boy complained of pain at tooth 11 following an accidental fall 1 d ago. Clinical examination showed a crack line on the crown of tooth 11. Cone beam computed tomography (CBCT) images of tooth 11 showed signs of hard tissue deposition between the fractured fragments. The patient recalled that tooth 11 had struck the floor 1 year ago without seeking any other treatment. In case 2, a 10-year-old girl fell down 1 d ago and wanted to have her teeth examined. Clinical examination showed a fracture line on the crown of tooth 21. CBCT images of tooth 21 also showed signs of hard tissue deposition between the fractured fragments. She also had a history of dental trauma 1 year ago and her tooth 11 received dental treatment by another dentist. According to her periapical radiograph at that time, tooth 21 was fractured 1 year ago and the fracture was overlooked by her dentist. Both of these two cases showed spontaneous healing of complicated crown-root fractures. After over 4 years of follow-up, both fractured teeth showed no signs of abnormality. CONCLUSION: These findings may provide new insights and perspectives on the management and treatment of crown-root fractures in children.

Cognitive behavioural therapy (group) for schizophrenia.

BACKGROUND: Schizophrenia is a disabling psychotic disorder characterised by positive symptoms of delusions, hallucinations, disorganised speech and behaviour; and negative symptoms such as affective flattening and lack of motivation. Cognitive behavioural therapy (CBT) is a psychological intervention that aims to change the way in which a person interprets and evaluates their experiences, helping them to identify and link feelings and patterns of thinking that underpin distress. CBT models targeting symptoms of psychosis (CBTp) have been developed for many mental health conditions including schizophrenia. CBTp has been suggested as a useful add-on therapy to medication for people with schizophrenia. While CBT for people with schizophrenia was mainly developed as an individual treatment, it is expensive and a group approach may be more cost-effective. Group CBTp can be defined as a group intervention targeting psychotic symptoms, based on the cognitive behavioural model. In group CBTp, people work collaboratively on coping with distressing hallucinations, analysing evidence for their delusions, and developing problem-solving and social skills. However, the evidence for effectiveness is far from conclusive. OBJECTIVES: To investigate efficacy and acceptability of group CBT applied to psychosis compared with standard care or other psychosocial interventions, for people with schizophrenia or schizoaffective disorder. SEARCH METHODS: On 10 February 2021, we searched the Cochrane Schizophrenia Group's Study-Based Register of Trials, which is based on CENTRAL, MEDLINE, Embase, four other databases and two trials registries. We handsearched the reference lists of relevant papers and previous systematic reviews and contacted experts in the field for supplemental data. SELECTION CRITERIA: We selected randomised controlled trials allocating adults with schizophrenia to receive either group CBT for schizophrenia, compared with standard care, or any other psychosocial intervention (group or individual). DATA COLLECTION AND ANALYSIS: We complied with Cochrane recommended standard of conduct for data screening and collection. Where possible, we calculated risk ratio (RR) and 95% confidence interval (CI) for binary data and mean difference (MD) and 95% CI for continuous data. We used a random-effects model for analyses. We assessed risk of bias for included studies and created a summary of findings table using GRADE. MAIN RESULTS: The review includes 24 studies (1900 participants). All studies compared group CBTp with treatments that a person with schizophrenia would normally receive in a standard mental health service (standard care) or any other psychosocial intervention (group or individual). None of the studies compared group CBTp with individual CBTp. Overall risk of bias within the trials was moderate to low. We found no studies reporting data for our primary outcome of clinically important change. With regard to numbers of participants leaving the study early, group CBTp has little or no effect compared to standard care or other psychosocial interventions (RR 1.22, 95% CI 0.94 to 1.59; studies = 13, participants = 1267; I2 = 9%; low-certainty evidence). Group CBTp may have some advantage over standard care or other psychosocial interventions for overall mental state at the end of treatment for endpoint scores on the Positive and Negative Syndrome Scale (PANSS) total (MD -3.73, 95% CI -4.63 to -2.83; studies = 12, participants = 1036; I2 = 5%; low-certainty evidence). Group CBTp seems to have little or no effect on PANSS positive symptoms (MD -0.45, 95% CI -1.30 to 0.40; studies =8, participants = 539; I2 = 0%) and on PANSS negative symptoms scores at the end of treatment (MD -0.73, 95% CI -1.68 to 0.21; studies = 9, participants = 768; I2 = 65%). Group CBTp seems to have an advantage over standard care or other psychosocial interventions on global functioning measured by Global Assessment of Functioning (GAF; MD -3.61, 95% CI -6.37 to -0.84; studies = 5, participants = 254; I2 = 0%; moderate-certainty evidence), Personal and Social Performance Scale (PSP; MD 3.30, 95% CI 2.00 to 4.60; studies = 1, participants = 100), and Social Disability Screening Schedule (SDSS; MD -1.27, 95% CI -2.46 to -0.08; studies = 1, participants = 116). Service use data were equivocal with no real differences between treatment groups for number of participants hospitalised (RR 0.78, 95% CI 0.38 to 1.60; studies = 3, participants = 235; I2 = 34%). There was no clear difference between group CBTp and standard care or other psychosocial interventions endpoint scores on depression and quality of life outcomes, except for quality of life measured by World Health Organization Quality of Life Assessment Instrument (WHOQOL-BREF) Psychological domain subscale (MD -4.64, 95% CI -9.04 to -0.24; studies = 2, participants = 132; I2 = 77%). The studies did not report relapse or adverse effects. AUTHORS' CONCLUSIONS: Group CBTp appears to be no better or worse than standard care or other psychosocial interventions for people with schizophrenia in terms of leaving the study early, service use and general quality of life. Group CBTp seems to be more effective than standard care or other psychosocial interventions on overall mental state and global functioning scores. These results may not be widely applicable as each study had a low sample size. Therefore, no firm conclusions concerning the efficacy of group CBTp for people with schizophrenia can currently be made. More high-quality research, reporting useable and relevant data is needed.

Gender differences in attentive bias during social information processing in schizophrenia: An eye-tracking study.

Interpersonal communication is a specific scenario in which patients with psychiatric symptoms may manifest different behavioral patterns due to psychopathology. This was a pilot study by eye-tracking technology to investigate attentive bias during social information processing in schizophrenia. We enrolled 39 patients with schizophrenia from Shanghai Mental Health Center and 42 age-, gender- and education-matched healthy controls. The experiment was a free-viewing task, in which pictures with three types of degree of interpersonal communication were shown. We used two measures: 1) initial fixation duration, 2) total gaze duration. The Positive and Negative Syndrome Scale (PANSS) was used to determine symptom severity. The ratio of first fixation duration for pictures of communicating vs. non-communicating persons was significantly lower in patients than in controls (Mann-Whitney U = 512, p = 0.004). We found that male patients showed a significantly lower ratio of first fixation duration than male controls (Mann-Whitney U = 190, p = 0.028), while it was marginally lower in female patients than female controls (Mann-Whitney U = 77, p = 0.057). The ratio of first fixation duration for pictures of communicating persons vs. no persons was negatively correlated with PANSS negative symptoms in male patients (rho = -0.458, p = 0.024). In contrast, it was negatively correlated with PANSS positive symptoms in female patients (-0.701, p = 0.004). These findings suggest altered attentive bias during social information processing with a pattern of avoidance at first sight towards pictures of communicating persons in schizophrenia. It is worthwhile to note that social functioning impairment is associated with the severity of symptoms.

Prolactin levels influenced by antipsychotic drugs in schizophrenia: A systematic review and network meta-analysis.

Prolactin increase is a common side effect in antipsychotic treatment of schizophrenia, which crucially impacts drug choice and treatment compliance. As previous reviews by our group on this topic have included only few Chinese studies, we aimed to compare and rank antipsychotics based on broader evidence. This systematic review pooled data of 92 included studies from previous systematic review by Huhn et al. and 38 newly-added studies from Chinese-database search, including Chinese databases of China National Knowledge Infrastructure (CNKI), WANFANG DATA, WEIPU Journal Net (VIP) and Sino Biomedicine Service System (SinoMed) up to 20 May 2020. We conducted both network meta-analysis (NMA) and pairwise meta-analysis. The primary outcome was prolactin increase (continuous data). We calculated mean differences (MDs) for prolactin level with 95% confidence intervals (CIs) using random-effects model as primary analysis. 130 RCTs with 25,610 participants were included. Newer antipsychotics (risperidone, amisulpride and paliperidone) and older antipsychotics (chlorpromazine, haloperidol and sulpride) increase prolactin levels with large effect sizes. The SMD results were not identical to the MD results because consistency and heterogeneity assumption was tested to be different in calculations. Sensitivity analyses removing two studies with massive baseline imbalance or removing Chinese studies with high risk of bias did not affect the result. In contrast to a previous review clozapine and zotepine were no longer associated with decreased prolactin levels compared to placebo. Risperidone's ranking has more implications supported by CINeMA. This NMA draws the conclusion with larger sample size and extends evidence to more literature in this field.

Magnetic seizure therapy for treatment-resistant depression.

BACKGROUND: Magnetic seizure therapy (MST) is a potential alternative to electroconvulsive therapy (ECT). Reports to date on use of MST for patients with treatment-resistant depression (TRD) are limited. OBJECTIVES: To evaluate the effects of MST in comparison with sham-MST, antidepressant, and other forms of electric or magnetic treatment for adults with TRD. SEARCH METHODS: In March 2020, we searched a wide range of international electronic sources for published, unpublished, and ongoing studies. We handsearched the reference lists of all included studies and relevant systematic reviews and conference proceedings of the Annual Meeting of the American College of Neuropsychopharmacology (ACNP), the Annual Scientific Convention and Meeting, and the Annual Meeting of the European College of Neuropsychopharmacology (ECNP) to identify additional studies. SELECTION CRITERIA: All randomised clinical trials (RCTs) focused on MST for adults with TRD. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently. For binary outcomes, we calculated risk ratios (RRs) and 95% confidence intervals (CIs). For continuous data, we estimated mean differences (MDs) between groups and 95% CIs. We employed a random-effects model for analyses. We assessed risk of bias for included studies and created a 'Summary of findings' table using the GRADE approach. Our main outcomes of interest were symptom severity, cognitive function, suicide, quality of life, social functioning, dropout for any reason, serious adverse events, and adverse events that led to discontinuation of treatment. MAIN RESULTS: We included three studies (65 participants) comparing MST with ECT. Two studies reported depressive symptoms with the Hamilton Rating Scale for Depression (HAMD). However, in one study, the data were skewed and there was an imbalance in baseline characteristics. Analysis of these two studies showed no clear differences in depressive symptoms between treatment groups (MD 0.71, 95% CI -2.23 to 3.65; 2 studies, 40 participants; very low-certainty evidence). Two studies investigated multiple domains of cognitive function. However most of the outcomes were not measured by validated neuropsychological tests, and many of the data suffered from unbalanced baseline and skewed distribution. Analysis of immediate memory performance measured by the Wechsler Memory Scale showed no clear differences between treatment groups (MD 0.40, 95% CI -4.16 to 4.96; 1 study, 20 participants; very low-certainty evidence). Analysis of delayed memory performance measured by the Wechsler Memory Scale also showed no clear differences between treatment groups (MD 2.57, 95% CI -2.39 to 7.53; 1 study, 20 participants; very low-certainty evidence). Only one study reported quality of life, but the data were skewed and baseline data were unbalanced across groups. Analysis of quality of life showed no clear differences between treatment groups (MD 14.86, 95% CI -42.26 to 71.98; 1 study, 20 participants; very low-certainty evidence). Only one study reported dropout and adverse events that led to discontinuation of treatment. Analysis of reported data showed no clear differences between treatment groups for this outcome (RR 1.38, 95% CI 0.28 to 6.91; 1 study, 25 participants; very low-certainty evidence). Adverse events occurred in only two participants who received ECT (worsening of preexisting coronary heart disease and a cognitive adverse effect). None of the included studies reported outcomes on suicide and social functioning. No RCTs comparing MST with other treatments were identified. AUTHORS' CONCLUSIONS: Evidence regarding effects of MST on patients with TRD is currently insufficient. Our analyses of available data did not reveal clearly different effects between MST and ECT. We are uncertain about these findings because of risk of bias and imprecision of estimates. Large, long, well-designed, and well-reported trials are needed to further examine the effects of MST.

Prevalence and dynamic features of psychological issues among Chinese healthcare workers during the COVID-19 pandemic: a systematic review and cumulative meta-analysis.

BACKGROUND: The COVID-19 pandemic has placed tremendous pressure on healthcare workers who are at the frontline in the battle against it, causing various forms of psychological distress. AIMS: To outline the prevalence and dynamic changing features of medical workers' psychological issues and to review the related national policies during the COVID-19 pandemic in China. METHODS: We systematically searched for studies on the psychological states of Chinese medical staff from 1 January 2020 to 8 May 2020. The aggregate prevalence of each psychological issue was calculated and plotted to observe the changes over time. Policies on psychological support for medical staff during the pandemic were reviewed to explore their link to the prevalence of psychological problems. RESULTS: In total, 26 studies were included in this study. A total of 22 062 medical workers were surveyed from 31 January to 27 February 2020. Medical staff exhibited a substantial prevalence of anxiety symptoms, depression symptoms, stress-related symptoms and sleep problems during the survey period, with aggregate prevalence rates of 27.0%, 26.2%, 42.1% and 34.5%, respectively. Cumulative meta-analyses revealed that the prevalence of psychological distress peaked at the beginning of the pandemic and subsequently exhibited a slow downward trend. CONCLUSION: Chinese medical staff displayed significant psychological disturbance during the outbreak of the COVID-19 pandemic, which was especially severe at the early stage. Implementing supportive policies may help alleviate ongoing psychological problems in healthcare workers.

The Prevalence of Psychological Status During the COVID-19 Epidemic in China: A Systemic Review and Meta-Analysis.

The COVID-19 is creating panic among people around the world and is causing a huge public mental health crisis. Large numbers of observational studies focused on the prevalence of psychological problems during the COVID-19 pandemic were published. It is essential to conduct a meta-analysis of the prevalence of different psychological statuses to insight the psychological reactions of general population during the COVID-19 epidemic in China. Sixty six observational studies about the psychological statuses of people during the COVID-19 were included, searching up to 1 December 2020. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) was used to evaluate the quality of the included studies. OpenMeta[Analyst] was used for the data analysis. High prevalence of acute stress and fear symptoms were observed in the early period of the epidemic. Additionally, anxiety and depression symptoms continued at a high prevalence rate during the epidemic. It should alert the lasting mental health problems and the risk of post-traumatic stress disorder and other mental disorders. Systematic Review Registration: PROSPERO CRD 42020171485.

Repetitive Transcranial Magnetic Stimulation for Improving Cognitive Function in Patients With Mild Cognitive Impairment: A Systematic Review.

Background: Mild cognitive impairment (MCI) is an early stage of Alzheimer's disease. Repetitive transcranial magnetic stimulation (rTMS) has been widely employed in MCI research. However, there is no reliable systematic evidence regarding the effects of rTMS on MCI. The aim of this review was to evaluate the efficacy and safety of rTMS in the treatment of MCI. Methods: A comprehensive literature search of nine electronic databases was performed to identify articles published in English or Chinese before June 20, 2019. The identified articles were screened, data were extracted, and the methodological quality of the included trials was assessed. The meta-analysis was performed using the RevMan 5.3 software. We used the GRADE approach to rate the quality of the evidence. Results: Nine studies comprising 369 patients were included. The meta-analysis showed that rTMS may significantly improve global cognitive function (standardized mean difference [SMD] 2.09, 95% confidence interval [CI] 0.94 to 3.24, p = 0.0004, seven studies, n = 296; low-quality evidence) and memory (SMD 0.44, 95% CI 0.16 to 0.72, p = 0.002, six studies, n = 204; moderate-quality evidence). However, there was no significant improvement in executive function and attention (p > 0.05). Subgroup analyses revealed the following: (1) rTMS targeting the left hemisphere significantly enhanced global cognitive function, while rTMS targeting the bilateral hemispheres significantly enhanced global cognitive function and memory; (2) high-frequency rTMS significantly enhanced global cognitive function and memory; and (3) a high number of treatments ≥20 times could improve global cognitive function and memory. There was no significant difference in dropout rate (p > 0.05) between the rTMS and control groups. However, patients who received rTMS had a higher rate of mild adverse effects (risk ratio 2.03, 95% CI 1.16 to 3.52, p = 0.01, seven studies, n = 317; moderate-quality evidence). Conclusions: rTMS appears to improve global cognitive function and memory in patients with MCI and may have good acceptability and mild adverse effects. Nevertheless, these results should be interpreted cautiously due to the relatively small number of trials, particularly for low-frequency rTMS.

Milkvetch root improves immune function in patients with acute exacerbation of COPD.

Milkvetch root as a medicine has been used for more over 2000 years in China, can strengthen immune function, protect liver, promote urination, resist aging and stress, reduce blood pressure and extensively resist bacterium. This study explored the effects of milkvetch root on the immune function of patients with a definitive diagnosis of acute exacerbation of chronic obstructive pulmonary disease (COPD). The patients were randomly assigned to either the experimental or control group. All patients received conventional clinical therapy; those in the experimental group were also administered milkvetch root. The serum levels of cytokines including tumor necrosis factor alpha (TNF-α), interleukin-8 (IL-8), IL-1ß, and IL-32 and immunocytes including T helper (Th), cytotoxic T (Tc), natural killer (NK), regulatory T (Treg) and B cells were measured 1 day before treatment and 7 and 14 days post-treatment. After bronchodilator inhalation, pulmonary function was evaluated at these same time points. The serum TNF-α, IL-8, IL-1ß, and IL-32 levels were significantly lower in the experimental group than in the control group 14 days post-treatment. The Th/Tc ratio and NK cell ratio was significantly higher but the Treg cell ratio was significantly lower in the experimental group than in the control group. The forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC) were significantly higher in the experimental group than in the control group 14 days post-treatment. These results indicate that milkvetch root can improve the immune function of patients with acute exacerbation of COPD.

[Expression of TRPV1 and CGRP in rat trigeminal ganglion during orthodontic tooth movement].

PURPOSE: Sprague-Dawley rat models of tooth movement were established to investigate the expression of transient receptor potential vanilloid 1 (TRPV1) and calcitonin gene related peptide (CGRP) in rat trigeminal ganglion during orthodontic tooth movement, and to explore the roles of TRPV1 and CGRP in orthodontic pain. METHODS: Sixty-six Sprague-Dawley rats were randomly divided into control group (n=6), sham operation group (n=6), and experimental group (n=54). Tooth movement models were established, orthodontic force (50 g) was applied on the maxillary first molar in the rats of experimental group, and then the trigeminal ganglia were collected at 4, 8 h, 1 d (3 subgroups were set up according to the force: 1 d-30 g, 1 d-50 g, 1 d-80 g), 3, 5, 7, 14 d after tooth movement. The changes of TRPV1 and CGRP expression were detected by immunofluorescence staining. SPSS16.0 software package was used for statistical analysis. RESULTS: According to immunofluorescence staining, the TRPV1-IR and CGRP-IR neurons were mostly small to medium sized. The percentages of TRPV1-IR and CGRP-IR neurons in trigeminal ganglion increased after applying force, and reached the peak at 1-3 d and then fell to the initial level gradually. In addition, the application of greater force during experimental tooth movement induced higher percentages of TRPV1-IR and CGRP-IR neurons in trigeminal ganglion. CONCLUSIONS: Experimental tooth movement leads to the regular changes of TRPV1-IR and CGRP-IR neurons in trigeminal ganglion, indicating that TRPV1 and CGRP may play important roles in orthodontic pain.

Increased expression of TRPV1 in the trigeminal ganglion is involved in orofacial pain during experimental tooth movement in rats.

To investigate whether transient receptor potential vanilloid type 1 (TRPV1) is involved in pain induced by experimental tooth movement, experiments were performed in male Sprague-Dawley rats weighing 200-250 g. Directed face-grooming behavior was used to evaluate nocifensive behavior in rats during experimental tooth movement. The distribution of TRPV1 in the trigeminal ganglion (TG) was evaluated by immunohistochemistry, and its expression was detected by western blotting at several time points following the application of various magnitudes of force during tooth movement. Immunohistochemical analysis revealed that TRPV1 was expressed in TG, and its expression was increased after experimental tooth movement. Western blot results also showed that experimental tooth movement led to a statistically significant increase in expression of TRPV1 protein in TG. Meanwhile, the time spent on directed face-grooming peaked on day 1 and thereafter showed a gradual decrease. In addition, both the change in TRPV1 expression in the TG and directed face-grooming behavior were modulated in a force-dependent manner and in concert with initial orthodontic pain responses. Our results reveal that TRPV1 expression is modulated by experimental tooth movement and is involved in tooth-movement pain.

Low-intensity pulsed ultrasound accelerates tooth movement via activation of the BMP-2 signaling pathway.

The present study was designed to determine the underlying mechanism of low-intensity pulsed ultrasound (LIPUS) induced alveolar bone remodeling and the role of BMP-2 expression in a rat orthodontic tooth movement model. Orthodontic appliances were placed between the homonymy upper first molars and the upper central incisors in rats under general anesthesia, followed by daily 20-min LIPUS or sham LIPUS treatment beginning at day 0. Tooth movement distances and molecular changes were evaluated at each observation point. In vitro and in vivo studies were conducted to detect HGF (Hepatocyte growth factor)/Runx2/BMP-2 signaling pathways and receptor activator of NFκB ligand (RANKL) expression by quantitative real time PCR (qRT-PCR), Western blot and immunohistochemistry. At day 3, LIPUS had no effect on the rat orthodontic tooth movement distance and BMP-2-induced alveolar bone remodeling. However, beginning at day 5 and for the following time points, LIPUS significantly increased orthodontic tooth movement distance and BMP-2 signaling pathway and RANKL expression compared with the control group. The qRT-PCR and Western blot data in vitro and in vivo to study BMP-2 expression were consistent with the immunohistochemistry observations. The present study demonstrates that LIPUS promotes alveolar bone remodeling by stimulating the HGF/Runx2/BMP-2 signaling pathway and RANKL expression in a rat orthodontic tooth movement model, and LIPUS increased BMP-2 expression via Runx2 regulation.