Effect of Dietary Components on the Shear Bond Strength of Orthodontics Brackets after Thermal Aging

Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various dietary components on the performance of orthodontic brackets. Methods: Metal orthodontic brackets were bonded to 66 extracted anterior teeth divided into groups based on the solution type: Milk, Gatorade, Cold Coffee, and a control group using water. Each group consisted of 20 teeth except for the control group, which included six teeth. The bracketed teeth were submerged in their respective solutions for 15 minutes three times daily at different intervals to mimic an in vivo environment and were stored in artificial saliva at room temperature (23?C). The specimens underwent artificial aging through 10,000 cycles of thermocycling (representing one clinical year) between 5?C and 55?C. Shade measurements were taken using a VITA Easy Shade device, capturing the classic shade and L*, a*, and b* values. Delta E values were calculated immediately post-bonding and after 7 days, 1 month, 1, and 2 clinical years. The shear bond strength of each bracket was measured using an ultra-tester machine. Results: After two clinical years, significant differences in ΔE color values were observed across all groups, with the most substantial change noted in teeth immersed in cold coffee. Brackets submerged in milk demonstrated lower shear bond strength than other solutions, whereas the control group exhibited the highest shear bond strength (P = 0.01). Conclusion: The study indicates that dietary components significantly influence tooth color stability and the shear bond strength of orthodontic brackets, underscoring the importance of considering these factors in orthodontic treatment planning.

线上线下混合多元化教学模式在口腔医学本科留学生Orthodontics课程教学中的应用研究

目的探讨线上线下混合多元化教学模式在口腔医学本科留学生Orthodontics课程教学中的应用效果。方法于2020—2023年选取西安交通大学口腔医学院2015—2018级(大五)本科留学生为研究对象,将2015级和2016级留学生设为对照组(18名,传统教学模式),2017级和2018级留学生设为试验组(28名,线上线下混合多元化教学模式)。比较两组的教学效果。结果试验组学生的学习兴趣、课堂表现评分高于对照组(P<0.05);试验组教师的课堂参与评分高于对照组(P<0.05)。试验组的课程考核成绩高于对照组(P<0.05)。结论线上线下混合多元化教学模式在一定程度上可提高学生的学业水平和Orthodontics课程教学效果。

A Multi-Objective Optimization for Locating Maintenance Stations and Operator Dispatching of Corrective Maintenance

In this study,we introduce a novel multi-objective optimization model tailored for modern manufacturing,aiming to mitigate the cost impacts of operational disruptions through optimized corrective maintenance.Central to our approach is the strategic placement of maintenance stations and the efficient allocation of personnel,addressing a crucial gap in the integration of maintenance personnel dispatching and station selection.Our model uniquely combines the spatial distribution of machinery with the expertise of operators to achieve a harmonious balance between maintenance efficiency and cost-effectiveness.The core of our methodology is the NSGA Ⅲ+Dispatch,an advanced adaptation of the Non-Dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ),meticulously designed for the selection of maintenance stations and effective operator dispatching.This method integrates a comprehensive coding process,crossover operator,and mutation operator to efficiently manage multiple objectives.Rigorous empirical testing,including a detailed analysis from a taiwan region electronic equipment manufacturer,validated the effectiveness of our approach across various scenarios of machine failure frequencies and operator configurations.The findings reveal that the proposed model significantly outperforms current practices by reducing response times by up to 23%in low-frequency and 28.23%in high-frequency machine failure scenarios,leading to notable improvements in efficiency and cost reduction.Additionally,it demonstrates significant improvements in oper-ational efficiency,particularly in selective high-frequency failure contexts,while ensuring substantial manpower cost savings without compromising on operational effectiveness.This research significantly advances maintenance strategies in production environments,providing the manufacturing industry with practical,optimized solutions for diverse machine malfunction situations.Furthermore,the methodologies and principles developed in this study have potential applications in various other sectors,including healthcare,transportation,and energy,where maintenance efficiency and resource optimization are equally critical.

Development of pulmonary hypertension remains a major hurdle to corrective surgery in Down syndrome

Down syndrome is the most common chromosomal abnormality encountered in clinical practice with 50%of them having associated congenital heart disease(CHD).Shunt lesions account for around 75%of all CHDs in Down syndrome.Down syndrome patients,especially with large shunts are particularly predisposed to early development of severe pulmonary hypertension(PH)compared with shunt lesions in general population.This necessitates timely surgical correction which remains the only viable option to prevent long term morbidity and mortality.However,despite clear recommendations,there is wide gap between actual practice and fear of underlying PH which often leads to surgical refusals in Down syndrome even when the shunt is reversible.Another peculiarity is that Down syndrome patients can develop PH even after successful correction of shunt.It is not uncommon to come across Down syndrome patients with uncorrected shunts in adulthood with irreversible PH at which stage intracardiac repair is contraindicated and the only option available is a combined heartlung transplant.However,despite the guidelines laid by authorities,the rates of cardiac transplant in adult Down syndrome remain dismal largely attributable to the high prevalence of intellectual disability in them.The index case presents a real-world scenario highlighting the impact of severe PH on treatment strategies and discrimination driven by the fear of worse outcomes in these patients.

Teachers' Oral Corrective Feedback and Its Influence on Learner Uptake in the Classes of Teaching English as a Foreign Language for Minority Students in Xinjiang Junior High Schools

The present study explored the features and the effectiveness of teachers' oral CF in the classrooms of Teaching English as a Foreign Language(TEFL) for minority students in Xinjiang junior high schools. The analytical framework of this study consulted Lyster's(1998) coding scheme. 720 minutes of classroom observation were recorded and transcribed. The database was coded and the distribution of errors, CF and uptake was analyzed.

Applications of stem cells in orthodontics and dentofacial orthopedics:Current trends and future perspectives

A simple overview of daily orthodontic practice involves use of brackets, wires and elastomeric modules. However, investigating the underlying effect of orthodontic forces shows various molecular and cellular changes. Also, orthodontics is in close relation with dentofacial orthopedics which involves bone regeneration. In this review current and future applications of stem cells(SCs) in orthodontics and dentofacial orthopedics have been discussed. For craniofacial anomalies, SCs have been applied to regenerate hard tissue(such as treatment of alveolar cleft) and soft tissue(such as treatment of hemifacial macrosomia). Several attempts have been done to reconstruct impaired temporomandibular joint. Also, SCs with or without bone scaffolds and growth factors have been used to regenerate bone following distraction osteogenesis of mandibular bone or maxillary expansion. Current evidence shows that SCs also have potential to be used to regenerate infrabony alveolar defects and move the teeth into regenerated areas. Future application of SCs in orthodontics could involve accelerating tooth movement, regenerating resorbed roots and expanding tooth movement limitations. However, evidence supporting these roles is weak and further studies are required to evaluate the possibility of these ideas.

Role of third molars in orthodontics

The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too.

Periodontally accelerated osteogenic orthodontics with platelet-rich fibrin in an adult patient with periodontal disease:A case report and review of literature

BACKGROUND In the clinical scenario,adult patients with periodontal diseases and dental malformation,characterized by dental crowding in lower anterior teeth with the thin biotype,often require orthodontic treatment.This case report aimed to evaluate the clinical and radiographic outcomes of periodontally accelerated osteogenic orthodontics(PAOO)combined with autologous platelet-rich fibrin(PRF)in an adult patient with class I malocclusion along with dental crowding,a thin periodontal biotype,and buccal plate deficiency.CASE SUMMARY A 32-year-old female complaining of dental crowding and gingival bleeding was referred to the orthodontic clinic.The patient underwent periodontal risk assessment prior to orthodontic treatment.She was diagnosed with a high risk of gingival recession due to dental crowding,root prominence,loss of buccal plates,and a thin gingival tissue biotype.The treatment regimen included PAOO combined with autologous PRF for alveolar augmentation and interproximal enamel reduction for moderate dental crowding.Clinically,PAOO-assisted orthodontic tooth movement in this case showed enhanced periodontium remodeling.Radiographic outcomes also showed statistically significant improvements(P<0.01)in the mandibular buccal alveolar bone.CONCLUSION This case report suggests the combination of autologous PRF with PAOO to enhance bone augmentation and long-term tissue support in adult orthodontic patients with periodontal disease.

Effects of Written Corrective Feedback on College EFL Students’Writing Accuracy and Linguistic Knowledge Acquisition

Set at the interface between second language acquisition and second language writing,this study examines how different types of written corrective feedback(WCF)influence the writing accuracy of Chinese college students learning English as a Foreign Language(EFL)and whether WCF facilitates the students’grasp of the focused linguistic knowledge.The participants(n=60)were divided into direct correction group(n=20),indirect error-coding group(n=20)and metalinguistic explanation group(n=20).The three groups wrote four essays in two months and received WCF for the first three essays on the five targeted error types,namely tense errors,confusion of different forms of a word,word(articles,prepositions,etc.)missing,errors in subjectverb agreement and inappropriate verb-noun collocations.The results show that all three types of WCF improved students’writing accuracy but none of them had any statistical advantage,and the metalinguistic WCF was more effective than the other two forms in facilitating the acquisition of the targeted linguistic features.These results shed some light on teaching and consolidation of language points through writing in EFL contexts.

Miniscrew appliances and their use in orthodontics

Anchorage is an important factor in orthodontics and must be properly managed for a successful treatment outcome. Orthodontists have historically used many devices to prevent unwanted tooth movement. The use of miniscrews as a source of skeletal anchorage has become routine in present-day orthodontic practice. Skeletal anchorage opens up alternative treatments, to borderline surgery patients for example, who can now be treated by taking advantage of the biomechanical properties of miniscrews. Because they are bone-borne and provide excellent control over tooth movement in the three spatial planes of movement, mini-implants can be used to serve many purposes in addition to anchorage. Therefore, a variety of successful mini-implant appliances are explained in relation to the three planes of movement: sagittal, vertical, and transverse. The aim of this review is to illustrate the clinical versatility of miniscrews in the three spatial planes of malocclusion in orthodontic and orthopedic management and to define clinical guidelines for the selection, application and biomechanics of mini-implants.

Macao Secondary School EFL Teachers' Perspectives on Written Corrective Feedback: Rationales and Constraints

Corrective feedback on writing(WCF)has been one of the most controversial topics in ESL/EFL teaching.In the past decades,much has been disputed regarding the effectiveness and preferences of the quantity,focus,directness and source of WCF.With so much uncertainty,the researcher set out to investigate how research-informed secondary school teachers in Macao reported their beliefs,rationales,practices and constraints of administering corrective feedback for EFL writing in Macao secondary schools.Twelve secondary school teachers were recruited at a TESOL conference to conduct focus-group discussions.Similar to previous findings,results suggest teachers had clear rationales as to their ways of practising WCF.However,many expressed difficulties in acting according to rationales and beliefs.Despite their experience and knowledge,practical constraints such as school policies and teacher workload made it unlikely for them to follow their thoughts with feedback on writing.This study identified six sources of constraints that could prohibit practices and potentially reshape ones’beliefs,which sheds light on future directions of WCF research.

Face Adaptation in Orthodontics

Bilateral Controversy in orthodontic science is widely present in different patterns;one of the most common is the debate between early versus late orthodontic treatment. This paper is going to demonstrate two clinical cases of class III malocclusion which are treated orthodontically, one in early mixed dentition and the other in permanent dentition. The face is highly capable to adapt to the changes achieved by orthodontics provided the earlier treatment begins, the more the face adapts to our standards;the later treatment begins, the more our standards have to adapt to the face.

Microbiological Advances in Orthodontics:An Overview and Detailed Analysis of Temporary Anchorage Devices

Dental biofilm is the initiating factor of oral diseases,such as periodontitis and caries.Orthodontic treatment could alter the microbiome structure balance,and increase the risk of such diseases.Furthermore,fixed appliances can induce temporary changes in the microbiome community,and the changes that clear aligners bring are smaller by comparison.Temporary anchorage devices(TADs)are skeletal anchorages that are widely used in orthodontic treatment.Microorganisms affect the occurrence and development of inflammation surrounding TADs.At present,existing researches have verified the existence of plaque biofilm on the surface of TADs,but the formation of plaque biofilm and plaque composition under different stable conditions have not been fully understood.The development of high-throughput sequencing,molecular biology experiments,and metabonomics have provided new research ideas to solve this problem.They can become an effective means to explore the microbiome surrounding TADs.

Root Resorption of Central Incisor by Impacted Canine in Unusual Transposition: Orthodontics and Implant Rehabilitation: 3-Year Follow-Up

This case presents an unusual transposition of an impacted canine on the central incisor that provides a multidisciplinary approach to its resolution. The patient comes to the consultation for mobility of the central incisor. Clinically, tooth mobility was confirmed with tooth crowding and persistence of the temporary canine. Cone beam tomography (CBCT) observed the atypical position of the permanent canine that caused root resorption of the ipsilateral central incisor and the need to extract both teeth. The conservative treatment of the bone structures during the dental enucleation of the impacted canine carried out by odontosection and the immediate bone grafting of the defect projected an acceptable regeneration of the bone volume for the insertion of the implant. The orthodontic treatment managed to correct the bite, position the upper premolar in the place of the canine tooth and maintain the space to place the implant in the central incisor. The three-year follow-up shows maintenance of the peri-implant crestal bone level, the success of orthodontic treatment with recovery of the patient’s function and aesthetics.

Consolidating the Bilingual Education in the Major of Finance:Existing Defects and Corrective Measures

Under the trend of globalization and international financial integration,Chinese scholars have argued that executing bilingual education in the major of finance is necessary to advance the comprehensive quality and competitive ability of college students.However,universities attempting to implement bilingual education are procrastinated with many obstacles.To resolve this issue,corrective measures are to be given in the aspects of textbook publishing,professor training and curriculum adjustments.

Effect of Periodontal Serial Therapy Combined with Orthodontics on Periodontal Parameters in Patients with Periodontitis

Objective:To investigate the clinical efficacy of periodontal sequence in combination with orthodontic treatment of patients with periodontitis.Methods:Retrospective analysis of periodontitis patients(54 cases)treated at our hospital between February 2018 and June 2019.The clinical data of all the enrolled participants were subjected to periodontal serial combined orthodontic treatment,and all the registered participants were observed at the initial consultation,periodontal serial treatment1 Periodontal parameters at the end of months and at the end of orthodontic treatment,serial periodontal treatment and orthodontic treatment for all enrolled individuals,x-rays and Oral examinations were performed,and the results were analyzed.Results:Compared to the initial visit,all enrolled individuals had a higher plaque index(PLI)after 1 month of periodontal treatment and at the end of orthodontic treatment.Bleeding index(BI),periodontal probe depth(PD),and periodontal attachment loss(CAL)levels were all lower than those detected at the initial visit.The difference was statistically significant(P<0.05);after serial periodontal treatment and orthodontic treatment,the x-ray results showed that the patients’Alveolar bone resorption or regeneration ceased;The results of the oral examination showed that the patient’s occlusal relationship improved significantly and basically returned to normal.Status,a masticatory function was significantly improved,and individual tooth loosening due to occlusal trauma was improved considerably.Conclusion:The combination of periodontal sequence and orthodontic treatment of patients with periodontitis is beneficial to enhance periodontal parameters,improve occlusal relationships,and improve masticatory function.

Discussion about the Side Effect of Error Corrective Feedback and Possible Alternatives to Error Correction

Feedbacks given by teachers is possibly a common instruction in second language writing classes, to help students makeprogress in writing. At one time, feedback was almost entirely at a superficial level--identifying the grammatical errors and givingthe correct form. However, recently, this type of feedback has begun to be challenged by some researchers(eg.,Krashen, 1984, Trus-cott, 1996),who argue that teachers should be more concerned with the content of essay instead of grammatical errors. This essaywill discuss some research surrounding feedback to students' writing and will try to find the answer to the question whether the er-ror corrective feedback should be abandoned. In order to find the answer, the essay will elaborate on two parts: some literary reviewabout the issue and some suggested solutions to the issue.

ANALYSIS OF HUMAN PLACENTA BY ^(31)P NUCLEAR MAGNETIC RESONANCE AND THIN-LAYER CHROMATOGRAPHY SCANNING COMBINED WITH THE CORRECTIVE METHOD OF ABSORBANCE PROPORTIONAL COEFFICIENT

Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.

The Effects of Learner’s Individual Differences on the Written Corrective Feedback

From the perspective of individual learner differences,this paper aims to show the readers an outline of the influence of individual learner differences on written corrective feedback.Based on 200 eighth and ninth grade junior high school students’thinking patterns and tests,60 students were selected as subjects in this study.Based on the comparative analysis and error analysis in second language acquisition as the main theoretical basis,this study analyzed the common types of errors in the use of nonpredicate verbs in junior high school students and their causes.There are three main questions in this study:how about the error frequency of the five forms(present participle,past participle,infinitive,gerund and independent nominative structure)in the nonpredicate verb learning of junior high school students?What kind of mistakes do junior high school students make in the process of learning non-predicate verbs?According to the conclusion of the investigation and research,the author puts forward some suggestions from the aspects of teachers and students in the last part of the article.

Computer-aided Design and Custom-made Guide in Corrective Osteotomy for Complex Femoral Deformity

Summary： Preoperative planning of corrective osteotomy with traditional radiography has limitations in regards to determining the ideal osteotomy location and orientation in three-dimensional femoral de- formities. Though a successful operation can be planned preoperatively, intraoperative contingencies might adhere to the procedural plan in the performance of operation. To efficiently perform a planned procedure, proposed is a design to implement three-dimensional reconstruction photography, based on computer-tomography （CT） scan. A custom-made guide was designed to navigate the osteotomy as planned, and additionally, a personalized intramedullary nail was used for fixation after osteotomy. Three-dimensional （3D） photography of deformed femur was established based on the CT dataset and transferred into 3D photography processing software for further planning. Osteotomy planes were de- signed and adjusted at deformity sites to correct the 3D deformities. The methodology of a custom-made osteotomy guide was introduced in femoral corrective osteotomy, for the first time, to navigate the op- eration as planned. After the virtual osteotomy and reduction of bone segments, the parameters of a custom-made intramedullary nail were measured for manufacturing. Findings Virtual operation in computer shows complete correction of the 3D deformity. The osteotomy guide, obtained by rapid-prototyping techniques, navigates mimicking surgery on rapid-prototyping model of the involved femur as planned. Internal fixation was achieved using the custom-made intramedullary nail. Interpreta- tion three-dimensional visualization introduces an advantage in preoperative planning for corrective os- teotomy of 3D femoral deformity, and the custom-made osteotomy guide is crucial to realize such a de- liberate plan during the actual procedures. The internal fixator, such as an intramedullary nail, can be modified or personalized for fixation in unique cases.