Investigation of mechanical properties, remineralization, antibacterial effect, and cellular toxicity of composite orthodontic adhesive combined with silver-containing nanostructured bioactive glass.

BACKGROUND: The formation of white spots, which represent early carious lesions, is a major issue with fixed orthodontics. The addition of remineralizing agents to orthodontic adhesives may prevent the formation of white spots. The aim of this study was to produce a composite orthodontic adhesive combined with nano-bioactive glass-silver (nBG@Ag) for bracket bonding to enamel and to investigate its cytotoxicity, antimicrobial activity, remineralization capability, and bond strength. METHODS: nBG@Ag was synthesized using the sol-gel method, and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy with an attenuated total reflectance attachment (ATR-FTIR). The cytotoxicity test (MTT) and antimicrobial activity of adhesives containing 1%, 3%, and 5% (wt/wt) nBG@Ag were evaluated, and the shear bond strength of the adhesives was measured using a universal testing machine. Remineralization was assessed through microhardness testing with a Vickers microhardness tester and scanning electron microscopy (SEM). Statistical analyses were conducted using the Shapiro-Wilk test, Levene test, one-way ANOVA, Robust-Welch test, Tukey HSD method, and two-way ANOVA. RESULTS: The biocompatibility of the adhesives was found to be high, as confirmed by the lack of significant differences in the cytotoxicity between the sample and control groups. Discs made from composites containing nBG@Ag exhibited a significant reduction in the growth of Streptococcus mutans (p < 0.05), and the antibacterial activity increased with higher percentages of nBG@Ag. The shear bond strength of the adhesives decreased significantly (p < 0.001) after the addition of nanoparticles, but it remained above the recommended value. The addition of nBG@Ag showed improvement in the microhardness of the teeth, although the differences in microhardness between the study groups were not statistically significant. The formation of hydroxyapatite deposits on the tooth surface was confirmed through SEM and energy-dispersive X-ray spectroscopy (EDX). CONCLUSION: Adding nBG@Ag to orthodontic adhesives can be an effective approach to enhance antimicrobial activity and reduce enamel demineralization around the orthodontic brackets, without compromising biocompatibility and bond strength.

Orthodontic camouflage treatment of a hyperdivergent adolescent patient with anterior open bite and TMD: a case report.

BACKGROUND: In orthodontics, anterior open bite is a common malocclusion that recurs frequently. Because the causes of anterior open bite are so varied, medical professionals must create customized treatment programs for each patient based on their unique etiology. Through the lowering of the posterior teeth, closure of the anterior teeth gap, and cooperation with intermaxillary traction, the treatment plan outlined in this case study sought to achieve a stable occlusion. CASE PRESENTATION: This case report aims to describe an orthodontic camouflage treatment of a 15-year-old female patient with anterior open bite, arch width discrepancy and a history of temporomandibular joint disorder. The patient was treated with intermaxillary vertical elastics and the multiple edgewise arch wire (MEAW) approach. A satisfactory occlusion with a neutral molar relationship was attained after 29 months of orthodontic therapy. The condylography recording showed that this patient's occlusion tended to be more stable both before and after our treatment. The purpose of this case study is to provide an overview of an orthodontic camouflage treatment for a female patient, who had a history of temporomandibular joint disease, anterior open bite, and arch width disparity. CONCLUSIONS: Our results demonstrated that more attention should be paid to levelling the occlusal plane, intrusion of the molars, decompression of temporomandibular joints and the etiology factors of malocclusion during the orthodontic period for those patients with anterior open bite.

Assessment of changes in enamel colour following fixed orthodontic therapy using an advanced spectrophotometer: An in vivo study.

BACKGROUND: Any manipulation of the surface of natural teeth may result in a variation of their colour. The fixed orthodontic treatment (FOT) is one such procedure which alters the enamel surface during the procedure. OBJECTIVE: To clinically evaluate the colour changes in teeth associated with comprehensive FOT (to compare the changes in test and control groups) and to determine the relationship of age and gender on enamel colour due to FOT by using an advanced spectrophotometer. METHODS: The selection of sixty patients for the study was done randomly and among these thirty patients who underwent the FOT as the case group, the other thirty patients who did not need FOT, were the control group. The recordings of spectrophotometric data were done in a standardized manner for all patients in the labial circular region of every anterior tooth, following debonding and cleaning operations, and before bracket bonding. The Commission Internationale de l'Eclairage's L*, a*, and b* (lightness, red/green, and blue/yellow) tooth-type characteristics were used to measure color, and the associated color differences (DE) between the groups were computed. One-way ANOVA (a < 0.05) and the paired t-test were used to evaluate any changes in these color characteristics. RESULTS: Fixed orthodontic treatment is associated with changes in colour parameters. L* values decreased (P< 0.001), while a* and b* values increased (P< 0.001) at the end of treatment. All measured tooth types showed significant colour change (DE); their mean differences ranged from 1.64 to 2.96 DE units. CONCLUSIONS: Fixed orthodontics can change the natural colour of teeth. The CIE colour parameters L*, a*, and b* of natural teeth showed statistically significant differences after debonding the orthodontic appliances. The L* values decreased making the teeth look darker. The adolescent and male patients had more tooth colour changes than the adult and female groups.

A systematic review of the clinical outcomes for various orthodontic and physiotherapy appliances used for the management of temporomandibular joint ankylosis.

Ankylosis of the temporomandibular joint (TMJ) is associated with restricted mandibular movements, with deviation to the affected side. The management of TMJ ankylosis involves surgery to mitigate the effects of ankylosis, and adjunctive appliance therapy to supplement the results achieved through surgery. Several appliances have been used to help maintain jaw mobility postsurgery, but have been rarely documented in the literature. Our systematic review aimed to examine the clinical outcomes of various appliances for TMJ ankylosis management. A comprehensive electronic search of the literature was performed in July 2022 to identify eligible articles that had tested the use of orthodontic or physiotherapy appliances for the management of TMJ ankylosis. In total, 13 publications were included in the narrative synthesis. Both generic and custom-made appliances were used, with overall findings suggesting that using these appliances improved mouth opening and reduced chances of re-ankylosis. In this review no universally accepted appliance was found to be utilized, and the criteria used for appliance selection were unclear. The field of research in developing appliances for the treatment of TMJ ankylosis is open to advancement, and this review will help guide future research in this area.

Small nucleolar RNA host gene 5 plays a role in orthodontic tooth movement by inhibiting osteoclast differentiation.

BACKGROUND AND OBJECTIVES: The alveolar bone remodelling promoted by reasonable mechanical force triggers orthodontic tooth movement (OTM). The generation of osteoclasts is essential in this process. However, the mechanism of mechanical force mediating osteoclast differentiation remains elusive. Small nucleolar RNA host gene 5 (SNHG5), which was reported to mediate the osteogenic differentiation of bone marrow mesenchymal stem cells in our previous study, was downregulated in human periodontal ligament cells (hPDLCs) under mechanical force. At the same time, the RANKL/OPG ratio increased. Based on this, we probed into the role of SNHG5 in osteoclast formation during OTM and the relevant mechanism. MATERIALS AND METHODS: SNHG5 and the RANKL/OPG ratio under different compressive forces were detected by western blotting (WB) and qRT-PCR. Impact of overexpression or knockdown of SNHG5 on osteoclast differentiation was detected by qRT-PCR, WB and transwell experiments. The combination of SNHG5 and C/EBPß was verified by RNA immunoprecipitation and RNA pull-down assays. The expression of SNHG5 and osteoclast markers in gingiva were analysed by qRT-PCR and the paraffin sections of periodontal tissues were used for histological analysis. RESULTS: Compressive force downregulated SNHG5 and upregulated the RANKL/OPG ratio in hPDLCs. Overexpression of SNHG5 inhibited RANKL's expression and osteoclast differentiation. SNHG5 combined with C/EBPß, a regulator of osteoclast. The expression of SNHG5 in periodontal tissue decreased during OTM. CONCLUSION: SNHG5 inhibited osteoclast differentiation during OTM, achieved by affecting RANKL secretion, which may provide a new idea to interfere with bone resorption during orthodontic treatment.

Strategic Intervention: Ectopic Premolar Management for Preventing Molar-Premolar Transposition in Class III Malocclusion.

Class III malocclusion often leads to the ectopic eruption of premolars in the upper arch, posing unique challenges for orthodontic practitioners. This case report explores the clinical implications of ectopic maxillary premolars in a Class III malocclusion patient, emphasizing the importance of early intervention and comprehensive treatment strategies. Factors contributing to ectopic eruption, including genetic predisposition and anatomical variations, are discussed, guiding orthodontists in effective diagnosis and management. A 14-year-old patient with Class III malocclusion, anterior crossbite, and ectopic maxillary premolars sought orthodontic consultation. The treatment plan involved extracting the deciduous second molar, realigning the ectopic premolar, and addressing arch length discrepancies. Utilizing fixed orthodontic appliances and strategic force application, the patient achieved Class I molar and canine relationships, resolving the ectopic premolar alignment within 10 months. Ectopic eruption of maxillary premolars, especially in Class III malocclusion, is a critical concern for oral health. Genetic predisposition, arch crowding, and developmental disturbances contribute to this condition. Early intervention, as demonstrated in this case, plays a pivotal role in restoring dentoskeletal harmony. The study underscores the need for a multidisciplinary approach, combining orthodontic, surgical, and restorative interventions for optimal outcomes. Thus, this case report highlights the successful management of ectopic maxillary premolars in a Class III malocclusion patient through strategic orthodontic intervention. Understanding the etiological factors and employing a comprehensive treatment approach facilitate timely diagnosis and prevent complications. Orthodontists must navigate the complexities of ectopic eruption, considering occlusal effects and collaborating with other specialists for holistic patient care.

Evaluation of the surface characteristics and antibacterial properties of Titanium dioxide nanotube and methacryloyloxyethylphosphorylcholine (MPC) coated orthodontic brackets-a comparative invitro study.

OBJECTIVES: White spot lesions are the most common iatrogenic effect observed during orthodontic treatment. This study aimed to compare the surface characteristics and antibacterial action of uncoated and coated orthodontic brackets. MATERIALS AND METHODS: Sixty commercially available stainless steel brackets were coated with TiO2 nanotubes and methacryloyloxyethylphosphorylcholine. The sample was divided into Group 1: uncoated orthodontic brackets, Group 2: Stainless steel brackets with TiO2 nanotubes coating, Group 3: Stainless steel brackets with methacryloyloxyethylphosphorylcholine coating, and Group 4: Stainless steel brackets with TiO2 nanotubes combined with methacryloyloxyethylphosphorylcholine coating. Surface characterization was assessed using atomic force microscopy and scanning electron microscopy. Streptococcus mutans was selected to test the antibacterial ability of the orthodontic brackets, total bacterial adhesion and bacterial viability were assessed. The brackets were subjected to scanning electron microscopy to detect the presence of biofilm. RESULTS: The surface roughness was the greatest in Group 1 and least in Group 2 followed by Group 4 and Group 3 coated brackets. The optical density values were highest in Group 1 and lowest in Group 4. Comparison of colony counts revealed high counts in Group 1 and low counts in Group 4. A positive correlation between surface roughness and colony counts was obtained, however, was not statistically significant. CONCLUSIONS: The coated orthodontic brackets exhibited less surface roughness than the uncoated orthodontic brackets. Group 4 coated orthodontic brackets showed the best antibacterial properties. CLINICAL RELEVANCE: Coated orthodontic brackets prevent adhesion of streptococcus mutans and reduces plaque accumulation around the brackets thereby preventing formation of white spot lesions during orthodontic treatment.

Application of Robotics in Orthodontics: A Systematic Review.

Robotics has various applications in dentistry, particularly in orthodontics, although the potential use of these technologies is not yet clear. This review aims to summarize the application of robotics in orthodontics and clarify its function and scope in clinical practice. Original articles addressing the application of robotics in any area of orthodontic practice were included, and review articles were excluded. PubMed, Google Scholar, Scopus, and DOAJ were searched from June to August 2023. The risk of bias was established using the risk of bias in non-randomized studies (ROBINS) and certainty assessment tools following the grading of recommendations, assessment, development, and evaluation (GRADE) guidelines. A narrative synthesis of the data was generated and presented according to its application in surgical and non-surgical orthodontics. The search retrieved 2,106 articles, of which 16 articles were selected for final data synthesis of research conducted between 2011 and 2023 in Asia, Europe, and North America. The application of robotics in surgical orthodontics helps guide orthognathic surgeries by reducing the margin of error, but it does not replace the work of a clinician. In non-surgical orthodontics, robotics assists in performing customized bending of orthodontic wires and simulating orthodontic movements, but its application is expensive. The articles collected for this synthesis exhibited a low risk of bias and high certainty, and the results indicated that the advantages of the application of robotics in orthodontics outweigh the disadvantages. This project was self-financed, and a previous protocol was registered at the PROSPERO site (registration number: CRD42023463531).

Pre-Epiglottic Baton Plate in Newborns With Pierre Robin Sequence: Revisiting the Practical Workflow.

We demonstrate pre-epiglottic baton plate as non-invasive treatment modality for initial airway management in newborns with Pierre Robin Sequence. A case example illustrates management of upper airway obstruction and feeding using digital technology to facilitate customization. Laryngoscope, 2024.

Cross-sectional and retrospective study regarding the changes in the spatial position of the hyoid bone and upper airways before and after orthodontic therapy in developing patients with normocclusion.

OBJECTIVE: The objective was to study the effect of orthodontic therapy regarding the position of the hyoid bone and upper airways in nighty-one 6-21 year-old Caucasian patients with normoclussion. METHODS: Nineteen variables were analyzed by teleradiography. The differences were analyzed with the ANOVA test of repeated measures with an intra-group factor for two occasions. RESULTS: The statistical analysis revealed a greater influence on the variables Hy-MP (12.3 vs 14.2), Hps-C3 (25.2 vs 28.1), Hpi-C3 (28.8 vs 35.5), H°-C3 (14.4 vs 12.7), Hps-Rg (36.0 vs 42.7), Hpi-Rg (34.1 vs 39.7), USP (16.2 vs 20.2), MPP (12.9 vs 14.8), C3P (10.6 vs 12.8), PNS-Ba (43.5 vs 66.5), PtV-Ad (12.0 vs 17.1) and PtM-Ba (33.9 vs 35.9), and Ad2-SO (24.16 vs 20.87). DISCUSSION: Significant differences were observed between most of the airway and hyoid bone variables before and after orthodontic treatment in our Spanish pediatric population, especially in the nasopharynx.

Global scholarly output on orthodontic temporary anchorage devices (TADs): A silver jublee scientometric analysis.

OBJECTIVES: This study aimed to analyze the global scholarly production of articles related to temporary anchorage devices (TADs) from 1998-2023 in peer-reviewed dental journals indexed in the Web of Science. MATERIALS AND METHODS: A database of TADs-related articles was created via a Web of Sciences structured search. The bibliometric characteristics of the studies, including the number of citations, publication year, journal title, journal impact factor (IF), authorship, contributing institutions and countries, thematic field, and study design, were extracted. Keyword co-occurrence network analyses and the correlation between the number of citations and the article age, journal IF, and journal quartile of each article were performed. RESULTS: The top 50 cited articles were published from 1999-2016, and the total number of citations ranged from 82-602, with 160.36 citations/paper on average. Most of the articles originated from Japan (n = 12), with the most remarkable contributions from Nihon and Okayama Universities, Japan (n = 5, each). The American Journal of Orthodontics and Dentofacial Orthopedics had the most cited articles, with 196.57 citations/paper on average. A significant positive correlation occurred between the number of citations and publication age (rho = 0.392, P = 0.005). CONCLUSION: Our scientometric analysis reported the characteristics of TADs-related articles published over 25 years. Most highly-cited articles were published between 2005 and 2008. The positive correlation between articles' publication date and the number of citations might impact the top 50 within the next 5-10 years.

Transforming Adolescent Smiles: Correcting Skeletal Mandibular Retrusion and Bimaxillary Protrusion with Clear Aligners.

Maxillary protrusion combined with mandibular retraction is a highly prevalent but extremely complex maxillofacial deformity that can have a serious negative impact on patients' facial aesthetics and mental health. The traditional orthodontic treatment strategy often involves extracting 4 first premolars and conventional fixed techniques, combined with mini-implant screws, to retract the anterior teeth and improve facial protrusion. In recent years, an invisible orthodontic technique, without brackets, has become increasingly popular. However, while an invisible aligner has been used in some cases with reasonable results, there remain significant challenges in achieving a perfect outcome. This case report presents an adolescent patient with bimaxillary protrusion and mandibular retrognathia. Based on the characteristics of the invisible aligners and the growth characteristics of the adolescent's teeth and jawbone, we designed precise three-dimensional tooth movement and corresponding resistance/over-correction for each tooth, while utilizing the patient's jawbone growth potential to promote rapid development of the mandible, accurately and efficiently correcting bimaxillary protrusion and skeletal mandibular retrognathia. The patient's facial aesthetics, especially the lateral morphology, have been greatly improved, and various aesthetic indicators have also shown significant changes, and to the patient's great benefit, invasive mini-implant screws were not used during the treatment. This case highlights the advantages of using invisible aligners in adolescent maxillary protrusion combined with mandibular retraction patients. Furthermore, comprehensive and accurate design combined with good application of growth potential can also enable invisible orthodontic technology to achieve perfect treatment effects in tooth extractions, providing clinical guidance for orthodontists.

Identification, Evaluation, and Correction of Supracrestal Tissue Attachment (Previously Biologic Width) Violation: A Case Presentation With Literature Review.

The supracrestal tissue attachment (SCTA) is the new terminology for biologic width. SCTA is defined as the physiologic dimension of a solitary functional unit composed of junctional epithelium and connective tissue attachment. Its preservation is critical for the well-being of periodontal health. SCTA has been widely studied and scientific literature is indicative of its significance during the placement of restoration, including prosthetic crowns. This should be taken care of in cases of anterior teeth within the smile zone, where dental crowns are regularly placed subgingivally for aesthetic reasons. In addition, any violation of SCTA while restoring the dentition will present as gingival inflammation and pain, consequently, leading to failure of the clinical procedure.

Effect of Elastomeric Module Degradation and Ligation Methods on Kinetic Friction between NiTi or Stainless Steel Wires and Stainless Steel Brackets.

Objectives: The reduction of resistance to sliding between the archwire and bracket promotes more seamless tooth movement, leading to a faster and improved orthodontic treatment experience. This research aimed to examine how the degradation of elastomeric modules, different ligation methods, bracket-wire angle, and wire type (nickel titanium, NiTi or stainless-steel, SS) impact the kinetic friction resulting from the interaction between NiTi or SS archwires and SS brackets. Materials and Methods: The current in vitro study was conducted on nine groups, including NiTi and SS archwires with three types of ligations (O-ring, figure of 8, and SS wire ligature) and two bracket-wire angles (0˚ and 10˚). The kinetic friction in each group was measured using a Universal Testing Machine at four time intervals: baseline, day one, week one, and week four. Repeated measures ANOVA, Mauchly test of sphericity followed by the Greenhouse-Geisser test, and relevant post hoc tests were used for statistical analysis (P<0.05). Results: The authors found a decrease in kinetic friction in all types of ligations, which confirmed the effect of time on the degradation of ligation modules. The kinetic friction of figure of 8 ligations was higher than both O-ring and SS wire ligations. No difference was observed between O-ring and SS wire ligations. Furthermore, the bracket-wire angle did not affect friction. Conclusion: The authors suggest that the use of figure of 8 ligations in NiTi and SS wires should be limited due to their high friction and replaced with other types of ligations, if possible.

The role of orthodontics in children identification: a case report of two victims of mass disaster.

INTRODUCTION: Human Identification based on dental evidence cannot be accomplished if antemortem dental records are unavailable or of poor quality. The involvement of the orthodontist in mass disaster victim identification processes may be crucial in relation to the amount and quality of the records which can be obtained before, during, and following the treatment. AIM: The aim of the study is the description of the contribution of the findings drawn from orthodontic records to the identification of victims of mass disasters who had received an orthodontic treatment, through the presentation of two cases. The first case involves the identification of a child victim of a plane crash and the second case involves the identification of two identical twin girls who died in a fire. In both cases, the identification was based on the findings obtained from the ante-mortem records provided by the orthodontist. CONCLUSIONS: The orthodontists apply customized orthodontic appliances and keep a comprehensive file of images, casts, radiographs, and other records in their practice. As a result, they can make a substantial contribution to the identification of young people or even adult victims of mass disasters in any case in which the authorities make a request.

An investigation of the corrosion behavior of zinc-coated stainless steel orthodontic wires: the effect of physical vapor deposition method.

BACKGROUND: Releasing of metal ions might implicate in allergic reaction as a negative subsequent of the corrosion of Stainless Steel (SS304) orthodontic wires. The aim of this study was to evaluate the corrosion resistance of zinc-coated (Zn-coated) SS orthodontic wires. METHODS: Zinc coating was applied on SS wires by PVD method. Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization tests and Tafel analysis methods were used to predict the corrosion behavior of Zn-coated and uncoated SS wires in both neutral and acidic environments. RESULTS: The values of Ecorr ,icorr and Rct ,which were the electrochemical corrosion characteristics, reported better corrosion behavior of Zn-coated SS wires against uncoated ones in both artificial saliva and fluoride-containing environments. Experimental results of the Tafel plot analyses were consistent with that of electrochemical impedance spectroscopy analyses for both biological solutions. CONCLUSION: Applying Zn coating on bare SS orthodontic wire by PVD method might increase the corrosion resistance of the underlying stainless-steel substrate.

Low-intensity pulsed ultrasound promotes the osteogenesis of mechanical force-treated periodontal ligament cells via Piezo1.

Background: Low-intensity pulsed ultrasound (LIPUS) can accelerate tooth movement and preserve tooth and bone integrity during orthodontic treatment. However, the mechanisms by which LIPUS affects tissue remodeling during orthodontic tooth movement (OTM) remain unclear. Periodontal ligament cells (PDLCs) are pivotal in maintaining periodontal tissue equilibrium when subjected to mechanical stimuli. One notable mechano-sensitive ion channel, Piezo1, can modulate cellular function in response to mechanical cues. This study aimed to elucidate the involvement of Piezo1 in the osteogenic response of force-treated PDLCs when stimulated by LIPUS. Method: After establishing rat OTM models, LIPUS was used to stimulate rats locally. OTM distance and alveolar bone density were assessed using micro-computed tomography, and histological analyses included hematoxylin and eosin staining, tartrate-resistant acid phosphatase staining and immunohistochemical staining. GsMTx4 and Yoda1 were respectively utilized for Piezo1 functional inhibition and activation experiments in rats. We isolated human PDLCs (hPDLCs) in vitro and evaluated the effects of LIPUS on the osteogenic differentiation of force-treated hPDLCs using real-time quantitative PCR, Western blot, alkaline phosphatase and alizarin red staining. Small interfering RNA and Yoda1 were employed to validate the role of Piezo1 in this process. Results: LIPUS promoted osteoclast differentiation and accelerated OTM in rats. Furthermore, LIPUS alleviated alveolar bone resorption under pressure and enhanced osteogenesis of force-treated PDLCs both in vivo and in vitro by downregulating Piezo1 expression. Subsequent administration of GsMTx4 in rats and siPIEZO1 transfection in hPDLCs attenuated the inhibitory effect on osteogenic differentiation under pressure, whereas LIPUS efficacy was partially mitigated. Yoda1 treatment inhibited osteogenic differentiation of hPDLCs, resulting in reduced expression of Collagen Ⅰα1 and osteocalcin in the periodontal ligament. However, LIPUS administration was able to counteract these effects. Conclusion: This research unveils that LIPUS promotes the osteogenesis of force-treated PDLCs via downregulating Piezo1.

Is Antibiotic Prophylaxis Needed for the Extraction of Premolars for Orthodontic Purposes?

Introduction Antibiotic prophylaxis for tooth extractions is a common practice in dentistry to prevent postoperative infections. However, the routine use of antibiotics has been questioned due to concerns about bacterial resistance and potential side effects. This study aimed to evaluate the necessity of postoperative antibiotics in patients undergoing orthodontic tooth extraction. Materials and methods This prospective study involved 100 patients requiring orthodontic tooth extraction, divided into two groups. The patients were recruited from Saveetha Dental College and Hospital, Chennai, India, after obtaining approval from the Institutional Human Ethics Committee, Saveetha Dental College (approval number: IHEC/SDC/OMFS-2103/23/293). Group 1 (n = 50) received antibiotics (amoxicillin 500 mg, three times a day for three days) after extraction, while Group 2 (n = 50) did not receive antibiotics. Postoperative infection was assessed on postoperative days (POD) 3 and 7. Data analysis was conducted using IBM SPSS Statistics for Windows, version 26.0 (released 2019, IBM Corp., Armonk, NY). Categorical variables were presented as frequencies and percentages, and differences between groups were assessed using chi-square or Fisher's exact tests. A p-value of <0.05 was considered statistically significant. Results The incidence of postoperative infection was recorded in both groups. In group 1 at POD 3 and POD 7, there were two patients and one patient with infection, respectively. In group 2 at POD 3 and POD 7, there were four patients and two patients with infection, respectively. Conclusion The findings of this study suggest that the routine administration of antibiotics for the non-traumatic extraction of teeth in healthy patients might not be necessary. The absence of postoperative infections in patients who did not receive antibiotics indicates that antibiotics may be avoidable in many cases of orthodontic tooth extraction. These results emphasize the importance of reconsidering the widespread use of antibiotics to combat the growing concern of bacterial resistance. Antibiotics should be prescribed judiciously, only for patients with specific medical conditions who are prone to infection. One of the limitations of this study is the limited sample size; hence, studies with larger and heterogeneous groups should be done to validate the same.

Resorptions and orthodontics / Résorptions et orthodontie

Introduction: It's generally accepted that one of the risks associated with orthodontic treatment is apical root resorption, even though this may occur outside orthodontic treatment. In any case, it causes root shortening. Orthodontists are probably the only dental surgeons who use the inflammatory process as a therapeutic tool. They need to be aware of the risk factors for root inflammation. Along with recurrence, leukemia and periodontal problems, resorption is one of the "inconveniences" of orthodontics, which, if not inevitable, must at least be minimized. Material and Method: At present, the orthodontic literature on root resorption provides some clues as to the factors associated with the onset, severity and management of root resorption, although the complexity of this phenomenon does not allow us to arrive at a clear and unequivocal consensus. For this reason, it is important to identify potential risk factors for resorption, to take them into account before/during and after treatment, and to know what attitude to adopt in the event of resorption appearing, all in order to minimize this phenomenon, as everyone agrees that it can be a source of harm and stress for both patient and practitioner. Conclusion: There are still many grey areas in our understanding of the phenomenon, including how the elements of orthodontic treatment influence orthodontic resorption. Irreversible in nature, resorption can be sufficiently extensive to cast doubt on the benefit of successful orthodontic treatment.

Introduction: Il est généralement admis que l'un des risques associés au traitement orthodontique est la résorption radiculaire apicale même si elle peut se produire en dehors de tout traitement orthodontique. Quoi qu'il en soit, elle provoque le raccourcissement radiculaire. Les orthodontistes sont sans doute les seuls spécialistes de la chirurgie dentaire qui utilisent le processus inflammatoire en tant que moyen thérapeutique. Ils doivent connaître les facteurs de risque de cette inflammation sur la racine. La résorption fait partie, au même titre que la récidive, les leucomes et les problèmes parodontaux, des « inconvénients ¼ de l'orthodontie qui, à défaut d'être inévitables, doivent au moins être minimisés. Matériels et méthode: Actuellement, la littérature orthodontique sur la résorption radiculaire fournit quelques pistes sur les facteurs associés à l'apparition, la gravité et la gestion de la résorption radiculaire, même si la complexité de ce phénomène ne nous permet pas d'en dégager un consensus clair et équivoque. Pour cette raison, il est important d'identifier les facteurs de risque de résorption potentiels pour en tenir compte avant/pendant et après le traitement et connaître l'attitude à adopter en cas d'apparition de résorptions, tout ceci afin de minimiser ce phénomène, car tout le monde s'accorde sur le fait qu'elle peut être source de préjudice et de stress pour le patient et le praticien. Conclusion: De nombreuses zones d'ombres subsistent dans la compréhension du phénomène, notamment sur comment les éléments du traitement orthodontique influencent la résorption orthodontique. De nature irréversible, la résorption peut être suffisamment étendue pour jeter un doute sur le bénéfice apporté au succès du traitement orthodontique.

Macrophage M2 polarization promotes pulpal inflammation resolution during orthodontic tooth movement.

Mechanical force induces hypoxia in the pulpal area by compressing the apical blood vessels of the pulp, triggering pulpal inflammation during orthodontic tooth movement. However, this inflammation tends to be restorable. Macrophages are recognized as pivotal immunoreactive cells in the dental pulp. Whether they are involved in the resolution of pulpal inflammation in orthodontic teeth remains unclear. In this study, we investigated macrophage polarization and its effects during orthodontic tooth movement. It was demonstrated that macrophages within the dental pulp polarized to M2 type and actively participated in the process of pulpal inflammation resolution. Inflammatory reactions were generated and vascularization occurred in the pulp during orthodontic tooth movement. Macrophages in orthodontic pulp show a tendency to polarize towards M2 type as a result of pulpal hypoxia. Furthermore, by blocking M2 polarization, we found that macrophage M2 polarization inhibits dental pulp-secreting inflammatory factors and enhances VEGF production. In conclusion, our findings suggest that macrophages promote pulpal inflammation resolution by enhancing M2 polarization and maintaining dental health during orthodontic tooth movement.