Orthodontic Force Research Articles

Recent progress in alleviating orthodontic discomfort: Mechanism and management-the state of evidence

Orthodontic treatment has demonstrated efficacy in enhancing dental health and rectifying tooth misalignments. Nevertheless, patients experience substantial discomfort and distress. Advancements in orthodontic technology and treatment procedures have led to a decrease in orthodontic discomfort. Orthodontic discomfort refers to the inflammation that occurs due to the obstruction of blood vessels by orthodontic force. This leads to inflammatory responses, which encompass alterations in blood vessels, recruitment of inflammatory and immune cells, and heightened sensitivity of nerves along with the release of chemicals that promote inflammation. The body's inherent analgesic systems ultimately regulate the inflammatory response, thereby diminishing pain. Orthodontic pain signals are transmitted by three-order neurons, beginning with the trigeminal neuron located in the trigeminal ganglia. The signals subsequently arrive at the trigeminal nucleus caudalis located in the medulla oblongata, as well as the ventroposterior nucleus in the thalamus, where the sensation of pain is perceived. The processing of orthodontic pain involves the interplay of emotion, cognition, and memory in many parts of the brain. The structures encompassed in this list are the insular cortex, amygdala, hippocampus, locus coeruleus, and hypothalamus. The inherent analgesic neuronal pathway of the periaqueductal gray and dorsal raphe regions alleviates orthodontic discomfort. Various techniques are employed to manage orthodontic discomfort. These therapies encompass pharmacological, mechanical, behavioral, and low-level laser treatments. Nonsteroidal anti-inflammatory medicines (NSAIDs) alleviate pain, but their impact on tooth movement remains uncertain. Additional research is required to establish the effectiveness of alternative modalities. Gene therapy provides a new, practical, and hopeful approach to treating orthodontic pain. This article explores new advancements and techniques that have enhanced the level of comfort experienced by orthodontic patients.

The Hydrostatic Pressure Distribution in the Periodontal Ligament and the Risk of Root Resorption-A Finite Element Method (FEM) Study on the Nonlinear Innovative Model.

Excessive orthodontic force can induce inflammatory tooth root resorption due to sustained high stresses within the periodontal ligament (PDL). This study aimed to analyze the PDL pressures during upper incisor retraction using the en masse method with TISAD. The finite element method (FEM) ensured consistent conditions across cases. The models included bone geometry, adjacent teeth, PDL, and orthodontic hardware, analyzed with LS-Dyna. The pressure ranged from 0.37 to 2.5 kPa across the dental arch, with the central incisors bearing 55% of the load. The pressure distribution remained consistent regardless of the force or hook height. The critical pressure (4.7 kPa) was exceeded at 600-650 g force, with notable pressure (3.88 kPa) on the palatal root wall of the right central incisor. Utilizing 0.017 × 0.025 SS archwires in MBT 0.018 brackets provided good torque control and reduced the root resorption risk when forces of 180-200 g per side were applied, maintaining light to moderate stress. Triple forces may initiate resorption, highlighting the importance of nonlinear finite element analysis (FEA) for accurate oral cavity simulations.

Properties and Application of the Gummetal Wire for the Treatment of an Open Bite—Brief Narrative Review and Case Report

The swift integration of ‘Gummetal’ into the orthodontic armamentarium can be attributed to its distinct advantages as an entirely new Ti-Nb-based beta titanium alloy. Developed by Toyota Central R&D Labs and publicly revealed in April 2003, this innovative material is rapidly reshaping orthodontic practices. Its sui generis properties allow its use as a potential substitute for the Multi-Loop Edgewise Archwire (MEAW) method. Three-dimensional orthodontic movement using this new alloy could eliminate the disadvantages of the MEAW method, such as its technical complexity and patient discomfort. In our comprehensive review of the current literature, we examined relevant publications sourced from the PUBMED database and explored one seminal work on Gummetal from the journal literature. Characteristic properties of Gummetal, such as its exceptional flexibility, superelasticity, and malleability (approximately 10 times greater than conventional metals), enable seamless formation of bends without posing challenges, thereby allowing precise control over orthodontic force application. Also worthy of mention are Gummetal’s biocompatibility and non-toxic properties, along with its low coefficient of friction. The wire seems to be a relatively easy way to achieve good occlusion. Its usage does not require extensive experience in terms of manual skill, and it is not time consuming. Diligent usage of any prescribed plastics by the patient is crucial to prevent complications and ensure successful orthodontic outcomes.

Correlation of Leptin Concentration in Gingival Crevicular Fluid on the Rate of Orthodontic Tooth Movement - A Prospective Study.

The evaluation of genetic markers in the gingival crevicular fluid (GCF) and their connection to tooth movement can be helpful. The objective of this research is to assess the relationship involving leptin levels and orthodontic tooth movement (OTM). Thirty individuals reporting to the Department of Orthodontics participated in an observational prospective study. Thirty orthodontic patients (15 male and 15 female) were included in the current study. The association of leptin concentration (GCF) was measured before and after orthodontic force was applied to move the mesially impacted canine distally (tooth movement distance on dental cast). With the help of SPSS software version 21, the data were statistically examined using the " t " test, one-way ANOVA, and Bonferroni correction in Chicago. The average degree of tooth movement was calculated using Pearson's correlation coefficient, and it was connected to the average leptin levels. Average leptin levels in GCF elevated from baseline (T0, 285.315 picograms/micro litre) to 1 h after force application (T1, 384.683 pg/μL), then raised to a maximum at after 24 h (T2, 927.64 pg/μL), and decreased to the least amount after 15 days (T3, 29.26 pg/μL) and another time increase after two months (242.31 pg/μL). The degree of OTM was significantly correlated with the levels of leptin. While OTM was occurring, a biphasic fluctuation in the leptin level was noted. The amount of tooth movement was significantly correlated with the GCF leptin level.

Autotransplanted premolars for substituting traumatic maxillary central incisors in a Class II growing patient

A 10-year-old young Hispanic male patient was referred to the Endodontics Department with the chief complaint of color change of maxillary central incisors. The parents reported trauma one year before and as a result root canal treatment; maxillary central incisors extractions were necessary due to poor prognosis, so he was referred to the Orthodontics Department to evaluate if the patient could be the candidate for orthodontic treatment, as he showed severe crowding. The patient had no medical conditions, and the pretreatment records showed a Class II skeletal relation and vertical pattern. Dental findings were mixed dentition, an Angle Class II molar relationship, moderate upper and lower anterior crowding, 4 mm of overbite, and 7 mm of overjet. The patient underwent autotransplantation of maxillary second premolars into the place of maxillary central incisors that needed to be extracted as stated by the endodontist (premolar extractions were needed to solve the orthodontic problems). The suggested position for the autotransplant teeth was not accomplished by the surgeon, so orthodontic forces were applied to the autotransplant teeth to the ideal position. At the end of orthodontic treatment, the autotransplanted teeth were restored by the prosthodontist. Therefore, the facial balance improved, and the final occlusal relationships were good. COVID-19 global lockdown was a challenging obstacle to overcome during treatment. This case report intends to highlight the potential benefits of tooth autotransplantation and to increase awareness of this treatment protocol.

Perbedaan Jumlah Hitung Osteoblas pada Pergerakan Ortodontik Gigi Setelah Pemberian Jintan Hitam

Osteoblasts are important for orthodontic tooth movement because they influence the activity of bone formation on the tension area. The administration of natural ingredients such as black cumin is proven to increase the number of osteoblasts because it contains thymoquinone as antioxidants to accelerate the process of tooth movement. The study aims to determine the differences in osteoblast count and their effect on the orthodontic movement of teeth after oral administration of black cumin. The method used in this research is experimental laboratory in vivo with a randomized post-test only control group design using 16 male Sprague-Dawley rat samples that were devided into four groups: the control group (K) with distilled water for 7 and 14 days, also the treatment group (P) with black cumin (Nigella sativa) for 7 and 14 days Elastomeric separators were placed on the upper jaw central incisors (right central incisor) using a separator applier to provide orthodontic mechanical force conditions. Alveolar bone tissue samples were taken after treatment then the number of osteoblasts was calculated histologically. Data were anaylzed using One Way Anova Test and LSD (p<0.05). Result of this research indicated that there was an increase in the number of osteoblasts in orthodontic movement after oral administration of black cumin.

Evaluation of Root Resorption and Tooth Inclination in Class II Malocclusion Patients Treated with Advansync2 Appliance – A CBCT Study

The Advansync2 appliance is known as a tooth-borne fixed functional appliance consisting of bands cemented on permanent first molars in the upper and lower arches, to dissipate orthodontic forces. These fixed functional appliances could cause excessive proclination of the lower incisors, which could lead to inflammatory root resorption. Therefore, the purpose of this study was to evaluate the degree of root resorption and incisor tooth inclination changes in subjects with class II malocclusion who were treated with the Advansync2 appliance. 10 patients (6 males and 4 females ) between the age group of 13-20 years with class II malocclusion treated with Advansyc2 appliance were included. A CBCT of each of these patients was taken before and after the treatment with the Advansync2 appliance and evaluated for the amount of root resorption and tooth inclination in the mandibular incisor tooth region. The measurement of root resorption was made using the axial navigation method. Statistical analysis was done using SPSS software (version 22.0). A paired t-test was used to detect changes in the root length before and after the use of the Advansync2 appliance. Wilcoxon signed-rank test was used to compare the parameters of the angle of inclination as the data was not normally distributed. There was a statistically significant reduction of the mandibular anterior tooth roots by 0.52mm (p =0.01). The angle of inclination for the mandibular incisor region was reduced by 5.73 ° indicative of proclined incisors (p = 0.005).

Aucubin produces anti-osteoporotic effects under mechanical stretch stress and orthodontic tooth movement

Aucubin (AU), an iridoid glycoside extracted from Eucommia ulmoides, exerts anti-osteoporotic effects by promoting osteogenesis, as reported in previous studies. Here, we investigated the effects of AU under mechanical stretch stress. MC3T3-E1 cells were treated with dexamethasone (DEX) in vitro and subjected to mechanical stretch stress to establish an osteoporotic orthodontic force cell model. AU treatment increased the mRNA and protein expressions of BMP2, OPN, RUNX2, COL-1 and other osteogenic differentiation factors in MC3T3-E1 cells. Furthermore, we established an in vivo orthodontic tooth movement (OTM) model of osteoporosis. Serum parameter detection of ALP concentration, radiography of the femur, hematoxylin-eosin (HE) staining, and micro-CT of the maxilla confirmed that AU could partially reverse the damage induced by DEX. Immunohistochemical (IHC) analysis showed that AU increased the expression of COL-1, OCN, and OPN on the tension side of the periodontium. In conclusion, AU treatment promotes osteogenic differentiation under mechanical stretch stress and positively affects bone remodeling during OTM in DEX-induced osteoporosis.

Bone Remodeling of Maxilla after Retraction of Incisors during Orthodontic Treatment with Extraction of Premolars Based on CBCT Study: A Systematic Review.

Background: Incisor retraction is often a crucial phase in ongoing orthodontic treatment, with significant implications for alveolar remodeling mechanisms. There are two prevailing theories which seek to explain this. According to the first, teeth move with the bone, while according to the second, teeth move within the bone. This systematic review seeks to assess morphometric changes in the maxillary alveolar process resulting from incisor retraction following premolar extraction and to evaluate the potential for bone remodeling associated with orthodontic movement. Methods: The study was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The following electronic databases were searched: PubMed, Google Scholar, Web of Science EMBASE and the Cochrane Central Register of Controlled Trials. The databases were searched using the following keywords: "Bone remodeling and retraction of incisors", "Alveolar bone and incisor retraction", "Bone thickness and incisor retraction", and "Bone changes and orthodontic treatment". Search filters were utilized to identify relevant papers and articles written in English and published during the last 10 years. Based on the information provided in their abstracts, papers and articles were selected according to the following criteria: randomized clinical trials (RCTs), controlled clinical prospective trials (CCTs), and retrospective studies. Articles unrelated to the study's scope or failing to meet inclusion criteria were excluded. These generally comprised individual case reports, case series reports, literature reviews, experimental studies, studies with limited data (including conference abstracts and journal writings), studies involving an unrepresentative group of patients (less than 10 patients), studies concerning patients with syndromes, and animal experiments. The remaining articles which were deemed relevant underwent comprehensive reference review and such journals as the American Journal of Orthodontics, Dentofacial Orthopedics, International Orthodontics, Journal of Clinical Orthodontics, and Angle Orthodontist were manually searched. Results: Seven articles meeting the inclusion criteria articles were selected for final evaluation, with a total of 284 participants, including 233 women and 51 men. During the analysis of the results included in the publications, a lack of homogeneity was observed, rendering a reliable statistical analysis and heterogeneity assessment unobtainable. Noteworthy disparities in methodologies and measurements posed a risk of drawing inappropriate conclusions. Consequently, emphasis was placed on qualitative analysis, emphasizing the need for standardization in future studies of a similar nature, to enable valid and comparable analyses. Conclusions: The research findings incorporated in this review demonstrate that significant bone loss occurs because of incisor retraction, which diminishes distance between the bone surface and the root surface on the palatal aspect. The magnitude of this change may vary, contingent upon both the extent of incisor displacement and alterations in their inclination, thereby affecting the positioning of the root tips. This change is significantly higher in adults than in growing adolescents. The rationale behind this assertion lies in the widely recognized phenomenon of declining cellular activity with advancing age. The decrease in the speed and intensity of cellular changes may explain the diminished capacity for remodeling as patient age increases. There is ongoing discourse regarding alterations in the volume of bone on the labial aspect of the alveolar process. Further research is necessary to measure whether bone remodeling during orthodontic movement is contingent upon other factors, such as the speed and biomechanics of retraction, the level of applied orthodontic force, and the patient age.

Micro-Osteoperforations Accelerate Tooth Movement without Exacerbating the Progression of Root Resorption in Rats.

A recent study reported that micro-osteoperforations (MOPs) accelerated tooth movement by activating alveolar bone remodeling. However, very little is known about the relationship between MOPs and external apical root resorption during orthodontic treatment. In this study, in order to investigate the mechanism through which MOPs accelerate tooth movement without exacerbating the progression of root resorption, we measured the volume of the resorbed root, and performed the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) method on exposed MOPs during experimental tooth movements in rats. Male Wistar rats (11 weeks old) were divided into three groups: 10 g orthodontic force (optimal force) applied to the maxillary first molar (optimal force: OF group), 50 g orthodontic force application (heavy force: HF group), and 10 g force application plus three small perforations of the cortical plate (OF + MOPs group). On days 1, 4, 7, 10, and 14 after force application, the tooth movement and root volume were investigated by micro-computed tomography. Furthermore, the number of apoptotic cells in the pressured sides of the periodontal ligament (PDL) and surrounding hard tissues were determined by TUNEL staining. The OF + MOPs group exhibited a 1.8-fold increase in tooth movement on days 7, 10, and 14 compared with the OF group. On days 14, the HF group had a higher volume of root loss than the OF and OF + MOPs groups. On the same day, the number of TUNEL-positive cells in the HF group increased at the root (cementum) site whereas that in the OF group increased at the alveolar bone site. Furthermore, the number of TUNEL-positive cells in the OF + MOPs group increased at the alveolar bone site compared with the OF group. These results suggest that MOPs accelerate orthodontic tooth movement without exacerbating the progression of root resorption.

Use of an intraoral scanner to evaluate orthodontic treatment for dental malocclusion in a dog.

In human dental practice, intraoral scanners (IOSs) are increasingly used to evaluate the oral cavity. However, there have been no reports concerning evaluation of the canine oral cavity using IOSs in veterinary dentistry. In this case, optical impressions obtained with an IOS were used for 3-D evaluation of the orthodontic treatment outcome. Additionally, few reports have addressed the optimal orthodontic force for canine teeth. Therefore, this case explored whether sufficient tooth movement into the extraction site could be achieved with a lighter orthodontic force than previously reported. An 8-month-old spayed female dog. A retained right maxillary third deciduous incisor (503) caused distoversion of the right maxillary third permanent incisor (103), leading to dental malocclusion that involved contact between 103 and the right mandibular canine teeth. All retained deciduous teeth were extracted. Mesial tipping movement of 103 into the extraction site of 503 was achieved with light orthodontic force using an elastomeric chain. An IOS was used to construct 3-D optical impression data from oral stone models taken before and after treatment, and tooth movement was evaluated. The results showed that 103 had sufficient tipping movement and no anchorage loss; comfortable occlusion was achieved. In addition to crown length extension, labioversion and mesioversion of maxillary incisors (other than 103) were observed. Detailed intraoral evaluation with optical impressions was beneficial in the orthodontic treatment of a dog. Light orthodontic force may be sufficient for movement into the extraction site.

The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats

The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment. However, the sensitivity of existing detection techniques is not sufficient, and the criteria for evaluating optimal force have not been yet established. Here, by employing 3D finite element analysis methodology, we found that the apical distal region (A-D region) of mesial roots is particularly sensitive to orthodontic force in rats. Tartrate-resistant acidic phosphatase (TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams (g), leading to alveolar bone resorption and tooth movement. When the force reached 80 g, TRAP-positive osteoclasts started appearing on the root surface in the A-D region. Additionally, micro-computed tomography revealed a significant root resorption at 80 g. Notably, the A-D region was identified as a major contributor to whole root resorption. It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement, inclination, and hyalinization. These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model. Collectively, our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients’ orthodontic treatment.

Biological Effects of Orthodontic Tooth Movement on the Periodontium in Regenerated Bone Defects: A Scoping Review.

The aim of this scoping review is to analyse the biological effects of the orthodontic tooth movement (OTM) in areas with bone defects that are undergoing regeneration using different types of regenerative materials and techniques. The electronic research was performed on four databases as follows: PubMed, Scopus, EMBASE, and Web of Science. Data were extracted according to publication information, study design, sample characteristics, parameters of OTM, biological repercussions on the periodontium complex, methods of analysis, and conclusions. A total of thirty studies were included in the final review. In twenty-two studies, the most widely adopted grafting materials were alloplastics. In most studies, the orthodontic force used was 10 or 100 g, and the timing of application ranged from immediate to 6 months after grafting surgery. Twenty-four studies showed an increase in osteogenesis; in five studies, the clinical attachment level (CAL) increased; in five others, the probing pocket depth (PPD) decreased; in sixteen studies, there was root resorption of a different magnitude. Though the effects of OTM on the periodontium in the grafted areas were positive, the outcomes should be interpreted with caution as future preclinical and clinical studies are needed to extrapolate more valid conclusions.

Nociceptor mechanisms underlying pain and bone remodeling via orthodontic forces: toward no pain, big gain.

Orthodontic forces are strongly associated with pain, the primary complaint among patients wearing orthodontic braces. Compared to other side effects of orthodontic treatment, orthodontic pain is often overlooked, with limited clinical management. Orthodontic forces lead to inflammatory responses in the periodontium, which triggers bone remodeling and eventually induces tooth movement. Mechanical forces and subsequent inflammation in the periodontium activate and sensitize periodontal nociceptors and produce orthodontic pain. Nociceptive afferents expressing transient receptor potential vanilloid subtype 1 (TRPV1) play central roles in transducing nociceptive signals, leading to transcriptional changes in the trigeminal ganglia. Nociceptive molecules, such as TRPV1, transient receptor potential ankyrin subtype 1, acid-sensing ion channel 3, and the P2X3 receptor, are believed to mediate orthodontic pain. Neuropeptides such as calcitonin gene-related peptides and substance P can also regulate orthodontic pain. While periodontal nociceptors transmit nociceptive signals to the brain, they are also known to modulate alveolar bone remodeling in periodontitis. Therefore, periodontal nociceptors and nociceptive molecules may contribute to the modulation of orthodontic tooth movement, which currently remains undetermined. Future studies are needed to better understand the fundamental mechanisms underlying neuroskeletal interactions in orthodontics to improve orthodontic treatment by developing novel methods to reduce pain and accelerate orthodontic tooth movement-thereby achieving "big gains with no pain" in clinical orthodontics.

Potential Analysis of Belimbing Wuluh (Averhoe bilimbi L.) leaf extract on increasing Fibroblasts, TGFß1 expression and density of Collagen fibers in the Periodontal ligament during Orthodontic Tooth Movement

Background: Orthodontic treatment is a treatment to correct malocclusion. The periodontal ligament plays an important role in preventing recurrence after orthodontic treatment. Fibroblast cells play a role in the regeneration of the periodontal ligament to maintain the stability of orthodontic treatment. Fibroblast cells play a role in the formation of collagen fibers that will connect teeth to bones. TGFß1 is a growth factor that plays a role in inducing the proliferation and transformation of fibroblasts into myofibroblasts and stimulates the accumulation of matrix proteins, including laminin, collagen 1 and 3, and fibronectin. Orthodontic treatment takes a long time so we need a method to speed it up. Belimbingwuluh leaf extract (Averrhoa bilimbi L.) contains antioxidants and anti-inflammatories which are expected to increase the number of fibroblasts and the density of collagen fibers. Objective : To analyze the potential of belimbingwuluh leaf extract in increasing the number of fibroblasts, TGFß1 expression and collagen fiber density during orthodontic tooth movement. Method: using 36 rats divided into 6 groups. The control group was fitted with orthodontic appliances without extracts, and the treatment group was fitted with orthodontic appliances and starfruit leaf extract for 7 days, 14 days and 21 days. An orthodontic appliance in the form of a closed coil spring Ni-Ti was installed to move the maxillary first molars mesially with orthodontic mechanical force. Histological preparations were made on M1 RA teeth with their periodontal ligament, then the tissue was stained with HE to observe fibroblasts, and Trichome Mallory staining for collagen fiber density and immunohistochemical staining to examine TGFß1 expression. Observation of fibroblasts and TGFß1 expression using a microscope and collagen density were observed using a microscope using the Adobe CS 6.0 application. Results: showed a significant increase in the number of fibroblasts, TGFß1 expression and density of collagen fibers in the 7, 14 and 21 day treatment group compared to the control group (p<0.05). Conclusion: BelimbingWuluh leaf extract increases fibroblasts, TGFß1 expression and collagen fiber density in the periodontal ligament during orthodontic tooth movement.

The Correlation between the Bone Morphotype and Density and Root Apical Resorption of the Anterior Teeth Due to Orthodontic Forces

The potential side effects of modern orthodontic treatment and its unfavorable impact on dentition and hard tissues have been extensively discussed in professional literature for decades. The presence of uncontrolled forces can result in pulp necrosis, radicular reabsorption, and/or loss of alveolar bone. Dehiscence and fenestration are more commonly found in anterior than posterior teeth, where only the periodontal ligament and the mucosa protect the dental root.
 Most studies investigating the effect of periodontal phenotype over gingival recession in orthodontic patients have primarily focused on examining the soft tissues. However, due to the vulnerability of thin alveolar bone, the previous evaluation of orthodontic candidate patients may also include the analysis of hard tissues. Bone density plays an important role in facilitating orthodontic tooth movement, such that reductions in bone density can significantly increase movement velocity. These types of localized density changes can affect the rate of orthodontic tooth movement and may also influence the risk of unwanted outcomes, such as the occurrence of dental external apical root resorption.
 According to the literature, the links of root resorption with the bone morphotype and the density are relevant in clinical dentistry but have not been studied in detail. However, the existing data is not yet conclusive.

Efficacy of microchips and 3D sensors for orthodontic force measurement: A systematic review of invitro studies.

To evaluate the efficacy of microchips and 3D microsensors in the measurement of orthodontic forces. Through September 2023, comprehensive searches were conducted on PubMed/MEDLINE, SCOPUS and SCIELO without restrictions. After removing duplicate entries and applying the eligibility criteria, 23 studies were included for analysis. All the studies were conducted invitro, and slightly more than half of them were centred on evaluating orthodontic forces exerted by aligners. Eight utilized microchips as measurement tools, while the remaining studies made use of 3D microsensors for their assessments. In the context of fixed appliances, key findings included a high level of agreement in 3-dimensional orthodontic force detection between simulation results and actual applied forces. Incorporating critical force-moment combinations during smart bracket calibration reduced measurement errors for most components. Translational tooth movement revealed a moment-to-force ratio, aligning with the bracket's centre of resistance. The primary findings in relation to aligners revealed several significant factors affecting the forces exerted by them. Notably, the foil thickness and staging were found to have a considerable impact on these forces, with optimal force transmission occurring at a layer height of 150 μm. Furthermore, the type of material used in 3D-printing aligners influenced the force levels, with attachments proving effective in generating extrusive forces. Deliberate adjustments in aligner thickness were observed to alter the forces and moments generated. Microchips and 3D sensors provide precise and quantitative measurements of orthodontic forces in invitro studies, enabling accurate monitoring and control of tooth movement.

A narrative review of the effects of vitamin D3 on orthodontic tooth movement: Focus on molecular and cellular mechanisms.

Orthodontic tooth movement (OTM) is a critical process in dental alignment, driven by the application of calibrated orthodontic forces. This study delves into the intricate molecular and cellular mechanisms by which vitamin D3 influences OTM. Vitamin D3 is identified as a critical regulator in bone metabolism, enhancing osteoblast activity and bone formation while also modulating osteoclast quantity and RANKL expression, essential for the remodeling of the alveolar bone. The precise mechanisms through which vitamin D3 facilitates these processes are explored, highlighting its potential in accelerating bone remodeling and, consequently, tooth alignment. This comprehensive review underscores vitamin D3's anabolic impact on bone metabolism and its pivotal role in the synthesis and mineralization processes governed by osteoblasts. The findings illuminate vitamin D3's promise in augmenting orthodontic therapy, suggesting its utility in improving treatment efficiency and reducing duration. However, the need for further research into the optimal application of vitamin D3 in orthodontics is emphasized, particularly concerning dosage, timing, and delivery methods.

Management of anchor loss with the use of infrazygomatic implants – A case series

The mesial tipping of the first molar marks the onset of anchorage loss, and changes in the angulation of the first molar are closely related to anchorage loss. Despite the various treatment strategy, different patients show different tendencies towards anchorage loss, which influences the treatment results and must be managed. The quest for search for an ideal intraoral anchorage device has led orthodontists to micro-implants or temporary anchorage devices (TADs), which offer to solve one of the greatest dilemmas of “anchorage control. The use of miniscrews has been increased recently due to their ease of insertion and removal, reasonable cost, biocompatibility and capability to withstand orthodontic forces The introduction of the mini screw and infrazygomatic implant has provided orthodontists with a solution to the significant challenge of "anchorage control." This case series describes the successful management of anchor loss with the infrazygomatic implant(IZC) that occurred during premolar extraction space closure in a Class I and Class II malocclusion patients with severely proclined maxillary incisors.

Long non-coding RNA LncTUG1 regulates favourable compression force-induced cementocytes mineralization via PU.1/TLR4/SphK1 signalling.

Orthodontic tooth movement (OTM) is a highly coordinated biomechanical response to orthodontic forces with active remodelling of alveolar bone but minor root resorption. Such antiresorptive properties of root relate to cementocyte mineralization, the mechanisms of which remain largely unknown. This study used the microarray analysis to explore long non-coding ribonucleic acids involved in stress-induced cementocyte mineralization. Gain- and loss-of-function experiments, including Alkaline phosphatase (ALP) activity and Alizarin Red S staining, quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and immunofluorescence analyses of mineralization-associated factors, were conducted to verify long non-coding ribonucleic acids taurine-upregulated gene 1 (LncTUG1) regulation in stress-induced cementocyte mineralization, via targeting the Toll-like receptor 4 (TLR4)/SphK1 axis. The luciferase reporter assays, chromatin immunoprecipitation assays, RNA pull-down, RNA immunoprecipitation, and co-localization assays were performed to elucidate the interactions between LncTUG1, PU.1, and TLR4. Our findings indicated that LncTUG1 overexpression attenuated stress-induced cementocyte mineralization, while blocking the TLR4/SphK1 axis reversed the inhibitory effect of LncTUG1 on stress-induced cementocyte mineralization. The in vivo findings also confirmed the involvement of TLR4/SphK1 signalling in cementocyte mineralization during OTM. Mechanistically, LncTUG1 bound with PU.1 subsequently enhanced TLR4 promotor activity and thus transcriptionally elevated the expression of TLR4. In conclusion, our data revealed a critical role of LncTUG1 in regulating stress-induced cementocyte mineralization via PU.1/TLR4/SphK1 signalling, which might provide further insights for developing novel therapeutic strategies that could protect roots from resorption during OTM.