Orthodontic Force Research Articles

The Influence of the Periodontal Breakdown over the Amount of Orthodontic Force Reaching the Dental Pulp and NVB During Orthodontic Movements—A Biomechanical Finite Element Analysis

Background/Objectives: Most orthodontic forces are absorbed–dissipated before reaching the dental pulp and its neuro-vascular bundle (NVB); nonetheless, no data are available about this issue during the periodontal breakdown. The current study’s objective was to investigate how much orthodontic force reaches the dental pulp and NVB during the orthodontic movements in periodontal breakdown. Methods: Herein, an assessment was performed on the second lower premolar of nine patients (72 3D models) and included 1440 numerical simulations. A gradual horizontal periodontal breakdown (1–8 mm loss) was simulated. Five orthodontic movements (intrusion, extrusion, rotation, translation, and tipping) under 0.5 N/5 KPa and 4 N/40 KPa were assessed. The numerical methods used were Von Mises/VM (overall homogenous) and Tresca (shear non-homogenous), suitable for the ductile resemblance of dental tissues. Results: Both methods showed similar color-coded projections for the two forces. Quantitatively, Tresca was 1.14 times higher than VM and lower than the maximum physiological hydrostatic circulatory pressure. During the bone loss simulation, the NVB stress was 5.7–10.7 times higher than the pulpal stress. A gradual tissue stress increase was seen, strictly correlated with the bone loss level. For 1 mm bone loss, only 2–3% of the applied force manifested at the NVB level (0.27–0.5% for pulp), while for 8 mm loss, the received stress was 4–10% for the NVB (0.6–0.9% for pulp) when compared to the applied force. Only translation displayed pulpal stress. Conclusions: When assessing NVB stress, the tooth absorption–dissipation ability of dental tissues varied between 90 and 93% (8 mm loss) and 97% (1 mm bone loss) and 99% when assessing pulpal stress.

Compression force regulates cementoblast mineralization via S1PR1/mitophagy axis.

Orthodontically induced inflammatory root resorption (OIIRR) poses a significant clinical challenge, as excessive orthodontic force shortens tooth longevity by impairing cementoblast-mediated cementum mineralization and promoting root resorption. Cementoblasts, essential for mineralized cementum formation and resistance to resorption, exhibit altered mechanosensitivity and mechanotransduction under orthodontic force, yet the role of mitophagy in this process remains poorly understood. In this study, we investigated how the S1PR1/mitophagy axis modulates cementoblast mineralization and OIIRR progression. The invivo orthodontic loading model revealed that heavy compression force triggered OIIRR and impaired cementoblast mineralization along with suppression of mitophagy in cementoblasts by downregulating PINK1 and PARKIN expression. The invitro experiments further confirmed that heavy compression force increased reactive oxygen species (ROS) levels, disrupted mitochondrial membrane potential (MMP), and inhibited mitophagy in OCCM30 cells, thereby impairing their mineralization capacity. Mechanistically, S1PR1 upregulation activated mitophagy, which in turn restored cementoblast mineralization under heavy compression force. Moreover, pharmacological activation of S1PR1 with SEW2871 alleviated OIIRR invivo. These findings highlight the pivotal role of the S1PR1/mitophagy axis in maintaining cementoblast function and mineralization under orthodontic force, offering novel insights into the molecular mechanisms underlying OIIRR and suggesting potential therapeutic strategies to prevent OIIRR during orthodontic treatment.

Nociceptor Neurons Facilitate Orthodontic Tooth Movement via Piezo2 in Mice.

Multiple sensory afferents, including mechanosensitive and nociceptive nerves, are projected to the periodontium. Peptidergic afferents expressing transient receptor potential vanilloid 1 (TRPV1), a receptor for capsaicin, mediate pain caused by orthodontic forces. However, their role in orthodontic force-induced alveolar bone remodeling is poorly understood as is the contribution of mechanosensitive ion channels such as Piezo2 in nociceptive nerves. To investigate this role, we studied orthodontic tooth movement and alveolar bone remodeling using neural manipulations and genetic mouse models. Chemical ablation of TRPV1-expressing afferents localized to the trigeminal ganglia decreased orthodontic force-induced tooth movement and the number of osteoclasts in alveolar bone on the compression side. The extent of the force-induced increase in the ratio of receptor activator of nuclear factor kappa-B ligand/osteoprotegerin in the periodontium was modestly decreased in the chemical ablation group. Furthermore, chemogenetic silencing of TRPV1-lineage afferents reduced orthodontic tooth movement and the number of osteoclasts. Piezo2 was expressed in most periodontal afferents, and chemogenetic inhibition of Piezo2-expressing neurons decreased orthodontic tooth movement and the number of osteoclasts. In addition, the conditional knockout of Piezo2 in TRPV1-lineage afferents decreased orthodontic tooth movement and the number of osteoclasts. Overall, these results suggest that nociceptor neurons play critical roles in orthodontic force-induced alveolar bone remodeling and that the mechanical activation of neuronal Piezo2 in nociceptive nerves facilitates orthodontic tooth movement and associated alveolar bone remodeling.

The effect of clear aligner and fixed orthodontic treatment on the development of pulp stones: a retrospective observational study.

To report the prevalence of pulp stones (PSs) in molars of orthodontically treated patients, investigate the impact of orthodontic treatment (ORT) using clear aligners (CAs) and fixed appliances (FAs) on the development of PSs in molars, and investigate the association between the incidence of PSs during ORT and the studied variables. Pretreatment orthopantomograms (OPGs) of 600 patients were assessed. Of those, posttreatment OPGs of 272 patients were available. Molars were subdivided into four subgroups based on type of appliance and force application: group 1, first molars included in FA (n = 707); group 2, first molars included in CA (n = 157); group 3, second molars included in CA (n = 189); group 4, second molars not included in FA during treatment (n = 880). PSs were diagnosed when radiopaque bodies were detected in the coronal and/or radicular pulp space. PS changes after treatment were recorded and analyzed using SPSS. The prevalence of PSs was 16.6%. The overall incidence of PSs increased by 5.9% and 4.5% in groups 1 and 2, and by 3.7% and 5.3% in groups 3 and 4, respectively (P ≤ .05). No significant differences were found between appliance type groups (1 and 2) and force application groups (3 and 4). The association between PS development and the type of appliance or treatment duration was not significant. The incidence of PSs increased during ORT, which was more pronounced in maxillary molars. PS development during ORT was not associated with orthodontic appliance type, force application, and duration of ORT.

Application of pulp tissue genetic profile in orthodontic tooth movement: a needle in a haystack?

Zhao Z, Attanasio C, Zong C, Pedano M S, Cadenas de Llano-Pérula M. How does orthodontic tooth movement influence the dental pulp? RNA-sequencing on human premolars. Int Endod J 2024; 57: 1783-1801. Sample selection- The study sample consisted of healthy individuals requiring extraction of maxillary or mandibular premolars for fixed appliance orthodontic treatment. Exclusion criteria included systemic diseases, a history of smoking, antibiotic or analgesic use within the past three months, periodontal probing depths greater than 3 mm, alveolar bone resorption, and premolars with prior endodontic treatment. Participants were randomly divided into 3 groups:control, 7-day, and 28-day groups. Extractions were performed prior to orthodontic treatment, and 7 days and 28 days after application of orthodontic forces (OF) in the control, 7-day and 28-day group respectively. The applied orthodontic forces were in the range of 50-150 g. RNA extraction from pulp tissues was performed using the RNeasy mini kit. After total RNA extraction, a library was prepared, and RNA sequencing was conducted to examine and compare the genetic data among the groups within each jaw. Differentially expressed genes (DEGs) were identified in the 7-day and 28-day groups, followed by functional enrichment analysis to understand their biological significance. Furthermore, protein-protein interaction network analysis was conducted to investigate the complex network of protein interactions and locate key genes involved in orthodontic tooth movement. Immune response, hypoxia, DNA damage, and epigenetic regulation were the pulpal reactions reflected after 7 days of OF. Whereas, at 28 days, processes such as cell adhesion, migration, organization, and tissue repair became prominent. Pulp tissues in the maxilla and mandible responded differently to orthodontic force. The maxilla showed minimal changes, primarily involving immune response at 7 days and tissue repair at 28 days. In contrast, the mandible exhibited significant DNA damage and epigenetic regulation at 7 days, with a return to its baseline condition by 28 days. Dental pulp demonstrated different reactions at 7 and 28 days, with maxillary and mandibular pulp tissues presenting distinct responses. The study provided knowledge about gene regulatory mechanisms modulating pulp tissue response to OF.

Investigating the Effect of Vitamin a on Orthodontic Tooth Movement: An Experimental Study.

Vitamin A is essential not only for bone metabolism and development but also for the normal functioning of many physiological processes in the body. Despite vitamin A's important involvement in bone metabolism, its effect on orthodontic tooth movement is not entirely known. Previous studies on animals have suggested that vitamin A may influence alveolar bone remodelling and tooth movement, but the effect of various doses of vitamin A on these processes remains poorly understood. This experiment was designed to examine the effect of vitamin A on the orthodontic tooth movement of male rats. Eighty male rats weighing 200-250 grams were divided into eight equal parallel groups. An initial orthodontic force was applied to all groups with a specific appliance, and six different doses of vitamin A were administered (250-2500 IU/Kg intraperitoneally). Two control groups were also considered. Orthodontic tooth movement was measured at the beginning and end of the study period (day 14), and serum alkaline phosphatase (ALP) level was evaluated. The maxillary sections were also evaluated by histological examination. Although there was a dose-dependent increase in tooth movement observed with vitamin A administration, the differences were not statistically significant. There was no significant difference in the number of osteoclasts or the presence of lacunae on the root surface between the study groups. Root resorption was observed in different areas of the root and was not related to different doses of vitamin A. The serum ALP level did not show any significant difference between the groups treated with different doses of vitamin A. Despite the known effects of vitamin A on bone metabolism, the results of this study suggest that vitamin A did not increase alveolar bone remodeling and orthodontic tooth movement in male rats.

Breaking Barriers in Orthodontics: An Experimental Study on How Stabilization Discs Improve Mini-Implant Outcomes

Background/Objectives: The stabilization disc (SD) for orthodontic mini-implants is a novel device designed to enhance anchorage stability and minimize the risk of mini-implant mobility. The disc features a flat structure with four prongs and is crafted from biocompatible materials such as titanium or stainless steel. It provides additional support to mini-implants by improving force distribution and reducing stress concentration around the insertion site. This study aims to evaluate the biomechanical performance of mini-implants with an SD compared to without-SD mini-implants, with a specific focus on their ability to maintain anchorage under orthodontic loading conditions. Methods: A finite element analysis (FEA) model was created for a commercially available mini-implant (2.0 mm in diameter and 12 mm in length). The mandible’s anatomical structure was reconstructed in 3D from computed tomography (CT) scans using SpaceClaim software 2023.1. To simulate real-world orthodontic conditions, forces of 10 N were applied at an angle of 30°. This retrospective study explores the role of SDs in enhancing mini-implant stability by reducing displacement and optimizing stress distribution. The evaluation included analyzing von Mises stress, cortical bone deformation, and mini-implant movement under simulated orthodontic loading. Results: The results demonstrate that the SD significantly reduces maximum total displacements by over 41% and redistributes von Mises stresses more evenly across the mini-implant and surrounding bone. Cortical bone stress and deformation were reduced in cases utilizing the SD, indicating enhanced implant stability and durability. Conclusions: The stabilization disc enhances mini-implant stability by improving stress distribution and reducing deformation without requiring permanent implant modifications. Its adaptability makes it a valuable solution for managing variable bone density and high orthodontic forces, offering a promising advancement in orthodontic anchorage.

The Relationship Between Bone Morphotype, Bone Density, and Apical Root Resorption of Posterior Teeth Induced by Orthodontic Forces

The Relationship Between Bone Morphotype, Bone Density, and Apical Root Resorption of Posterior Teeth Induced by Orthodontic Forces

Orthodontic forces and moments of three-bracket geometries.

To test the hypothesis of Burstone and Koenig that a three-bracket geometry can be simplified into two adjacent two-bracket geometries, to evaluate the impact of a third bracket on two-bracket geometries, to identify the force systems of 36 three-bracket geometries using archwires of different materials, and to apply these principles to clinical scenarios. A custom-designed orthodontic force jig supported three force transducers fitted with passive self-ligating brackets (Brackets A, B, and C). In Experiment 1, the force system of a three-bracket geometry was compared with two adjacent two-bracket geometries. In Experiment 2, 36 three-bracket geometries were tested when straight wires of varying materials were engaged. Experiment 1 results showed that the force system of a three-bracket geometry could be simplified into two adjacent two-bracket geometries. Experiment 2 results showed that the impact of the third bracket (Bracket C) affected the force system of the adjacent bracket only (Bracket B), with Bracket C having no statistically significant effect on the force systems at Bracket A. A distinct pattern of forces and moments was found in each of the 36 three-bracket geometries. In this study, we experimentally validated the hypothesis of Burstone and Koenig, showing that a three-bracket geometry can be simplified into two adjacent two-bracket geometries. The force system of 36 three-bracket geometries was determined, assisting clinicians with better anticipating previously unpredicted and undesirable movements, thereby improving treatment efficiency.

Cemento-osseous Dysplasia Mimicking Periapical Cyst After the Orthodontic Treatment of the Mandible.

Cemento-osseous dysplasia (COD) is a non-neoplastic condition, characterized by the replacement of normal cancellous bone with fibrous tissues containing woven bone and cementum in the tooth-bearing areas. This report presents the case of a 21-year-old male who developed COD following orthodontic treatment. A panoramic radiograph showed a periapical radiolucent lesion in the right mandibular canine area. Cone beam computed tomography revealed a mixed radiolucent and radiopaque lesion. Histologically, the lesion exhibited cementum-like calcifications and woven bone scattered within the hemorrhagic fibrous tissue. Ultimately, the lesion was diagnosed as cemento-osseous dysplasia, focal type. This case highlights the importance of careful monitoring of orthodontic forces to minimize risks and prevent unexpected complications during orthodontic treatment.

Importance of the early phase of orthodontic force application in the induction of root resorption.

To investigate the effectiveness of early and short-term administration of lithium (Li) during orthodontic force application (OFA) in preventing orthodontically induced root resorption (OIRR) and verify the importance of the early phase of OFA in the induction of OIRR. Bilateral maxillary first molars of 10-week-old male Wistar rats were moved for 14 days using a closed coil spring inserted between the first molar and the incisor. The rats were randomly grouped into three groups: a group receiving Li for the first 4 days, a group receiving Li daily for 14 days, and a control group receiving a vehicle (saline). Orthodontic tooth movement (OTM) was measured using microcomputed tomography on day 14. The OIRR, osteoclasts, and odontoclasts were evaluated via histological analysis. Immunohistochemical staining for the receptor-activated NF-kB ligand and osteoprotegerin was also performed. The OTM distance did not differ among the three groups, and the pattern of OTM changed from tipping to bodily movement for both Li groups. Early and short-term administration of Li suppressed OIRR on day 14 as effectively as long-term administration for 14 days. The observed odontoclasts on days 4 and 14 were significantly reduced in both Li groups. Osteoprotegerin expression was significantly increased on day 14 in both groups receiving Li relative to the vehicle group. Early and short-term Li administration effectively suppressed OIRR. This suggests that the early phase of OFA plays an important role in the induction of OIRR.

Balancing the Load: How Optimal Forces Shape the Longevity and Stability of Orthodontic Mini-Implants.

Objective: This study aims to investigate the mechanical behavior of titanium (Ti6Al4V) mini-implants (MIs) under varying orthodontic forces using finite element analysis (FEA) and to evaluate their performance and durability under realistic clinical conditions. Optimal orthodontic forces significantly influence the structural integrity and functional longevity of MIs while minimizing adverse effects on surrounding bone tissues. Materials and Methods: A commercially available MI (diameter: 2.0 mm, length: 12 mm) was modeled using FEA. The mandible geometry was obtained using computed tomography (CT) scanning, reconstructed in 3D using SpaceClaim software 2023.1, and discretized into 10-node tetrahedral elements in ANSYS Workbench. Material properties were assigned based on the existing literature, and the implant-bone interaction was simulated using a nonlinear frictional contact model. Orthodontic forces of 2 N and 10 N, inclined at 30°, were applied to simulate clinical loading conditions. Total displacement, von Mises stresses, equivalent strains, fatigue life, and safety factors were analyzed to assess the implant's mechanical performance. Results: At 2 N, the MI demonstrated minimal displacement (0.0328 mm) and sustained approximately 445,000 cycles under safe fatigue loading conditions, with a safety factor of 4.8369. At 10 N, the implant's lifespan was drastically reduced to 1546 cycles, with significantly elevated stress (6.468 × 105 MPa) and strain concentrations, indicating heightened risks of mechanical failure and bone damage. The findings revealed the critical threshold beyond which orthodontic forces compromise implant stability and peri-implant bone health. Conclusions: This study confirms that maintaining orthodontic forces within an optimal range, approximately 2 N, is essential to prolong MI lifespan and preserve bone integrity. Excessive forces, such as 10 N, lead to a rapid decline in durability and increased risks of failure, emphasizing the need for calibrated force application in clinical practice. These insights provide valuable guidance for enhancing MI performance and optimizing orthodontic treatment outcomes.

Association Between Different Biomarkers and Initial Orthodontic Tooth Movement in Children and Adults: A Systematic Review and Meta-Analysis.

The present systematic review aims to bridge the existing knowledge gap by evaluating the influence of various biomarkers on initial orthodontic tooth movement in children and adults. A systematic electronic search was conducted using relevant keywords across the databases PubMed, Google Scholar, and EBSCOhost to identify articles published in English until December 2023. The "Risk of Bias (ROB) in Non-randomized Studies of Interventions" (ROBINS-I) tool was used to assess the risk of bias, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was applied to critically appraise the quality of evidence. A total of 10 studies were identified, all of which were non-randomised clinical trials that compared biomarker expression in patients belonging to the growing age group (children, juveniles, or adolescents) and adults, using gingival crevicular fluid (GCF) or saliva analysed by the ELISA method. Overall, younger patients consistently exhibited faster and more pronounced biological responses to orthodontic forces, with biomarker levels peaking within the first 72 hours of force application.

The Effect of Heparin on Bone Metabolism and Orthodontic Tooth Movement in Rats.

Various attempts have been made to increase the rate of orthodontic tooth movement (OTM). The aim of this study was to determine the effect of different doses of heparin on OTM and paraclinical factors related to bone metabolism in rats. A total of 24 Sprague-Dawley rats were randomly divided into three groups of 8 animals each and injected with 0 (control), 3000, and 6000 U/Kg/d heparin sulfate for 4 weeks. Radiographs were obtained at the initiation and at the end of the study period. Orthodontic forces were applied on Day 14 and continued for the next 2 weeks, after which, OTM, optical density, parathyroid hormone (PTH) level, and histologic variables were assessed for each rat. The latter was performed on hematoxylin/eosin-stained sections of the mesial roots of the first molar and included calculation of the osteoclast number, and resorption lacunae depth and number. One-way analysis of variance, the Tukey test, and a paired-t-test were used for statistical analysis (p < 0.05). A significant increase in OTM, the number of resorptive lacunae, and PTH secretion was observed in the group that received 6000 U/Kg/d compared with both the other groups. There was no significant difference in optical density, and, therefore, bone density, among the study groups (p > 0.05). Heparin injection affects bone metabolism in rats, as shown by the increases in OTM and PTH and its impact on histologic parameters. These effects seem to be dose-dependent and may be a factor that should be taken into consideration during orthodontic treatment planning.

Adult Scissor Bite Case Treatment With Moving Teeth Through Maxillary Sinus.

This case report demonstrates the orthodontic treatment to correct a severe scissor bite and occlusal disharmony in a 26-year-old female patient, including the use of temporary anchorage devices (TADs) and fixed orthodontic appliances. Severe scissor bite is associated with vertical problems, such as molar extrusion. For orthodontic treatment, interradicular TADs were used to intrude the extruded molars, control the inclination of molars, correct dental midline, and improve dental relationships. This treatment not only achieved successful correction of the scissor bite but also provided adequate occlusion function and improved facial esthetics. TADs provided an effective orthodontic force system to correct the scissor bite. In severe scissor bite cases, a significant amount of maxillary molar intrusion is required, which can increase the risk of moving teeth through the maxillary sinus. Using CBCT images could help in treatment planning for the three-dimensional movement of teeth during the orthodontic treatment.

Summed Tissue Resistance of Periodontal Ligaments and Alveolar Bone in Orthodontic Distal Retraction of Maxillary Canines: Mathematical Simulation of Clinical Data and Interpretation of Results.

Background: The mechanical properties of either alveolar bone or periodontal ligaments under orthodontic loading, as well as orthodontic tooth movement, have been studied in recent years using computational approaches. In previous studies, we developed a theoretical mathematical approach that uses a weighting coefficient of the summed resistance of periodontal structures, namely the bone and periodontal ligaments, in relation to apex movement, the center of rotation, orthodontic force loading, and time in order to quantify the biological response to orthodontic biomechanics. Methods: We analyzed the distal retraction of three maxillary canines and integrated the clinical data obtained in the previously developed mathematical programs. Results: The values of the (σ) weighting coefficient of the tissue resistance were interpreted in the context of the clinical data obtained: the smaller the value of (σ), the higher the actual tissue resistance, with a greater difference between the crown and root movement; also, the higher the value of (σ), the lower the actual tissue resistance, with a small difference between the crown and apex movement. Conclusions: The clinical interpretation of the results allows us to set a premise for the refinement of the mathematical programs so that we can use them in assessing the orthodontic biomechanics of larger patient groups over longer periods of time and create premises of treatment protocol simplification and adjustment.

Periodontal response to nonsurgical accelerated orthodontic tooth movement.

Tooth movement is a complex process involving the vascularization of the tissues, remodeling of the bone cells, and periodontal ligament fibroblasts under the hormonal and neuronal regulation mechanisms in response to mechanical force application. Therefore, it will inevitably impact periodontal tissues. Prolonged treatment can lead to adverse effects on teeth and periodontal tissues, prompting the development of various methods to reduce the length of orthodontic treatment. These methods are surgical or nonsurgical interventions applied simultaneously within the orthodontic treatment. The main target of nonsurgical approaches is modulating the response of the periodontal tissues to the orthodontic force. They stimulate osteoclasts and osteoclastic bone resorption in a controlled manner to facilitate tooth movement. Among various nonsurgical methods, the most promising clinical results have been achieved with photobiomodulation (PBM) therapy. Clinical data on electric/magnetic stimulation, pharmacologic administrations, and vibration forces indicate the need for further studies to improve their efficiency. This growing field will lead to a paradigm shift as we understand the biological response to these approaches and their adoption in clinical practice. This review will specifically focus on the impact of nonsurgical methods on periodontal tissues, providing a comprehensive understanding of this significant and understudied aspect of orthodontic care.

The IL-17 level in gingival crevicular fluid as an indicator of orthodontically induced inflammatory root resorption.

Interleukin (IL)-17 expression in the periodontal ligament is associated with orthodontically induced inflammatory root resorption (OIIRR). Seeking aconvenient, rapid, and non-invasive IL-17 detection approach could help predict OIIRR. In this study, we assessed the potential of the IL-17 level in gingival crevicular fluid (GCF) to be an indicator of OIIRR. To enable tooth movement, 8‑ to 10-week-old male Wistar rats were subjected to 20 g/60 g orthodontic force for up to 14days. GCF and peripheral blood were collected for the IL-17 enzyme-linked immunosorbent assay (ELISA). Histological changes and the expression of IL-17, receptor activator of nuclear factorκB ligand (RANKL), and osteoprotegerin (OPG) in periodontal tissue were evaluated by hematoxylin-eosin and immunohistochemistry staining, respectively. Osteoclasts were visualized by tartrate-resistant acid phosphatase (TARP) staining. GCF IL-17 level rapidly rose in the early phase of orthodontic loading, accompanied by bone and tooth root destruction. At the later stage, the GCF IL-17 level gradually decreased, while the inflammatory destruction was reduced and the periodontal tissue began to repair. GCF IL-17 expression generally tended to be coincident with the periodontal tissue reaction: GCF IL-17 was robustly correlated to the RANKL/OPG ratio (rs = 0.72, p = 0.002) or osteoclast number (rs = 0.84, p < 0.001). Additionally, the GCF IL-17 level was correlated to serum IL-17 (rs = 0.61, p = 0.016) or periodontal IL-17 (rs = 0.84, p < 0.001). The IL-17 level in GCF during orthodontic treatment is associated with OIIRR and, thus, could be an early indicator for developing OIIRR. The advantages of being aconvenient, rapid, and non-invasive GCF IL-17 measurement make it apromising method for early detection of OIIRR.

Application of orthodontic force in autotransplanted teeth: a longitudinal study.

To longitudinally follow up a cohort of patients with autotransplanted teeth, assessing how the timing of starting orthodontic treatment impacts root length. Patients under 18 with at least one open-apex autotransplanted premolar (AP) replaced to a central incisor position were included. Root/crown ratio (RCR) was calculated on periapical radiographs taken at intervals of 3-6 months after transplantation. The RCR of AP in patients without orthodontic treatment and patients where orthodontic treatment was initiated at different time points (3,6,9,12,18 months) were compared. 52 autotransplanted premolars were included and 315 peri-apical radiographs were collected. The median timespan between autotransplantation and the start of orthodontic force (OF) application was 8.5 (IQR 2-23) months, with a mean follow-up period of 32 (IQR 9-46) months. Early OF post-autotransplantation correlated with early stagnation of root development. When OF was delayed, AP tended to show more root lengthening. Delayed OF was linked to a higher incidence of External Apical Root Resorption (EARR) once forces were introduced, ultimately resulting in root lengths comparable to those with early OF. The presence or absence of OF is the factor most notably influencing the final root length of AP. The timing of OF application did not compromise the final root length of autotransplanted teeth. Early OF to prevent ankylosis is feasible without affecting root length. Future research should utilize 3D imaging to provide a deeper understanding of orthodontic treatment's effects on autotransplanted teeth. The study underscores the importance of tailored orthodontic intervention timing in autotransplanted teeth, balancing early force application to avoid ankylosis against the risk of EARR.

Moringa oleifera L. Nanosuspension Extract Administration Affects Heat Shock Protein-10 and -70 under Orthodontics Mechanical Force In Vivo.

The mechanical stimulation known as orthodontic mechanical force (OMF) causes biological reactions in orthodontic tooth movement (OTM). Heat shock protein-70 (HSP-70) needs pro-inflammatory cytokines to trigger bone resorption in OTM; nevertheless, heat shock protein-10 (HSP-10), a "Alarmin" cytokine, should control these pro-inflammatory cytokines to get the best alveolar bone remodeling (ABR). Moringa oleifera L. nanosuspension extract (MONE) has anti-inflammatory, antioxidant, and ABR-stimulating properties. The aim of the study was to examine in vivo HSP-10 and HSP-70 expressions under OMF following MONE application in Wistar rats (Rattus norvegicus). A total of 36 Wistar rats (R. norvegicus) were split up into eight groups: one for treatment (OMF + MONE) and one for control (OMF + MONE administration for days 1, 7, 14, and 21). By employing nickel-titanium coil springs and using 10 g of light force per millimeter to implant the orthodontic device, the OMF was completed. According to the day of observation, all of the samples were sacrificed. To perform an immunohistochemistry investigation, the premaxilla of the sample was isolated. Tukey's Honest Significant Different (HSD) test (p < 0.05) was performed after an Analysis of Variance (ANOVA) analysis of the data. In both the OMF and MONE groups, HSP-70 peaked on day 14 and began to fall on day 21. HSP-10 peaked on day 21, but along with MONE, it also began to progressively decline on days 14 and 21, with significant differences (p < 0.05). According to immunohistochemistry evidence, postadministration of MONE markedly elevated HSP-10 but lowered HSP-70 expression in the alveolar bone of Wistar rats under OMF.