Tooth Movement Research Articles

The effect of single versus multiple piezocisions on the rate of canine retraction: a randomized controlled trial

BackgroundPiezocision is a minimally invasive surgical method aiming to accelerate tooth movement. However, its effect was found to be transient, appertaining to the regional acceleratory phenomenon (RAP). Hence, the aim of the study was to evaluate the effect of single and multiple piezocisions on the rate of orthodontic tooth movement (OTM). Moreover, the impact of both protocols on canine tipping and orthodontically induced inflammatory root resorption (OIIRR) has been assessed.MethodsThirty indicated patients for the therapeutic extraction of maxillary first premolars were enlisted in this split-mouth study, and they were randomly split into two equal groups, each including 15 subjects. In the Single Application Group (SAG), one side of the maxillary arch arbitrarily received a single piezocision before the onset of canine retraction, whereas in the Multiple Application Group (MAG), piezocisions were randomly performed on one side, three times on a monthly basis, over the 12-week study period. The contralateral sides of both groups served as the controls. Canine retraction was carried out bilaterally using nickel-titanium closed-coil springs, delivering 150 g of force, and the rate of tooth movement, as well as canine tipping were evaluated on a monthly basis, over a 3-month period. Cone-bean computed tomography scans were also conducted pre- and post- canine retraction, and OIIRR was assessed using Malmgren Index.ResultsThe reported outcomes revealed a significant increase in the amount of canine retraction, canine tipping, as well as root resorption scores on the experimental sides in both groups SAG and MAG post-retraction (p < 0.001). However, upon comparing the experimental sides in both groups, non-significant differences have been observed between them regarding all the assessed outcomes (p > 0.05).ConclusionsSingle and multiple piezocisions effectively accelerate OTM in comparison to conventional orthodontic treatment, with relative outcomes reported by both intervention frequencies. Accordingly, single piezocision is recommended as an adjunct to OTM. Furthermore, significant tooth tipping as well as a significantly higher root resorption risk accompanies both single and multiple piezocision applications in conjunction with OTM.Name of the RegistryClinicaltrials.govTrial Registration NumberNCT05782088Date of Registration23/03/2023 “Retrospectively registered”.URLhttps://clinicaltrials.gov/ct2/show/NCT05782088

Accelerated Orthodontics: A Descriptive Bibliometric Analysis of the Top 50 Cited Articles from 2012 to 2023.

Accelerated orthodontics represents a significant shift in dental practice aimed at reducing treatment times while maintaining optimal patient outcomes. This bibliometric analysis evaluated the research landscape of accelerated orthodontics from 2012 to 2023, focusing on publication trends, citation patterns, influential journals, leading institutions, and key contributors. A comprehensive search in Scopus identified 600 relevant articles, with the top 50 most-cited papers encompassing systematic reviews, randomized controlled trials, and experimental studies. Key techniques, such as corticotomy and piezocision, have been frequently highlighted for their effectiveness in expediting tooth movement. The analysis revealed fluctuating annual scientific outputs, with notable peaks driven by technological advancements and increased patient demand for quicker orthodontic solutions. However, the production of high-impact papers was hindered by delays in citation accumulation and disruptions caused by the COVID-19 pandemic. Keyword analysis identified critical themes, such as orthodontic tooth movement, malocclusion, and demographic factors, while a global collaboration map underscored extensive international research partnerships. Leading journals included the American Journal of Orthodontics and Dentofacial Orthopedics, and prominent institutions such as the University of California at Los Angeles played significant roles in advancing the field. This study provides a comprehensive overview of the current state of accelerated orthodontics, emphasizing the need for continued research, particularly RCTs, to further refine and validate accelerated orthodontic techniques and improve clinical outcomes.

Periosteum response to static forces stimulates cortical drifting: A new orthopedic target

The mechanism of cortical bone adaptation to static forces is not well understood. This is an important process because static forces are applied to the cortical bone in response to the growth of soft tissues and during Orthodontic and Orthopedic corrections. The aim of this study was to investigate the cortical bone response to expanding forces applied to the maxilla. Overall, 375 adult Sprague-Dawley rats were divided into three groups: 1) static force group, 2) static force plus stimulation group, and 3) sham group. In addition to static force across the maxilla, some animals were exposed to anti-inflammatory medication. Samples were collected at different time points and evaluated by micro-computed tomography, fluorescence microscopy, immunohistochemistry, and gene and protein analyses. The application of expansion forces to the maxilla increased inflammation in the periosteum and activated osteoclasts on the surface of the cortical plate. This activation was independent of the magnitude of tooth movement but followed the pattern of skeletal displacement. Bone formation on the surface of the cortical plate occurred at a later stage and resulted in the relocation of the cortical boundary of the maxilla and cortical drifting. This study demonstrates that cortical bone adaptation to static forces originates from the periosteum, and it is an inflammatory-based phenomenon that can be manipulated by the clinician. Our findings support a new theory for cortical adaptation to static forces and an innovative clinical approach to promote cortical drifting through periosteal stimulation. Being able to control cortical drift can have a significant impact on clinical orthodontic and dentofacial orthopedics by allowing corrections of severe deformities without the need for maxillofacial surgery.

The Role of Bone and Root Resorption on the Biomechanical Behavior of Mandibular Anterior Teeth Subjected to Orthodontic Forces: A Finite Element Approach.

This study was conducted to systematically evaluate the biomechanical impact of varying degrees of root and bone resorption resulting from periodontitis and orthodontic tooth movement (OTM) on the mandibular anterior teeth. The objective was to determine whether these distinct resorption patterns exert a specific influence on tooth displacement and strain patterns. A finite element (FE) model of an idealized anterior mandible from the first premolar in the third to the fourth quadrant was developed without bone or root resorption and a constant periodontal ligament (PDL) thickness of 0.2 mm. Variations included three root resorption levels (0%, 20%, 50%) and three bone resorption types (circular 50%, circular 80%, vestibular 80%). Models ranged from 200,000 to 440,000 elements and 55,000 to 130,000 nodes. Orthodontic forces, namely root torque (5 Nmm), intrusion (0.2 N), and distalization (0.5 N) were applied for subsequent crown displacement and PDL strain analysis. A total of 180 simulations were performed. Simulations showed that displacement was similar across different bone resorption conditions, irrespective of modeled root resorptions. Circumferential bone resorption increased tooth displacement, regardless of root resorption status. Vestibular bone resorption exhibited less increase in tooth displacement. However, when accompanied by root resorption, the combination exacerbated tooth displacement. Strains in the PDL clearly increased with a circumferential bone resorption of 80%. This study highlights the critical role of bone resorption in tooth displacement during OTM, particularly the challenges associated with circumferential resorption. Clinicians must consider both bone and root resorption for personalized medicine treatment of patients with severe periodontitis, in favor of low-force application strategies to optimize outcomes and minimize complications linked to excessive tooth displacement.

Three-dimensional analysis of posttreatment tooth movements despite bonded retainers: partI-upper jaw.

Adverse side effects of fixed retainers in terms of unwanted tooth movements have been described for both the upper and lower jaw, but data about the extent and movement patterns for the maxilla are scarce. The purpose of the present retrospective case-control study was to analyze the amount and direction of unwanted tooth movements despite upper bonded retainers as well as to analyze possible predisposing pretreatment- and treatment-related factors. Plaster casts of 1026 patients who completed orthodontic treatment and asubsequent retention phase of 2years were screened for unintentional tooth movements. The study group comprised 57patients with visually obvious tooth movements in the upper jaw, while 57randomly selected patients without visible tooth movements served as control group. For all patients, plaster casts after debonding of multibracket appliance (T1) and after supervised retention (T2) were digitized, and superimposed digitally using astable palatal reference area. Thereafter, translational and rotational movements were measured in all three planes of space. Pretreatment- and treatment-related factors of the study and control groups were compared by χ2 test, exact Fisher test, Mann-Whitney U test, and the T‑test for independent samples. The mean translational movements ranged between 0 and 0.6 mm and the average rotational movements between 0 and 1.3°. Large individual movements up to 2.7 mm translation and 15.9° rotation were seen. Amovement pattern around the Y‑ and Z‑axis with an opposite rotational peak at the canines ("upper twist effect") was identified. Compared to the control group, patients of the study group showed asignificantly smaller intercanine width pretreatment. Also, study group patients presented alarger intercanine expansion and aslightly larger overjet reduction during treatment, and were more often affected by retainer bonding site detachments and wire fractures, but without reaching statistically significance. Upper bonded retainers show asimilar unwanted movement pattern ("twist effect") like the one described for mandibular retainers.

Three-dimensional analysis of posttreatment tooth movements despite bonded retainers: partII-lower jaw.

Complications of bonded lingual retainers in terms of unexpected tooth movements have been reported with increasing frequency during the last decade, but the vast majority of the literature comprises case reports. The purpose of the present retrospective case-control study was to analyze the amount and direction of unwanted tooth movements despite lower bonded retainers, to analyze possible predisposing pretreatment- and treatment-related factors, and to seek for movement thresholds which could enhance the rapid and objective identification of critical cases. Plaster casts of 1026 patients who completed orthodontic treatment and asubsequent retention phase of 2years were screened for unintentional tooth movements. The study group comprised 39patients with tooth movements in the lower jaw, while 39randomly selected patients without visible tooth movements served as the control group. For all patients, plaster casts after debonding of multibracket appliances (T1) and after supervised retention (T2) were digitized, and athree-dimensional (3D) digital superimposition based on the best fit of premolars and molars was undertaken. Thereafter, translational as well as rotational movements were measured in all three planes of space. Pretreatment- and treatment-related factors of the study and control groups were compared. Aseverity classification based on rotational movement thresholds was applied to seek acritical amount of translational movements. The mean translational movements ranged between 0 and 0.4 mm and the average rotational movements between 0 and 1.6°. Large individual movements up to 1.9 mm translation and 16° rotation were seen. Atwist-effect with opposite movements of the canines along the Y‑axis could be confirmed. Compared to the control group, patients of the study group had asmaller intercanine distance at all timepoints. In addition, study group patients presented aslightly larger intercanine expansion during treatment and were more often affected by retainer bonding site detachments. Applying the severity classification based on rotational thresholds, translational movements of 0.5-1.0 mm along the X‑ and Y‑axis could serve as acritical threshold. It can be assumed that extrusive translational movements along the Z‑axis seem to be of specific nature and perhaps do not reflect aretainer complication in terms of unwanted tooth movements. Patients with alarger intercanine distance after active treatment and those with more frequent retainer bonding site detachments could be at higher risk for unwanted tooth movements during fixed retention. Sagittal and transverse movements of 0.5-1.0 mm should sensitize the practitioner for further measures.

Comparison of clinical efficacy between autologous partially demineralized dentin matrix and deproteinized bovine bone mineral for bone augmentation in orthodontic patients with alveolar bone deficiency: a randomized controlled clinical trial

BackgroundIt is common to see patients who need orthodontic treatment but with insufficient alveolar bone volume. However, safe and effective tooth movement requires sufficient alveolar bone width and height. The aim of this study is to compare the bone augmentation efficacy of Autologous Partially Demineralized Dentin Matrix (APDDM) and Deproteinized Bovine Bone Mineral (DBBM) in orthodontic patients with insufficient bone by using a randomized controlled clinical trial approach.Materials and methodsTwenty-seven orthodontic patients involving 40 posterior teeth alveolar sites (n = 40) with insufficient alveolar bone volume were randomly divided into a control group (n = 20) and an experimental group (n = 20). The patients in the experimental group were treated with APDDM, and those in the control group were treated with DBBM. After surgery, the adjacent teeth are moved toward the bone grafting sites according to the orthodontic treatment plan. Patients completed a postoperative response questionnaire by the Visual Analogue Scale (VAS) score to indicate pain and swelling in the bone grafted area at the time of suture removal; and CBCT scans were conducted before surgery, 6 months and 2 years after surgery to assess changes in buccal and central alveolar heights, as well as widths at the alveolar ridge apex and 3 mm, 5 mm below the apex, respectively. The CBCT image sequences were imported into Mimics 21.0 software in DICOM format. The data of the patients in both groups were collected and analyzed by SPSS 25.0.ResultsThe VAS scores were significantly lower in the APDDM group than in the DBBM group (p < 0.05). Significant increases were observed in alveolar bone height and width at 6 months and 2 years postoperative (p < 0.05); At 2 years, the APDDM group exhibited a reduction in buccal crest height and in 3 mm, 5 mm width below alveolar ridge apex, relative to 6 months (p < 0.05), while the DBBM group showed a decrease only in the central height of the alveolar bone (p < 0.05). There was a significant bone augmentation increase found only 3 mm below the alveolar ridge apex in the APDDM group compared with the DBBM group among all 6 months group comparison (p < 0.05). At 2 years, the augmentation effects were similar across both groups (p > 0.05).ConclusionRadiomics analysis indicates that APDDM serves as a viable bone augmentation material for orthodontic patients with insufficient alveolar bone volume, achieving comparable clinical efficacy to DBBM. Additionally, APDDM is associated with a milder postoperative response than DBBM.The registration number (TRN)ChiCTR2400084607.

Longitudinal bibliometric investigation of published orthodontic research 2013-23: are we investigating patient-reported outcomes?

The published literature represents the fundamental basis of any academic specialty, including orthodontics. Orthodontic research outputs provide useful insight into clinical and research priorities, which can help inform future research efforts and resource outputs. In recent years, the need for more patient-reported outcomes in orthodontic research has been highlighted. To identify the most common reported research subjects in orthodontics between 2013-23; (2) identify the main outcomes and types of study design associated with this research, including study design related to patient-reported outcomes; and (3) identify trends in this research activity based upon these findings. A literature search was performed in a single electronic database (Scopus) to return all indexed publications with relevance to orthodontics published from 2013 to 2023. The 50 most-cited publications per year were then identified. Publication characteristics were extracted using a data collection sheet. Descriptive statistics including frequency distributions were calculated. A total of 14397 publications were identified. Publications on orthodontic bonding made up 7.02% of all output, followed by materials (5.88%) and tooth movement (5.42%). Subsequent analysis of the most-cited publications per year revealed the most frequently published subjects were aligners (12.5%), orthodontic tooth movement (9.45%), and digital workflow (9.09%), and the most common study designs were in vitro (19.09%) and retrospective observational studies (15.45%). The most common outcome type was morphological features of malocclusion (26.9%). Conversely, patient-focused measures were only reported in 12.7% of studies. Orthodontic research outputs are dynamic but do show consistent research interest in certain subjects. There is a predilection for the reporting of clinician-focused outcomes; whilst these have some value, more efforts should be focused on conducting rigorous and robust studies that include patient-reported outcomes.

Genetic polymorphisms in external apical root resorption and orthodontic tooth movements: A systematic review.

External apical root resorption (EARR) is characterized by permanent loss of dental structure at the root apex. This study aimed to systematically review gene polymorphisms associated with EARR in orthodontic patients. Electronic database searches were performed across several databases. This systematic review included 21 studies. Outcome measures were based on tooth dimensions observed on radiographs obtained before and after treatment. Polymorphisms in the following genes were genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis: purinergic-receptor-P2X, ligand-gated ion channel 7 (P2RX7), caspase-1/interleukin-converting enzyme (CASP1/ICE), caspase-5 (CASP5), IL-1beta (IL1B), IL-1alpha (IL1A), interleukin-1 receptor antagonist gene (IL1RN), tissue non-specific alkaline phosphatase (TNSALP), tumor necrosis factor-alpha (TNFα), tumor necrosis factor receptor superfamily gene member 11a (TNFRSF11A), secreted phosphoprotein 1 (SPP1), tumor necrosis factor receptor superfamily gene member 11b (TNFRSF11B), interleukin 17A (IL17), interleukin 6 (IL6), receptor activator of nuclear factor-kappa B (RANK), osteoprotegerin (OPG), stromal antigen 2 (STAG2), vitamin D receptor (VDR), cytochrome P450 family 24 subfamily A member 1 (CYP24A1), cytochrome P450 family 27 subfamily B (CYP27B1), group-specific component (GC), and interleukin-1 receptor-associated kinases 1 (IRAK1). Almost all studies suggested that IL1 gene is associated with EARR. Additionally, P2RX7 may be an important factor contributing to the etiopathogenesis of EARR. TNFRSF11A, SPP1, IL1RN, IL6, TNFRSF11B, STAG2, VDR, IRAK1, IL-17, CASP1/ICE and CASP5 have been identified in isolated studies. Further observational studies are needed to better explain the association between these genes and EARR.

Reviewing the benefits and clinical outcomes of oral fibroblasts over mesenchymal stem cells for repairing periodontal defects during or after orthodontic tooth movement.

Orthodontic therapy applies forces to teeth, causing an inflammatory reaction in the periodontal ligament. This is repaired by remodeling of the periodontium, allowing tooth displacement. Although orthodontic therapy is mostly initiated during childhood and adolescence, the number of adults seeking this treatment is increasing as our society's esthetic awareness rises. However, adults may already have periodontal tissue abnormalities, rendering orthodontic treatment inefficient because a healthy periodontium is essential for success. Numerous risk factors have been linked to periodontal lesions, with orthodontic tooth movement possibly playing a minimal influence. Although such tissue damages are mostly of esthetic rather than functional concern for patients, restoration frequently requires invasive procedures. Autologous cells for the treatment of periodontal complications have grown in popularity as a less intrusive alternative. The present review analyzed the literature on the use of mesenchymal stem cells and oral tissue-derived fibroblasts for the healing of periodontal defects that may be related to orthodontic tooth movement. Furthermore, the advantages and challenges of the two cell types have been examined. Although the number of clinical studies is currently limited, our study demonstrates that oral fibroblasts have the potential to be the next emergent frontrunners for tissue engineering in the periodontium.

Effect of estrogen depression on alveolar bone microarchitecture and periodontal ligament cells during orthodontic movement.

This study aimed to evaluate the effects of the estrogen depression during orthodontic tooth movement on alveolar bone microarchitecture and periodontal ligament. Female Wistar rats were divided into two groups, one consisting of non-ovariectomized animals subjected to orthodontic tooth movement, and one comprising ovariectomized animals subjected to orthodontic tooth movement. Micro-CT assessment of bone volume to total volume (BV/TV), total porosity, trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp) in the alveolar bone of the orthodontically moved tooth was performed. Histomorphometric analyses were made in the periodontal ligament, and immunoexpression of RANK, RANKL, OPG, and TUNEL were quantified. Orthodontic tooth movement in the group of ovariectomized rats was faster than in non-ovariectomized animals. The alveolar bone area showed lower values of BV/TV and trabecular thickness, and higher bone porosity and trabeculae numbers in the ovariectomized rats. Histological analyses in the ovariectomized group revealed an increase in collagen fibers in the periodontal ligament. The apoptotic cell counts in the periodontal ligament were higher in the group of ovariectomized rats than in the sham-operated rats. Ovariectomy resulted in an increase in tooth movement and alteration of the alveolar bone microstructure in the first 7day of orthodontic tooth movement, and in the presence of apoptotic cells in the periodontal ligament.

Efficacy of low-level laser therapy enhances the rate of canine retraction by increasing &amp;beta; glucoronidase and pentraxin – 3 in gingival crevicular fluid: A clinical study

The aim of the study was to evaluate the efficacy of low-level laser therapy in enhancing the rate of orthodontic tooth movement using β glucoronidase and pentraxin-3 (TNF) biomarkers in gingival crevicular fluid.A split-mouth design was used in 16 subjects (8 experimental and 8 controlled) aged 14 to 25 years, who’s maxillary first premolars were extracted. A gallium-aluminium-arsenide semiconductor diode laser (wavelength, 810 nm; energy density, 10 J/cm2; power output, 100 mW) delivered low-level laser therapy to the experimental canine undergoing distalization at 10 points. The control canine was distalized without low-level laser therapy. The experimental and control canines were distalized using a force of 150 g provided by nickel-titanium closed coil springs. Gingival crevicular fluid was collected at 5 time points from the control and experimental sides, and the levels of β glucoronidase and pentraxin-3 were analysed by enzyme-linked immuno-sorbent assay (ELISA). The rate of canine retraction was calculated by using ortho analyser software.Increased levels of β glucoronidase and pentraxin-3 were observed in the experimental canines compared with the control canines (P &amp;#60;0.001). Cumulative tooth movements over an 8-week experimental period were greater for the experimental canines compared with the control canines. A positive correlation existed between the β glucoronidase and pentraxin-3 levels and the amounts of tooth movement across all time intervals.Low level laser therapy in adjunct with continuous and light forces leads to increase in β glucoronidase and pentraxin-3 leading to accelerated orthodontic tooth movement.: Low-level laser therapy fastens the rate of canine retraction thus accelerating the orthodontic tooth movement. The levels of β glucoronidase and Pentraxin 5 are increased significantly after laser irradiation which aids in accelerating orthodontic tooth movement.

Comparison of various modes of acceleration of orthodontic tooth movement- A clinical study

The objective of the present study is to evaluate the effects of Micro-osteoperforations (MOPs), Corticision, Low Level Laser Therapy (LLLT) and Platelet Rich Plasma (PRP) on the rate of orthodontic tooth movement. Randomly10 patients were selected in each study group. All the studies had a split-mouth study design. All the patients were bonded with MBT 0.022 X 0.028 inch brackets and maxillary canine retraction was performed on 0.019 X 0.025 stainless steel wires with different methods of accelerating tooth movement. Data was collected from the orthodontic study models prepared from alginate impression taken at each appointment interval. The results of the study revealed that the amount of maxillary canine retraction was rapid in all the groups as compared to conventional method of orthodontic tooth movement and the results conclude thatmicro-osteoperfortaions showed better rate of accelerated orthodontic tooth movement as compared to other methods.

Effects of coenzyme Q10 on orthodontic tooth movement and alveolar bone remodeling in rats.

To evaluate the effects of coenzyme Q10 (CoQ10) on alveolar bone remodeling and orthodontic tooth movement (OTM). An orthodontic appliance was placed in 42 female Sprague‒Dawley rats were divided into two groups: the orthodontic force (OF) group (n = 21) and the OF + CoQ10 (CoQ10) treatment group (n = 21). Each group was divided into 3 subgroups, and the rats were sacrificed on days 3, 7 and 14. The rats in CoQ10 and OF groups were administered 100mg/kg b.w./day CoQ10 (in 1 mL/b.w. soybean oil) and 1 mL b.w./day soybean oil, respectively, by orogastric gavage. The OTM was measured at the end of the experiment. The osteoclast, osteoblast and capillary numbers; vascular endothelial growth factor (VEGF), receptor activator nuclear kappa B ligand (RANKL) and osteoprotegrin (OPG) levels in tissue; and total antioxidant status (TAS) and total oxidant status (TOS) in blood were determined. Compared with the OF group, the CoQ10 treatment group exhibited decreased orthodontic tooth movement and osteoclast and capillary numbers. Indeed, the levels of VEGF and RANKL decreased, while the levels of OPG increased except on day 7. Additionally, the CoQ10 treatment group exhibited lower TOS and higher TAS on days 7 and 14 (p < 0.05). Histological findings showed that the morphology of osteoblasts changed in the CoQ10 group; however, there was no significant difference in the number of osteoblasts between the groups (p > 0.05). Due to its effect on oxidative stress and inflammation, CoQ10 regulates bone remodeling by inhibiting osteoclast differentiation, promoting osteoblast differentiation and reducing the amount of OTM. Considering that OTM may be slowed with the use of CoQ10, topics such as orthodontic treatment duration, orthodontic force activation and appointment frequency should be considered in treatment planning. It is predicted that the use of CoQ10 will support the effectiveness of treatment in clinical applications such as preventing relapse in orthodontic treatment by regulating bone modulation and anchorage methods that suppress/optimize unwanted tooth movement.

Age-related mitophagy regulates orthodontic tooth movement by affecting PDLSCs mitochondrial function and RANKL/OPG.

A thorough comprehension of age-related variances in orthodontic tooth movement (OTM) and bone remodeling response to mechanical force holds significant implications for enhancing orthodontic treatment. Mitophagy plays a crucial role in bone metabolism and various age-related diseases. However, the impact of mitophagy on the bone remodeling process during OTM remains elusive. Using adolescent (6 weeks old) and adult (12 months old) rats, we established OTM models and observed that orthodontic force increased the expression of the mitophagy proteins PTEN-induced putative kinase 1 (PINK1) and Parkin, as well as the number of tartrate-resistant acid phosphatase-positive osteoclasts and osteocalcin-positive osteoblasts. These biological changes were found to be age-related. Invitro, compression force loading promoted PINK1/Parkin-dependent mitophagy in periodontal ligament stem cells (PDLSCs) derived from adolescents (12-16 years old) and adults (25-35 years old). Furthermore, adult PDLSCs exhibited lower levels of mitophagy, impaired mitochondrial function, and a decreased ratio of RANKL/OPG compared to young PDLSCs after compression. Transfection of siRNA confirmed that inhibition of mitophagy in PDLSC resulted in decreased mitochondrial function and reduced RANKL/OPG ratio. Application of mitophagy inducer Urolithin A enhanced bone remodeling and accelerated OTM in rats, while the mitophagy inhibitor Mdivi-1 had the opposite effect. These findings indicate that force-stimulated PDLSC mitophagy contributes to alveolar bone remodeling during OTM, and age-related impairment of mitophagy negatively impacts the PDLSC response to mechanical stimulus. Our findings enhance the understanding of mitochondrial mechanotransduction and offer new targets to tackle current clinical challenges in orthodontic therapy.

Evaluation of the Distortion of Essix Retainer Formed From Biostar Machine Using Intraoral Digital Scans: An In Vitro Study.

Introduction Retention is essential to prevent unwanted tooth movement due to growth changes, to allow the gingival and periodontal tissues affected by orthodontic treatment to realign, and to stabilize teeth that have been moved to potentially unstable positions, thus reducing the risk of relapse. This study aimed to evaluate the distortion of Essix retainers over time to enhance their retention and stability. Methods Patients who visited the Department of Orthodontics and Dentofacial Orthopedics at Ranjeet Deshmukh Dental College & Research Centre, Nagpur, India, after completing their orthodontic treatment were included in the study, according to the established inclusion and exclusion criteria. A total of 26 patients participated. Each patient received an Essix retainer fabricated from a Duran+ Biostar round sheet (1 mm thickness) using a Biostar machine based on their post-debonded maxillary cast. The patients were instructed on the correct insertion and removal of the Essix retainer. The inner surface of the retainers was scanned at one month, three months, and six months using an intraoral digital scanner. These scans were analyzed and compared for distortion at different time intervals using Medit software. Results The Essix retainers exhibited varying degrees of distortion at different time intervals. Notably, distortion was more significant in the posterior region compared to the anterior region. Additionally, distortion increased over time, with the least amount observed at one month and progressively worsening by the sixth month. Specifically, the average distortion in the posterior region ranged from 0.133 mm after the first month to 0.304 mm after six months. In contrast, the average distortion in the anterior region was lower, ranging from 0.057 mm at one month to 0.068 mm at six months. Conclusions Distortion was more pronounced on the posterior surface of the Essix retainer compared to the anterior region.

How accurate is predicted root movement achieved in four first-premolar extraction cases with Invisalign?

This study aims to compare the achieved and predicted root movements in adults after four first-premolar extractions and Invisalign treatment. Thirty-three consecutive adults (22 Class I, 9 Cusp-to-cusp Class II and 2 Cusp-to-cusp Class III) from a single clinical division who completed the first series of aligners after premolar extractions were included in this retrospective study. A pretreatment cone-beam computed tomography model was registered onto the pretreatment surface-scanned dental model (SSDM) to locate the pretreatment root apices of the whole dentition. These were copied and transferred to the predicted and achieved post-treatment SSDMs to acquire the locations of the predicted and achieved post-treatment root apices. The differences between predicted and achieved root movements (DPARMs) were tested using the paired t-test or Wilcoxon signed rank test. In the anteroposterior direction, posterior root movements of maxillary and mandibular anterior teeth were poorly achieved (3.24-5.74 mm DPARMs, p < .05). In the vertical direction, roots of maxillary anterior teeth achieved greater intrusion (0.70-0.93 mm DPARMs, p < .05), while those of mandibular incisors achieved less intrusion (0.57-0.65 mm DPARMs, p < .05) than predicted. In the mediolateral direction, lateral incisor roots did not move distally (-0.65 to -0.96 mm DPARMs, p < .05), while those of canines did not move buccally, compared with the prediction (-0.75 mm DPARMs, p < .05). In the four first-premolar extraction treatments with Invisalign, root movements were not achieved as predicted, particularly for anterior teeth in the anteroposterior direction.

KAT6A/YAP/TEAD4 pathway modulates osteoclastogenesis by regulating the RANKL/OPG ratio on the compression side during orthodontic tooth movement

BackgroundOrthodontic tooth movement (OTM) is a dynamic equilibrium of bone remodeling, involving the osteogenesis of new bone and the osteoclastogenesis of old bone, which is mediated by mechanical force. Periodontal ligament stem cells (PDLCSs) in the periodontal ligament (PDL) space can transmit mechanical signals and regulate osteoclastogenesis during OTM. KAT6A is a histone acetyltransferase that plays a part in the differentiation of stem cells. However, whether KAT6A is involved in the regulation of osteoclastogenesis by PDLSCs remains unclear.ResultsIn this study, we used the force-induced OTM model and observed that KAT6A was increased on the compression side of PDL during OTM, and also increased in PDLSCs under compression force in vitro. Repression of KAT6A by WM1119, a KAT6A inhibitor, markedly decreased the distance of OTM. Knockdown of KAT6A in PDLSCs decreased the RANKL/OPG ratio and osteoclastogenesis of THP-1. Mechanistically, KAT6A promoted osteoclastogenesis by binding and acetylating YAP, simultaneously regulating the YAP/TEAD axis and increasing the RANKL/OPG ratio in PDLSCs. TED-347, a YAP-TEAD4 interaction inhibitor, partly attenuated the elevation of the RANKL/OPG ratio induced by mechanical force.ConclusionOur study showed that the PDLSCs modulated osteoclastogenesis and increased the RANKL/OPG ratio under mechanical force through the KAT6A/YAP/TEAD4 pathway. KAT6A might be a novel target to accelerate OTM.

Effects of isotretinoin on tooth movement, orthodontically induced and non-orthodontic root resorption: A micro-CT study.

This study aims to investigate whether cumulative dose-dependent isotretinoin (Roaccutane®) could affect orthodontic tooth movement (OTM) and root resorption. Ninety male Wistar Albino rats were divided into 4 groups. While, the control (SALINE), solvent (SOYBEAN) and orthodontic drug (ISOTM) groups underwent orthodontic force, the non-orthodontic drug group (ISO) did not. The rats were administrated saline, soybean oil (SBO) and isotretinoin diluted in SBO (ISOTM, ISO) for 30 days, respectively. Six rats were euthanized in each orthodontic group. Fifty grams of orthodontic force was applied to the remaining rats' first molars using the incisors as anchorage. Six more rats in each group were euthanized on the 7th, 14th and 21st days of the force application. In the ISO group, six rats were euthanized on the 37th, 44th and 51st days of administration. Six rats that were euthanized for ISOTM on the 30th day were also used for ISO to reduce the number of rats used. Micro-computed tomography (micro-CT) and histological analysis were performed. Independent of orthodontic force, isotretinoin caused root resorption in the apical region. However, there was no statistically significant influence of isotretinoin on OTM and orthodontically induced root resorption (OIRR). Despite the lack of strong evidence supporting the orthodontically induced resorptive effect of isotretinoin, this study provided findings regarding the resorptive effects of isotretinoin on non-orthodontic root resorption. Therefore, the present results underscore the importance of close monitoring during orthodontic treatment to mitigate potential root resorption in patients who use isotretinoin because of acne complaints.

Biomodulation effects induced by ultrasound stimulation in periodontal cells implicated in orthodontic tooth movement: A systematic review.

Accelerating orthodontic tooth movement (OTM) is increasingly important for shorter treatment times, which reduces periodontal risks, root resorption and dental caries. Techniques to accelerate OTM focus on stimulating bone remodelling by enhancing osteoclast and osteoblast activity and include both surgical and non-surgical methods. The therapeutic potential of ultrasounds is highly recognized among many medical areas and has shown promising results in modulating bone remodelling and inflammation phenomena. This systematic review aims to collect and analyse the current scientific invitro and exvivo evidence on ultrasound stimulation (US) bioeffects in cells implicated in tooth movement. This review was conducted according to PRISMA 2020 guidelines. A bibliographic search was carried out in the PubMed, Scopus and Web of Science databases. Sixteen articles were selected and included in this review. The revised studies suggest that US of 1.0 and 1.5 MHz, delivered at 30 mW/cm2, 10 to 30 min daily over three to 14 days seems to be effective in promoting osteoclastogenic activity, while US of 1.5 MHz, 30 to 90 mW/cm2, in 5- to 20-min sessions delivered daily for 5 to 14 days exhibits the potential to stimulate osteogenic activity and differentiation. Previous research yielded varied evidence of the effectiveness of US in orthodontics. Future animal studies should employ the recommended US parameters and investigate how distinct protocols can differentially impact tissue remodelling pathways. The knowledge arising from this review will ultimately potentiate the application of US to accelerate OTM in the clinical setting.