Tooth Movement Research Articles

Involvement of RAMP1/p38MAPK signaling pathway in osteoblast differentiation in response to mechanical stimulation: a preliminary study

ObjectiveThe present study aimed to investigate the underlying mechanism of mechanical stimulation in regulating osteogenic differentiation.Materials and methodsOsteoblasts were exposed to compressive force (0–4 g/cm2) for 1–3 days or CGRP for 1 or 3 days. Expression of receptor activity modifying protein 1 (RAMP1), the transcription factor RUNX2, osteocalcin, p38 and p-p38 were analyzed by western blotting. Calcium mineralization was analyzed by alizarin red straining.ResultsUsing compressive force treatments, low magnitudes (1 and 2 g/cm2) of compressive force for 24 h promoted osteoblast differentiation and mineral deposition whereas higher magnitudes (3 and 4 g/cm2) did not produce osteogenic effect. Through western blot assay, we observed that the receptor activity-modifying protein 1 (RAMP1) expression was upregulated, and p38 mitogen-activated protein kinase (MAPK) was phosphorylated during low magnitudes compressive force-promoted osteoblast differentiation. Further investigation of a calcitonin gene-related peptide (CGRP) peptide incubation, a ligand for RAMP1, showed that CGRP at concentration of 25 and 50 ng/ml could increase expression levels of RUNX2 and osteocalcin, and percentage of mineralization, suggesting its osteogenic potential. In addition, with the same conditions, CGRP also significantly upregulated RAMP1 and phosphorylated p38 expression levels. Also, the combination of compressive forces (1 and 2 g/cm2) with 50 ng/ml CGRP trended to increase RAMP1 expression, p38 activity, and osteogenic marker RUNX2 levels, as well as percentage of mineralization compared to compressive force alone. This suggest that RAMP1 possibly acts as an upstream regulator of p38 signaling during osteogenic differentiation.ConclusionThese findings suggest that CGRP-RAMP1/p38MAPK signaling implicates in osteoblast differentiation in response to optimal magnitude of compressive force. This study helps to define the underlying mechanism of compressive stimulation and may also enhance the application of compressive stimulation or CGRP peptide as an alternative approach for accelerating tooth movement in orthodontic treatment.

Medications and Orthodontic Tooth Movement: What Accelerates and Diminishes Tooth Movement?

The biological aspect of orthodontic tooth movement is influenced by the magnitude and duration of the applied force. This initiates signaling cascades essential for bone remodeling, which involve activating various cell signaling pathways that enhance the metabolism of the periodontal ligament, leading to localized bone resorption and deposition. This process facilitates tooth movement on the pressure side and promotes healing on the tension side. The remodeling associated with orthodontic tooth movement is an inflammatory reaction involving mediators. Key components in this process include hormones, systemic influences, cyclic adenosine monophosphate, specific cytokines like interleukin 1, colony-stimulating factors, calcium, collagenase, and prostaglandins, all of which are essential for the biological adjustments necessary for tooth movement. Medications that influence molecular pathways critical for the homeostasis of periodontal tissues or that affect changes during orthodontic tooth movement and clastic cell regulationcan potentially modulate tooth movement. With the recent increase in prescription medication use, it is essential for clinicians to be aware of medication consumption in prospective patients and understand its potential impact on orthodontic treatment. This review aimed to explore the effects of commonly prescribed medications on the rate of orthodontic tooth movement, thoroughly review the existing evidence on this topic, and identify potential areas for future research.

Mandibular cortical bone remodeling characteristics in patients with extraction: A cone-beam computed tomography study

This study evaluated the labial and lingual cortical bone remodeling characteristics of mandibular central incisors after retraction, which remain controversial among orthodontists. Cortical bone remodeling and central incisor movement of 33 patients (aged 23.64 ± 4.30 years) who underwent mandibular first premolar extraction and incisor retraction at the crestal (S1), midroot (S2), and apical (S3) levels were analyzed using superimposed cone-beam computed tomography images on the basis of voxel-based registration of the mandibular stable region. Multivariate linear regression was used to explore the relationships between labial bone remodeling/tooth movement (BT) ratios and factors such as the ANB angle, mandibular plane angle (Mp-SN), and incisor movement patterns. The patients were divided into 4 groups according to the lingual cortical bone remodeling condition and the relationship between posttreatment incisor roots and the original lingual cortical bone border. At the 3 levels (S1, S2, and S3), the classifications of cortical bone remodeling of the mandibular incisors were calculated; t tests were used to compare the amount of labial and lingual bone remodeling, BT ratios, and lingual bone remodeling/root over the original border (BRo) ratios. The mean labial BT ratios at all 3 levels were close to 1. Multivariate linear regression indicated that the tooth movement pattern negatively correlated with the BT ratio at the S2 and S3 levels (P<0.05). Lingual bone apposition occurs when the root penetrates the original lingual cortical bone border in most patients. BRo ratios can more accurately reflect the inherent remodeling ability of the lingual cortical bone than BT ratios. The mean lingual BRo ratios were (1) S1 level: mandibular left central incisor (T31), 0.87 ± 0.25 and mandibular right incisor (T41), 0.86 ± 0.25; (2) S2 level: T31, 0.81 ± 0.12 and T41, 0.80 ± 0.22; and (3) S3 level: T31, 0.76 ± 0.20 and T41, 0.83 ± 0.26. There was no significant difference between labial BT ratios and lingual BRo ratios at the S2 and S3 levels. The amount of labial cortical bone resorption caused by mandibular incisor retraction showed varied relationships with the amount of tooth movement. Bodily retraction may decrease the labial BT ratios at the S2 and S3 levels. Active lingual cortical bone apposition occurred when the roots penetrated the original lingual border and exhibited strong remodeling ability.

The effect of Atorvastatin on relapse after orthodontic tooth movement

The effect of Atorvastatin on relapse after orthodontic tooth movement

A Bibliometric Analysis of Clear Aligner Treatment (CAT) From 2003 to 2023.

Clear aligner treatment (CAT) has been evolving over the past two decades. This study aims to conduct a comprehensive and up-to-date bibliometric analysis of publications related to CAT, presenting the research trends, landscapes, and hot spots in this field. All publications were retrieved from the Web of Science Core Collection from 2003 to 2023. In addition to a general analysis of research landscapes, the following items were analyzed, i.e., countries, institutions, authors, journals, publications, and keywords. A total of 1031 relevant publications were included in this study. From 2003 to the present, the number of publications and citations in this field showed an increasing trend. Italy led in terms of publication counts, and Sichuan University in China had the highest publication counts among institutions. In total, 33 scholars had published a minimum of 10 articles, and the collaborations among them were mostly within each country. The American Journal of Orthodontics and Dentofacial Orthopedics published the most relevant publications. "Predictability of tooth movements," "influencing factors for clinical efficacy," "biomechanics," and "patients' perception and periodontal health" stood out as the core research focus on CAT. Our study identified the most influential countries, institutions and authors, and their cooperative relationships, and detected hot research topics on CAT, calling for more high-quality international collaborative research in the future.

The minimal important difference in orthodontic treatment duration: a survey across adult patients.

The minimal important difference (MID) is defined as the smallest difference that the patient perceives as important. Furthermore, the smallest worthwhile effect (SWE) is the important change measured with the benefit-harm trade-off method. The aim of this study was to evaluate the MID in orthodontic treatment duration to inform the decision regarding seeking procedures to accelerate orthodontic tooth movement and reduce treatment duration. We constructed a survey eliciting views of the MID from adult participants from four countries undergoing orthodontic treatment. Ten questions addressed reduction in the treatment duration for both durations 12 and 24 months, and four questions were related to the reduction in treatment duration that the patients would require to undergo surgical or non-surgical adjunctive procedures. We applied a univariable random effects logistic regression model to examine the association between the participants' characteristics and the MID. Then, we fitted a multivariable logistic random effects regression including significant predictors. Four hundred and fifty adults, with a median age of 21 (interquartile range: 19-24), undergoing orthodontic treatment participated in the survey. Of the respondents, 60% considered 15 days as a trivial reduction from 12 months duration of therapy and 70% considered15 daysa trivial reduction from 24 months. Of the respondents, 48% considered the period of 2 months a moderate reduction from 12 months, and 60% considered 2 months a moderate reduction from 24 months. From these results, we inferred that patients considered reductions of approximately 1 month as the MID in the treatment duration for both 12 and 24 months. However, SWE was considerably more than the MID for most of the participants to decide undergoing surgical adjunctive procedures to reduce the time of therapy. The participants required smaller SWE to undergo non-surgical procedurescompared to surgical procedures. The MID in the treatment duration is one month for both treatment durations 12 and 24 months. Patients require a greater SWE than the MID to undergo adjunctive procedures to shorten the duration, particularly for surgical procedures.

Detection of type I collagen fragments in the gingival crevicular fluid and saliva during orthodontic tooth movement

Detection of type I collagen fragments in the gingival crevicular fluid and saliva during orthodontic tooth movement

Aligners: review of their chemical components, recycling, mechanical properties and therapeutic needs - Part 1

The aligner is a thermoformed plastic device composed of various chemical components: polyurethane, polyethylene terephthalate glycol, polypropylene…All these plastics must be sufficiently resistant to abrasion and translucent for aesthetic purposes, but their solubility to salivary enzymes, insertion-disinsertion fatigue and recyclability vary according to material. From an orthodontic point of view, they must facilitate tooth movement. However, their behavior differs from that of orthodontic archwires: their Young's modulus, resilience and unloading curve are distinct, resulting in mechanical properties that fall significantly below the orthodontic requirements of multi-bracket systems. The aim of this article was to review the chemical composition, recycling and mechanical properties of aligners, and to put them into perspective with therapeutic indications. Literature data were approximated to orthodontic needs. Neither plastic nor direct printing can match the mechanical properties of our archwires or the procedures of a reliable vestibular multi-attachment appliance. Aligners remain an interesting tool in targeted indications.

Biological alterations associated with the orthodontic treatment with conventional appliances and aligners: A systematic review of clinical and preclinical evidence

Background&objectivesMechanical forces applied during an orthodontic tooth movement (OTM) propel several biochemical and molecular responses in the periodontal ligament and alveolar bone. Here, we compile the existing clinical and preclinical evidence on these biological changes, aiming to provide a comprehensive discussion on the influence of the mechanical parameters of the OTM in the biological profile of the periodontium. Material and methodsThis systematic integrative review was conducted according to PICOS strategy and PRISMA guidelines. A bibliographic search was performed in three electronic databases (PubMed, Scopus, and Web of Science) to find research articles published until 2023 and written in English. This search resulted in a total of 2279 publications, which were independently assessed by two evaluators using appropriate tools. ResultsForty-six studies were selected for this review. These revealed that compression, and stretching of the periodontal ligament fibers and cells are observed in the initial phase of the OTM. Specifically, on the tension side, high levels of IL-1β, OPG, and TIMPs are identified. On the compression side, an increase of RANKL, RANK, and MMPs levels predominate. ConclusionThis paper describes the release profile of common biomarkers according to the orthodontic protocol, suggesting the most appropriate parameters to keep the teeth and their supporting structures healthy. Overall, this manuscript provides a better understanding of the OTM-associated biological phenomena, also highlighting the importance of early evaluation of oral health, and thus it contributes as a fundamental basis for the development of more effective and safe orthodontic treatments with conventional appliances and aligners.

Changes in Osteocalcin Levels During Orthodontic Tooth Movement in Periodontally Affected Mandibular Anterior Teeth

Changes in Osteocalcin Levels During Orthodontic Tooth Movement in Periodontally Affected Mandibular Anterior Teeth

Clinical limitations and its solutions of the digital clear aligner treatment

The digital clear aligner is widely used due to the convenience and efficiency of simultaneously manufacturing the entire aligner used in treatment with a single setup. However, due to the characteristics of clear aligners, which make it difficult to effectively transmit orthodontic force to the teeth compared to traditional brackets, the teeth do not move as planned, resulting in repeated refinements and increased treatment periods. The following measures have been proposed to solve these problems:1. Partial production of Clear aligner: Manufacturing the entire aligner not all at once but in stages, typically 8-10 at a time, allows for more precise management of the individual tooth movement. Additionally, adjustments can be made promptly if treatment does not go as planned.2. Direct 3D printing of clear aligners: Direct 3D printing offers the possibility of creating more efficient aligners that adhere more closely to the teeth than vacuum-formed ones. Moreover, effective tooth movement can be achieved by adjusting the aligner's thickness or designing structures to apply orthodontic forces as required.3. Digital hybrid treatment: Using 3D-printed brackets with two strands of NiTi wire allows for rapid and accurate tooth movement with gentle force. In particular, the ability to manufacture clear aligners and 3D-printed brackets together in a single digital setup enables various clinical applications. This not only shortens the treatment period but also allows for better treatment results.

Mechanical and biological properties of current materials of clear aligner

With the development of new materials related to clear aligners, the physical properties are improving, and the clinical performance of the devices is expected to improve. Clear aligners require constant, controlled force on the teeth to achieve the desired tooth movement. However, unlike superelastic wires for orthodontic treatment, clear aligner materials are characterized by significant short-term or long-term stress relaxation after installation of the device. In addition, clear aligners are a complex manufacturing process that requires creating a tooth model and trimming the aligners, and various degrees of shrinkage and expansion may occur during the thermoforming process or direct printing of device. These changes can affect the thickness or fit of each tooth area and make it difficult to achieve the clinical treatment goals of clear aligner.Recently, multi-layered clear orthodontic products with improved physical properties have been introduced to increase the predictability of aligner treatment, and with the recent introduction of direct printing materials, innovative manufacturing methods for clear orthodontic devices have become possible. As shape memory properties have been reported among direct printing materials, interest in related materials is increasing. In this issue, we will introduce the latest materials related to clear aligners and explain the physical and biological properties that clinicians need to know for proper use.

Manufacture and use of In-house clear aligners using digital technology

With the development of digital technology, in-house manufacturing of clear aligners is increasing. As a result, it has become possible to create more elaborate and precise aligners compared to the manual manufacturing method. In addition, along with the technology to print clear aligners directly from a 3D printer, a material with completely different properties were also created. Since this new material with shape memory properties is created through a chemical reaction into the aligners with properties appropriate for tooth movement, only through the right processes and procedures can a safe aligner without harmful effects and excellent properties be completed. Thanks to the unique properties of this aligners, there is a possibility of overcoming the limitations of existing clear aligners. The author explained the process of manufacturing a clear aligners using digital technology in your clinic, and summarized the things you need to know when manufacturing a new aligners using shape memory polymer.

Clinical effectiveness of regenerative periodontal surgery and orthodontic tooth movement with clear aligners in stage IV periodontitis: a case series.

To evaluate the clinical effectiveness of regenerative treatment of intrabony defects in combination with consecutive orthodontic therapy with clear aligners in stage IV (type 2) periodontitis. Ten patients with a total of 103 intrabony defects were analyzed after regenerative surgery using collagen-deproteinized bovine bone mineral with or without collagen membrane or enamel matrix derivative followed by orthodontic therapy with clear aligners. Changes in radiographic bone level and probing pocket depths were evaluated after 1 year (T1) and at final splinting (T2) after orthodontic tooth movement. Mean radiographic bone level gain was significant, with 2.13 ± 1.64 mm at T1 and 3.02 ± 2.00 mm at T2. Mean probing pocket depth was significantly reduced from 5.40 ± 1.80 mm at baseline to 3.78 ± 1.73 mm at T1, and remained stable with 3.73 ± 1.70 mm at T2. Pocket closure (≤ 4 mm probing pocket depth) was accomplished in 76% of all defects. Tooth loss amounted to 2.9%. Within the limitations of the retrospective study design, the findings suggest that the interdisciplinary treatment of periodontitis stage IV by regenerative periodontal surgery and consecutive orthodontic therapy with clear aligners can lead to favorable results.

New insights in the 3-D rheological properties and collagen fibers orientation in murine periodontal ligaments

The rheological properties of the periodontal ligament are key parameters to understand the homeostatic stability of the tooth supporting apparatus. The objective of this study is to lay new insights on the rheological properties and structural information of different regions in murine periodontal ligament by using atomic force (AFM) and multi-photon microscopy (MPM). A significant variation in elasticity of different regions was measured. The elasticity of periodontal ligament showed a significant tendency to become softer towards the furcation, the nearest area to the center of resistance of the tooth. This can open a new prospective for connecting the rheological adaptation of periodontal ligament to the tooth geometry that defines the center of resistance. Another important finding revealed by the second harmonic generation (SHG) signal exhibited by collagen fibers and measured by MPM is that the orientation of fibers in the furcation region can both provide space for tooth vertical movement with high compressive loads and prevent horizontal tooth movement. Additionally, it was found that the dispersion of the angles at different levels of cutting indicates homogeneity in the directionality of fibers across different regions. These results provide an accurate description of the rheological properties and structural information of periodontal ligament, which can serve as a base for comparison with other local and systemic diseases that may influence the periodontal ligament.

Clinical implications of amathematical-geometrical model to predict changes in the anterior arch dimension.

Anterior arch length (AL) and the alterations in its dimension following incisor movements were shown to be predictable for an individual patient using amathematical-geometrical model based on athird-degree parabola. Although the model has been validated previously, it is hard to apply in daily orthodontic routine. Thus, the aim of this study was to modify the model using different approaches to allow its establishment in daily routine. This retrospective study was based on astudy collective, which was described previously and consisted of 50randomly chosen dental casts and lateral cephalograms taken before (T0) and after (T1) orthodontic treatment with fixed appliances. AJAVA computer program (Oracle, Austin, TX, USA) was developed to predict AL changes following therapeutic changes of arch width, depth or incisor inclination/position, taking the type of tooth movement into account. Performing exemplary AL calculations with the computer program, general rules and nomograms were set up, followed by multiple linear regression analyses to establish easy-to-use regression equations. The JAVA computer program is available for download. Sagittal changes showed more effect on AL than transverse modifications. Protruding incisors increased AL, but also reduced overbite. The extent of alteration in AL depended on the initial depth, width, incisor inclination, tooth movement type and distance between the incisal edge and the centre of rotation. The computer program precisely predicts individual changes in AL but is time-consuming. The presented regression equations and nomograms, considering metric variables, are easier to apply clinically and the differences compared to the AL calculated by the computer program are negligible.

Effectiveness of autologous leukocyte-platelet-rich fibrin on the rate of maxillary canine retraction, rotation, pain, and soft tissue healing: A split-mouth randomized controlled trial.

To assess the effectiveness of leukocyte-platelet-rich fibrin (L-PRF) compared with conventional treatment on canine retraction, rotation, pain, and soft tissue healing. Sixteen adult patients aged 18-25 years (10 females, and 6 males; mean age 22.25 ± 2.26 years) with Class I bimaxillary protrusion and Class II div 1 malocclusion participated in this single-center, split-mouth randomized controlled trial at the Orthodontics Department of a single hospital in SCB Dental College and Hospital, Cuttack, India. Randomization was performed using a computer-assisted function with a 1:1 allocation ratio. The intervention included the placement of L-PRF on the experimental side and follow-up for 90 days. The primary outcome measures were canine retraction, rotation, pain, and soft tissue healing. The range of tooth movement was evaluated at 15-day intervals: 0th day (T0), 15th day (T1), 30th day (T2), 45th day (T3), 60th day (T4), 75th day (T5), and 90th day (T6). Canine rotation was assessed at T0 and T6, and pain and soft tissue healing were evaluated on the 3rd, 7th, and 15th days of the treatment. Cumulatively, the L-PRF group demonstrated a significantly greater tooth movement as compared to conventional treatment group (P < 0.001). Overall, canine retraction was 1.5 times greater on the L-PRF side than on the control side. Canine rotation showed no significant relationship, whereas pain and soft tissue healing were significantly better on the L-PRF side than on the control side. Local administration of L-PRF amplifies canine retraction while improving pain and soft tissue repair.

The gingival crevicular fluid biomarkers with micropulse vibration device: A pilot study

PurposeThe aim of this study is to investigate the impact of vibration stimulation on gingival crevicular fluid biomarkers and orthodontic tooth movement. MethodsForty patients were randomly assigned to receive therapy with an intraoral vibration device (n = 20, AcceleDent®) or no treatment (n = 20) at a university orthodontic clinic. The quantity of fluid in the gingival sulcus, biomarkers of each fluid in the gingival sulcus, and orthodontic tooth movement were analyzed at three-time intervals (T1, T2, T3) before and after therapy (T0). ResultsThe results showed that vibration treatment led to higher levels of osteoclast biomarkers (RNAKL, RANKL/OPG) and inflammatory biomarkers (TNF-, IL-11, IL-18) compared to the control group. Additionally, vibration treatment at T1, T2, and T3 significantly improved tooth mobility and GCF volume. The gingival crevicular fluid biomarker levels of the T0, T1, and T2 vibration groups, as well as IL-11, IL-18, TGF-1, and TNF-α vibration groups, were significantly higher than those of the control group at different time points. Conclusionvibration therapy was found to be closely associated with bone-breaking cells and inflammatory factor levels.

Exploring biological mechanisms in orthodontic tooth movement: Bridging the gap between basic research experiments and clinical applications – A comprehensive review

ObjectivesThe molecular mechanisms behind orthodontic tooth movements (OTM) were investigated by clarifying the role of chemical messengers released by cells. MethodsUsing the Cochrane library, Google scholar, and PubMed databases, a literature search was conducted, and studies published from 1984 to 2024 were considered. ResultsBoth bone growth and remodeling may occur when a tooth is subjected to mechanical stress. These chemicals have a significant effect on the stimulation and regulation of osteoblasts, osteoclasts, and osteocytes during alveolar bone remodeling. This regulation can take place in pathological conditions, such as periodontal diseases, or during OTM alone. This comprehensive review outlines key molecular mechanisms underlying OTM and explores various clinical assumptions associated with specific molecules and their functional domains during this process. Furthermore, clinical applications of certain molecules such as relaxin, prostaglandin E (PGE), and interleukin-1β (IL-1β) in accelerating OTM have been reported. Our findings underscore the existing gap between OTM clinical applications and basic research investigations. ConclusionA comprehensive understanding of orthodontic treatment is enriched by insights into biological systems. We reported the activation of osteoblasts, osteoclast precursor cells, osteoclasts, and osteocytes in response to mechanical stress, leading to targeted cellular and molecular interventions and facilitating rapid and regulated alveolar bone remodeling during tooth movement. Despite the shortcomings of clinical studies in accelerating OTM, this review highlights the crucial role of biological agents in this process and advocates for prioritizing high-quality human studies in future research to gain further insights from clinical trials.

Evaluating stress and displacement in the craniomandibular complex using Twin Block appliances at varied angles: A finite element study

ObjectivesThe objective of this investigation was to assess the stress and displacement pattern of the craniomandibular complex by employing finite element methodology to simulate diverse angulations of inclined planes that are incorporated in the Twin Block appliance. MethodsA 3D finite element representation was established by use of Cone Beam Computed Tomography (CBCT) scans. This comprehensive structure included craniofacial skeletal components, the articular disc, a posterior disc elastic layer, dental elements, periodontal ligaments, and a Twin Block appliance. This investigation is the first to incorporated inclined planes featuring three distinct angulations (45, 60, and 70°) as the study models. Mechanical impacts were evaluated within the glenoid fossa, tooth, condylar, and articular disc regions. ResultsIn all simulations, the stress generated by the Twin Block appliance was distributed across teeth and periodontal ligament, facilitating the anterior movement of mandibular teeth and the posterior displacement of maxillary teeth. Within the temporomandibular joint region, compressive forces on the superior and posterior facets of the condyle diminished, coinciding with the stress configuration that fosters condylar and mandibular growth. Stress dispersion homogenized in the condylar anterior facet and articular disc, with considerable tensile stress in the glenoid fossa's posterior aspect conforming to stress distribution that promote fossa reconfiguration. The 70° inclined plane exerts the highest force on the tissues. The condyle's maximum and minimum principal stresses are 0.36 MPa and −0.15 MPa, respectively, while those of the glenoid fossa are 0.54 MPa and −0.23 MPa. ConclusionThree angled appliances serve the purpose of advancing the mandible. A 45° inclined plane relative to the occlusal plane exerts balanced anteroposterior and vertical forces on the mandibular arch. Steeper angles yield greater horizontal forces, which may enhance forward growth and efficient repositioning.