Orthodontic Movement Research Articles

Ridge split assisted molar protraction

Protraction of a second molar into the gap left by a missing first molar is an option, although it is challenging to maintain root parallelism during mesial migration due to the thick and dense cortical bone. This study was carried out to make an attempt to evaluate whether molar protraction in subjects with missing mandibular first molar and knife edge ridges is possible or not using ridge split procedure (expansion).The sample consisted of 12 subjects with missing mandibular first molar and knife edge ridges. All pre-treatment records were taken, after initial leveling and alignment ridge split procedure was performed and molar protraction was carried out using mini implants. Data was collected at a fixed interval of every six weeks. Statistical analysis using Repeated-measures ANOVA and Paired t test were done for evaluation of the rate of molar protraction and mesial molar tipping 0.12mm per week and 0.9 mm per six weeks was the rate of molar protraction that was accomplished. The mean edentulous space decreased from pre protraction to third visit significantly with a p value of ≤ 0.001.There is mesial tipping of molar post protraction with a P value of 0.148 which is statistically non-significant. On an average duration for molar protraction was 8.4 months.Ridge split made molar protraction possible in subjects with missing mandibular molar and knife edge ridges and enhanced the rate of tooth movement. The absolute anterior dental anchorage for the desired orthodontic movement was achieved by utilisation of mini implants.

Micro-osteoperforation for enhancement of orthodontic movement: A mechanical analysis using the finite element method.

Micro-osteoperforation is a minimally invasive technique aimed at accelerating tooth movement. The goal of this novel experimental study was to assess tooth movement and stress distribution produced by the force of orthodontic movement on the tooth structure, periodontal ligament, and maxillary bone structure, with and without micro-osteoperforation, using the finite element method. Cone-beam computed tomography was used to obtain a virtual model of the maxilla and simulate the extraction of right and left first premolars. Three micro-osteoperforations (1.5 x 5 mm) were made in the hemiarch on the distal and mesial surfaces of upper canines, according to the power tip geometry of the Propel device (Propel Orthodontics, Ossining, New York, USA). An isotropic model of the maxilla was fabricated according to the finite element method by insertion of mechanical properties of the tooth structures, with orthodontic force (1.5 N) simulation in the distal movement on the upper canine of a hemiarch. Initial movement was larger when micro-osteoperforations were performed on the dental crown (24%) and on the periodontal ligament (29%). In addition, stress distribution was higher on the bone structure (31%) when micro-osteoperforations were used. Micro-osteoperforations considerably increased the movement of both the dental crown and periodontal ligament, which highlights their importance in the improvement of orthodontic movement, as well as in stress distribution across the bone structure. Important stress absorption regions were identified within micro-osteoperforations.

CHANGES IN THE WIDTH OF THE PERIODONTAL GAP OF RATS WITH SUPRAOCCLUSAL RELATIONSHIPS OF INDIVIDUAL TEETH IN THE AGE ASPECT

Introduction. The dentoalveolar apparatus is a complex of complicated interaction of the jaws, masticatory muscles, teeth, and temporomandibular joints. This connection is carried out by the trigeminal nerve system with sensory and motor nuclei closely connected to the cortical and subcortical centers of the brain. Occlusal trauma is a lesion that develops in the periodontium as a result of forces that exceed the periodontal potential for functional adaptation. Occlusal trauma can be classified as primary or secondary. The first one occurs in the pulp and periodontal ligament when the force of the action on the dental structures is greater than usual, under optimal periodontal support conditions. It includes orthodontic movements, "high" restorations, and parafunctional habits such as bruxism. Secondary occlusal trauma occurs when the teeth with previous supporting tissue changes are subjected to the action of normal and excessive forces with supporting tissue changes caused by periodontal disease or previous trauma. The available evidence has demonstrated that bacterial plaque bioactive substances lead to local inflammatory responses in periodontal tissues which contribute to bone tissue resorption through osteoclasts in periodontitis. Excessive functional stress can initiate inflammatory changes in the periodontium and thus, increase destructive bacterial processes. Traumatic occlusion can expand the space of the periodontal ligament and in this way stimulate apical bacterial migration and proliferation. However, few attempts have been made to investigate the molecular mechanisms that trigger bone tissue resorption in traumatic occlusion. The analysis of publications on the studies of morphological changes in periodontal tissues in individual teeth supraocclusion in the age aspect shows the contradictory data. The aim: to determine the morphometric changes of the periodontal gap as a component of the periodontal complex in rats of different age groups in the supraocclusal relationship of individual teeth in the age aspect. Materials and methods of the study. The scientific experiment was conducted on 60 white laboratory rats aged 4 to 22 months and weighing 90 to 330 g. The rats were divided into control (30 animals) and experimental (30 animals) groups. Each group was divided into 3 subgroups (10 animals each) depending on the age of the rats: young, mature and senile. Young animals included rats aged 3–4 months with a weight of 90–100 g; mature animals - aged 6–8 months with a weight of 150–170 g; senile rats – 20–22 months and weighing 200–220 g. The method of modelling the state of supraocclusal relations of individual teeth is described in the previous publication. For histological examination of dental blocks, the following was performed. Fixation in a 10% solution of neutral formalin for two days, dehydration in alcohols of increasing concentration and embedding in paraffin. After preparation, sections were made on a Shandon Finesse 325 rotary microtome with a section thickness of 4-6 µm. The histological sections were fixed on pre-degreased slides and dried. Van Gieson staining was performed. The width of the periodontal gap was determined using the ZEISS ZEN 3.7 program by Carl Zeiss Microscopy. For statistical data processing, the AtteStat v.12.5 software was used to determine the mean value and its standard error (M±m). The probability of a statistically significant difference between the data obtained was assessed using the Student's parametric test (at a significance level of p ≤ 0.05). All samples were tested for normality using the Gupta test. Results of the study. Statistical differences were observed in rats of all groups, as well as between the indicators of all rats of the control and experimental groups (≤0.05). The width of the periodontal gap increased by 34.1% in young rats, by 25.5% in mature rats, and by 21.1% in senile rats. Conclusions The presence of supraocclusal relationships of individual teeth causes an increase in the periodontal gap in rats of all age groups. The greatest expansion of the periodontal gap has occurred in young rats. The width of the periodontal gap in rats decreases with age.

Orthodontic space closure after loss of maxillary incisors and periodontal breakdown of the edentulous area and on adjacent teeth

The closure of an edentulous space with the orthodontic movement of adjacent teeth even if affected by severe loss of periodontal support is a treatment option nowadays supplanted by the implant-born crown substitution and periodontal regenerative/reconstructive therapy. Nevertheless it is important not to forget some fundamentals of dental research that still justify, even more when combined with the most recent innovations in the field of mucogingival surgery and guided tissue regeneration, the alternative of orthodontic space closure. The latter indeed represents a valuable alternative in many malocclusions complicated by lost maxillary incisors, first of all in the growing patients and when the gingival margins are visible during speech and smile.This article will outline crucial details about the orthodontic management of the reduced periodontal tissues in the pressure area.

Friction in orthodontics

Friction is a fundamental aspect of orthodontic movement. Researchers and clinicians must be acquainted with its biomechanical and physical principles, as well as the potential alterations that may occur with the use of diverse materials. This literature review presents an approach of the physical principles at work in frictional mechanics, an analysis of the friction, at macro and microscopic level, of different orthodontic materials; describes the influence of friction on tooth movement and presents an update on friction research and its relationship to various materials.

Designing of customized devices in orthodontics by digital imaging and CAD/FEM modeling

In current decade, patient’s demand of minimal orthodontic treatment have encouraged the introduction of appliance that will be lighter, improved profile and better esthetics with regard to conventional orthodontic treatment. Considering aesthetic treatment options, removable clear aligner treatment got popular among patients since it allows clinician to deliver comprehensive orthodontic treatment while maintaining comfort of patient. The aligners should exert an adequate force in order to shift the tooth to a desirable position. But, in recent times, the relation of applied force and aligner property (eg. thickness) is inadequately witnessed. This article focuses on a patient-focused framework has been formulated which depicts orthodontic movement of teeth with the help of aligners. Particularly, a finite element model is being formulated which optimizes the thickness of these aligners with respect to amount of force and moment system applied to a lower central incisor while tipping it bucco-lingually.

Morphological Evaluation of the Incisive Canal in the Aspect of the Diagnosis and Planning of Orthodontic Treatment—CBCT Study

Background: Understanding the anatomy of the incisive canal is crucial for effective diagnosis and treatment planning in clinical orthodontics. This is because, during orthodontic tooth movement, there is a risk of contact between the roots of the upper central incisors and the incisive canal. Objective: The aim of this study was to assess the anatomical variability of the incisive canal using cone beam computed tomography (CBCT), as well as to evaluate its correlation with age, sex, and the position of the maxillary central incisors. There are only a few studies on this topic. Materials and methods: We analysed CBCT data from 67 patients aged from 13 to 49 years. This study was conducted at the Wroclaw Medical University. Measurements were performed twice by two independent researchers, and intra-observer error and correlation were calculated. The mean difference between the first and second observations and between observers was also assessed. We examined the dimensions of the incisive canal and its relationship to the roots of the upper central incisors in relation to age and gender. Results: Our study results revealed a significant correlation between the width and length of the incisive canal. Males exhibited a significantly greater canal length at the lowest point of the incisive canal on the palatal wall. Additionally, males had wider canals compared to females. The analysis of canal width and distance between the most mesial point of the root and the line passing through the most anterior point of the incisive canal showed a negative correlation in all age groups of men. The analysis of incisal inclination and incisal canal inclination showed a very strong relationship, especially in the age group of 13 to 20 years. Several potential risk groups of contact between the roots of central incisors and the incisive canal have been identified based on their structure and the planned incisors’ orthodontic movement. Conclusions and implications: Knowledge of the anatomy of the incisive canal and the use of 3D imaging in high-risk patients can prevent resorption of the incisor root by considering the individual anatomical conditions of the patient when planning orthodontic tooth movement. We recommend performing a CBCT scan before starting orthodontic treatment in the case of moderate and significant retraction of the incisors, or a significant change in their inclination due to the wide anatomical diversity of the incisive canal, especially in adult patients.

Effect of Pharmacological Methods in Accelerated Orthodontics: A Literature Review

Aims: This study aimed to perform a literature review on the effect of pharmacological methods in accelerated orthodontics and the evidence of published studies. Materials and Methods: A search of the reported literature till December, 2020, was conducted using “PubMed,” “Google Scholar,” and “manual search.” The MesH terms and keywords in the search criteria were “tooth movement,” “orthodontics,” “pharmacological,” and “drugs” in various combinations. The search was confined to the English language. Data extraction was done under the heading authors, country and year, study design (level of evidence), study type, and pharmacological agents. The level of evidence of included studies was in accordance with the National Health and Medical Research Council. Results: Five hundred forty-seven studies were retrieved from different databases, and 12 were included in this review. Out of 12 included studies, 10 were animal studies, and two were human trials. Pharmacological agents utilized for intervention were prostaglandin, followed by relaxin, vitamin D, and parathyroid hormone. The level of evidence in the human study was reported as level II, and for animal studies, level III; all the included studies recorded accelerated tooth movement. The risk of bias in the included animal studies was unclear, and the risk was low and moderate for human studies. Conclusion: Prostaglandin, interleukins, parathyroid hormone, and vitamin D are commonly used in published literature for accelerating tooth movement. Nonetheless, all these experimented drugs have few or other unsolicited adverse effects. Further studies with long-term follow-ups are recommended to support the utilization of pharmacological methods in accelerated orthodontic movements.

Evaluation of the effect of class II fixed orthodontic treatment on the periradicular bone structure of endodontically treated mandibular molar teeth using fractal dimension analysis

Aim: The aim of this study was to investigate whether changes in periradicular tissues with orthodontic movement of root canal-treated teeth differ from those without root canal treatment using fractal dimension analysis (FA). Methodology: A retrospective archive study was performed using panoramic radiographs taken before (T1) and after (T2) fixed orthodontic treatment. Panoramic radiographs of a total of 32 mandibular 1st and 2nd molar teeth were divided into groups: Group 1 (n:17), the control group, comprised radiographs of mandibular 1st or 2nd teeth without root canal treatment, and Group 2 (n:15) comprised radiographs of 1st or 2nd mandibular molars with root canal treatment. Fractal analyses were performed in four different regions—the periapical, bifurcation, mesial periapical, and distal periapical regions—of the mandibular molar teeth included in the study for a total of 128 analyses. Results: In the control group, orthodontic treatment did not make a statistically significant difference to the fractal dimension values in the four regions of the tooth (p > 0.05). In the endodontically treated group, the fractal dimension values of the mesial periapical regions increased statistically significantly after orthodontic treatment (p < 0.05). Conclusion: The FA values of this study showed that more biological interaction occurred in the root canal treatment group and in the mesial periapical region. Thus, it is important to keep orthodontic force within the tooth’s physiological limits to avoid damaging the tooth in the periapical areas where stress accumulates during orthodontic treatment. How to cite this article: Küçükkaraca E, Sarıçam E. Evaluation of the effect of class II fixed orthodontic treatment on the periradicular bone structure of endodontically treated mandibular molar teeth using fractal dimension analysis. Int Dent Res 2023;13(S1):38-43. https://doi.org/10.5577/idr.2023.vol13.s1.6 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Orthodontic tooth extrusion to regenerate missing papilla adjacent to maxillary anterior single implants: A 2- to 7-year retrospective study.

Regeneration of the missing papilla adjacent to single implants in the esthetic zone has always been challenging, despite advances in vertical hard and soft tissue regeneration. Orthodontic tooth extrusion has been shown to effectively gain alveolar bone and gingival tissue. This retrospective study evaluated the effectiveness of orthodontic tooth extrusion on regenerating missing papilla between existing maxillary anterior single implant and its adjacent tooth. Patients who underwent orthodontic tooth extrusion to regenerate missing papilla adjacent to a single implant in the esthetic zone were included in this study. The gingival phenotype, orthodontic extrusion movement, proximal bone level, dento-implant papilla level, facial gingival level, mucogingival junction level, and keratinized tissue width, of the extruded tooth were recorded at pre-orthodontic extrusion (T0 ), post-orthodontic extrusion and retention (T1 ), and latest follow-up (T2 ). A total of 17 maxillary single tooth had orthodontic tooth extrusion to regenerate missing papilla adjacent to 14 maxillary anterior single implants in 14 patients. After a mean follow-up time of 48.4 months, implant success rate was 100% (14/14), with none of the orthodontically extruded teeth being extracted. After a mean extrusion and retention period of 14.3 months, a mean orthodontic extrusion movement of 4.62 ± 0.78 mm was noted with a mean proximal bone level gain of 3.54 ± 0.61 mm (77.0% efficacy), dento-implant papilla level gain of 3.98 ± 0.81 mm (86.8% efficacy), and facial gingival tissue gain of 4.27 mm ± 0.55 mm (93.4% efficacy). A mean keratinized tissue width gain of 4.17 ± 0.49 mm with minimal mean mucogingival junction level change of 0.10 ± 0.30 mm were observed. The efficacy of orthodontic eruption movement on dento-implant papilla gain was less in the thin (80.5%) phenotype group when compared with that in the thick (91.5%) phenotype group. Within the confines of this study, orthodontic extrusion is an effective, noninvasive method in regenerating mid-term stable proximal bone and papilla adjacent to maxillary anterior single implants. This retrospective study presents a mid-term result on orthodontic extrusion as a mean to regenerate dento-implant papilla defect. The extended retention period following orthodontic extrusion showed stable and efficacious proximal bone and papilla gain.

Orthodontic treatment in patients with periodontitis - anarrative literature review.

Patients with periodontitis often require an inter-disciplinary approach, including orthodontic treatment, for effective rehabilitation of masticatory function, aesthetics and quality of life. The aim of this narrative review was to comprehensively discuss literature focusing on the biology, indications and inter-disciplinary connections related to the orthodontic approach in patients with periodontitis and to present clinical concepts in accordance with valid guidelines. The outcomes of the experimental studies indicate that orthodontic tooth movement (OTM) can be performed safely for teeth with reduced periodontium, provided infection and inflammation are controlled. Orthodontic treatment can correct pathological tooth migration, is not associated with deterioration of clinical periodontal parameters and improves aesthetics. Intrusion is safe when performed with light forces and under a strict oral hygiene regimen. Teeth can be moved either towards or away from the intrabony defect previously subjected to regenerative procedures, and research suggests that OTM has the potential to enhance bone formation after regenerative therapy. The data on orthodontic movement of teeth with furcation involvement are very scarce. The improvement in furcation involvement following either combined periodontal and orthodontic treatment was only documented in animal model studies. Due to bone and tooth loss, special consideration should be given to orthodontic treatment mechanics. © 2023 Australian Dental Association.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials.

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810nm and energy density values ≤ 5.3J/cm2 were associated with faster orthodontic tooth movement.

Misusing Elastics for Midline Diastema Closure - Disaster and Treatment Via a Case Report in Vietnam

Midline diastema has been a popular aesthetic problem for children. Several treatment options are available, however, the use of elastic bands without other appliances for closing the diastema still remains a pressing issue in Vietnam, which could be done by the patient’s parents either themselves or under the dental practitioners’ suggestion. Objective: To report a specific case about the extensive extrusion regarding upper central incisors in a pediatric patient due to misusing the elastic band, in which management was complex due to an unfavorable situation for splinting. Case Report: Single rubber band usage for orthodontic movement in closing diastema has been an unresolved disaster in Vietnam, leading to the need for early diagnosis and immediate intervention when facing the complications. Conclusion: Significant information dissemination is paramount for long-term improvement in the oral health of pediatric patients in Vietnam and around the world.

Long-Term Clinical and Radiographic Observation of Previously Regenerated Treated Incisors Subjected to Orthodontic Movement. A Case Series

IntroductionWith an increasing number of anterior traumatized teeth treated with regenerative endodontic procedures (REPs) nowadays, orthodontic movement of such teeth is expected to become a common scenario in everyday clinical practice. However, little is known about the clinical implications and the response capacity of regenerated tissues to orthodontic forces. MethodsThe aim of this clinical article was to report on 4 cases of REP-treated immature anterior permanent teeth subjected to orthodontic forces, and to describe the long-term response of the regenerated apical and intracanal tissues. ResultsSigns of orthodontic-induced external root resorption were observed in 2 of the 4 presented cases without, however, the presence of any associated adverse events. No other complications were observed, either clinically or radiographically, throughout the observation period. In the long-term, all 4 cases responded favorably to orthodontic forces, maintaining healthy apical tissues and structural integrity of both intracanal as well as apically regenerated tissues. ConclusionsThe orthodontic movement of REP-treated teeth seems feasible, nevertheless, special care should be implemented. Lightly acting orthodontic forces, short duration of active movement, and close monitoring of the patient seem to be prerequisites to limit complications to a minimum and achieve a favorable healing of REP-treated teeth in the long-term following orthodontic treatment completion.

Acceleration Techniques for Teeth Movements in Extractive Orthodontic Therapy

For a world that is constantly trying to speed up every procedure while obtaining the maximum result, traditional orthodontics have the biological limitation of using light and constant forces that allow tooth movement in a time frame that is only sometimes short. The treatment time could be lengthened if surgical procedures are programmed in the plan. Methods to accelerate tooth movement and reduce the duration of treatment while minimising complications are investigated and reported in the dental literature (e.g., low-level laser therapy, corticotomy, and micro-osteoperforations). This systematic review aims to analyse and summarise the strategies for quickening orthodontic movement during extraction orthodontic treatment, including any potential drawbacks or adverse consequences. The review will evaluate each approach’s effectiveness, safety, and evidence quality, compare their benefits and disadvantages, and analyse the implications for clinical practice and future research. Pubmed, Science Direct, Scopus, and Web of Science were searched using the keywords “acceleration” AND “dental movement” AND “orthodontic” between 1 April 2003 and 1 April 2023. After carefully scanning the study findings, forty-four publications were chosen for the systematic review. Most therapies discussed and provided in the literature seem promising and successful in enhancing orthodontic treatments. The success of operations like corticotomies, piezo-incisions, micro-osteoperforations, osteogenic distraction, low-level laser therapy, the administration of pharmacological treatments, and infiltrations with PRF and PRP were statistically significant and appear to be promising and effective in optimising orthodontic treatments. These strategies expedite treatment and enhance the patient experience, potentially broadening orthodontic appeal and minimising issues like cavities and enamel demineralisation. Further studies, with larger samples and standardised treatment protocols, are needed to investigate the efficacy of these tooth movement acceleration modalities.

Ridge mini-implants, a versatile biomechanical anchorage device whose success is significantly enhanced by splinting: a clinical report

ObjectivesThis clinical report aims to highlight the factors affecting the clinical success of alveolar ridge mini-implants used for orthodontic anchorage and provide an overview of the biomechanical versatility of this miniscrew and steps involving the proper technique of its placement.MethodsFor this clinical report, charts for 295 patients who had temporary anchorage devices (TADs) were screened. Twenty patients [15 females and 5 males: mean age = 38.15 ± 15.10 years] with 50 alveolar ridge mini-screws were assessed. A descriptive summary of the main factors affecting their clinical success and the technique employed for their placement was comprehensively discussed and illustrated, in addition to the presentation of some clinical cases illustrating their potential clinical uses.ResultsThe survival duration (7.32 ± 9.01 months) and clinical success of the alveolar ridge mini-implants that failed (19/50) seem to be affected primarily by 2 factors: splinting; none of the splinted mini-implants failed (0/10) compared to (19/40) of the single mini-implants that failed, and the length of the used mini-implant; the average length of the mini-implants that did not fail was 9.23 mm. Additionally, it appears that these mini-implants are biomechanically robust and durable, those that did not fail had an average survival duration of 35.97 ± 19.79 months.ConclusionRidge mini-implants offer significant biomechanical versatility in patients with partially edentulous ridges needing complex pre-prosthetic orthodontic movements. The presence of splinting and the length of the used mini-implants are factors that might affect the clinical success of the alveolar ridge mini-implants.

Cortical and Trabecular Bone Stress Assessment during Periodontal Breakdown-A Comparative Finite Element Analysis of Multiple Failure Criteria.

Background and Objectives: This numerical analysis investigated the biomechanical behavior of the mandibular bone as a structure subjected to 0.5 N of orthodontic force during periodontal breakdown. Additionally, the suitability of the five most used failure criteria (Von Mises (VM), Tresca (T), maximum principal (S1), minimum principal (S3), and hydrostatic pressure (HP)) for the study of bone was assessed, and a single criterion was identified for the study of teeth and the surrounding periodontium (by performing correlations with other FEA studies). Materials and Methods: The finite element analysis (FEA) employed 405 simulations over eighty-one mandibular models with variable levels of bone loss (0-8 mm) and five orthodontic movements (intrusion, extrusion, tipping, rotation, and translation). For the numerical analysis of bone, the ductile failure criteria are suitable (T and VM are adequate for the study of bone), with Tresca being more suited. S1, S3, and HP criteria, due to their distinctive design dedicated to brittle materials and liquids/gas, only occasionally correctly described the bone stress distribution. Results: Only T and VM displayed a coherent and correlated gradual stress increase pattern for all five movements and levels of the periodontal breakdown. The quantitative values provided by T and VM were the highest (for each movement and level of bone loss) among all five criteria. The MHP (maximum physiological hydrostatic pressure) was exceeded in all simulations since the mandibular bone is anatomically less vascularized, and the ischemic risks are reduced. Only T and VM displayed a correlated (both qualitative and quantitative) stress increase for all five movements. Both T and VM displayed rotation and translation, closely followed by tipping, as stressful movements, while intrusion and extrusion were less stressful for the mandibular bone. Conclusions: Based on correlations with earlier numerical studies on the same models and boundary conditions, T seems better suited as a single unitary failure criterion for the study of teeth and the surrounding periodontium.

Modified surgery-first approach for management of severe class III malocclusion with maxillary skeletal midline discrepancy

This case report describes orthosurgical case that used the recently introduced surgery-first approach to correct a severe skeletal class III malocclusion with severe maxillary midline discrepancy. A 23-year-old adult male presented with severe mandibular prognathism and midline discrepancy associated with upper jaw. Firstly partial orthodontic movement were facilitated to decrowd the lower teeth in order to avoid any hindrance while anterior tooth advancement. After which prediction of the postsurgical tooth movement and surgical simulation was done by using Nemoceph software than 2-jaw surgery that included maxillary advancement differentially initiated to correct midline followed by mandibular setback was performed using a surgery-first approach. Immediate facial improvement was achieved and postsurgical orthodontic treatment was efficiently carried out. The total treatment time was 11 months. The patient's facial appearance improved significantly and a stable surgical orthodontic outcome was obtained even after patient was followed for six years.

Knowledge of Dental Trauma and Orthodontic Management of Traumatized Teeth by a Group of Lithuanian Orthodontists.

Background and Objectives. There is a deficiency of research on orthodontic movements and management strategies for traumatized teeth to avoid further treatment complications. The aim of the study was to evaluate the knowledge of Lithuanian orthodontists about dental trauma and the orthodontic management of traumatized teeth. Materials and Methods. Lithuanian orthodontists and orthodontic residents were introduced to the purpose, objectives and questionnaire of the study. The questionnaire was developed based on demographics, the participants' personal experience, specific questions about dental traumas and orthodontic treatment tactics for patients with a history of dental trauma. Results. A total of 54 participants (42 orthodontists and 12 orthodontic residents) completed the survey. The overall response rate was 42.9%. The results of the survey revealed that the largest share of the study participants-61%-stated that they had treated traumatized teeth just a few times during the whole practice. Briefly, 53.7% of respondents inquired about the dental trauma history only if they saw signs of complications. The results of the survey revealed that the frequency of correct answers to questions about dental trauma was 63.7%, and that about the orthodontic treatment of traumatized teeth was 54.9%. It is worth noting that one-third of physicians pointed out the lack of information about the orthodontic management of traumatized teeth. Conclusion. The knowledge of Lithuanian orthodontists and orthodontic residents about dental injuries and the orthodontic treatment of traumatized teeth is insufficient. Further educational training is recommended.

3D assessment of alveolar bone alterations in orthodontic movement among Indians.

Apical root resorption, which is characterised as a biological or abnormal phenomenon that shortens the length of the root apex, is additional typical iatrogenic impact of orthodontic tooth movement that may jeopardise the effectiveness of treatment and tooth lifespan. The main goals of the current retrospective investigation were to assess the dimensions of alveolar bone alterations that come along with orthodontic movement and to look into the frequency and extent of resorption of root in maxillary incisors across categories that were similarly managed with clear aligners (OCA) and fixed appliances (OFA) using CBCT. The study included 50 subjects who were divided into two categories with 25 study subjects in each category. Category OFA: Subjects receiving OFA (n=25). A CBCT scan was used to get three-dimensional pictures at the beginning of therapy as well as at the end of therapy. The overall resorption of root at apical region in OFA group was 0.63±0.21 mm. The overall resorption of root at apical region in OCA group was 0.32 ±0.36 mm. The difference in observation was statistically significant (p= 0.000) with reduced resorption of root at apical region in clear aligners. It was concluded that the decrease in thickness of alveolar bone was greater in orthodontic fixed appliances group as compared to clear aligners. The resorption of root at apical region was lesser in clear aligners group as compared to fixed appliances.