Force-induced Caspase-1-dependent pyroptosis regulates orthodontic tooth movement / 国际口腔科学杂志·英文版

Pyroptosis, an inflammatory caspase-dependent programmed cell death, plays a vital role in maintaining tissue homeostasis and activating inflammatory responses. Orthodontic tooth movement (OTM) is an aseptic force-induced inflammatory bone remodeling process mediated by the activation of periodontal ligament (PDL) progenitor cells. However, whether and how force induces PDL progenitor cell pyroptosis, thereby influencing OTM and alveolar bone remodeling remains unknown. In this study, we found that mechanical force induced the expression of pyroptosis-related markers in rat OTM and alveolar bone remodeling process. Blocking or enhancing pyroptosis level could suppress or promote OTM and alveolar bone remodeling respectively. Using Caspase-1-/- mice, we further demonstrated that the functional role of the force-induced pyroptosis in PDL progenitor cells depended on Caspase-1. Moreover, mechanical force could also induce pyroptosis in human ex-vivo force-treated PDL progenitor cells and in compressive force-loaded PDL progenitor cells in vitro, which influenced osteoclastogenesis. Mechanistically, transient receptor potential subfamily V member 4 signaling was involved in force-induced Caspase-1-dependent pyroptosis in PDL progenitor cells. Overall, this study suggested a novel mechanism contributing to the modulation of osteoclastogenesis and alveolar bone remodeling under mechanical stimuli, indicating a promising approach to accelerate OTM by targeting Caspase-1.

Uso de microvibración e inhibidores de la catepsina K en tratamientos de regeneración ósea dental / Use of micro-vibration and cathepsin K inhibitors in dental bone regeneration treatments

Introducción: el hueso está en remodelación constante para mantener la estructura del esqueleto, tener un ciclo de resorción por los osteoclastos y formación de hueso nuevo a cargo de los osteoblastos; el hueso también es susceptible a enfermedades sistémicas, traumas, edad y trastornos genéticos que afectarán el remodelado óseo, produciendo una pérdida masiva de masa ósea regulado por hormonas, citocinas, enzimas, etcétera. El objetivo es realizar una revisión sistemática de artículos que muestren cambio o alteración al utilizar tratamientos con microvibraciones y farmacológicos sobre la catepsina K en el hueso alveolar. Material y métodos: para realizar una comparación entre la efectividad del tratamiento a base de microvibraciones y con inhibidores de la catepsina K, se realizó una revisión sistemática en nueve bases de datos (Wiley Online Library, PubMed, Google Academic, Scopus, ScienceDirect, SciELO, Medline, EBSCO y Springer Link). La población de estudio fueron ratas y ratones. Resultados: en este estudio se incluyeron 20 artículos cuya investigación se realizó en estudios clínicos. En los resultados podemos observar cómo todos los tratamientos de alguna forma mejoran el proceso de remodelado óseo. Es difícil comparar cuál de los tratamientos dentro de cada grupo es mejor que otro, debido a que los resultados expresados son cualitativos. Conclusión: acorde a los resultados expresados se opta por realizar un tratamiento con microvibraciones debido a que el uso de inhibidores de la catepsina K aún no se encuentra completamente desarrollado y no se comprenden sus consecuencias debido a su manera sistémica de actuar (AU)

Introduction: the bone is in constant remodeling to maintain the skeletal structure, having a cycle of resorption by osteoclasts and formation of new bone by osteoblasts, the bone is also susceptible to systemic diseases, trauma, age and genetic disorders that affect bone remodeling, producing a massive loss of bone mass regulated by hormones, cytokines, enzymes, etcetera. The objective is to perform a systematic review of articles that show a change or alteration when using micro-vibration and pharmacological treatments on cathepsin K in the alveolar bone. Material and methods: in order to make a comparison between the effectiveness of micro-vibration and cathepsin K inhibitor treatments, a systemic review was carried out in nine databases (Wiley Online Library, PubMed, Google Academic, Scopus, ScienceDirect, SciELO, Medline, EBSCO and Springer Link). The study population was rats and mice. Results: this study included 20 articles whose research was carried out in clinical studies. In the results we can see how all the treatments in some way improve the bone remodeling process, it is difficult to compare which treatment within each group is better than the other, because the results expressed are qualitative. Conclusion: according to the results expressed, it is decided that it is better to perform a treatment with micro vibrations because the use of cathepsin K inhibitors are not yet fully developed and their consequences are not understood due to their systemic way of acting (AU)

Orthodontic treatment in traumatized permanent teeth: a systematic review / Tratamento ortodôntico em dentes permanentes traumatizados: uma revisão sistemática

Objective: to analyze, through literature review, the available literature on orthodontic treatment in traumatized permanent teeth. Methods: A literature search was performed in electronic databases (PubMed and SciELO) using the descriptors [tooth injuries] OR [injuries, teeth] OR [injury, teeth] OR [teeth injury] OR [injuries, tooth] OR [injury, tooth] OR [tooth injury] OR [teeth injuries] AND [orthodontics]. Observational studies and clinical trials were included, narrative reviews, laboratory and in vitro studies, case reports and series as well as articles that presented abstracts written in languages other than Portuguese, English and Spanish were excluded from the study. Two reviewers considered the eligibility, the risk of bias of the analyzed data and the qualitative synthesis of the studies included. A total of 1,322 references were found and 4 articles met all inclusion criteria and were included in the qualitative analysis. Some consequences like pulp necrosis and root resorption have been highlighted and trauma severity should be considered when orthodontically intervening in previously traumatized teeth. Final considerations: The traumatized teeth can be orthodontically treated as long as the time of tissue reorganization is respected, and the pull and periodontal conditions are followed up.(AU)

Objetivos: analisar, por meio de revisão de literatura, a respeito do tratamento ortodôntico em dentes permanentes traumatizados. Metodologia: Uma pesquisa bibliográfica foi realizada em bancos de dados eletrônicos (PubMed e SciELO) usando os descritores [tooth injuries] ou [injuries, teeth] ou [injury, teeth] ou [teeth injury] ou [injuries, tooth] ou [injury, tooth] ou [tooth injury] ou [teeth injuries] e [orthodontics]. Foram incluídos estudos observacionais e ensaios clínicos, revisões narrativas, estudos laboratoriais e in vitro, relatos de casos e séries, bem como artigos que apresentassem resumos redigidos em idiomas diferentes do português, inglês e espanhol foram excluídos do estudo. Dois revisores consideraram a elegibilidade, o risco de viés dos dados analisados e a síntese qualitativa dos estudos incluídos. Foram encontradas 1.322 referências e 4 artigos atenderam a todos os critérios de inclusão e foram incluídos na análise qualitativa. Algumas consequências como necrose pulpar e reabsorção radicular têm sido destacadas e a gravidade do trauma deve ser considerada na intervenção ortodôntica em dentes previamente traumatizados. Considerações finais: Os estudos incluídos nesta revisão sugerem que dentes traumatizados podem ser tratados ortodônticamente desde que respeitado o tempo de reorganização tecidual e acompanhadas as condições pulpares e periodontais.(AU)

Histological Evaluation of the Effect of Alendronate on the Maxillary Bone of Wistar Rats Combined with Orthodontic Movement of Intense Force / Evaluación Histológica del Efecto del Alendronate en el Hueso Maxilar de Ratas Wistar Combinado con Movimiento de Ortodoncia de Fuerzas Intensas

SUMMARY: To evaluate the histological adverse effects of alendronate administered systemically and topically in combination with orthodontic movement by intense force. Thirty-six 24-week-old female Wistar rats, ovariectomized, were used and divided into three groups (n = 12/group): control, locally treated with saline (0.07 ml/kg/week) (group 1) and experimental, treated with alendronic acid systemically (0.07 mg/kg/week) (group 2) and locally (7 mg/kg/week) (group 3). At 14 days, an orthodontic anchor was installed in the right first molar, and a force of 144 cN was applied for 28 days. The samples were processed for histological evaluation. Descriptive statistics, Shapiro-Wilk tests, one-way ANOVA with Bonferroni correction, one-way repeated measures ANOVA and chi-square tests were performed. All tests were statistically significant at p <0.05. The adverse events found in all groups were inflammation and osteoclastic activity. In the bisphosphonate-treated groups, there were statistically significant differences (p = 0.005) in the osteoclastic activity between the two hemiarcates. All rats in group 2 presented paralytic ileus. Compared to local administration, systemic treatment with alendronic acid produces more adverse effects, such as inflammation, fibrinoid necrosis, and osteoclastic activity. During the application of intense forces, it was not possible to show that there is necrosis associated with bisphosphonates.

Evaluar los efectos adversos histológicos del alendronato administrado sistémica y tópicamente en combinación con movimientos ortodóncicos de fuerza intensa. Treinta y seis ratas Wistar hembras de 24 semanas de edad, ovariectomizadas, fueron utilizadas y divididas en tres grupos (n = 12/grupo): control, tratado localmente con solución salina (0,07 ml/kg/semana) (grupo 1) y experimental, tratados con ácido alendrónico por vía sistémica (0,07 mg/kg/semana) (grupo 2) y local (7 mg/kg/semana) (grupo 3). A los 14 días se instaló un anclaje de ortodoncia en el primer molar derecho y se aplicó una fuerza de 144 cN durante 28 días. Las muestras fueron procesadas para evaluación histológica. Se realizó estadística descriptiva, pruebas de Shapiro-Wilk, ANOVA de una vía con corrección de Bonferroni, ANOVA de medidas repetidas de una vía y pruebas de chi-cuadrado. Todas las pruebas fueron estadísticamente significativas con un p <0,05. Los eventos adversos encontrados en todos los grupos fueron inflamación y actividad osteoclástica. En los grupos tratados con bisfosfonatos hubo diferencias estadísticamente significativas (p = 0,005) en la actividad osteoclástica entre los dos hemiarcados. Todas las ratas del grupo 2 presentaron íleo paralítico. En comparación con la administración local, el tratamiento sistémico con ácido alendrónico produce más efectos adversos, como inflamación, necrosis fibrinoide y actividad osteoclástica. Durante la aplicación de fuerzas intensas, no fue posible demostrar que existe necrosis asociada con los bisfosfonatos.

Analgesia por láser de baja potencia en pacientes con tratamiento ortodóncico / Low power laser analgesia in patients with orthodontic treatment i: en

Introducción: El dolor es el síntoma más común luego de la primera activación de la aparatología ortodóncica. El tratamiento analgésico más utilizado es el paracetamol; sin embargo, su uso inhibe la actividad de la ciclooxigenasa y la síntesis de prostaglandinas, lo que puede afectar el mecanismo del movimiento dental y el remodelado óseo. Objetivo: Evaluar la efectividad del láser de baja potencia para el alivio del dolor en pacientes con tratamiento ortodóntico. Métodos: Se realizó un estudio cuasiexperimental de intervención terapéutica, desde enero hasta diciembre de 2020, en 40 pacientes atendidos en la consulta de ortodoncia del Hospital General Docente Dr. Juan Bruno Zayas Alfonso de Santiago de Cuba, en quienes se aplicaría fuerza ortodóncica por primera vez. Estos fueron distribuidos de forma aleatoria en 2 grupos de 20 integrantes cada uno: el de estudio, tratado con láser de baja potencia, y el de control, que recibió medicación convencional (paracetamol). Para la validación estadística de la información se emplearon el porcentaje y la prueba de la t de Student para muestras independientes, con 95 % de confiabilidad. Resultados: Luego de tres sesiones terapéuticas, 90,0 % del grupo de estudio refirió no presentar dolor o sentirlo de forma leve, mientras que del grupo de control solo 10,0 % de los pacientes fue ubicado en cualquiera de las dos categorías anteriores. Existió diferencia significativa entre ambos grupos (p=0,00). Conclusiones: Se demostró que el láser, como terapia alternativa, fue más efectivo que el paracetamol.

Introduction: Pain is the most common symptom after the first activation of orthodontic appliance. The most widely used analgesic treatment is paracetamol; however, its use inhibits cyclooxygenase activity and prostaglandin synthesis, which can affect the mechanism of tooth movement and bone remodeling. Objective: To evaluate the effectiveness of low power laser for pain relief in patients with orthodontic treatment. Methods: A quasi-experimental study of therapeutic intervention was carried out, from January to December 2020, in 40 patients treated at the orthodontic clinic of Dr. Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba, in whom orthodontic force was applied for the first time. These were randomly distributed into 2 groups of 20 members each: the study group, treated with low-power laser, and the control group, that received conventional medication (paracetamol). For statistical validation of data, the percentage and the Student's t test for independent samples were used, with 95 % confidence interval. Results: After three therapeutic sessions, 90.0% of the study group reported not presenting pain or feeling it slightly, while only 10.0% of patients in control group were put in any of the two previous categories. There was a significant difference between both groups (p=0.00). Conclusions: Laser, as an alternative therapy, was shown to be more effective than paracetamol.

Tomographic evaluation of mandibular buccal shelf in patients with different vertical growth pattern / Evaluación de la placa ósea mandibular en pacientes con diferente patrón de crecimiento vertical

The purpose of this research was the tomographic evaluation of the Mandibular Buccal Shelf (MBS) in orthodontic patients with different vertical growth pattern. An observational, descriptive, cross-sectional and retrospective study was conducted. Tomographic images of patients aged 14 to 40 years were observed and a database was formed with those that met the inclusion criteria. The sample size was 10 for each group according to vertical growth pattern (hypodivergent, normodivergent and hyperdivergent). Then four zones of frequent insertion of extralveolar mini-screws were selected in the MBS, taking as a reference the mesial and distal roots of the first and second mandibular molar. When comparing the characteristics of MBS between vertical growth patterns, between sexes and hemiarchs, no statistically significant differences were found. However, when the characteristics of MBS were compared according to the reference root, it was found that there were statistically significant differences. The vestibular area to the distal root of the second mandibular molar presented the highest values in terms of angulation, height and thickness. There are no significant differences in the bone characteristics of MBS according to vertical growth patterns, sexes or hemiarchs. Angulation, height and thickness progressively increase from the vestibular bone of the mesial root of the first mandibular molar to the distal root of the second molar.

El propósito de esta investigación fue la evaluación tomográfica de la placa ósea mandibular (POM) en pacientes de ortodoncia con diferente patrón de crecimiento vertical. Se realizó un estudio de tipo observacional, descriptivo, transversal y retrospectivo. Se observó imágenes tomográficas de pacientes de 14 a 40 años de edad y se formó una base de datos con las que cumplían los criterios de selección. El tamaño de muestra fue de 10 para cada grupo según patrón de crecimiento vertical (hipodivergentes, normodivergentes e hiperdivergentes). Luego se seleccionaron cuatro zonas de inserción frecuente de minitornillos extralveolares en la POM, tomando como referencia las raíces mesial y distal del primer y segundo molar mandibular. Al realizar la comparación de las características de la POM entre patrones de crecimiento vertical, entre sexos y hemiarcadas no se encontraron diferencias estadísticamente significativas. Sin embargo, cuando se comparó las características de la POM según la raíz de referencia se encontró que había diferencias estadísticamente significativas. La zona vestibular a la raíz distal de la segunda molar mandibular presento los mayores valores en cuanto angulación, altura y grosor. No existen diferencias significativas en las características óseas de la POM según patrones de crecimiento vertical, sexos o hemiarcadas. La angulación, la altura y el grosor aumenta progresivamente desde el hueso vestibular de la raíz mesial del primer molar mandibular hacia la raíz distal del segundo molar.

O uso de bisfosfonatos causa implicações na movimentação dentária ortodôntica? / Does the use of biophosphonates cause implications on the orthodontic tooth movement?

Bisfosfonatos são medicamentos que reduzem a reabsorção óssea, inibindo a atividade enzimática dos osteoclastos. Por essa razão, são amplamente utilizados no tratamento de várias doenças, como a osteoporose. Durante o tratamento ortodôntico, a aplicação de forças compressivas no dente promove a reabsorção e remodelação óssea, permitindo sua movimentação. Vários estudos in vivo observaram a diminuição da movimentação ortodôntica por bisfosfonatos, tornando o tema relevante devido à crescente demanda de tratamento ortodôntico em idosos ­ principais usuários dessa droga. Assim sendo, o objetivo deste trabalho é avaliar evidências do uso de bisfosfonatos no decorrer do tratamento ortodôntico e, mais especificamente, examinar seus efeitos na movimentação ortodôntica através de mensurações clínico-laboratoriais. Para isso, foi realizada uma revisão sistematizada na base de dados Pubmed através dos descritores Ortodontia e Bisfosfonatos. Buscou-se estudos em inglês entre 2015 e 2020. De 39 artigos compatíveis à proposta, 8 artigos passaram pelos critérios de inclusão e exclusão. Desses, a maioria dos autores é categórica em se referir ao uso de bisfosfonatos como um fator relevante para índices inferiores de movimentação. Porém, tais dados devem ser vistos com cautela, pois os métodos utilizados são variados, havendo uma grande heterogeneidade. Ademais, pequenas amostras e tempo curto dos experimentos não permitem uma generalização para pacientes de rotina. Como conclusão temos que a administração de bisfosfonatos associada à movimentação ortodôntica aparenta provocar uma duração prolongada no tratamento devido, fundamentalmente, aos índices inferiores de movimentação dentária planejada. Entretanto, os fatores específicos para tal não estão plenamente explicados.

Bisphosphonates are drugs that provide bone resorption by inhibiting the enzyme activity of osteoclasts. For this reason, they are widely used in the treatment of various diseases, such as osteoporosis. During orthodontic treatment, the application of compressive forces on the tooth promotes bone resorption and remodeling, allowing its movement. Several in vivo studies observed a decrease in orthodontic movement caused by bisphosphonates, making the topic relevant due to the growing demand for orthodontic treatment in the elderly - the main users of this drug. Therefore, the aim of this study is to evaluate evidence of the use of bisphosphonates during orthodontic treatment and, more specifically, to examine their effects on orthodontic movement through clinical and laboratory measurements. For this, a systematized review was performed in the Pubmed database using the descriptors Orthodontics and Bisphosphonates. Studies in English between 2015 and 2020 were sought. Of 39 articles compatible with the proposal, 8 articles passed the inclusion and exclusion criteria. Most authors are categorical in referring to the use of bisphosphonates as a relevant factor for lower movement rates. However, such data must be viewed with caution, as the methods used are sundry, with great heterogeneity. Furthermore, small administrations and short experimental times do not allow generalization to routine patients. In conclusion, the administration of bisphosphonates associated with orthodontic movement seems to cause a prolonged duration of treatment, fundamentally due to the lower rates of planned tooth movement. However, the specific factors for this are not fully explained.

Channa Striata and Hyperbaric Oxygen Therapy Combination for Pressure Areas in Orthodontic Treatment

ABSTRACT Objective: To study the effect of using a combination of Channa Striata gel and hyperbaric oxygen therapy on pressure areas during orthodontic treatment. Material and Methods: The study was conducted using the ARRIVE Essential 10 guidelines. In this study, 35 3-4 months male guinea pigs (Cavia Cobaya) weighing 300-400 grams were used and divided into 5 groups (n=7). Decalcification was performed to dissolve the dental calcium and jawbone to cut the tissue properly. The decalcification was performed for 30 days. Then preparations were made with HE (Hematoxylin Eosin), observed using a microscope, and counted the number of osteoclasts and macrophages on a light microscope with 400 times magnification. The results of the preparations were analyzed using the SPSS program. Results: The Kruskal-Wallis test of macrophage cells and the ANOVA test of osteoclast cells showed significant results between all groups (p<0.05). Conclusion: The effect of hyperbaric oxygen therapy 2,4 ATA administered on days 8-14 and Channa Striata extract gel administered on days 3-14 can increase the number of macrophages in the periodontal ligament and osteoclasts in the alveolar bone in the pressure area during orthodontic tooth movement.

The Effects of Orthodontic Tooth Movement on Clinical Attachment Level Changes in Treated Periodontitis Adult Patients with Malocclusion: A Systematic Review and Meta-analysis

ABSTRACT Objective: To investigate the effects of orthodontic tooth movement on clinical attachment level (CAL) changes in treated periodontitis in adult patients with malocclusion. Material and Methods: Present study is based on PRISMA guidelines; all articles published in international databases such as PubMed, Scopus, Science Direct, and Embase between 2012 to May 2022 are included. 95% confidence interval (CI) for mean difference with fixed effect modal and inverse-variance were calculated. Data analysis was performed using STATA.V16 software. Results: In the initial review, duplicate studies were eliminated, abstracts of 175 studies were reviewed, two authors reviewed the full text of 21 studies, and finally, eleven studies were selected. The mean of CAL gain was 2.29 mm (MD, 95% CI -2.47 mm, -2.12 mm; p=0.00) (I2=91.81%; p=0.00; high heterogeneity). The mean difference of PPD changes was -1.93 mm (MD, 95% CI -2.07 mm, -1.80 mm; p=0.00) (I2=98.52%; p=0.00; high heterogeneity). Conclusion: Due to the limitations of the study and based on the meta-analysis, it is observed that orthodontic treatment is performed with higher success after reconstructive surgery with periodontal improvement.

Fotobiomodulación con láser de baja intensidad en el tratamiento integral ortodóntico: reporte de un caso / Photobiomodulation with low intensity laser in comprehensive orthodontic treatment: report of a case

El apiñamiento dental es una maloclusión frecuen-te y junto con los requerimientos de estética dental son una causa habitual de la solicitud de tratamien-to ortodóncico. El tiempo que demanda y las moles-tias que pudiera ocasionar el tratamiento produce inquietud en los pacientes y un esfuerzo de los or-todoncistas para optimizar el tiempo y prevenir los efectos adversos. Los tratamientos odontológicos multidisciplinarios permiten una mejor respuesta estética, funcional y de estabilidad post tratamiento. El tiempo de alineación dentaria y finalización, en los pacientes tratados con láser de baja intensidad po-dría mejorar tanto los índices gingivales como la res-puesta al dolor. Adicionalmente, las corticales óseas de los pacientes con ortodoncia tratados con láser, podrían verse menos afectadas en comparación con las de los pacientes no tratados. Se presenta un caso de fotobioestimulación con láser de baja intensidad aplicado en un paciente en fase de alineación, que forma parte de un estudio prospectivo aleatorizado que se desarrolla en la FOUBA y fue aprobado por el comité de Ética de la institución. El paciente aceptó y firmó el consentimiento informado. Finalizada la etapa de alineación, se evaluó la efectividad de la te-rapia con láser de baja intensidad actualmente de-nominada fotobiomodulación en incisivos superiores en la fase de alineación para acelerar el movimiento dentario, la respuesta gingival, el dolor, el estado de la cortical alveolar vestibular y la estética del perfil (AU)

Dental crowding, which is a frequent malocclusion, and dental aesthetic requirements are a common cause for requesting orthodontic treatment. The time that the treatment requires and the inconvenience that it could cause worries the patient and makes orthodontists strive to optimize time and prevent adverse effects. Multidisciplinary treatments would allow a better aesthetic, functional and post-treatment stability response. The dental alignment and completion time in patients treated with low-intensity laser could improve both gingival indices and response to pain. Additionally, the bone cortical of orthodontic patients treated with laser could be less affected compared to those of untreated patients. A case of low-intensity laser photobiostimulation applied to a patient in the alignment phase is presented, which is part of a prospective randomized study carried out at FOUBA and was approved by the institution's Ethics Committee. The patient accepted and signed the informed consent. After the alignment phase, the effectiveness of low-level laser therapy actually called photobiomodulation in upper incisors in the alignment phase is evaluated to accelerate tooth movement; the gingival response; the pain; the vestibular alveolar cortical and the aesthetics of the profile (AU)

Experimental study of subcutaneous adipose-derived stem cells inhibiting orthodontic root resorption / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR.@*METHODS@#Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 5 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining.@*RESULTS@#The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05).@*CONCLUSION@#Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.

RANKL+ senescent cells under mechanical stress: a therapeutic target for orthodontic root resorption using senolytics / 国际口腔科学杂志·英文版

In dentistry, orthodontic root resorption is a long-lasting issue with no effective treatment strategy, and its mechanisms, especially those related to senescent cells, remain largely unknown. Here, we used an orthodontic intrusion tooth movement model with an L-loop in rats to demonstrate that mechanical stress-induced senescent cells aggravate apical root resorption, which was prevented by administering senolytics (a dasatinib and quercetin cocktail). Our results indicated that cementoblasts and periodontal ligament cells underwent cellular senescence (p21+ or p16+) and strongly expressed receptor activator of nuclear factor-kappa B (RANKL) from day three, subsequently inducing tartrate-resistant acid phosphatase (TRAP)-positive odontoclasts and provoking apical root resorption. More p21+ senescent cells expressed RANKL than p16+ senescent cells. We observed only minor changes in the number of RANKL+ non-senescent cells, whereas RANKL+ senescent cells markedly increased from day seven. Intriguingly, we also found cathepsin K+p21+p16+ cells in the root resorption fossa, suggesting senescent odontoclasts. Oral administration of dasatinib and quercetin markedly reduced these senescent cells and TRAP+ cells, eventually alleviating root resorption. Altogether, these results unveil those aberrant stimuli in orthodontic intrusive tooth movement induced RANKL+ early senescent cells, which have a pivotal role in odontoclastogenesis and subsequent root resorption. These findings offer a new therapeutic target to prevent root resorption during orthodontic tooth movement.

Photobiomodulation therapy assisted orthodontic tooth movement: potential implications, challenges, and new perspectives / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Over the past decade, dramatic progress has been made in dental research areas involving laser therapy. The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster. Additionally, photobiomodulation therapy (PBMT), a non-invasive treatment, when applied in orthodontics, contributes to alleviating pain and reducing inflammation induced by orthodontic forces, along with improving tissue healing processes. Moreover, PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption (OIIRR) during orthodontic treatment (OT) due to its capacity to modulate inflammatory, apoptotic, and anti-antioxidant responses. However, a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement (OTM) in relation to OIIRR, casting doubt on its beneficial effects. In PBMT-assisted orthodontics, delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues. The penetration of light to the root surface is another crucial unknown factor. Both the penetration depth and distribution of light in periodontal tissues are unknown. Thus, advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations. This review explores possibilities for improving the application and effectiveness of PBMT during OTM. The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells, with a special focus on immunomodulatory effects during OTM.

Three-dimensional finite element study of mandibular first molar distalization with clear aligner / 华西口腔医学杂志

OBJECTIVES@#This study aimed to construct the finite element model of the mandibular first molar with the invisible appliance and explore the dentition movement characteristics of the mandibular first molar when using micro-implant anchorage and different initial positions of the first molar.@*METHODS@#Models of the mandible, tooth, periodontal membrane, and invisible appliance were constructed using cone beam computed tomography (CBCT) data. The two groups were divided into the non-anchorage group and the micro-implant group (between the roots of the first molar and the second molar) based on whether the elastic traction of the micro-implant was assisted or not. The two groups were divided into the following conditions based on the starting position of the first molar: Working condition 1: the distance between the first molar and the second premolar was 0 mm; working condition 2: the distance between the first molar and the second premolar was 1 mm; working condition 3: the distance between the first molar and the second premolar was 2 mm; working condition 4: the distance between the first molar and the second premolar was 3 mm. The data characte-ristics of total displacement and displacement in each direction of dentition were analyzed.@*RESULTS@#In the non-ancho-rage group, all the other teeth showed reverse movement except for the first molar which was moved distally. Meanwhile, in the micro-implant group, except for a small amount of mesial movement of the second molar in wor-king condition 1, the whole dentition in other working conditions presented distal movement and anterior teeth showed lingual movement, among which the distal displacement of the first molar in working condition 4 was the largest. With the change of the initial position of the first molar to the distal, the movement of the first molar to the distal, the premolar to the mesial, and the anterior to the lip increased, while the movement of the second molar to the mesial decreased.@*CONCLUSIONS@#The micro-implant can effectively protect the anterior anchorage, increase the expression rate of molar distancing, and avoid the round-trip movement of the second molar. The initial position of the first molar movement is related to the amount of distancing and the remaining tooth movement.

Tratamiento de Clase II, en dentición permanente, con péndulum Pend-X y anclaje esqueletal / Class II treatment, in permanent dentition, with Pend X and skeletal anchorage

El aspecto estético y, en especial, la protrusión marcada, a menudo alientan a los pacientes a so- licitar tratamiento de ortodoncia. El ortodoncista debe decidir, de acuerdo a las características biotipológicas del caso, qué solución es la más conveniente. El presente artículo describe el tratamiento de una paciente adolescente con una maloclusión de Clase II, división 1, en dentición permanente, braquifacial y que, además, presenta estrechez del maxilar superior. Atender en primer término el problema en el plano transversal es de vital importancia, pero asimismo, se debe planificar cómo corregir la Clase II y, si la distalización es el procedimiento indicado para tratarla, el verdadero reto es no perder anclaje. Se presenta un caso clínico tratado con aparato- logía fija y péndulum versión Pend-X (con tornillo de expansión transversal) y anclaje esqueletal(AU)

Aesthetic appearance, and especially marked protrusion, often encourage patients to request orthodontic treatment. The orthodontist must decide, according to biotypological characteristics of the case, which solution is the most convenient. This article describes the treatment of a teen patient with a Class II division 1 malocclusion, in permanent dentition, brachifacial and who also presents narrowness of upper jaw. Addressing the problem in the transverse plane first is of vital importance, but also, it must be planned how to correct Class II, and if distalization is the appropriate procedure to treat it, the real challenge is not to lose anchorage. It is presented a clinical case treated with fixed appliances and pendulum Pend-X version (with a transversal expansion screw) and skeletal anchorage(AU)

Ortodoncia estética. Tratamientos híbridos o combinados: ortodoncia lingual y vestibular / Aesthetic orthodontics. Hybrid or combined treatments: lingual and vestibular orthodontics

La ortodoncia lingual ha acercado a la consulta ortodóncica a pacientes que nunca antes hubie- ran aceptado un tratamiento ortodóncico. Los tratamientos estéticos son una de las opciones más solicitadas en este siglo por los pacientes adultos, que no solo desean un resultado estético sino que solicitan, también, aparatología estética. Se presenta el caso de una paciente adulta para el que se eligió un tratamiento híbrido: aparatología superior lingual (brackets linguales 2D) y apara- tología inferior vestibular (brackets autoligables, prescripción Roth pasiva-activa). Los brackets 2D son de autoligado, por lo que se utilizan fuerzas biológicas, suaves, constantes y continuas. Es importante en estos casos que ambos maxilares se trabajen con el mismo tipo de fuerzas.

Lingual orthodontics has brought to the orthodontic consultation patients who would never have accepted orthodontic treatment before. In this century, aesthetic treatments are one of the most requested options by adult patients who not only want an aesthetic result but also aesthetic appliances. It is presented the case of an adult patient to which a hybrid treatment was chosen: upper lingual appliances (2D lingual brackets) and lower vestibular appliances (self-ligating brackets, passive-active Roth prescription). 2D brackets are self-ligating, so constant and continuous biological gentle forces are used. In these cases, it is important that both jaws are worked with the same type of forces.

Uso dos laminados cerâmicos como alternativa restauradora para solucionar a presença de espaços negros no sorriso / Use of ceramic veneers as an alternative to solve the presence of black spaces in smile

Os avanços alcançados no desenvolvimento dos materiais restauradores e procedimentos adesivos têm possibilitado a realização de procedimentos minimamente invasivos nas reabilitações orais. Neste contexto, os laminados cerâmicos tornaram-se uma alternativa viável para a resolução de diversos problemas que acometem a função e estética. Assim, este trabalho apresentou como objetivo relatar um caso clínico de reabilitação estética do sorriso com o fechamento de espaços negros, originados a partir de um trauma, seguido de movimentação ortodôntica, através da utilização de laminados cerâmicos. Neste foram descritas as etapas clínicas de diagnóstico, planejamento e execução do procedimento restaurador, observando que o tratamento proposto foi uma alternativa conservadora e eficaz na resolução dos espaços negros existentes, reestabelecendo a estética do sorriso e devolvendo a auto-estima do paciente(AU)

The advances achieved in the development of restorative materials and adhesive procedures have made possible to perform minimally invasive procedures in oral rehabilitation. In this context, ceramic veneers have become a viable alternative for solving several problems that affect function and aesthetics. Thus, this study aimed to report a clinical case of aesthetic smile rehabilitation with the closure of black spaces, originated from trauma, followed by orthodontic movement, through the use of ceramic veneers. In this, the clinical stages of diagnosis, planning and execution of the restorative procedure were described, noting that the proposed treatment was a conservative and effective alternative in the resolution of existing black spaces, reestablishing the aesthetic of the smile and restoring the patient's selfesteem(AU)

Aplicación del láser de baja potencia para el alivio del dolor en pacientes con tratamiento ortodóncico / Application of low power laser for pain relief in patients with orthodontic treatment

Introducción: El dolor es el principal síntoma que refieren los pacientes después de la colocación y activación de los aparatos ortodóncicos. Objetivo: Evaluar la efectividad del láser de baja potencia en el alivio del dolor en pacientes con tratamiento de ortodoncia. Métodos: Se realizó un estudio cuasiexperimental de intervención terapéutica en 30 pacientes que se encontraban en los inicios de la fase de distalización de los caninos superiores (previa extracción de los primeros premolares de la misma arcada), los cuales fueron atendidos en el Servicio de Ortodoncia del Hospital General Docente Dr. Juan Bruno Zayas Alfonso de Santiago de Cuba, de enero a diciembre de 2020. A tal efecto, se conformaron 2 grupos de forma aleatoria, por el orden de llegada, de 15 integrantes cada uno: el de estudio, que fue tratado con láser de baja potencia, y el de control, que recibió paracetamol como analgésico habitual. Para la validación estadística de la información se emplearon el porcentaje y la prueba de la T de Student para muestras independientes, con 95 % de confiabilidad. Resultados: Existieron diferencias significativas en cuanto a la remisión de la intensidad del dolor, pues el síntoma estuvo ausente o en grado leve en todos los integrantes del grupo de estudio luego de tres sesiones terapéuticas (p=0,00), mientras que solo 13,3 % de los pacientes del grupo de control se ubicaron en estas dos categorías. Conclusiones: Se demostró que la terapia alternativa con láser fue más efectiva para paliar el dolor que el paracetamol.

Introduction: The pain is the main symptom that patients refer after placing and activation of the orthodontic appliances. Objective: To evaluate the effectiveness of the low power laser for pain relief in patients with orthodontics treatment. Methods: A quasi-experiment study of therapeutic intervention was carried out in 30 patients that were in the beginnings of the distancing phase of the upper canine teeth (previous extraction of the same arch first premolars), who were assisted in the Orthodontics Service of Dr. Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba, from January to December, 2020. To such an effect, 2 groups were conformed at random, by arrival order, of 15 members each one: the study group that was treated with low power laser, and the control group that received paracetamol as usual analgesic. For the statistical validation of the information the percentage and the Student´s t test were used for independent samples, with 95% of confidence. Results: There were significant differences as for the remission of pain intensity, because absence of this symptom or light pain was observed in all the members of the study group after three therapeutic sessions (p=0.00) while just 13.3 % of the control group patients was located in these two categories. Conclusions: It was demonstrated that the alternative therapy with laser was more effective to palliate the pain than the paracetamol.

Force decay and discoloration of thermoplastic and thermoset orthodontic elastomeric chains / Diminuição de força e descoloração de elásticos corrente termoplásticos e termofixos

Objective: Elastomeric chains are commonly used to apply force for orthodontic dental movements. However, force decay and discoloration are two important weak points of these materials. The present study intended to compare the force decay and color stability of different types of elastomeric chains. Material and Methods: This in vitro study evaluated 6 groups of elastomeric chains, including thermoplastic (TP) and thermoset (TS) chains made by the companies American Orthodontics (AO), Ormco (OR), and G&H Orthodontics (GH). The elastomeric chain forces were measured at the baseline, following 1 hour, 1 day, 1, 2, 3, 4, 5, and 6 weeks of stretching. The elongation required for the chains to exert a force of 250 g was calculated. ΔE of each group was calculated by a spectrophotometer following immersion in black tea solution for 6 days. Data were analyzed using the SPSS 22 software and the statistical methods of repeated measures analysis of variance and two-way analysis of variance (P<0.05). Results: The force decay of the TS chains were significantly lower than the TP chains in the 6-week study duration (P<0.05), and the lowest and highest force decay was observed in the products by AO and GH, respectively. The highest force degradation occurred during the first week in all groups. The elongation rate needed for the TS chains was significantly higher than the TP chains (P<0.05), and the highest elongation rate was observed in the products by OR. TS chains showed significantly higher color stability than TP chains, and products by OR and GH had better color stability than the products by AO. Conclusion: The present study showed that TS chains were superior to TP chains in force decay and color stability in all the brands studied. (AU)

Objetivo: Elásticos corrente são comumente utilizados para aplicar forças para a movimentação ortodôntica. Porém, a diminuição de força e descoloração são duas importantes fraquezas desses materiais. O presente estudo tem o objetivo de comparar a diminuição de força e estabilidade de cor de diferentes tipos de elásticos corrente. Material e Métodos: Este estudo in vitro avaliou 6 grupos de elásticos corrente, incluindo termoplástico (TP) e termofixo (TS) produzidos pelas empresas American Orthodontics (AO), Ormco (OR) e G&H Orthodontics (GH). A força dos elásticos corrente foram mensuradas no início, após 1 hora, 1 dia, 1, 2, 3, 4, 5 e 6 semanas de alongamento. A força de alongamento necessária para aplicação de 250g foi calculada. O ΔE de cada grupo foi calculado por um espectrofotômetro após a imersão em solução de chá preto por 6 dias. Os dados foram analizados utilizando o programa SPSS 22 e a análise estatística foi realizada por análise de variância e análise de variância dois fatores (p<0,05). Resultados: A diminuição da força do grupo TS foi significativamente menor que o grupo TP em 6 semanas de estudo (p<0,05), e o menor e maior valor de diminuição de força foi observado nos produtos da empresa AO e GH, respectivamente. A maior degradação de força ocorreu durante a primeira semana em todos os grupos. A taxa de alongamento necessária para o grupo TS foi significativamente maior que o grupo TP (p<0,05), e a maior taxa de alongamento foi observada nos produtos da empresa OR. Os elásticos TS obtiveram resultados significativamente maiores de estabilidade de cor que os elásticos TP, e os produtos da OR e GH tiveram melhor estabilidade de cor que oa produtos AO. Conclusão: O presente estudo demonstrou que os elásticos TS foram superiores aos elásticos TP em diminuição de força e estabilidade de cor em todas as marcas estudadas.(AU)