Análise de forças de movimentação e características físico-químicas em alinhadores ortodônticos: avanços tecnológicos e considerações críticas / Analysis of motion forces and physicochemical characteristics in orthodontic aligners: technological advances and critical considerations

O avanço tecnológico revolucionou a prática odontológica, com os alinhadores ortodônticos emergindo como uma escolha altamente popular entre pacientes que buscam tratamentos estéticos e confortáveis. No entanto, apesar de sua crescente demanda, permanecem questões cruciais relacionadas à eficácia e análise dimensional desses dispositivos. Este artigo oferece uma análise abrangente das características químicas, físicas e mecânicas dos alinhadores ortodônticos, iluminando a influência vital do processo de termoformação e da espessura nas propriedades desses materiais. Compreender profundamente essas características é essencial para aprimorar a eficácia e a durabilidade dos alinhadores ortodônticos, contribuindo, assim, para o sucesso e a evolução dos tratamentos ortodônticos modernos. Neste estudo, exploraremos: 1) as propriedades químicas dos materiais e como elas afetam a biocompatibilidade e a resistência à degradação; 2) as características físicas, incluindo textura de superfície, transparência e sua influência na adaptação bucal e no conforto do paciente; 3) as propriedades mecânicas, como flexibilidade e rigidez, e como essas características afetam a distribuição de forças de movimentação dentária; 4) a influência do processo de termoformação na precisão e reprodutibilidade dos alinhadores, bem como sua relação com a qualidade do tratamento; 5) a análise crítica da espessura dos alinhadores e seu papel na capacidade de aplicar forças adequadas para a movimentação dentária. Ao abordar esses aspectos, este artigo visa oferecer uma visão holística das complexidades envolvidas na fabricação e uso de alinhadores ortodônticos. Esperamos que esta revisão contribua para uma compreensão mais profunda desses dispositivos e promova avanços significativos na ortodontia, beneficiando tanto os profissionais quanto os pacientes.

Technological advancement has revolutionized dental practice, with orthodontic aligners emerging as a trendy choice among patients seeking aesthetic and comfortable treatments. However, despite their growing demand, crucial questions remain regarding these devices' effectiveness and dimensional analysis. This article offers a comprehensive analysis of the chemical, physical, and mechanical characteristics of orthodontic aligners, illuminating the vital influence of the thermoforming process and thickness on the properties of these materials. Understanding these characteristics in depth is essential to improving the effectiveness and durability of orthodontic aligners, thus contributing to the success and evolution of modern orthodontic treatments. In this study, we will explore 1) the chemical properties of materials and how these properties affect biocompatibility and resistance to degradation; 2) the physical characteristics, including surface texture, transparency and their influence on oral adaptation and patient comfort; 3) mechanical properties, such as flexibility and stiffness, and how these characteristics affect the distribution of tooth movement forces; 4) the influence of the thermoforming process on the precision and reproducibility of the aligners, as well as its relationship with the quality of the treatment; 5) critical analysis of aligner thickness and its role in the ability to apply adequate forces for tooth movement. By addressing these aspects, this article aims to offer a holistic view of the complexities involved in manufacturing and using orthodontic aligners. We hope this review will contribute to a deeper understanding of these devices and promote significant advances in orthodontics, benefiting professionals and patients.

Effect of different stretching lengths of lingual movable wing on the adduction of mandibular anterior teeth:a biomechanical study / 中国组织工程研究

BACKGROUND:Lingual movable wing is a new type of lingual orthodontic technique and the different stretching lengths of the wring affect the torque control effect of anterior teeth.However,there is yet no related biomechanical research. OBJECTIVE:To investigate the displacement trend of dentition during adduction of mandibular anterior teeth and the effect of different wing stretching lengths on the biomechanical effect of mandibular anterior teeth. METHODS:The data of the mandible and lower dentition were collected by cone-beam CT and reconstructed using Mimics software to establish a three-dimensional finite element model of mandibular anterior teeth adducted by the lingual movable wing.The ANSYS software was used to analyze the initial displacement of the mandibular anterior teeth under the following conditions:A,2 mm stretching length;B,2.5 mm stretching length;C,3 mm stretching length;and D,3.5 mm stretching length. RESULTS AND CONCLUSION:The trend of initial displacement of lower dentition:The central incisors moved lingually with depression,the lateral incisors and canines moved mildly lingually with mesial lingual torsion,the second premolar was tilted distally with a marked lingual inclination and the first molar showed an overall mesial inclination with mesial crown eversion.Therefore,in the adduction cases of mandibular tooth extraction,attention should be paid to the lingual movement of the second premolar,which could be offset by corresponding techniques in clinic.The trend of anterior tooth displacement in all directions:from condition A to condition D,in the sagittal direction,the difference value in crown-root displacement of central incisors changed from-11.891 μm to-5.757 4 μm,indicating that the central incisor changes from oblique movement to overall movement.The difference value in crown-root displacement of lateral incisors changed from-11.828 1 μm to-6.711 45 μm,and that of canines changed from-7.572 3 μm to-4.695 5 μm,indicating that the oblique movement of the lateral incisors and canines is also changing to an overall movement.In the vertical direction,from condition A to condition D,the reduction of incisors was gradually increased,while that of canines was gradually decreased.These findings indicate that the stretching length of the wing can affect the oblique movement trend of the anterior teeth.As the wing continues to stretch,the torque control of the lower anterior teeth will become better.

Calculation and Verification Method of Three-Dimensional Center of Gravity Based on Human Joint Points / 医用生物力学

Objective To explore the accuracy of the multiplication coefficient method and the moment synthesis method for determining the spatial position of the center of gravity(CoG)of the human body based on machine vision.Methods The mechanical measurement platform was built,and the three-dimensional(3D)human body CoG measurement method under static and dynamic conditions were designed to calculate the space coordinates of the CoG.Through experiments,the calculation accuracy of the multiplication coefficient and moment synthesis method were studied and analyzed.Results In the static experiments,the calculation results of the torque synthesis method were more accurate than those of the multiplication coefficient method for each dimension.The errors in the 3D CoG of the human body in the X,Y,and Z directions calculated using the torque synthesis method were 3.9%,4.1%,and 8.5%,respectively.In the dynamic experiment,the average and relative errors of the torque synthesis method in the X or Y direction were lower than those of the multiplication-coefficient method.When the action decomposition method was used to analyze the height direction of the CoG along the Z axis,the final rendering effect of the torque synthesis method improved.Conclusions The accuracy of the 3D CoG calculated by the moment synthesis method was relatively high,and was closer to the measurement data of the mechanical measurement platform.The 3D CoG calculated using the moment synthesis method can replace the mechanical measurement platform and can be used in subsequent studies.

Insertion torque, flexural strength and surface alterations of stainless steel and titanium alloy orthodontic mini-implants: an in vitro study

ABSTRACT Objective: This study aimed to compare the insertion torque (IT), flexural strength (FS) and surface alterations between stainless steel (SS-MIs) and titanium alloy (Ti-MIs) orthodontic mini-implants. Methods: Twenty-four MIs (2 x 10 mm; SS-MIs, n = 12; Ti-MIs, n = 12) were inserted on artificial bone blocks of 20 lb/ft3 (20 PCF) and 40 lb/ft3 (40 PCF) density. The maximum IT was recorded using a digital torque meter. FS was evaluated at 2, 3 and 4 mm-deflection. Surface topography and chemical composition of MIs were assessed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). General linear and mixed models were used to assess the effect of the MI type, bone density and deflection on the evaluated outcomes. Results: The IT of Ti-MIs was 1.1 Ncm greater than that obtained for the SS-MIs (p= 0.018). The IT for MIs inserted in 40 PCF test blocks was 5.4 Ncm greater than that for those inserted in 20 PCF test blocks (p < 0.001). SS-MIs inserted in higher density bone (40 PCF) had significantly higher flexural strength than the other groups, at 2 mm (98.7 ± 5.1 Ncm), 3 mm (112.0 ± 3.9 Ncm) and 4 mm (120.0 ± 3.4 Ncm) of deflection (p< 0.001). SEM evidenced fractures in the Ti-MIs. EDS revealed incorporation of 18% of C and 2.06% of O in the loaded SS-MIs, and 3.91% of C in the loaded Ti-MIs. Conclusions: Based on the findings of this in vitro study, it seems that SS-MIs offer sufficient stability and exhibit greater mechanical strength, compared to Ti-MIs when inserted into higher density bone.

RESUMO Objetivo: O objetivo deste estudo foi comparar o torque de inserção (TI), a resistência flexural (RF) e as alterações de superfície em mini-implantes ortodônticos de aço inoxidável (MIs-Ai) e de liga de titânio (MIs-Ti). Métodos: Vinte e quatro MIs (2 x 10 mm; MIs-Ai, n = 12; MIs-Ti, n = 12) foram inseridos em blocos de osso artificial de densidades de 20 lb/ft3 (20 PCF) e 40 lb/ft3 (40 PCF). O torque máximo de inserção foi registrado por meio de um torquímetro digital. A resistência flexural foi avaliada nas deflexões de 2, 3 e 4 mm. Topografia de superfície e composição química dos MIs foram avaliadas por Microscopia Eletrônica de Varredura (MEV) e Espectroscopia de Energia Dispersiva de Raios X (EDS). Modelos lineares gerais e mistos foram utilizados para avaliar o efeito do tipo de MI, da densidade óssea e da deflexão nos desfechos avaliados. Resultados: O TI dos MIs-Ti foi 1,1 Ncm maior do que o obtido para os MIs-Ai (P = 0,018). O TI para MIs inseridos em blocos de teste de 40 PCF foi 5,4 Ncm maior do que para aqueles inseridos em blocos de teste 20 PCF (p < 0,001). MIs-Ai inseridos em osso de maior densidade (40 PCF) apresentaram resistência flexural significativamente maior do que outros grupos, em deflexões de 2 mm (98,7 ± 5,1 Ncm), 3 mm (112,0 ± 3,9 Ncm) e 4 mm (120,0 ± 3,4 Ncm) (p < 0,001). A MEV evidenciou fraturas nos MIs-Ti. A EDS revelou incorporação de 18% de C e 2,06% de O nos MIs-Ai e 3,91% de C nos MIs-Ti, ambos submetidos a testes mecânicos. Conclusões: Com base nos resultados desse estudo in vitro, os MIs-Ai aparentam oferecer adequada estabilidade e maior resistência mecânica, em comparação aos MIs-Ti, quando inseridos em osso de maior densidade.

Influence of torque and bone type on stability quotient of two implant platforms: a clinical trial

Abstract The objective of this study was to analyze the influence of insertion torque, bone type, and peri-implant bone loss on implant stability quotient (ISQ) of cylindrical external hexagon (EH) and Morse Taper (MT) implants. Forty-four single implants were placed in the edentulous areas of 20 patients who met the inclusion and exclusion criteria. Immediately after implant placement (t1) and after osseointegration (four and six months for mandible and maxilla, respectively) (t2), insertion torque, resonance frequency, and peri-implant bone loss were measured using probing depths and digital periapical radiography. A significant difference was noted in the ISQ values between t1 and t2 in type III bone for EH and MT implants. No significant difference in bone loss values was observed when comparing bone types for EH or MT in all evaluated sites. Based on marginal bone loss assessed using radiography, there was no significant difference between the MT and EH groups. A positive correlation between torque and ISQ t1 value was observed for MT (correlation: 0.439; p = 0.041) and EH (correlation: 0.461; p = 0.031) implants. For EH and MT implants, the greater the insertion torque, the greater was the ISQ value (moderately positive correlation). A weak negative correlation was found between bone type and ISQ t1 for MT implants. Contrarily, no correlation was observed between bone type and ISQ t1 for EH implants. In all cases, bone loss around the implants was clinically normal.

Development of Grooved Belt Type Fertilizer Metering Mechanism for Spot Fertilizer Applicator

Higher risks involved in excess fertilizer application require precise placement of fertilizer in adequate amount in the root zone of the crop. The drawbacks of current fertilizer application techniques (band placement, pellet application, and ring basin method) include over-fertilization, soil acidity, nutritional imbalances, soil structure damage and an increase in bulk density. Development of a spot fertilizer applicator with precise fertilizer metering was planned to address the problem. The physical and mechanical properties of di-ammonium phosphate were determined. A new grooved belt type fertilizer metering mechanism was developed for orchard application using the fertilizer properties determined. The metering mechanism was equipped with a fertilizer box of 100 kg capacity. The torque requirement of metering mechanism was determined using torque transducer to select a DC motor. The maximum torque required was 4.5 N.m at 8 m.min-1 of metering belt speed. An automatic plant detection-based spot fertilizer applicator with developed fertilizer metering mechanism has potential to save about 20% fertilizer compared to band placement along with reduced labour requirement.

Cephalometric Evaluation of Maxillary Incisors Torque and Vertical Changes Utilizing Standard Edgewise Mechanics

In 1995 Gebeck & Merrifield studied a successful and unsuccessful treated Class I and Class II's samples; they found a -1.33 mm intrusion in the former and a 0.80 mm extrusion in the latter. The purpose of this article was to perform a cephalometric evaluation of maxillary incisors torque and vertical changes. We studied a sample of 129 patients, 30 males and 99 females, taken from The Charles H. Tweed Foundation Long Term Study, at pretreatment mean age 12.93 years, posttreatment mean age 16.19 years and follow up post retention mean age 29.83 years, a 13.88 years interval. The records were collected from private practitioners across the North American continent who used Standard Edgewise Mechanics and were members of the Charles H. Tweed Foundation. All patients were Class I and II American whites treated with the extraction of 4 premolars. We found an Upper anterior incisal edge to PP vertical linear measurement 28.7 and 29.2 mm, +0.53 mm (p<0.019) from pretreatment to posttreatment. The average Upper 1 to SN angle was 103.2 ° at pretreatment and 100.1° at posttreatment, -3.2° (p<0.000), Upper 1 to PP 111.0° and 108.9°, -2.2° (p<0.000), the three of them statistically significant. Conversely, Upper 1 to commissure was not. The four measurements were also statistically significant posttreatment to follow up, upper anteriors kept losing torque after posttreatment, and less upper anteriors surface was below the commissure. Some torque loss and vertical extrusion can be expected while treating patients with extractions of four premolars, therefore, upper incisor inclination increase and vertical change by itself cannot determine the success of treatment.

En 1995, Gebeck y Merrifield estudiaron muestras de Clase I y Clase II tratadas con éxito y sin éxito; encontraron una intrusión de -1,33 mm en el primero y una extrusión de 0,80 mm en el segundo. El propósito de este artículo fue realizar una evaluación cefalométrica del torque y los cambios verticales de los incisivos maxilares. Estudiamos una muestra de 129 pacientes, 30 hombres y 99 mujeres, tomados del estudio a largo plazo de la Fundación Charles H. Tweed, con una edad media previa al tratamiento de 12,93 años, una edad media posterior al tratamiento de 16,19 años y una edad media de seguimiento posterior a la retención de 29,83 años, con un intervalo de de 13,88 años. Los registros se recopilaron de médicos privados en todo el continente norteamericano que utilizaron Standard Edgewise Mechanics y eran miembros de la Fundación Charles H. Tweed. Todos los pacientes eran blancos americanos Clase I y II tratados con extracción de 4 premolares. Encontramos una medida lineal vertical del borde incisal anterior superior a PP de 28,7 y 29,2 mm, +0,53 mm (p<0,019) desde el pretratamiento hasta el postratamiento. El promedio del ángulo Superior 1 a SN fue de 103,2° en el pretratamiento y 100,1° en el postratamiento, -3,2° (p<0,000), Superior 1 a PP 111,0° y 108,9°, -2,2° (p<0,000), los tres estadísticamente significante. Por el contrario, Superior 1 a la comisura no lo era. Las cuatro mediciones también fueron estadísticamente significativas para el seguimiento después del tratamiento, los dientes anteriores superiores siguieron perdiendo torsión después del tratamiento y se observó menor superficie de los dientes anteriores superiores debajo de la comisura. Se puede esperar cierta pérdida de torque y extrusión vertical al tratar a pacientes con extracciones de cuatro premolares, por lo tanto, el aumento de la inclinación del incisivo superior y el cambio vertical por sí mismos no pueden determinar el éxito del tratamiento.

The anatomical limit and strategies for molar movement during orthodontic treatment / 口腔疾病防治

@#In many cases, tooth movement over a considerable distance is needed to meet the major goal of orthodontic treatment, which has always been to correct malocclusion and improve the facial profile in patients with skeletal malocclusion. However, tooth movement over a considerable distance also carries risks of dehiscence, fenestration, root exposure, and so forth. The reason lies in neglecting many limits for tooth movement, especially anatomical characteristics. This review focuses on structural limits for orthodontic molar movement, such as the alveolar cortex, the maxillary sinus floor, and the mandibular canal. In addition, we set the strategy in clinical orthodontics. For the alveolar cortex and the mandibular canal, orthodontists are recommended to move the root away from the cortical bone initially and formulate personalized molar movement plans according to clinical examination and cone-beam computed tomography (CBCT) and other imaging examinations. First, the molar root was controlled by torque away from the bone plate, and then, the molar movement amount and direction were controlled according to the personalized movement path. In regard to the maxillary sinus floor, light and continuous forces and scientific biomechanics are suitable for bodily tooth movement. In summary, better therapeutic efficacy and long-term stabilization could be achieved by circumventing the limits and risks caused by anatomical limitations and characteristics.

Analysis on Mandibular Anterior Tooth Intrusion with Clear Aligners / 医用生物力学

国家自然科学基金项目(11932012、81400536),上海申康医院发展中心临床创新三年行动计划(SHDC2020CR3009A),上海交通大学医工(理)交叉基金(JYJC202130)

Survival rate and stability of surface-treated and non-surface-treated orthodontic mini-implants: a randomized clinical trial

ABSTRACT Objectives: This clinical trial was conducted to evaluate the stability and failure rate of surface-treated orthodontic mini-implants and determine whether they differ from those of non-surface-treated orthodontic mini-implants. Trial Design: Randomized clinical trial with a split-mouth study design. Setting: Department of Orthodontics, SRM Dental College, Chennai. Participants: Patients who required orthodontic mini-implants for anterior retraction in both arches. Methods: Self-drilling, tapered, titanium orthodontic mini-implants with and without surface treatment were placed in each patient following a split-mouth design. The maximum insertion and removal torques were measured for each implant using a digital torque driver. The failure rates were calculated for each type of mini-implant. Results: The mean maximum insertion torque was 17.9 ± 5.6 Ncm for surface-treated mini-implants and 16.4 ± 9.0 Ncm for non-surface-treated mini-implants. The mean maximum removal torque was 8.1 ± 2.9 Ncm for surface-treated mini-implants and 3.3 ± 1.9 Ncm for non-surface-treated mini-implants. Among the failed implants, 71.4% were non-surface-treated mini-implants and 28.6% were surface-treated mini-implants. Conclusion: The insertion torque and failure rate did not differ significantly between the groups, whereas the removal torque was significantly higher in the surface-treated group. Thus, surface treatment using sandblasting and acid etching may improve the secondary stability of self-drilling orthodontic mini-implants. Trial registration: The trial was registered in the Clinical Trials Registry, India (ICMR NIMS). Registration number: CTRI/2019/10/021718

RESUMO Objetivos: Este ensaio clínico foi conduzido para avaliar a estabilidade e a taxa de falha de mini-implantes ortodônticos com superfície tratada, e determinar se elas diferem das dos mini-implantes ortodônticos sem superfície tratada. Desenho do estudo: Ensaio clínico randomizado com desenho de boca dividida. Instituição: Department of Orthodontics, SRM Dental College, Chennai/India. Participantes: Pacientes que necessitavam de mini-implantes ortodônticos para retração anterior em ambas as arcadas. Métodos: Mini-implantes ortodônticos autoperfurantes, cônicos, de titânio com ou sem tratamento de superfície, foram colocados em cada paciente, seguindo um desenho de boca dividida. Os torques máximos de inserção e de remoção foram medidos para cada mini-implante, usando um torquímetro digital. As taxas de falha foram calculadas para cada tipo de mini-implante. Resultados: O valor médio do torque máximo de inserção foi de 17,9 ± 5,6 Ncm para mini-implantes com superfície tratada e 16,4 ± 9,0 Ncm para mini-implantes sem superfície tratada. O valor médio do torque máximo de remoção foi de 8,1 ± 2,9 Ncm para mini-implantes com superfície tratada e 3,3 ± 1,9 Ncm para mini-implantes sem superfície tratada. Entre os implantes que falharam, 71,4% eram mini-implantes sem superfície tratada e 28,6% eram mini-implantes com superfície tratada. Conclusão: O torque de inserção e a taxa de falha não diferiram significativamente entre os grupos; porém, o torque de remoção foi significativamente maior no grupo com superfície tratada. Assim, o tratamento de superfície com jateamento e condicionamento ácido pode melhorar a estabilidade secundária dos mini-implantes ortodônticos autoperfurantes. Registro do estudo: Esse estudo foi registrado no Clinical Trials Registry, Índia (ICMR NIMS). Número de registro: CTRI/2019/10/021718

Does the early phase of aging affect the morphology of biceps brachii and torque and total work of elbow flexors in healthy volunteers?

Upper and lower limbs can be affected by several diseases and changes related to current life habits, such as the sedentarism, technological advances, and even eating habits. This cross-sectional study investigated morphological adaptations of the biceps brachii muscle and the performance of the elbow flexors in healthy individuals in the early phase of aging. Thirty-two volunteers were separated according to age range (3rd, 4th, and 5th decades of life) and sex. Smaller diameters and subtypes of fibers were evaluated using muscle biopsies, and peak torque and total work were assessed using an isokinetic dynamometer. The variables were compared considering sex and decade, using mixed-effects linear models. The smaller diameter of all fiber types did not differ significantly between age groups for either sex. The proportion of oxidative fibers was reduced in male participants in the 4th (-20%) and 5th (-6%) decades of life compared to the 3rd decade, and there was an increase in the number of oxidative fibers in women from the 4th (+14%) to the 5th decade of life. There were no significant changes in the peak torque and total work between the analyzed age groups. The early phase of aging starts with alterations in the proportion of fibers, with a decrease in oxidative fibers in men and an increase in oxidative fibers in women. Smaller diameter, torque, and total work did not change over these decades of life.

Progressive tension protocol for muscle strength with Kinesio tape in runners - double-blind randomized clinical trial / Protocolo de tensão progressiva para força muscular com Kinesio tape em corredores - ensaio clínico randomizado duplo-cego

Abstract Introduction Kinesio tape (KT), although frequently used in sports, is still a matter of debate, and the results of studies that evaluated its effects on muscle strength (MS) in athletes are still inconclusive and contradictory. Objective To evaluate the effect of a progressive KT tension protocol on knee MS in runners over an eight-week intervention. Methods Clinical trial involving 49 runners of both sexes randomized into two groups: KT (KT with progressive tension protocol) and placebo (KT without tension). The MS of knee flexors and extensors was evaluated by isokinetic dynamometer (60º/s and 90º/s) at four moments: (1) without KT; (2) with KT and without tension; (3) without KT (after 8 weeks after of intervention); (4) with KT and with tension (after 8 weeks after of intervention). Inter- and intra-group comparisons were made. The significance level adopted was 95% (p < 0.05). Results There were no significant differences in MS between the groups at any of the evaluated moments. There was a statistically significant difference in MS (60º/s) in both groups (KT and placebo) when comparing moments 4 and 2 for knee flexors, and in the placebo group between moments 4 and 2 and moments 4 and 3 for knee extensors. Conclusion The progressive tension protocol of KT was not able to intervene in the SM gain of knee flexors and extensors of runners in inter and intragroup comparisons.

Resumo Introdução A Kinesio tape (KT), apesar de muito utilizada na prática esportiva, ainda é motivo de debate e os resultados de estudos que avaliaram seus efeitos na força muscular (FM) em atletas ainda são inconclusivos e contraditórios. Objetivo Avaliar o efeito de um protocolo de tensão progressiva KT na FM do joelho em corredores ao longo de uma intervenção de oito semanas. Métodos Ensaio clínico envolvendo 49 corredores de ambos os sexos randomizados em dois grupos: KT (KT com protocolo de tensão progressiva) e placebo (KT sem tensão). A FM dos flexores e extensores do joelho foi avaliada por dinamômetro isocinético (60º/s e 90º/s) em quatro momentos: (1) sem KT; (2) com KT e sem tensão; (3) sem KT (após 8 semanas); (4) com KT e com tensão (pós-protocolo 8 semanas). Comparações inter e intragrupos foram feitas. O nível de significância adotado foi de 95% (p < 0,05). Resultados Não houve diferenças signi-ficativas na FM entre os grupos em nenhum dos momentos avaliados. Houve diferença estatisticamente significante na FM (60º/s) em ambos os grupos (KT e placebo, quando comparados os momentos 4 e 2 para flexores de joelho, e no grupo placebo entre os momentos 4 e 2 e os momentos 4 e 3 para extensores de joelho. Conclusão O protocolo de tensão progressiva de KT não foi capaz de intervir no ganho de FM de flexores e extensores de joelho de corredores em comparações inter e intragrupos.

Pain factors related to dental implant surgery: A 7-day observational clinical study

This article aims to associate patient-reported pain intensity in the immediate seven days after dental implant surgery with surgical factors, sex and patient age. The sample was composed of 108 patients from a dental school in southern Brazilian, between 2018 and 2020. The variables torque, pre- and postoperative medication, healing of first and second intention, gender, age, number of quadrants, number of implants and type of surgery were related to the outcome pain. Pain was reported every day by the patient until the seventh day after surgery, using a visual analogic scale (VAS). Univariate Poisson regression models were used to assess the relationship among pain and the factors. Rate ratios were obtained with 95% of confidence intervals. Overall pain was reported as moderate/intense (VAS: 3-10) by 30.56% of patients, mild pain (VAS: 1-3) by 55.56%, and no pain symptoms were reported by 13.89% of patients. Individuals which the implants were installed with high torques (50-80 N) showed more pain (p=0.03) compared to patients which the implants were installed with regular torque (30-45 N). The other factors evaluated were not significant. The torque was the most relevant factor related to pain among the evaluated by the study. High torque generates more postoperative pain than lower torque. The factors gender, age, number of operated quadrants, number of installed implants, type of surgery and pre and postoperative analgesic did not interfere in the patient's pain during the first week after surgery.

Influence of age and gender on knee and hip isometric strength of recreational physically active young and middle-aged subjects / Influencia de la edad y el sexo en la fuerza isométrica de la rodilla y la cadera de personas jóvenes y de mediana edad que practican actividades físicas recreativas / Influência da idade e do sexo na força isométrica do joelho e do quadril de indivíduos jovens e de meia idade praticantes recreacionais de atividades físicas

ABSTRACT Muscle strength is an essential part of the functional assessment of health professionals to select and analyze the effects of clinical interventions. This study aimed to determine the influence of gender and age on isometric strength of hip and knee muscle groups. A total of 127 subjects (50.4% men), aged from 20 to 49 years (stratified into three groups: 20-29 years; 30-39 years; and 40-49 years) participated in this study. A hand-held dynamometer was used to measure isometric normalized torque of the hip abductors, hip external rotators, knee extensors, and knee flexors muscles. Regressions and a two-way analysis of variance were used to identify the influence of age and gender on torque of each muscle group. Age and gender were included in the regression model for all groups. Generally, men aged 20-29 and 30-39 were stronger than age-paired women. For participants aged 40-49, torque was similar for men and women for all muscle groups. There was no difference among age groups for women. Generally, young men were stronger than older men. The association between age and gender in hip and knee strength was proved and liable of subgroup stratification after measurements with a hand-held isometric dynamometer.

RESUMEN La fuerza muscular es un componente básico de la evaluación funcional de los profesionales de la salud para seleccionar y analizar los efectos de las intervenciones clínicas. El objetivo de este estudio fue determinar la influencia del sexo y de la edad en las mediciones de fuerza isométrica de los grupos musculares de la cadera y la rodilla. En el estudio participaron 127 sujetos (50,4% hombres), de entre 20 y 49 años de edad (estratificados en grupos: 20 a 29 años; 30 a 39 años; y 40 a 49 años). El torque isométrico normalizado de los abductores y rotadores externos de la cadera y de los extensores y flexores de la rodilla se midió con un dinamómetro manual. Se utilizaron regresiones y el análisis de varianza (Anova) para identificar la influencia de la edad y el sexo en el torque. Tanto la edad como el sexo se incluyeron en el modelo para todos los grupos musculares. En general, los hombres de entre 20 y 29 años y los de 30 a 39 mostraron tener más fuerza que las mujeres del mismo grupo de edad. Para los participantes de 40 a 49 años, el torque fue similar entre hombres y mujeres para todos los grupos musculares. No hubo diferencias entre los grupos de edad en el grupo de mujeres. En general, los hombres más jóvenes demostraron ser más fuertes que los hombres de mediana edad. La relación entre la edad y el sexo en la fuerza muscular de la cadera y la rodilla se probó y demostró ser susceptible a la estratificación después de las mediciones realizadas con el dinamómetro manual.

RESUMO A força muscular é um componente essencial da avaliação funcional de profissionais da saúde para selecionar e analisar efeitos de intervenções clínicas. O objetivo do estudo foi determinar a influência do sexo e da idade sobre medidas de força isométrica de grupos musculares do quadril e do joelho. Participaram da pesquisa 127 sujeitos (50,4% homens), com idade de 20 a 49 anos (estratificados em grupos: 20 a 29 anos; 30 a 39 anos; e 40 a 49 anos). O torque isométrico normalizado de abdutores e rotadores externos de quadril e extensores e flexores de joelho foi medido com dinamômetro manual. Regressões e uma análise de variância (Anova) foram usados para identificar a influência da idade e do sexo sobre o torque. Tanto idade quanto sexo foram incluídos no modelo para todos os grupos musculares. Em geral, homens de 20 a 29 anos e de 30 a 39 anos demonstraram mais força do que mulheres da mesma faixa etária. Para participantes de 40 a 49 anos, o torque foi similar entre homens e mulheres para todos os grupos musculares. Não houve diferença entre as faixas etárias no grupo de mulheres. Em geral, homens mais jovens se mostraram mais fortes do que homens mais velhos. A relação entre idade e sexo na força muscular do quadril e do joelho foi provada e se mostrou passível de estratificação após as medições feitas com o dinamômetro manual.

Argon plasma application on the surface of titanium implants: osseointegration study / Aplicação de plasma de argônio na superfície de implantes de titânio: estudo de osseointegração

Introduction: The development of new biomaterials with improved properties is a trend in regenerative medicine. The successful healing of implants is related to their osseointegration and the topographic geometry of their surface. Treatment with argon plasma acts on the surface of the implants, bringing several benefits to their osseointegration in the body. Material and Methods: Previously the in vivo study, the topography implants were observed by scanning electron microscopy (SEM). Following the implants were inserted in 14 male rats, and one perforation was made in the right and left tibias for implant placement without the surface treatment (control group), and with the argon plasma surface treatment (experimental group), respectively. The rats were euthanized at 4 weeks, a time in which tibia fragments were submitted for histological and histomorphometric examination, and torque removal test for comparison and analysis of osseointegration. Results: The SEM images showed the argon plasma surface treatment altered the topography. At the end of the study, both greater bone formation and better osseointegration were verified in the experimental group, and a statistically significant difference between the groups was observed. Conclusion: It was concluded that implants with this surface treatment can bring more practicality in the rehabilitation treatment, and more comfort in the patients' postoperative time (AU)

Introdução: O desenvolvimento de novos biomateriais com propriedades aprimoradas é uma tendência na medicina regenerativa. A cicatrização bem-sucedida dos implantes está relacionada à sua osseointegração e à geometria topográfica de sua superfície. O tratamento com plasma de argônio atua na superfície dos implantes, trazendo diversos benefícios para sua osseointegração no corpo. Materiais e Métodos: Antes do estudo in vivo, a topografia dos implantes foi observada por microscopia eletrônica de varredura (MEV). Em seguida, os implantes foram inseridos em 14 ratos machos, e uma perfuração foi feita nas tíbias direita e esquerda para a colocação do implante sem o tratamento de superfície (grupo controle) e com o tratamento de superfície de plasma de argônio (grupo experimental), respectivamente. Os ratos foram sacrificados após 4 semanas, momento em que fragmentos das tíbias foram submetidos a exame histológico e histomorfométrico, além do teste de remoção de torque para comparação e análise da osseointegração. Resultados: As imagens de MEV mostraram que o tratamento de superfície com plasma de argônio alterou a topografia. Ao final do estudo, foi verificada maior formação óssea e melhor osseointegração no grupo experimental, e foi observada diferença estatisticamente significativa entre os grupos. Conclusão: Concluiu-se que os implantes com esse tratamento de superfície podem trazer mais praticidade no tratamento de reabilitação e maior conforto no pós-operatório dos pacientes (AU)

Fratura de implante dentário: relato de caso / Dental implant fracture: case report / Fractura de implante dental: informe de un caso

Com o aumento da população brasileira e consequentemente o número de edêntulos realizando tratamentos reabilitadores com implantes dentários, se tornou frequente aparições de complicações como, por exemplo, sua fratura. O presente trabalho tem por objetivo apresentar as causas prováveis relacionadas a fratura de implante dentário, através de um relato de caso clínico onde pode-se avaliar a condição da fratura apresentada e como foi solucionada. Após a analise do caso clínico, foi constatado que o principal fator que levou a sua fratura foram as sobrecargas oclusais associadas ao mal posicionamento e a qualidade do implante antigo. A partir disso, conclui-se que é de extrema importância o cirurgião dentista estar ciente de todas as possíveis complicações acerca do implante dentário, afim de realizar um bom planejamento cirúrgico diminuindo a taxa de insucesso levando a um bom prognóstico.

With the increase of the Brazilian population and, consequently, the number of edentulous individuals undergoing rehabilitation treatmentes with dental implants, the appearance of complications such as, for example, their fracture has become frequent. The present work aims to presente the probable causes related to dental implant fracture, trough a clinical case report where the condition of the fracture presented and how it was resolved can be evaluated. After analyzing the clinical case, it was found that de main factor that led to its fracture were the occlusal overloads associated with poor positioning and the quality of the old implant. From this , it is concluded that it is extremely important for the dental surgeon to be aware of all possible complications regarding the dental implant, in order to carry out a good surgical planning, reducing the failure rate, leading to a good prognosis.

Con el aumento de la población brasileña y, en consecuencia, del número de personas edéntulas que se someten a tratamientos de rehabilitación con implantes dentales, las complicaciones, como las fracturas, se han vuelto comunes. El presente trabajo tiene como objetivo presentar las probables causas relacionadas con la fractura de implantes dentales, a través del reporte de un caso clínico, donde se puede evaluar la condición de la fractura presentada y la forma en que fue resuelta. Tras analizar el caso clínico, se comprobó que el principal factor que condujo a la fractura fue la sobrecarga oclusal asociada a una mala colocación y a la calidad del implante antiguo. Esto lleva a la conclusión de que es muy importante que el cirujano dental conozca todas las posibles complicaciones de los implantes dentales, para realizar una buena planificación quirúrgica, reduciendo así la tasa de fracasos y consiguiendo un buen pronóstico.

The Reference Values for Muscle Mass and Strength in Healthy Indian Adults Using Whole-Body Potassium Counter and Isokinetic Dynamometer

The study aims to define the sex‑based reference data for muscle mass and strength among healthy young Indians and to compare the data from the present study with available literature. Healthy Indian adults (n = 100) aged between 18 and 40 years were recruited. The assessment of muscle mass and strength was performed. The body cell mass (BCM), fat‑free mass, and muscle strength parameters were significantly higher among males compared to females (P < 0.001). A comparison of the current study data with the available literature showed that though BCM was comparable, Indians demonstrated a significantly lower isometric peak torque (P < 0.001 for both sexes). These findings suggest that Indians tend to have a lower muscle strength compared to the Western population, despite having a comparable BCM content.

Nasal Wall Oriented Implants for All-on-4 Fix-Detachable Maxillary Reconstruction / Implantes nasales orientados a la pared para una reconstrucción maxilar desmontable fija All-on-4

Abstract Immediate loading of full-arch prostheses on dental implants in the upper arch is challenging, as the bone is of low quality and obtaining sufficient torque may be difficult. The purpose of this case report is to describe the rehabilitation of a full- arch by means of placement of four internal tapered connection tilted implants and immediate loading. A 65-year-old man sought dental care with a partially edentulous upper arch. The teeth presented mobility and were extracted. In a second step, two conventional-length implants were placed in the anterior region and two tilted and nasal wall-directed extra-long implants in the posterior region. The insertion torques of 60 N.cm allowed the installation of an immediate prosthesis (hybrid). The clinical case report suggests that the placement of tilted and extra-long implants in the paranasal bone and immediate loading may be a viable option for rehabilitation of the edentulous upper arch.

Resumen La carga inmediata de prótesis de arco completo en implantes dentales en el arco superior es un desafío, ya que el hueso es de baja calidad y puede ser difícil obtener un par suficiente. El propósito de este reporte de un caso es describir la rehabilitación de un arco completo mediante la colocación de cuatro implantes inclinados de conexión cónica interna y carga inmediata. Un hombre de 65 años buscó atención dental con un arco superior parcial sin dientes. Los dientes presentaron movilidad y fueron extraídos. En un segundo paso, se colocaron dos implantes de longitud convencional en la región anterior y dos implantes extralargos inclinados y dirigidos a la pared nasal en la región posterior. Los pares de inserción de 60 N.cm permitieron la instalación de una prótesis inmediata (híbrida). El informe del caso clínico sugiere que la colocación de implantes inclinados y extralargos en el hueso paranasal y la carga inmediata pueden ser una opción viable para la rehabilitación del arco superior desdentado.

Research progress on the three-dimensional finite element analysis of bite opening / 口腔疾病防治

@#Deep bite is a common clinical malocclusion that has a great impact on patients’ facial aesthetics and oral function. Bite opening is the key step in the treatment of deep bite, playing a decisive role in the development of mandible and the progress of orthodontic treatment. Torque and tip control during the correction of deep bites is a hot topic in orthodontics. The three-dimensional finite element method can accurately simulate clinical processes and conduct dynamic stress analysis, which provides the basis of the biomechanical mechanism. This paper reviewed the finite element analysis of various orthodontic systems for bite opening to provide a reference for clinical application. The emergence of mini-implants provided a new idea for anchorage control in bite opening. Finite element studies found that high-positioned mini-implants are beneficial for bodily tooth intrusion and proposed the ideal position for force application. For the finite element simulation of the reverse curve archwire, it was found that the intrusion and inclination of the anterior teeth increased with the curve depth of the archwire. The application of clear aligners has also been flourishing, but these forces are still difficult to effectively control. Finite element studies on their attachment design and corresponding tooth movement may be helpful to open the bite quickly and effectively. However, the existing studies still have modeling limitations. The structural simplification, linearization and nonstandard parameter definition of the model reduce model accuracy. Additionally, the existing research mostly focused on initial tooth movement, and studies on long-term tooth movement after bone remodeling are lacking. These studies are needed in the future.

Isokinetic muscle strength of knee for patients with chondromalacia patellae / 中国康复理论与实践

@#Objective To analyze the characteristics of the muscle strength around the knee joint of chondromalacia patellae patients, and to explore the difference with normal people.Methods In March, 2021, 70 knee-onset chondromalacia patellae patients (experimental group) and 35 normal people (control group) were measured isokinetic muscle strength of flexion and extension of knee in angular velocities of 60°/s and 180°/s.Results At 60°/s and 180°/s, the peak torque, the peak torque-to-weight ratio and the total work of the flexor and extensor muscles on the affected side in the experimental group were lower than that of the control group (U > 1097.0, P<0.001). The peak torque, the peak torque-to-weight ratio and the total work of the flexor and extensor muscles at 60°/s and extensor muscles at 180°/s were lower on the affected side than on the healthy side in the experimental group (|Z| > 2.121, P<0.05). The peak torque ratios at 60°/s and 180°/s were more in the affected knees than in the healthy knees of experimental group and in the control group (U > 1810.0, |Z| >3.691, P<0.01).Conclusion The explosive force and endurance of the knee flexor and extensor has weakened in patients with chondromalacia patellae, and there is imbalance in knee joint muscle strength.