O papel da infecção e inflamação na etiopatogênese da osteonecrose dos maxilares induzida por medicamentos / The role of infection and inflammation in the etiopathogenesis of medication-related osteonecrosis of the jaw

Objetivo: O objetivo desta revisão de literatura é evidenciar o papel da infecção e inflamação na etiopatogenia da osteonecrose dos maxilares induzida por medicamentos (MRONJ). Revisão da literatura: A MRONJ é uma condição rara e grave que impacta negativamente a vida dos pacientes afetados. Sua etiopatogenia é multifatorial e ainda não foi totalmente compreendida. Uma das hipóteses propostas para explicá-la sugere que, além da inibição do turnover ósseo pelos medicamentos antirreabsortivos, a infecção associada à exodontia e a inflamação local desempenham papel decisivo no desencadeamento da condição. O entendimento da etiopatogenia da MRONJ permite ao cirurgião-dentista a identificação dos pacientes com risco maior para a doença, assim como o auxilia no monitoramento e escolha do manejo mais adequado. No campo da pesquisa, ele pode aprimorar estudos pré-clínicos e aprofundar a investigação de biomarcadores para diagnóstico precoce de MRONJ. Considerações finais: Conhecer a contribuição da infecção e inflamação na etiopatogênese da MRONJ é fundamental para orientar a pesquisa e a adoção de estratégias preventivas para os pacientes em risco, e de manejo e monitoramento adequado para aqueles já acometidos. (AU)

Aim: The aim of this literature review is to highlight the role of infection and inflammation in the etiopathogenesis of drug-induced osteonecrosis of the jaw (MRONJ). Literature review: MRONJ is a rare and serious condition that negatively impacts the lives of affected patients. Its etiopathogenesis is multifactorial and has not yet been fully understood. One of the hypotheses proposed to explain it suggests that, in addition to the inhibition of bone turnover by antiresorptive drugs, the infection associated with tooth extraction and local inflammation play a decisive role in triggering the condition. Understanding the etiopathogenesis of MRONJ allows the dentist to identify patients at higher risk for the disease, as well as assisting in monitoring and choosing the most appropriate management. In research, it can improve preclinical studies and deepen the investigation of biomarkers for early diagnosis of MRONJ. Conclusion: Knowing the contribution of infection and inflammation in the etiopathogenesis of MRONJ is essential to guide research and the adoption of preventive strategies for patients at risk, and adequate management and monitoring for those already affected.(AU)

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)

Resveratrol Modulates Bone Mineral Density and Bone Mineral Content in A Rat Model of Male Hypogonadism / 中国结合医学杂志

OBJECTIVE@#To determine whether resveratrol (Res) can correct osteoporosis induced in a rat model of male hypogonadism.@*METHODS@#Thirty-two rats were randomly divided into 4 groups, 8 in each group; 1) a control sham group: underwent a similar surgical procedure for induction of orchiectomy (ORCD) without ligation of any arteries or veins or removal of the testis and epididymis; 2) a control + Res-treated group (Con+Res): underwent sham surgery similar to the control, but was then treated with Res, as described below; 3) an ORCD-induced group: bilateral ORCD surgery as described above, and 4) a ORCD+Res-treated group: bilateral ORCD surgery followed by Res treatment. Res treatment began 4 weeks after ORCD and continued for 12 weeks. After 12 weeks, bone mineral density (BMD) and bone mineral content (BMC) were measured in the tibia and femur of each rat's right hind leg. Blood levels of bone turnover indicators such as deoxypyridinoline (Dpd), N-telopeptide of type I collagen (NTX I), alkaline phosphatase (ALP), and osteocalcin (OC), as well as receptor activator of nuclear factor kappa B (RANK) and osteoprotegerin (OPG) were assessed.@*RESULTS@#ORCD significantly decreased BMD (P<0.01) and significantly increased bone resorption, manifested by increased RANK. In addition, it inhibited serum levels of OPG and OC. Res treatment after ORCD effectively increased serum levels of bone formation markers such as OPG and OC, compared with testisectomized rats (P<0.05).@*CONCLUSION@#Res could ameliorate bone loss induced by male hypogonadism, possible via restoration of the normal balance between RANK and OPG.

Revisión sistemática de los efectos de microvibración de baja magnitud alta frecuencia en osteocitos cultivados / Systematic review of the effects of low intensity high frequency microvibration on osteocytes cultivated

Introducción: El hueso, reservorio de minerales y moléculas orgánicas, es un tejido dinámico que detecta y se adapta a las cargas mecánicas de los órganos y tejidos del cuerpo, el cual mantiene la estructura ósea del esqueleto durante el crecimiento y a través de la vida del ser humano. Las células óseas son sensibles a las cargas mecánicas y microvibra- ciones que recibe el esqueleto. Objetivo: El propósito de este estudio fue realizar una revisión sistemática acerca de los efectos que ejerce la microvibración de alta frecuencia-baja intensidad, en osteocitos cultivados in vitro sobre la síntesis de factores solubles, con el propósito de entender si la microvibración tiene influencia en la aceleración del movimiento dentario. Material y métodos: Se realizó una búsqueda de artículos de revisión de osteocitos y otras células óseas in vitro, a través de la estrategia PICO (Paciente, Intervención, Comparación, Resultado [Outcome]), con el empleo de palabras clave como: «os- teocitos¼, «microvibración¼, «remodelación¼, «osteoclastogénesis¼, «citocinas¼ y «osteoblastos¼. Se estructuró por medio de PRISMA (informe de revisiones sistemáticas y meta-análisis). La captación de datos finales se hizo por medio del método de puntuación de calidad Jadad y Cochrane (modelo de correlación) como herramientas para evaluar el riesgo de sesgo de cada uno de los artículos. Se incluyeron 11 artículos con alta calidad metodológica. Resultados: La mayoría de los experimentos in vitro demostraron que la microvibración tuvo un aumento estadísticamente significativo en la proliferación y dife- renciación de las células madre mesenquimales (MSC), en osteoblastos (MC3T3-E1), en la expresión de proteínas para inducir osteogénesis y en los osteocitos (MLO-Y4). Asimismo, sobrerregularon la expresión de osteoprotegerina (OPG), prostaglandina (PGE2) y óxido nitroso (NO) al alterar y regular los factores solubles como las citocinas, factores de crecimiento y quimiocinas, de las demás células, además de mostrar una disminución en la actividad de los osteoclastos (RAW246.7) en la resorción ósea. Conclusión: La microvibración induce remodelación ósea. Los osteocitos son sensibles a los estímulos mecánicos y producen factores solubles para inducir la remodelación ósea, razón por la cual se emplea la microvibración como una terapia innovadora y prometedora, no invasiva y no farmacológica en la estimulación de la formación ósea de la superficie del hueso (AU)

Impacto del tratamiento de adultos mayores con ISRS y su relación con los tratamientos odontológicos / The impact of treating older adults with SSRI and its relationship with dental treatments

La población mayor de 60 años es el grupo etario de mayor crecimiento en el mundo. Debido a que la depresión es una patología frecuente en la persona adulta mayor y anciana, los inhibidores de la recap- tación de la serotonina (ISRS) son el tratamiento de primera línea de elección. Este trabajo referencia la asociación del consumo de estos fármacos con la disminución de la densidad ósea mineral (DMO), el riesgo de fracturas y su repercusión en la atención odontológica. Además, incluye una breve descripción de la homeostasis ósea y la relación depresión-carga alostática. El trabajo interdisciplinario y una correcta anamnesis pueden detectar posibles complicaciones y riesgos vinculados con este tipo de medicamen- tos. Ello facilitaría un mejor manejo, más aún en el adulto mayor, donde una pequeña variable puede repercutir en su integridad (AU)

The population over 60 is the fastest growing age group in the world. Depression is a frequent pathology in the elderly and the elderly, with serotonin reuptake inhibitors (SSRI) being the 1st line treatment of choice. The association of the consumption of this drug with a decrease in bone mineral density (BMD), risk of fractures and its impact on dental care are referenced in this work. In addition, it includes a brief description of bone homeostasis and the depression-allostatic load relationship. Interdisciplinary work and a correct anamnesis can detect possible complications and risks linked to this type of medication, facilitating better management and even more so in the elderly, where a small variable can affect their integrity (AU)

The Use of Bio-Inks and the Era of Bioengineering and Tooth Regeneration

Abstract Objective: To review existing literature and provide an update on the current use of Bio-Inks and potential future use. Material and Methods: A MeSH keyword search was conducted to find out relevant articles for this short review. Results: Bio inks used in 3D printing grafting require various properties essential for the selection. Combining multiple methods and improved properties is essential for developing successful bio-inks for 3D grafting of functional tissues and tooth pulp regeneration from stem cells. To date, researchers have made many efforts to grow teeth based on stem cells and inculcate regeneration of teeth along with surrounding tissues like alveolar bones and periodontal ligaments. Conclusion: 3D printing with Bio-Inks requires strict adherence to safety protocols for successful outcomes, making it difficult to employ this routinely.

Immediate autogenous extracted tooth as a grafting material for fresh socket preservation: a systematic review / Diente autógeno de extracción inmediata como material de injerto para la conservación de alvéolos frescos: una revisión sistemática

Objectives: To evaluate the use of extracted autogenous teeth for socket preservation after tooth extraction. Material and Methods: Cochrane, Scopus, and PubMed databases search was conducted to identify human clinical studies reporting the clinical, radiographic and/or histological outcomes of socket preservation techniques with autogenous extracted tooth Only studies published in English language in the last 10 years were included in the study. Results: In total, 82 articles were identified. Five articles were included in the review. They included 58 teeth that were prepared as a graft for socket preservation. The grafts derived from autogenous teeth were presented in three forms: particles, blocks and powder. The mean bone loss ranged from 0.28 mm to 0.41mm in height and 0.15 mm in width. Conclusion: Immediate autogenous extracted tooth as a grafting material for fresh socket preservation is promising for future daily clinical practice. More clinical comparative studies are needed.

Objetivo: Evaluar el uso de dientes extraídos autógenos para la preservación del alveolo tras la extracción dental.Material y Métodos: Se realizó una búsqueda en las bases de datos Cochrane, Scopus y PubMed para identificar estudios clínicos en humanos que informaban los resultados clínicos, radiográficos y / o histológicos de las técnicas de preservación de alveolos con dientes extraídos autógenos. Solo se incluyeron estudios publicados en inglés en los últimos 10 años. Resultados: En total se identificaron 82 artículos. Se incluyeron cinco artículos en la revisión. Incluyeron 58 dientes que se prepararon como injerto para la preservación del alveolo. Los injertos derivados de dientes autógenos se presentaron en tres formas: partículas, bloques y polvo. La pérdida ósea media osciló entre 0,28 mm y 0,41 mm de altura y 0,15 mm de ancho. Conclusión: El diente autógeno extraído de forma inmediata utilizado como material de injerto para la conservación del alveolo fresco es prometedor para la práctica clínica diaria futura. Se necesitan más estudios clínicos comparativos.

Ensaio clínico controlado, randomizado e cego, para avaliar a preservação alveolar, utilizando biomaterial de colágeno: resultados preliminares / Controlled, randomized and blind clinical trial to evaluate alveolar preservation using collagen biomaterial: preliminary results

Foi proposito desse trabalho analisar a eficiência na manutenção óssea alveolar após extração dentária pelo biomateral xenógeno (Hemospon®) por meio de imagens tomográficas pré e pósoperatórias de 1 mês e 18 meses de acompanhamento. Trata-se de um estudo clínico controlado, randomizado e cego, onde foram realizadas 18 exodontias, e os alvéolos dentários tratados foram selecionados de forma randomizada e divididos em dois grupos. O grupo 1, grupo teste (G1) foi inserido esponja de colágeno xenógena (porco) e o grupo controle (G2), foi mantido apenas o coágulo sanguíneo local. Os alvéolos foram analisados nos sentidos horizontais e verticais e os resultados foram avaliados através dos testes de Wilcoxon e Mann-Whitney, assumindo uma significância estatística de p<0,05. Além das análises tomográficas os pacientes foram acompanhados diariamente na primeira semana para verificar se os tecidos locais apresentavam possíveis complicações, como a presença de infecção, fistulas e dor persistente. Os resultados iniciais (1 mês) constataram que numa análise em conjunto avaliando altura (p<,0,863), comprimento total (p<1,000) e espessura total do alvéolo (p<0,222), não foram observadas diferenças significativas entre os grupos teste e controle, respectivamente. Na análise de 18 meses, observa-se diferença estatística (p < 0,05) em relação a espessura total do alvéolo, porém em relação ao comprimento total do alvéolo e a altura alveolar não foram observados diferenças estatisticamente significativas (p = 0,36; p = 0,674 ­ respectivamente). Quando de compara-se o G1 em momentos diferentes 1 mês e 18 meses em relação as variáveis observa-se diferenças estatísticas significativas no comprimento total do alvéolo e na espessura (p<0,05), porém não houve signicancia em relação à altura do alvéolo (p=0,575). Analisando em separado cada variável em relação aos grupos G1 e G2 não houve diferença estatística numa análise após 18 meses (p = 0,773 ­ altura alveolar e espessura alveolar; p = 1 ­ comprimento total do alvéolo). Durante o acompanhamento clínico em ambos os grupos não houve diferença no padrão do processo de reparo tecidual, sendo possível reabilitação oral dos pacientes. Mediante os dados preliminares apresentados, a pesquisa demonstrou que os alvéolos tratados com esponja de colágeno porcina (Hemospon®) tiveram perdas ósseas menores, principalmente em relação a espessura, podendo-se inferir que há indícios de uma manutenção alveolar com o uso do biomaterial, podendo ser um biomaterial em potencial e de baixo custo para preservação alveolar, sem aumentar os índices de complicações, porém sugere-se uma análise de uma amostra maior para uma melhor análise estatística (AU).

The purpose of this work was to analyze the efficiency of alveolar bone maintenance after tooth extraction by xenogenous biomaterial (Hemospon®) by means of pre and postoperative tomographic images of 1 month and 18 months of follow-up. This is a controlled, randomized, blinded, clinical study, in which 18 extractions were performed, and the treated dental alveolo were randomly select and devided into two groups. Group 1 test group (G1) a xenogen collagen sponge (pig) was inserted and the control grouop (G2), only the local blood clot was maintained. The alveoli were analyzed in the horizontal and vertical directions and the results were evaluated using the Wilcoxon and Mann ­ Whitney tests assumig a statistical significance of p<0,05. In addition to tomographic analyzes, patients were followed up daily in the first week to check whether local tissues had possible complications such as the presence of infection fistulas and persistent pain. The initial results (1 month) found that in a joint analysis evaluanting height (p<0,863) total length (p<1,00) and total thickness of the socket (p<0,222), no significant differences were observed between the test groups and control respectively. When G1 is compared at different times 1 month and 18 months in relation to the variables there are statistically significant differences in the total length of the alveolus and in the thickness (p<0,05) but there was no significance in relation to the height of the alveolus (p = 0,575). Analyzing each variable separately in relation to groups G1 and G2 there was no statistical difference in an analysis after 18 months (p=0,773 ­ alveolar height and alveolar thickness; p = 1 ­ total alveolar length). During clinical follow-up in both groups there was no difference in the pattern of the tissue repair process with patients oral rehabilitation being possible. Through the preliminary data presented the research demonstrated that the alveoli treated with porcine collagen sponge (Hemospon®) had smaller bone losses mainly in relation to thickness and it can be inferred that there are signs of alveolar maintenance with the use of biomaterial it can be a potential and low-cost biomaterial for alveolar preservation without increasing the complication rates however an analysis of a larger sample is suggested for a better statistical analysis (AU).

Análise do fêmur de ratas tratadas com ocitocina e submetidas ao treinamento de força durante a periestropausa / Analysis of the femur of rats treated with oxytocin and submitted to strength training during periestropause

A diminuição nas concentrações de estrógeno, como o que ocorre no período da perimenopausa e menopausa, contribui para o aumento do turnover ósseo, com taxa de reabsorção superior à de formação óssea que favorece a instalação da osteoporose, doença silenciosa que determina fragilidade óssea e maior probabilidade de fraturas. Entre as intervenções utilizadas para prevenção da osteoporose, destaca-se o treinamento de força (TF) e a ocitocina (OT), hormônio promissor com ação anabólica no osso. O objetivo deste estudo foi verificar a ação da associação da OT ao TF, em comparação às intervenções isoladas, no processo de remodelamento ósseo do colo do fêmur de ratas Wistar na periestropausa (18 a 21 meses). Quarenta ratas Wistar com ciclo estral irregular (18 meses) foram randomizadas nos grupos: 1- Veículo (Veh); 2-Ocitocina (Ot); 3-Treinamento de força (Tf); 4-Ot+Tf. Os animais do grupo 1 receberam salina (0,15 mol/L) e dos grupos 2 e 4 receberam OT (134 µg/kg), sendo duas injeções intraperitoneais com intervalo de 12 horas a cada 30 dias, totalizando 8 injeções ao final do período experimental. Os animais dos grupos 3 e 4 realizaram TF em escada 3 vezes por semana com realização mensal do teste de capacidade de carga máxima voluntária (CCMV). Após 120 dias, os animais foram eutanasiados, os fêmures foram coletados para análises de ensaio mecânico, densitometria, microtomografia óssea, espectroscopia de Raman e técnica de reação em cadeia da polimerase de transcrição reversa em tempo real (qRT-PCR), e o sangue para análises de marcadores bioquímicos do metabolismo ósseo, dano hepático e estresse oxidativo. A principal novidade deste estudo é a adição da OT ao TF, a qual apresentou, no ensaio de compressão, maior força máxima em relação ao Veh e menor elasticidade em relação ao Tf e, no ensaio de flexão de três pontos, maior rigidez em relação ao Veh e Ot, menor rigidez e menor elasticidade em relação ao Veh; maior espessura cortical (Ct.Th) em relação aos demais grupos, menor número de poros (Po.N) em relação ao Veh e Ot, e maior momento polar médio (J) em relação ao Tf. Houve também maior volume do osso trabecular (BV/TV) em relação ao Ot e maior espessura trabecular (Tb.Th) em relação aos demais grupos. A densidade mineral óssea areal (aDMO) do colo do fêmur foi maior que o Ot, e a DMO do fêmur total foi maior que os demais grupos. Quanto a expressão gênica, houve maior expressão do fator de transcrição relacionado ao Runt 2 (Runx2) em relação ao Veh, o fator de transcrição Osterix (Osx/Sp7) foi menor que o Ot e Tf. A proteína morfogenética óssea 2 (Bmp2) apresentou menor expressão em relação ao Veh, e a expressão da fosfatase alcalina óssea (Fal) foi maior que os demais grupos. A expressão do membro da família do fator de necrose tumoral 11b (Opg) e do ligante do fator de necrose tumoral (Rankl) foi maior que os outros grupos, a expressão do membro do fator de necrose tumoral 11a (Rank) e catepsina K (Ctsk) foi maior que Veh e Ot. Também foi observado menor atividade de fosfatase ácida resistente ao tartarato (TRAP) e capacidade antioxidante total (CAT) no ensaio bioquímico em relação aos demais grupos. Na intervenção com OT, houve maior elasticidade no ensaio de flexão de três pontos, e maior Ct.Th em relação ao Veh. A expressão gênica de Runx2, Osx/Sp7 foi maior e Bmp2 foi menor que o grupo Veh. No TF houve maior elasticidade que o Veh e Ot no ensaio de compressão, maior rigidez e elasticidade em relação ao Veh no ensaio de flexão de três pontos. Houve menor Ct.Th em relação ao Ot, maior DMO do fêmur total em relação ao Veh, e a taxa de mineralização foi maior que o Veh e Ot. Na expressão gênica, Runx2 e Osx/Sp7 foram maiores que o Veh. A Bmp2 e osteocalcina/proteína óssea gama-carboxiglutamato (Ocn) foram menores que o Veh, e a Fal foi menor que Ot. Em relação a Rank e Ctsk, estas foram maiores que Veh e Ot. Por fim, a atividade de aspartato aminotransferase (AST) foi menor que o Veh. Esses resultados mostraram que a associação de intervenções é estratégia anabólica promissora para a prevenção da osteoporose no período da periestropausa, destacando-se dos efeitos das intervenções isoladas, ao preservar aspectos mecânicos, estruturais e gênicos do osso, além de parecer controlar fatores relacionados ao cross-talk entre tecido ósseo e tecido adiposo a favor da homeostase oxidativa e de fatores relacionados a atividade de marcadores ósseos(AU)

The decrease in estrogen concentrations, such as that which occurs during perimenopause and menopause, contributes to an increase in bone turnover, with a rate of resorption higher than that of bone formation, which favors the installation of osteoporosis, a silent disease that determines bone fragility and greater probability of fractures. Among the interventions used to prevent osteoporosis, strength training (ST) and oxytocin (OT), a promising hormone with anabolic action on bone, stand out. The objective of this study was to verify the action of the association of OT and ST, compared to isolated interventions, in the process of bone remodeling of the femoral neck of Wistar rats in periestropause (18 to 21 months). Forty Wistar rats with irregular estrous cycle (18 months) were randomized into groups: 1-Vehicle (Veh); 2-Oxytocin (Ot); 3-Strength training (St); 4-Ot+St. The animals in group 1 received saline (0.15 mol/L) and in groups 2 and 4 received OT (134 µg/kg), with two intraperitoneal injections with an interval of 12 hours every 30 days, totaling 8 injections at the end of the period. trial period. The animals in groups 3 and 4 performed ST on a ladder 3 times a week with monthly performance of the maximum voluntary carrying capacity test (MVCC). After 120 days, the animals were euthanized, the femurs were collected for mechanical assay analysis, densitometry, bone microtomography, Raman spectroscopy and real-time reverse transcription polymerase chain reaction (qRT-PCR) technique, and blood for analysis of biochemical markers of bone metabolism, liver damage and oxidative stress. The main novelty of this study is the addition of OT to ST, which presented, in the compression test, greater maximum force in relation to Veh and less elasticity in relation to St and, in the three-point bending test, greater stiffness in relation to to Veh and Ot, less rigidity and less elasticity in relation to Veh; greater cortical thickness (Ct.Th) in relation to the other groups, smaller number of pores (Po.N) in relation to Veh and Ot, and greater mean polar moment (J) in relation to St. There was also greater trabecular bone volume (BV/TV) in relation to Ot and greater trabecular thickness (Tb.Th) in relation to the other groups. The areal bone mineral density (aBMD) of the femoral neck was higher than the Ot, and the BMD of the total femur was higher than the other groups. As for gene expression, there was greater expression of the transcription factor related to Runt 2 (Runx2) in relation to Veh, the transcription factor Osterix (Osx/Sp7) was lower than Ot and St. Bone morphogenetic protein 2 (Bmp2) showed lower expression compared to Veh, and boné alkaline phosphatase (Alp) expression was higher than the other groups. The expression of tumor necrosis factor 11b family member (Opg) and tumor necrosis factor ligand (Rankl) was higher than the other groups, tumor necrosis factor 11a member (Rank) and cathepsin K (Ctsk) was greater than Veh and Ot. It was also observed lower activity of tartrate resistant acid phosphatase (TRAP) and total antioxidant capacity (CAT) in the biochemical assay in relation to the other groups. In the intervention with OT, there was greater elasticity in the three-point bending test, and greater Ct.Th in relation to Veh. The gene expression of Runx2, Osx/Sp7 was higher and Bmp2 was lower than the Veh group. In ST intervention there was greater elasticity than Veh and Ot in the compression test, greater stiffness and elasticity in relation to Veh in the three-point bending test. There was lower Ct.Th in relation to Ot, higher BMD of the total femur in relation to Veh, and the mineralization rate was higher than Veh and Ot. In gene expression, Runx2 and Osx/Sp7 were higher than Veh. Bmp2 and osteocalcin/bone protein gammacarboxyglutamate (Ocn) were lower than Veh, and Fal was higher than Ot. In relation to Rank and Ctsk, these were higher than Veh and Ot. Finally, aspartate aminotransferase (AST) activity was lower than Veh. These results showed that the association of interventions is a promising anabolic strategy for the prevention of osteoporosis in the periestropause period, standing out from the effects of isolated interventions, by preserving mechanical, structural and genetic aspects of the bone, in addition to seeming to control factors related to the cross -talk between bone tissue and adipose tissue in favor of oxidative homeostasis and factors related to the activity of bone markers(AU)

Recombinant human insulin-like growth factor-1 promotes osteoclast formation and accelerates orthodontic tooth movement in rats

Abstract Background: IGF-1 may be an important factor in bone remodeling, but its mechanism of action on osteoclasts during orthodontic tooth movement is complex and unclear. Methodology: The closed-coil spring was placed between the left maxillary first molar and upper incisors with a force of 50 g to establish an orthodontic movement model. Eighty SD rats were randomized to receive phosphate buffer saline or 400 ng rhIGF-1 in the lateral buccal mucosa of the left maxillary first molar every two days. Tissue sections were stained for tartrate-resistant acidic phosphatase (TRAP), the number of TRAP-positive cells was estimated and tooth movement measured. Results: The rhIGF-1 group exhibited evidential bone resorption and lacuna appeared on the alveolar bone compared to the control group. Moreover, the number of osteoclasts in compression side of the periodontal ligament in the rhIGF-1 group peaked at day 4 (11.37±0.95 compared to 5.28±0.47 in the control group) after the orthodontic force was applied and was significantly higher than that of the control group (p<0.01). Furthermore, the distance of tooth movement in the rhIGF-1 group was significantly larger than that of the control group from day 4 to day 14 (p<0.01), suggesting that rhIGF-1 accelerated orthodontic tooth movement. Conclusion: Our study has showed that rhIGF-1 could stimulate the formation of osteoclasts in the periodontal ligament, and accelerate bone remodeling and orthodontic tooth movement.

Citotoxicidade e efeito indutor de mineralização de flavonoides sobre células osteoblásticas / Cytotoxicity and inducing effect of mineralization of flavonoids on osteoblastic cells

A perda óssea dentária e a formação de lesões periapicais surgem como uma consequênc ia do desequilíbrio da homeostase óssea. Os osteoblastos, juntamente com os osteoclastos e osteócitos, atuam na formação e na reabsorção óssea. Vários marcadores de formação óssea são produzidos por osteoblastos ativos e refletem diferentes aspectos da dif erenciação osteoblástica e da remodelação óssea. Com isso, muitos autores têm explorado o uso de fitoterápicos, visando obter novos compostos que apresentem propriedades terapêuticas, como os flavonoides, e que estimulem a neoformação óssea e o reparo da r egião periapical. O objetivo deste estudo foi avaliar in vitro a citotoxicidade e efeito indutor de mineralização de flavonoides sobre células osteoblásticas humanas. Para isso, células osteoblásticas da linhagem Saos expostas aos seguintes flavono2 foram ides: quercetina, miricetina e seus derivados taxifolina, isoquercitrina, rutina, ampelopsina e EGCG, além de pinocembrina, crisina e canferol, de forma isolada e combinada. Foi avaliado o efeito citotóxico, a atividade de fosfatase alcalina e indução de n mé todo de Shapiroódulos de mineralização. Os resultados foram analisados p elo Wilk, e as variáveis foram submetidas à análise de ANOVA seguida pelo teste de Tukey para comparar entre os grupos e/ou concentrações ou teste de Dunnett para comparar entre cada grupo e o controle, com nível de significância de 5%. A viabilidade da cultura de osteoblastos não teve uma redução estatisticamente significativa na presença da maioria dos compostos, exceto crisina a 100µM. Taxifolina, isoquercitrina, rutina, ampelopsina e EGCG foram os compostos que estimularam significativamente a atividade da fosfatase alcalina, juntamente com as combinações taxifolina+isoquercitrina, taxifolina+ampelopsina e taxifolina+rutina a 25/25 µM. Quanto a formação de nódulos de mine ralização, ampelopsina, isoquercitrina, rutina, pinocembrina e miricetina isolados e taxifolina+isoquercitrina, taxifolina+ampelopsina e taxifolina+rutina combinados obtiveram os melhores resultados, variando de acordo com as concentrações. Concluise que a taxifolina, isoquercitrina, rutina e ampelopsina e combinações de taxifolina com esses flavonoides são citocompatíveis e apresentam efeito indutor de mineralização em osteoblastos Saos-2(AU)

Dental bone loss and the formation of periapical lesions arise as a consequence of imbalance of bone homeostasis. Osteoblasts, together with osteoclasts and osteocytes, act in bone formation and resorption. Several markers of bone formation are produced by active osteoblasts and reflect different aspects of osteoblastic differentiation and bone remodeling. Thus, many authors have explored the use of phytotherapics in order to obtain new compounds with therapeutic properties, such as flavonoids, and also stimulate bone neoformation and periapical region repair. The objective of this study was to evaluate in vitro the cytotoxicity and inducing effect of flavonoid mineralization on human osteoblastic cells. For this, osteoblastic cells of the Saos-2 lineage were exposed to the following flavonoids: quercetin, myricetin and its derivatives taxifoline, isoquercitrin, rutin, ampelopsin and EGCG, in addition to pinocembrin, chrysin and kaempferol, in an isolated and combined manner. The cytotoxic effect, the activity of alkaline phosphatase and the induction of mineralization nodules were evaluated. The results were analyzed using the Shapiro-Wilk method, and the variables were submitted to ANOVA analysis followed by the Tukey test to compare between groups and/or concentrations or Dunnett's test to compare between each group and the control, with a level of 5% significance. The viability of the osteoblast culture did not have a statistically significant reduction in the presence of most compounds, except 100 µM chrysin. Taxifoline, isoquercitrin, rutin, ampelopsin and EGCG were the compounds that significantly stimulated the activity of alkaline phosphatase, together with the combinations taxifoline+isoquercitrin, taxifoline+ampelopsin and taxifoline+rutin at 25/25 µM. As for the formation of mineralization nodules, ampelopsin, isoquercitrin, rutin, pinocembrin and myricetin alone and taxifoline+isoquercitrin, taxifoline+ampelopsin and taxifoline+rutin combined obtained the best results, varying according to the concentrations. It is concluded that taxifoline, isoquercitrin, rutin and ampelopsin and combinations of taxifolin with these flavonoids are cytocompatible and have a mineralization-inducing effect on Saos-2 osteoblasts(AU)

Salivary molecules of bone remodeling and tissue repair after head and neck radiotherapy

Abstract Head and neck radiotherapy causes quantitative and qualitative changes in saliva. The objective of this case-control study was to evaluate the salivary biomarkers associated with bone remodeling and tissue repair in patients submitted to radiotherapy for head and neck cancer treatment, compared with non-irradiated individuals. Total unstimulated saliva was collected for ELISA assay analysis of receptor activator for nuclear factor κ B (RANK) and its ligand (RANK-L), osteoprotegerin, matrix metalloproteinase-9/ tissue inhibitor of metalloproteinase-2, vascular endothelial growth factor, and epidermal growth factor. Statistics were performed, and revealed that salivary RANK (p = 0.0304), RANK-L (p = 0.0005), matrix metalloproteinase-9/ tissue inhibitor of metalloproteinase-2 (p = 0.0067), vascular endothelial growth factor (p = 0.0060), and epidermal growth factor (p < 0.0001) were reduced in patients, compared with the control group. Osteoprotegerin did not differ between the groups (p = 0.3765). Salivary biomarkers did not differ according to radiotherapy completion time (p > 0.05). In conclusion, the lower output of the salivary molecules - essential for bone remodeling and tissue repair - may disrupt tissue homeostasis and play a role in the pathogenesis of the radiotherapy-induced deleterious effects in the oral cavity.

Mechanism, prevention, and treatment for medication-related osteonecrosis of the jaws / 华西口腔医学杂志

The morbidity rate of medication-related osteonecrosis of the jaws (MRONJ) increased rapidly in recent years. Thusfar, the mechanism of MRONJ has no consensus. The possible mechanisms may include bone remodeling inhibition theory, angiogenesis inhibition theory, oral microorganism infection theory, immunosuppression theory, cytotoxicity-targeted oral epithelial cells, microcrack formation of maxillary or mandibular bone, and single nucleotide polymorphism. However, the efficacy of prevention and treatment based on a single mechanism is not ideal. Routine oral examination before MRONJ-related drug treatment, treatment of related dental diseases, and regular oral follow-up during drug treatment are of great significance for the prevention of MRONJ. During the treatment of MRONJ, the stage of MRONJ must be determined accurately, treatment must be standardized in accordance with the guidelines, and personalized adjustments must be made considering the specific conditions of patients. This review aimed to combine the latest research and guidelines for MRONJ and the experiences on the treatment of MRONJ in the Maxillofacial Surgery Department of West China Hospital of Stomatology, Sichuan University, and discuss the strategies to improve the clinical process.

Graft application and dexamethasone treatment influences new bone formation in rat tibial bone defects / Aplicación de injerto y tratamiento con dexametasona influyen en la formación de hueso nuevo en los defectos en la tibia de rata

SUMMARY: The objective of this study were bone defect complications that occur due to traumas or infections. Bone grafts are required to provide support, fill gaps and improve biological repair in skeletal damage. Dexamethasone plays role in calcium signaling modulation and used in diseases. Aim of this study was to evaluate osteonectin and osteopontin expressions in new bone development after dexamethasone application on tibial bone defects. Rats were divided into defect, defect+graft and defect+graft+dexamethasone treated groups. Tibial bone defect created, and rats were kept immobile for 28 days. Alloplastic material was placed in defect area in second and group third groups. 2.5 mg/kg Dex and normal saline were injected to dexamethasone and defect groups twice a week for 56 days. Inflammation and congestion were increased in defect and defect+graft groups. Defect+graft+dexamethasone group; increased number of osteoblast and osteocyte cells, dense bone matrix, formation of new bone trabeculae was observed. Defect+graft group; osteonectin expression in graft regions, osteoblast cells, some connective tissue cells and fibers were seen whereas in defect+graft+dexamethasone group; osteopontin expression in osteoblast and osteocyte cells of new bone trabeculae were observed. Dexamethasone may lead to formation of new bone trabeculae into the graft material resulting in increased osteoconduction and osteoinductive effect for differentiation of osteon.

RESUMEN: Los defectos óseos son complicaciones que ocurren debido a traumas o infecciones. Se requieren injertos óseos para proporcionar apoyo, llenar los espacios y mejorar la reparación biológica en el hueso dañado. La dexametasona desempeña un papel importante en la modulación de la señalización del calcio y se usa en enfermedades. El objetivo de este estudio fue evaluar las expresiones de osteonectina y osteopontina en el desarrollo óseo después de la aplicación de dexametasona en defectos óseos tibiales. Las ratas se dividieron en grupos: defecto, defecto + injerto y defecto + injerto + grupos tratados con dexametasona. Se creó un defecto óseo tibial, y las ratas se mantuvieron inmóviles durante 28 días. El material aloplástico se colocó en el área del defecto en el segundo y tercer grupo. Se inyectaron 2,5 mg / kg de dexametasona y solución salina normal a grupos de defectos dos veces por semana durante 56 días. La inflamación y la congestión aumentaron en los grupos de defectos y defectos + injerto; En el grupo defecto + injerto + grupo tratado con dexametasona se observó un aumento en el número de osteoblastos y osteocitos, de matriz ósea densa y en la formación de nuevas trabéculas óseas. En el grupo defecto + grupo de injerto se observó la expresión de osteonectina en las áreas de injerto, osteoblastos, algunas células y fibras de tejido conectivo, mientras que en el grupo defecto + injerto + dexametasona se observó la expresión de osteopontina en osteoblastos y osteocitos y formación de nuevas trabéculas óseas . En conclusión la dexametasona puede conducir a la formación de nuevas trabéculas óseas en el material de injerto, lo que resulta en un aumento de la osteoconducción y un efecto osteoinductivo para la diferenciación del osteón.

Rol de los fitoestrógenos en la calcificación vascular e interacciones óseo-vasculares / Role of phytoestrogens in vascular calcification and bonevascular interactions

La osteoporosis y las enfermedades cardiovasculares son patologías prevalentes en mujeres posmenopáusicas. La calcificación vascular es un proceso en el que se produce una distorsión de la arquitectura natural del tejido arterial con una transformación símil osteogénica. La fisiología vascular y la osteogénesis (formación y remodelación ósea) comparten una complejidad metabólica y funcional crítica, que ha sido poco explorada en forma conjunta, lo que ha impulsado la concepción del Eje Óseo-Vascular como nueva área de investigación, con una visión de estudio integradora con la finalidad de identificar vínculos entre ambos sistemas. En virtud de la controversia planteada sobre los riesgos/beneficios de la terapia de reemplazo hormonal para prevenir enfermedades asociadas a la menopausia, se ha incentivado la búsqueda de nuevas opciones de tratamiento. Los fitoestrógenos, como compuestos nutracéuticos, surgen como una potencial alternativa terapéutica. En particular, las isoflavonas presentan gran analogía estructural con el estrógeno humano 17ß-estradiol, lo que les permite unirse al receptor de estrógenos e inducir acciones estrogénicas tanto en células animales como humanas. Basado en la experiencia propia como en lo reportado en la bibliografía, este artículo analiza la información disponible sobre las acciones vasculares y óseas de los fitoestrógenos (específicamente la isoflavona genisteína), con una visión de ciencia traslacional. Es de esperar que los avances en el conocimiento derivado de la ciencia básica, en un futuro cercano, pueda contribuir a decisiones clínicas a favor de promover terapias naturales de potencial acción dual, para la prevención de enfermedades de alta prevalencia y significativo costo social y económico para la población. (AU)

Osteoporosis and cardiovascular diseases are prevalent diseases in postmenopausal women. Vascular calcification is a cellmediated process that leads to the loss of the natural architecture of the arterial vessels due to osteogenic transdifferentiation of smooth muscle cells, and matrix mineralization. Vascular physiology and osteogenesis (bone formation and remodeling) share a critical metabolic and functional complexity. Given the emerging integrative nature of the bonevascular axis, links between both systems are a matter of ongoing interest. In view of the controversy stated about the risks/benefits of hormone replacement therapy to prevent diseases associated with menopause, phytoestrogens arise as a potential natural therapeutic alternative. In particular, isoflavones have a strong structural analogy with the human estrogen 17ß-estradiol, that allows them to bind to the estrogen receptor and induce estrogenic actions in animal and human cells. Based in on our own experience and the information available in the literature, in this paper we provide an overview of the role of phytoestrogens on vascular and bone tissues, with focus on Genistein actions. We wish that the basic knowledge acquired may contribute to guide clinical decisions for the promotion of natural therapies for the treatment of diseases that conspire against human health. (AU)

Capacidad funcional, densidad mineral ósea y marcadores de neoformación-reabsorción ósea en pacientes menores de 18 años con movilidad reducida / Functional capacity, bone mineral density and neoformation-resorption bone markers in patients under 18 years of age with reduced mobility

Resumen: Introducción: La inmovilización prolongada asociada a diversas enfermedades neurológicas, causa osteoporosis secundaria con fracturas patológicas y dolor óseo persistente. Objetivos: Establecer la asociación entre densidad mineral ósea (DMO), marcadores de neoformación y reabsorción ósea y grado de capacidad funcional en pacientes menores de 18 años con movilidad reducida. Pacientes y Método: Estudio transversal, realizado entre 1/1/2016 y 31/12/2017 en pacientes de 6 a 18 años diagnosticados de distintas enfermedades neurológicas en Ciudad Real (España). Se analizaron las variables biodemográficas, capacidad funcional según la Functional Mobility Scale (FMS), que valora la movilidad en 5, 50 y 500 metros, DMO, 25-hidroxi-vitamina D, fosfatasa alcalina, osteocalcina en sangre y telopéptido amino terminal de cadena cruzada de colágeno tipo I en orina (NTX-I). Se expresan DMO, fosfatasa alcalina, osteocalcina y NTX-I en Z score según valores de referencia para edad y sexo. Se utilizaron estadísticas descriptivas y correlaciones de Pearson y Spearman. Resulta dos: 36 pacientes (52,7% niñas), edad media de 8,6 ± 4,7 años. Valor medio de FMS: 5,3 sobre 18. DMO media: -1,99 ± 1,7 desviaciones estándar (DE), fosfatasa alcalina media: -2,64 ± 1,08, osteocalcina media: -2,15 ± 1,39, y NTX-I medio: +3 ± 1,72. Hubo asociación significativa entre DMO y FMS para 5 metros (r = 0,395; p = 0,017) y para la puntuación total (r = 0,365; p = 0,029). No se encon traron diferencias significativas según estadios de desarrollo puberal. Conclusiones: En la población estudiada se observa disminución en la DMO y en marcadores de neoformación ósea y elevación de marcadores de reabsorción ósea sin asociación con el desarrollo puberal. Los pacientes con menor grado de movilidad presentan una DMO inferior.

Abstract: Introduction: Prolonged immobilization associated with several neurological disorders causes se condary osteoporosis with pathological fractures and persistent bone pain. Objectives: To establish the association between bone mineral density (BMD), neoformation and bone resorption markers and the degree of functional capacity in children under 18 years of age with reduced mobility. Pa tients and Method: Cross-sectional study conducted in Ciudad Real, Spain between January 1, 2016, and December 31, 2017 with patients aged between 6 and 18 years diagnosed with different neurological disorders. The following variables were analyzed: age, sex, pubertal stage, functional capacity according to the Functional Mobility Scale (FMS), which assesses the ability to walk from 5, 50 to 500 meters, BMD, 25-hydroxy-vitamin D, alkaline phosphatase and osteocalcin in blood, and N-terminal telopeptide crosslinks in collagen type I (NTX-I) in urine. BMD, alkaline phosphatase, osteocalcin, and NTX-I values are expressed in Z score according to reference values for age and sex. The Pear son and Spearman correlations were used for data analysis. Results: 36 patients (52.7% girls) with an average age of 8.6±4.7 years. Mean FMS value: 5.3 out of 18. Mean BMD: -1.99 ± 1.7 standard deviations (SD), mean alkaline phosphatase: -2.64 ± 1.08, mean osteocalcin: -2.15 ± 1.39, and mean NTX-I: +3 ± 1.72. There was a significant association between BMD and FMS for 5 meters (r = 0.395; p = 0.017) and for total score (r = 0.365; p = 0.029). There were no significant differences according to the stages of pubertal development. Conclusions: In this population, there was a decrease in BMD and bone neoformation markers, and an increase of bone resorption markers with no association with pubertal development. Patients with a lower degree of mobility present a lower BMD.

Digital radiography as an alternative method in the evaluation of bone density in uremic rats / Radiografia digital como método alternativo na avaliação da densidade óssea em ratos urêmicos

ABSTRACT Introduction: Digital radiography (DRx) may provide a suitable alternative to investigate mineral and bone disorder (MBD) and loss of bone density (BD) in rodent models of chronic kidney disease (CKD). The objective of this study was to use DRx to evaluate BD in CKD rats, and to evaluate the correlation between DRx findings and serum MBD markers and bone histomorphometry. Methods: Uremia was induced by feeding Wistar rats an adenine-enriched diet (0.75% for 4 weeks/0.10% for 3 weeks); outcomes were compared to a control group at experimental weeks 3, 4, and 7. The following biochemical markers were measured: creatinine clearance (CrC), phosphate (P), calcium (Ca), fractional excretion of P (FeP), alkaline phosphatase (ALP), fibroblast growth factor-23 (FGF-23), and parathyroid hormone (PTH). DRx imaging was performed and histomorphometry analysis was conducted using the left femur. Results: As expected, at week 7, uremic rats presented with reduced CrC and higher levels of P, FeP, and ALP compared to controls. DRx confirmed the lower BD in uremic animals (0.57±0.07 vs. 0.68 ± 0.06 a.u.; p = 0.016) compared to controls at the end of week 7, when MBD was more prominent. A severe form of high-turnover bone disease accompanied these biochemical changes. BD measured on DRx correlated to P (r=-0.81; p = 0.002), ALP (r = -0.69, p = 0.01), PTH (r = -0.83, p = 0.01), OS/BS (r = -0.70; p = 0.02), and ObS/BS (r = -0.70; p = 0.02). Conclusion: BD quantified by DRx was associated with the typical complications of MBD in CKD and showed to be viable in the evaluation of bone alterations in CKD.

RESUMO Introdução: A radiografia digital (RxD) pode representar uma alternativa adequada para investigar o distúrbio mineral e ósseo (DMO) e a perda de densidade óssea (DO) em modelos de roedores da doença renal crônica (DRC). O objetivo deste estudo foi utilizar a RxD para avaliar a DO em ratos com DRC, e avaliar a correlação entre os achados da RxD e marcadores séricos de DMO e histomorfometria óssea. Métodos: A uremia foi induzida pela alimentação de ratos Wistar com dieta enriquecida com adenina (0,75% por 4 semanas/0,10% por 3 semanas); os resultados foram comparados com um grupo controle nas semanas experimentais 3, 4 e 7. Os seguintes marcadores bioquímicos foram medidos: clearance de creatinina (CCr), fosfato (P), cálcio (Ca), fração excretada de P (FeP), fosfatase alcalina (ALP), fator de crescimento de fibroblastos-23 (FGF-23) e paratormônio (PTH). A imagem da RxD foi obtida e a análise histomorfométrica foi realizada com o fêmur esquerdo. Resultados: como esperado, na semana 7, os ratos urêmicos apresentaram redução do CCr e níveis mais altos de P, FeP e ALP em comparação aos controles. A RxD confirmou a menor DO em animais urêmicos (0,57 ± 0,07 vs. 0,68 ± 0,06 u.a.; p = 0,016) em comparação aos controles no final da semana 7, quando a DMO foi mais proeminente. Uma forma grave de doença óssea de alta renovação celular acompanhou essas mudanças bioquímicas. A DO, medida na RxD foi correlacionada a P (r = -0,81; p = 0,002), ALP (r = -0,69, p = 0,01), PTH (r = -0,83, p = 0,01), OS/BS (r = -0,70 p = 0,02) e Ob.S/BS (r = -0,70; p = 0,02). Conclusão: A DO quantificada por RxD esteve associada às complicações típicas da DMO na DRC e mostrou-se viável na avaliação de alterações ósseas na DRC.

Biomechanical Analysis of Orthopedic Screw Under Bone Remodeling / 中国医疗器械杂志

In order to evaluate the biomechanical stability of titanium alloy screw with different structural parameters under bone remodeling, some three-dimensional finite element models were established and the bone remodeling process after implanting the screw was simulated. Three-dimensional finite element models consist of bone and screw with different lengths and diameters. Bone remodeling process was simulated by user-defined subroutine. It is found that the stress on the bone is concentrated on the groove and root of the internal thread. The screw stress is mainly on the beginning of the thread, and the whole stress decreases along the long axis of the screw. The stress distribution trend of bone and screw did not change significantly during the bone remodeling. The maximum equivalent stress value was different, the maximum equivalent stress on the screw and cancellous bone increased while the maximum equivalent stress value on the cortical bone decreased.