Actualidad en ortodoncia: las micro-osteoperforaciones en la aceleración del tratamiento ortodóncico / An update in orthodontics: micro-osteoperforations for accelerating orthodontic treatment

La búsqueda por encontrar métodos para acortar la duración de los tratamientos de ortodoncia tiene un pasado reciente, un presente y un futuro. Las fuerzas ortodóncicas que se ejercen sobre la membrana periodontal producen movimientos dentarios por modificaciones histológicas y biomoleculares. El conocimiento de los procesos biológicos da lugar a implementar cambios para favorecer la aceleración de los procesos resortivos y neoformativos. El objetivo de esta publicación es hacer una breve síntesis de lo acontecido con este tema y exponer el procedimiento de las micro-osteoperforaciones (MOPs) como una opción complementaria al tratamiento de ortodoncia convencional. Aún no existe suficiente apoyo de ensayos clínicos en humanos para aseverar su éxito. Más aún, distintos autores publican conclusiones contradictorias. Es de esperar que, en breve, nuevas investigaciones contribuyan a respaldarlo o desestimarlo (AU)

The quest to find methods to shorten the duration of orthodontic treatments has a recent past, a present, and a future. Orthodontic forces exerted on the periodontal membrane produce tooth movements by histological and biomolecular modifications. Knowledge of biological processes results in changes to promote the acceleration of spring and neoformative processes. The objective of this publication is to make a brief synthesis of what happened with this topic and expose the micro-osteoperforations (MOPs) procedure as a complementary option to conventional orthodontic treatment. There is not yet enough support from human clinical trials to assert its success. Moreover, different authors publish conflicting conclusions. It is to be expected that, shortly, further investigations will help to support or dismiss it (AU)

Analysis of Estrogen Effects on Eruption of Rat Molars / Análisis de los Efectos del Estrógeno en la Erupción de Molares de Rata

ABSTRACT: Tooth eruption requires resorption of the alveolar bone interposed between the tooth germ and the oral mucosa (coronal bone). The cells responsible for bone resorption are the osteoclasts and their activity can be reduced or inactivated by estrogen hormone. We aimed to investigate the effects of estrogen on the process of tooth eruption in rats. Thirty-three Wistar rats, aged two-to-17-days, were divided into control, sham and estrogen-treated groups. After daily injections with estrogen, the animals were euthanized and the jaws removed and processed for histological analysis. We performed clinical examination, morphological analysis, quantification of the number of osteoclasts on the surface of the coronal bone and immunohistochemical analysis of estrogen receptor type alpha (ERα). Estrogen therapy was effective, which could be confirmed by the higher estrogen plasma levels on treated animals. However, it had no effect on tooth development or tooth eruption. Progressive bone resorption was observed and the number of osteoclasts on coronal bone was not affected on hormoneinjected animals, allowing tooth to erupt at the same time observed in untreated animals. Immunohistochemistry for ERα confirmed the presence of this type of receptor in osteoclasts, osteoblasts and osteocytes. Taken together, our results showed that estrogen stimulation was not sufficient to decrease the number of osteoclasts on the coronal bone, supporting the idea that, although estrogen may have a protective activity on bone resorption, this may not apply to the alveolar bone that is meant to be resorbed during eruptive process.

RESUMEN: La erupción dental requiere la resorción del hueso alveolar interpuesto entre el germen dental y la mucosa oral (hueso coronal). Las células responsables de la resorción ósea son los osteoclastos y su actividad puede reducirse o inactivarse por la hormona del estrógeno. Objetivos: apuntamos a investigar los efectos del estrógeno en el proceso de la erupción dental en ratas. Treinta y tres ratas Wistar, de dos a 17 días de edad, se dividieron en grupos de control, Sham y se trataron con estrógenos. Los animales fueron eutanizados después del tratamento con estrógeno y se procesaron las mandíbulas para el análisis histológico. Se realizó el examen clínico, el análisis morfológico, la cuantificación del número de osteoclastos en la superficie del hueso coronal y el análisis inmunohistoquímico del tipo de receptor de estrógeno alfa (ERα). La terapia de estrógeno fue eficaz, lo que podría ser confirmado por los niveles plasmáticos más altos de estrógeno en los animales tratados. Sin embargo, no se observó ningún efecto sobre el desarrollo de los dientes o la erupción dental. Se observó una resorción ósea progresiva y el número de osteoclastos en el hueso coronal no se vio afectado en los animales inyectados con hormonas, permitiendo que el diente erupcionó durante el mismo período de tiempo observado en animales no tratados. La inmunohistoquímica para el ERα confirmó la presencia de este tipo de receptor en los osteoclastos, osteoblastos y osteocitos. Nuestros resultados mostraron que la estimulación del estrógeno no fue suficiente para reducir el número de osteoclastos en el hueso coronal confirmando que, si bien el estrógeno puede tener una actividad protectora en la resorción ósea, esto puede no se aplica al hueso alveolar que está destinado a ser rerecurrido durante el proceso eruptivo.

Implantes cortos como alternativa terapéutica actual en el tratamiento de maxilares atróficos / Short implants as current therapeutic alternatives to the treatment of athrophic jaws

La variación en el volumen óseo producida tras la pérdida dental, hace que el tratamiento de los pacientesque presentan atrofias avanzadas en los maxilares sea un desafío para todo cirujano. En la actualidad, el uso de implantes dentales para reemplazar piezas dentarias perdidas es una opción de tratamiento. El tratamiento con implantes cortos se comporta tanpredecible como el uso de implantes convencionales, pero estos resultados siguen siendo objeto de controversia. Los implantes cortos tienen tasas de éxito similares a las de los implantes de longitud estándar, pueden ser utilizados como alternativa en el tratamiento de maxilares atróficos, siempre que sean manejadosbajo una cuidadosa planificación de tratamiento. El objetivo del presente trabajo es exponer una revisiónde la literatura actual sobre el uso de implantes cortos como alternativa de tratamiento terapéutico en presencia de maxilares atróficos.

The variation in the bone volume produced afterdental loss makes the treatment of patientswith advanced atrophies in the jaws a challengefor every surgeon. At present, the use of dental implants to replace lost teeth is a treatment option.Treatment with short implants behaves aspredictably as the use of conventional implants,but these results remain controversial. Short implants have similar success rates to thoseof standard length implants and can be usedas an alternative in the treatment of atrophic jaws, provided they are handled under careful treatment planning.The aim of the present study is to presenta review of the current literature on the use of short implants as an alternative therapeutic treatment in the presence of atrophic jaws.

Marcadores de formación y resorción ósea y su utilidad para determinar el final del periodo de aposición ósea / Bone formation and resorption markers to evaluate the end of bone apposition

El pico de masa ósea (PMO) se alcanza entre los 20 y 35 años, pero la aposición ósea continúa hasta alcanzar el pico de fortaleza ósea (PFO). Se crea así una ventana entre ambos picos que podría ser evaluada mediante marcadores bioquímicos de recambio óseo, ya que durante dicho período la densidad mineral permanece constante. El objetivo fue determinar el final de la aposición ósea mediante marcadores bioquímicos óseos. Se evaluaron por décadas entre 20 y 49 años de edad 139 sujetos sanos de ambos sexos (69 hombres y 70 mujeres), determinando fosfatasa alcalina ósea (FAO), osteocalcina (OC), propéptido amino terminal del colágeno tipo 1 (P1NP) y telopéptido C-terminal del colágeno tipo 1 (CTX). Los marcadores correlacionan negativamente con la edad (OC: r= -0,3; p<0,01; P1NP: r= -0,4; p< 0,01 y CTX: r= -0,4; p<0,01), exceptuando FAO. En hombres de 20-29 años, P1NP y el CTX fueron significativamente mayores vs. 30-39 años (p<0,05 y p<0,001, respectivamente), y entre 30-39 años vs. de 40-49 años en P1NP y CTX (p<0,05; p<0,001, respectivamente). En mujeres de 20-29 años, P1NP y CTX fueron significativamente mayores vs. 30-39 años (p<0,0001 y p<0,01, respectivamente). Conclusión: los marcadores de remodelado óseo más sensibles y específicos permitirían determinar bioquímicamente el fin de la aposición ósea que se produce entre el PMO y el PFO. Si bien es necesario ampliar el número de sujetos evaluados, los datos que surgen de la presente investigación sentarían las bases para futuros estudios epidemiológicos referidos al fin de la aposición ósea. (AU)

Peak bone mass is achieved between 20-35 years; however bone apposition continues to reach an optimal skeleton strength. The window between peak bone mass and peak bone apposition may be evaluated by biochemical bone turnover markers. The objective of this study was to determine the end of bone apposition through biochemical bone markers in both sexes. A total of 139 subjects (69 men and 70 women) were divided by decades between 20 and 49 years of age. Bone alkaline phosphatase (BAL), osteocalcin (OC), type I collagen propeptide (P1NP) and type I collagen C-terminal telopeptide (CTX) were evaluated. Except BAL, the other bone markers negatively correlated with the age [OC (r= -0.3; p<0.01); P1NP (r= -0.4; p<0.01) and CTX (r= -0.4; p<0.01)]. Regarding men aged 20 to 29 years, P1NP and CTX were significantly higher vs. 30-39 years (p<0.05 y p<0.001, respectively) and. vs. 40-49 years (p<0.05; p<0.001, respectively). In women, the results were similar. Regarding 20-29 years, P1NP and CTX were higher vs. 30-39 years (p<0.001 y p<0.01, respectively). Bone remodeling rate decreases after the third decade, suggesting the end of the apposition period of peak bone mass. Conclusion: The most specific and sensitive bone markers would biochemically determine the end of bone apposition that extends between the peak of bone mass and the peak of bone strength. Although it is necessary to increase the number of subjects evaluated, the data that emerge from the present study would establish the bases for future epidemiological studies referring to the end of bone apposition. (AU)

Bone turnover markers in sheep and goat: A review of the scientific literature

ABSTRACT Bone turnover markers (BTMs) are product of bone cell activity and are generally divided in bone formation and bone resorption markers. The purpose of this review was to structure the available information on the use of BTMs in studies on small ruminants, especially for monitoring their variations related to diet, exercise, gestation and metabolic lactation state, circadian and seasonal variations, and also during skeletal growth. Pre-clinical and translational studies using BTMs with sheep and goats as animal models in orthopaedic research studies to help in the evaluation of the fracture healing process and osteoporosis research are also described in this review. The available information from the reviewed studies was systematically organized in order to highlight the most promising BTMs in small ruminant research, as well as provide a wide view of the use of sheep and goat as animal models in orthopaedic research, type of markers and commercial assay kits with cross-reactivity in sheep and goat, method of sample and storage of serum and urine for bone turnover markers determination and the usefulness and limitations of bone turnover markers in the different studies, therefore an effective tool for researchers that seek answers to different questions while using BTMs in small ruminants.

Marcadores de remodelamiento óseo en pacientes con enfermedad periodontal / Bone remodeling biomarkers in patients with periodontal disease

La Fosfatasa Alcalina Ósea (FAO) es una isoforma de la Fosfatasa Alcalina (FAL). La medición de su actividad en saliva es una medida indirecta del proceso de formación ósea, más sensible y específica que la FAL. La catepsina K es la principal colagenasa del proceso de resorción ósea, es capaz de degradar al colágeno tipo I en varios sitios dando lugar a pequeños péptidos N- y C- terminales. El telopéptido C-terminal (CTx) es el marcador más sensible y específico en el aumento de la resorción ósea, ya que el colágeno tipo I constituye más del 90 por ciento de la matriz orgánica del hueso...

Peri-implant evaluation of osseointegrated implants subjected to orthodontic forces: results after three years of functional loading

ABSTRACT Objective: The objective of this study was to clinically and radiographically assess the peri-implant conditions of implants used as orthodontic anchorage. Methods: Two groups were studied: 1) a test group in which osseointegrated implants were used as orthodontic anchorage, with the application of 200-cN force; and 2) a control group in which implants were not subjected to orthodontic force, but supported a screw-retained prosthesis. Clinical evaluations were performed three, six and nine months after prosthesis installation and 1- and 3-year follow-up examinations. Intraoral periapical radiographs were obtained 30 days after surgical implant placement, at the time of prosthesis installation, and one, two and three years thereafter. The results were compared by Kruskal-Wallis test. Results: There was no statistically significant difference in clinical probing depth (p = 0.1078) or mesial and distal crestal bone resorption (p = 0.1832) during the study period. After three years of follow-up, the mean probing depth was 2.21 mm for the control group and 2.39 mm for the test group. The implants of the control group showed a mean distance between the bone crest and implant shoulder of 2.39 mm, whereas the implants used as orthodontic anchorage showed a mean distance of 2.58 mm at the distal site. Conclusion: Results suggest that the use of stable intraoral orthodontic anchorage did not compromise the health of peri-implant tissues or the longevity of the implant.

RESUMO Introdução: o objetivo do presente estudo foi avaliar, clínica e radiograficamente, as condições peri-implantares de implantes usados como ancoragem ortodôntica. Métodos: dois grupos foram estudados: 1) Grupo Teste - no qual os implantes osseointegráveis foram utilizados como ancoragem ortodôntica, com aplicação de uma força de 200cN; e 2) Grupo Controle - no qual os implantes não foram submetidos à ancoragem ortodôntica, apenas serviram de suporte para fixação de prótese implantossuportada. Avaliações clínicas foram realizadas aos 3, 6 e 9 meses após a instalação das próteses, e após 1 e 3 anos de acompanhamento. Radiografias periapicais intrabucais foram obtidas 30 dias após a colocação do implante, no momento da instalação da prótese e após 1, 2 e 3 anos de acompanhamento. Os resultados foram comparados pelo teste de Kruskal-Wallis. Resultados: não houve diferenças quanto à profundidade clínica de sondagem (p = 0,1078) e a reabsorção das cristas ósseas mesial e distal (p = 0,1832) durante o período avaliado. Após três anos de acompanhamento, a média de profundidade de sondagem foi de 2,21mm para o Grupo Controle e de 2,39mm para o Grupo Teste. Os implantes do Grupo Controle apresentaram distância média de 2.39mm entre a crista óssea e o ombro do implante, enquanto os implantes usados como ancoragem ortodôntica mostraram distância média de 2,58mm na distal. Conclusão: esses resultados sugerem que o uso de uma ancoragem intrabucal estável não compromete a saúde dos tecidos peri-implantares ou a longevidade do implante.

Efectos óseos de la cirugía bariátrica / Effects of bariatric surgery on bone

La cirugía bariátrica es un recurso terapéutico cuyo uso para el manejo de la obesidad mórbida crece rápidamente. La intervención induce varios cambios en el perfil hormono-metabólico de los pacientes: disminuye la absorción de calcio, caen los niveles de vitamina D, se produce un hiperparatiroidismo secundario que acelera el recambio óseo, aumentan algunas citoquinas como la adiponectina, el GLP-1 y la esclerostina, y disminuyen otras como la leptina, la ghrelina, el GIP y la amilina. El estradiol cae por disminución de la aromatización periférica de la testosterona. Hay disminución de la carga mecánica en el esqueleto, especialmente en los miembros inferiores. Todo esto lleva a pérdida de la masa ósea, que es variable y más marcada en el fémur proximal que en la columna. El riesgo de fractura aumenta, aunque no todas las series lo han demostrado. Los pacientes con marcada disminución del peso corporal poscirugía deberían ser controlados, procurandoun buen aporte de calcio y otros nutrientes, la suplementación con vitamina D y el monitoreo de la densitometría ósea. (AU)

Bariatric surgery is a therapeutic resource for the management of morbid obesity; its use is growing rapidly. The intervention induces several changes in the hormonal and metabolic profile of patients: decreased calcium absorption, falling levels of vitamin D, secondary hyperparathyroidism which accelerates bone turnover; increased level of some cytokines such as adiponectin, GLP-1 and sclerostin, and decreased levels of others such as leptin, ghrelin, GIP and amylin. Estradiol falls due to decreased peripheral aromatization of testosterone. There is a decrease in the mechanical load on the skeleton, especially in the lower limbs. All this leads to loss of bone mass, which is variable and more marked in the proximal femur than in the spine. The risk of fracture increases, although it has not been shown in all series. Patients with marked decrease in body weight after bariatric surgery should be controlled carefully to insure a good supply of calcium and other nutrients, vitamin D supplementation, and the monitoring of bone mineral density. (AU)

Avaliação microtomográfica e histomorfométrica do processo de reparo de defeitos ósseos em calvária de coelhos tratados com diferentes materiais de enxerto / Microtomographic and histomorphometric evaluation of bone repair in rabbit cranial defects treated with different graft materials

Um dos grandes desafios para o tratamento de defeitos ósseos extensos na região bucomaxilofacial têm sido o desenvolvimento de um biomaterial substituto ósseo ao enxerto autógeno. No presente trabalho avaliou-se a formação óssea e a biodegrabilidade do osso desproteinizado bovino Bio-Oss® e do seu similar GenOx Inorg® e da cerâmica bifásica GenPhos® XP no processo de reparo de defeitos ósseos cranianos em coelhos, comparativamente ao osso autógeno (controle positivo) e coágulo sanguíneo (controle negativo). Foram realizados cirurgicamente defeitos bilaterais de 8-mm de diâmetro nos ossos parietais de 39 coelhos. A seguir os defeitos foram preenchidos aleatoriamente com 0,1cm3 de material ou coágulo conforme cada grupo de tratamento. Após os períodos de 4, 8 e 24 semanas os crânios foram coletados, analisados no microtomógrafo e processados histologicamente. O percentual de volume do defeito ocupado pelo material e osso neoformado foi avaliado pela microtomografia e histomorfometria, enquanto que, para a medula óssea, tegumento e tecido conjuntivo, apenas pela análise histomorfométrica. Os resultados quantitativos obtidos foram comparados estatisticamente pela ANOVA a dois critérios (período e tratamento) e teste de Tukey com p<0,05. A intensidade da associação linear dos dados microtomográficos e histomorfométricos avaliada pelo coeficiente de correlação de Pearson, mostraram correlação moderada a forte. Nos períodos iniciais de reparo (30 e 60 dias), os defeitos tratados com Bio-Oss®, GenOx® Inorg e GenPhos® XP apresentaram manutenção do volume do material enxertado (Vvi médio de 34% ) e formação óssea menor e mais imatura em relação grupo autógeno (Vvi = 22% vs. 32% no grupo autógeno). No período mais tardio (180 dias) a quantidade de formação óssea foi estatisticamente similar nos grupos Bio-Oss® (Vvi = 27%), GenOx® Inorg (Vvi = 26%) e GenPhos® XP (Vvi = 20%) porém, o GenOx® Inorg promoveu a formação de um tecido ósseo mais organizado e com maior acúmulo de biomaterial+osso+medula óssea (Vvi = 67,9%) comparado ao GenPhos® XP (Vvi =58,9%) e Bio Oss (Vvi = 55,6%) mas, inferior ao do enxerto autógeno (Vvi = 78%). Os resultados aqui obtidos permitem concluir que o osso autógeno promove rápida formação e maturação óssea, porém não consegue promover o reestabelecimento completo da díploe removida cirurgicamente. Os materiais BioOss, GenOx® Inorg e GenPhos® XP são excelentes materiais osteocondutores levando a formação óssea em toda extensão do defeito, sendo o GenOx® Inorg o que apresenta menor grau de reabsorção e maior e melhor preenchimento do defeito.(AU)

One major challenge for treatment of critical size defects in maxillofacial region has been the development of a substitute biomaterial to the autogenous bone grafts. In present study we evaluated the bone formation and biodegradability of deproteinized bovine bone Bio-Oss® and GenOx® Inorg, and biphasic calcium phosphate GenPhos XP® during bone repair process in rabbits cranial defects compared to autogenous bone (positive control) and blood clot (negative control). In parietal bone of 39 rabbits were made bilateral 8-mm diameter defects, which were filled randomly with 0,1cm3 material or clot as each treatment group. After periods of 4, 8 and 24 weeks skulls of animals were collected, analyzed the MicroCT scanner and histologically processed. The percentage of defect volume occupied by biomaterial and new-formed bone were assessed by histomorphometry and microtomography, while the bone marrow, connective tissue and tegument only by first analysis. The quantitative data were compared by two-way ANOVA analysis (time and treatment) and Tukey's test at p <0.05. The intensity of the linear association of MicroCT and morphometric data evaluated by the Pearson correlation coefficient, showed moderate to strong correlation. In the early repair periods (30 and 60 days), the defects treated with Bio- Oss, GenOx® Inorg and GenPhos® XP showed maintenance of the graft material volume (average Vvi of 34%) and lower and more immature bone compared autograft group (Vvi = 22% vs. 32% in the autograft group). In the later period (180 days) the amount of bone formation was statistically similar to the groups Bio-Oss® (Vvi = 27 %), GenOx® Inorg (Vvi = 26%) and GenPhos® XP (Vvi = 20%) however, the bone formation in GenOx® Inorg was more organized and with greater accumulation of particles + bone tissue + bone marrow (Vvi = 67.9%), when compared to GenPhos® XP (Vvi = 58.9%) and Bio-Oss® (Vvi = 55.6%) but lower than the autograft (Vvi = 78%). It was concluded that the autogenous bone promotes rapid bone formation and maturation, but cannot promote the complete reestablishment of diploe surgically removed. The Bio-Oss®, GenOx® Inorg and GenPhos® XP are excellent osteoconductive materials leading to bone formation in the full extent of the defects, and the GenOx® Inorg showing less absorption promotes more and better defect filling.(AU)

Orthodontic movement in deciduous teeth

Deciduous teeth exfoliate as a result of apoptosis induced by cementoblasts, a process that reveals the mineralized portion of the root while attracting clasts. Root resorption in deciduous teeth is slow due to lack of mediators necessary to speed it up; however, it accelerates and spreads in one single direction whenever a permanent tooth pericoronal follicle, rich in epithelial growth factor (EGF), or other bone resorption mediators come near. The latter are responsible for bone resorption during eruption, and deciduous teeth root resorption and exfoliation. Should deciduous teeth be subjected to orthodontic movement or anchorage, mediators local levels will increase. Thus, one should be fully aware that root resorption in deciduous teeth will speed up and exfoliation will early occur. Treatment planning involving deciduous teeth orthodontic movement and/or anchorage should consider: Are clinical benefits relevant enough as to be worth the risk of undergoing early inconvenient root resorption?.

O dente decíduo é esfoliado graças à apoptose em seus cementoblastos, que desnuda a parte mineralizada da raiz e atrai os clastos. A rizólise é lenta, pois faltam mediadores em quantidade para acelerar o processo, mas ela se acelera e unidireciona quando se aproxima um folículo pericoronário de dente permanente rico em EGF e outros mediadores da reabsorção óssea - os responsáveis pelas reabsorções óssea na erupção e dentária decídua na rizólise e esfoliação. Se houver movimentação ortodôntica ou ancoragem em dentes decíduos, aumenta-se, também, o nível local desses mesmos mediadores, devendo-se estar bem consciente de que haverá uma aceleração da rizólise e, em decorrência, uma antecipação de sua esfoliação. No planejamento de casos em que dentes decíduos estejam envolvidos na movimentação ortodôntica e/ou ancoragem, deve-se ponderar: o benefício clínico para o paciente será relevante, a ponto de valer o risco de uma rizólise abreviada e inconveniente?.

The effects of binge-pattern alcohol consumption on orthodontic tooth movement

OBJECTIVE: This study aimed to assess tissue changes during orthodontic movement after binge-pattern ethanol 20% exposure. METHODS: Male Wistar rats (n = 54) were divided into two groups. The control group (CG) received 0.9% saline solution, while the experimental group (EG) received 20% ethanol in 0.9% saline solution (3 g/kg/day). On the 30th day, a force of 25 cN was applied with a nickel-titanium closed coil spring to move the maxillary right first molar mesially. The groups were further divided into three subgroups (2, 14 and 28 days). Tartrate-resistant acid phosphatase and picrosirius were used to assess bone resorption and neoformation, respectively. Data were compared by two-way ANOVA, Tukey's HSD, Games-Howell and chi-square test. Significance level was set at 5%. RESULTS: There was a decrease in the number of osteoclasts in EG at day 28. The percentage of collagen showed no interaction between group and time. CONCLUSION: Binge-pattern 20% ethanol promoted less bone resorption at the end of tooth movement, thereby suggesting delay in tooth movement. .

OBJETIVO: objetivou-se avaliar as alterações teciduais decorrentes da administração de etanol a 20% no padrão binge, durante o movimento ortodôntico. MÉTODOS: foram utilizados ratos Wistar machos (n = 54), divididos em dois grupos, sendo Grupo Controle (GC), com administração de soro fisiológico a 0,9%; e Grupo e Experimental (GE), com administração de etanol a 20% em soro fisiológico a 0,9%, no volume de 3g/kg/dia. Após o 30º dia de administração, foi aplicada força de 25cN com mola fechada de níquel-titânio para mover o primeiro molar superior direito para mesial. Os grupos foram subdivididos nos subgrupos 2, 14 e 28 dias, correspondendo ao número de dias de movimentação dentária. Utilizou-se as colorações de fosfatase ácida-tartarato resistente e picrosírius para avaliar reabsorção óssea e neoformação óssea, respectivamente. Os dados foram comparados por ANOVA a dois critérios, Tukey HSD e Games-Howell, ao nível de significância de 5%. RESULTADOS: verificou-se diminuição no número de osteoclastos no GE II no 28º dia. A percentagem de colágeno não demonstrou alteração na interação grupo x tempo. CONCLUSÕES: o etanol no padrão binge a 20% promoveu menor reabsorção óssea no final da movimentação dentária, sugerindo atraso na movimentação dentária. .

Mini-implants and miniplates generate sub-absolute and absolute anchorage

The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces.Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage.

Uma demanda funcional sobre o osso promove alterações na forma espacial da rede de osteócitos e seus prolongamentos, distribuídos uniformemente na estrutura mineralizada. A partir da deformação espacial captada, os osteócitos comandam a necessidade de adaptações estruturais, formando osso em novas áreas e reabsorvendo em outras, para que sejam atendidas as demandas funcionais. O endósteo e o periósteo são os verdadeiros efetores desses estímulos osteocíticos adaptativos, nas superfícies internas e externas. As alterações de forma, volume e posição dos ossos maxilares, nas correções esqueléticas da maxila e mandíbula, requerem uma ancoragem para que a remodelação óssea redefina a morfologia, a estética e as funções, a partir de deformações espaciais dirigidas por aparelhos. Verificar o grau de alterações na forma, volume e relações estruturais das áreas onde se fixaram os mini-implantes e as miniplacas poderá levar à classificação dos mini-implantes como dispositivos de ancoragem subabsoluta e as miniplacas, como de ancoragem absoluta.

Expressão imuno-histoquímica de proteínas relacionadas com a absorção óssea em carcinoma epidermoide de palato duro e língua / Immunohistochemical expression of proteins related to bone resorption in squamous cell carcinoma of the hard palate and tongue

O carcinoma epidermóide oral (CEO) apresenta uma tendência marcante de invadir o osso quando localizado em palato duro e rebordo. O mecanismo preciso desta invasão permanece incompletamente descrito, apesar de sugerirem na literatura que a destruição óssea, invasão e metástase seja mediada por osteoclastos e não diretamente por células do carcinoma. As moléculas RANK/RANKL /OPG são fundamentais na oesteoclastogênese, assim como a IL-6 que regula suas expressões. O objetivo desta pesquisa foi avaliar a expressão imuno-histoquímica de fatores de reabsorção óssea (RANKL e OPG) e da citocina (IL-6) no carcinoma epidermóide de palato duro (com invasão óssea) e língua (sem invasão óssea), correlacionandoas com os parâmetros clinicopatológicos e prognósticos. A amostra foi constituída por 30 carcinomas epidermóides com invasão óssea (localizados no palato) e 31 sem invasão óssea (localizados na língua). Foram avaliados a intensidade e a média das células tumorais, estromais e inflamatórias imunomarcadas para os anticorpos anti-RANKL, anti-OPG e anti-IL-6, no front de invasão e no centro tumoral. O escore (s) da imunorreatividade das células foi estabelecido através da multiplicação do percentual de células positivas (P) pelo valor da intensidade da marcação (I) (S = P x I), em cinco campos (400×). A análise da expressão da proteína RANKL foi significativamente mais expressa (p=0,002) nas células inflamatórias, com tendência há uma maior expressão nas células dos carcinomas epidermóides do palato duro. Entre os parâmetros clinicopatológicos foi observado associação do RANKL com o pior prognóstico, com significância estatística apenas para o estágio avançado do tumor (p= 0,033). A OPG demonstrou fraca expressão tanto nos casos de língua (0,77 ±1,85) quanto de palato duro (1,32 ± 2,48), com ausência de significância estatística (p>0,05). Em relação aos parâmetros clinicopatológicos a OPG apresentou tendência de associação com o pior prognóstico, com associação estatística significante para o óbito (p=0,048) e invasão perivascular (p=0,047). A IL-6 foi significantemente mais expressa (p<0,001) em células tumorais e inflamatórias nos carcinomas epidermóides de palato duro. E dentre os parâmetros clinicopatológicos, a IL-6 apresentou tendência de associação com o bom prognóstico, com diferença estatística para a ausência de metástase e as células tumorais (p = 0,020), estromais (p = 0,027) e inflamatórias (p = 0,017). Com base nos resultados pode-se concluir que a IL-6 pode ser utilizada como um marcador do carcinoma epidermóide oral com invasão óssea, e que a relação RANKL/OPG está alterada no carcinoma epidermóide oral. (AU)

Oral squamous cell carcinoma (CEO ) has a marked tendency to invade the bone when located in the palate and lip . The precise mechanism of this invasion is still not completely described , although the literature suggests that the bone destruction ABSTRAT , invasion and metastasis is mediated by osteoclasts and not directly by carcinoma cells . The molecules RANK / RANKL / OPG are fundamental in oesteoclastogênese, and IL-6 that regulates its expression. The objective of this research was to evaluate the immunohistochemical expression of factors of bone resorption ( RANKL and OPG ) and cytokine ( IL - 6 ) in squamous cell carcinoma of the hard palate (with bone invasion ) and tongue (without bone invasion ) , correlating with the clinicopathological parameters and prognosis. The sample consisted of 30 squamous cell carcinoma with bone invasion (located on the palate) and 31 without bone invasion (located on the tongue). Were evaluated and the average intensity of the tumor cells , stromal and inflammatory immunostained for anti-RANKL antibodies , anti- OPG and anti -IL- 6 at the invasive front and center of the tumor. The score (s) of the immunoreactivity of cells was established by multiplying the percentage of positive cells (P) for marking intensity value (I) (S = P x I) in five fields (× 400). The analysis of the expression of RANKL protein was expressed significantly higher (p = 0.002) in inflammatory cells, there is a trend to higher expression in squamous cell carcinomas of the hard palate. Among the clinicopathologic parameters was observed association of RANKL with the worst prognosis, with statistical significance only for the advanced stage of the tumor (p = 0.033). The OPG showed weak expression both in cases of tongue (0.77 ± 1.85) and hard palate (1.32 ± 2.48), with no statistical significance (p > .05). In relation to clinicopathological parameters OPG tended association with worse prognosis, with a statistically significant association for death (p = 0.048) and perivascular invasion (p = 0.047). IL- 6 was expressed significantly more (p < 0.001) in tumor and inflammatory cells in squamous cell carcinoma of the hard palate. In addition, among the clinicopathologic parameters, IL- 6 showed a tendency of association with good prognosis, with a statistical difference for the absence of metastasis and tumor cells (p = 0.020), stromal (p = 0.027) and inflammatory (p = 0.017). Based on the results it can be concluded that IL -6 may be used as a marker of oral squamous cell carcinoma with bone invasion, and the ratio RANKL / OPG is changed in oral squamous cell carcinoma. (AU)

Reabsorción ósea del reborde residual mandibular en desdentados totales / Bone resorption of the residual ridge in edentulous patients

Al perder los elementos dentarios, la remodelación ósea y mucosa produce una nueva estructura anatómica, el reborde residual. La reducción del reborde residual (RRR) es considerada como una enfermedad crónica, progresiva, irreversible, acumulativa en el tiempo, de etiología multifactorial. Objetivo: evaluar la pérdida del hueso alveolar en pacientes edéntulos usuarios y no de prótesis. Métodos: estudio en 115 pacientes, de 41 a 88 años, ambos sexos, edéntulos. Se realizó radiografía panorámica junto a historia clínica. Se cuantificó la altura ósea vertical, lado izquierdo y derecho, desde el borde inferior de la mandíbula al foramen mentoniano y desde el borde inferior mandibular al superior de la cresta. Se recabaron datos sobre edad, sexo, uso de prótesis dental y enfermedades sistémicas. Resultados: edad promedio 64,5 años; 71 por ciento usaba prótesis (71,91 por ciento mujeres y 28,09 por ciento varones). Hubo diferencias significativas en ambos sexos entre uso y no uso de prótesis y RRR en cada sector, derecho p=0,0173 e izquierdo p=0,0153. Los valores de RRR fueron 14,24 mm en varones y 18,03 mm en mujeres. La pérdida ósea fue mayor en mujeres posmenopáusicas y en hombres de más de 70 años. No se observaron asociaciones significativas con edad y con enfermedades sistémicas. Conclusión: la pérdida ósea aumenta en desdentados con la edad, por un factor fisiológico y pérdida de la función, el hueso no recibe fuerzas estimulantes. Las mujeres pierden más hueso que los hombres por factores hormonales propios u otros.

Atrofia paraprotética de los maxilares I / Paraprosthetic atrophy of the jaws I

El objetivo de esta presentación es ampliar los contenidos de "Atrofia paraprotética de los maxilares", publicado en el número anterior de la RAAO. Acotamos el estudio, presentación y resolución de casos aaquellos que presentan una brecha desdentada con soporte dento mucoso, donde las prótesis ejercen presión sobre el terreno mucoso que finalmente essoportado por el hueso remanente. Como consecuencia de esta presión obtenemos reabsorciones que, según extensión y localización, tendrán diferentes niveles de complejidad.Aquí también haremos la evaluación de los efectos no deseados de las prótesis parciales removibles dentomuco-soportadas. Incluiremos también su biomecánica, su diseño más aconsejado y resoluciones implantoasistidasde mínima, mediana y óptima prevención.

Osteoporosis following spinal cord injury

To assess the extent of bone loss among 30 patients with Spinal Cord Injury at the Spinal Unit, King Hussein Medical Center. A total of 30 patients with Spinal Cord Injury before one to 15 years and who completed their medical and rehabilitation program were included in this descriptive study during the period July 2003 to April 2010 at The Royal Jordanian Rehabilitation Center, King Hussein Medical Center. There were 25 males and 5 females. Bone Mineral Density was measured by Dual Energy X-ray Absorptiometry in the lumbar spine and femoral neck, patients were diagnosed to have osteoporosis according to World Health Organization criteria and their fracture's risk was described from this score using published data. Their spinal injuries were classified according to American Spinal Injury Association Criteria, ranging from A-D. Simple descriptive statistics [frequency, mean, percentage] were used to describe the study variables. Bone loss indicated by low bone mineral density revealed that femoral region is predominantly affected with relative preservation of the lumbar spine. Abnormal bone mineral density values were detected in 80% of patients. A relation was noticed between the time following the injury and the degree of osteoporosis. Individuals with complete injuries showed lower bone mineral density values than those with incomplete lesions. Relation was found regarding their age and gender. Spinal Cord Injury patients are at high risk of developing osteoporosis which can lead to significant morbidity, particularly lower extremity fractures without significant trauma

Atrofia paraprotética de los maxilares / Paraprosthetic atrophy of the jaws

El objetivo de esta presentación es describir las alteraciones provocadas por la desadaptación o sobrecarga sectorizada de las prótesis mucosoportadas sobre el terreno de soporte óseo. Luego, relacionarlas con las alteraciones periprotéticas asociadas más comunes, y realizar la descripción de una de las alteraciones atróficas paraprotéticas de mayor casuística, con sus consecuencias en el sistema estomatognático. Finalmente, describir los tratamientos protéticos no implantológicos y la prevención de estas alteraciones con prótesis convencionales e implanto-asistidas

Ischemic Stroke in Rats Enhances Bone Resorption in Vitro

We hypothesized that the formation and differentialtion of osteoclasts are accelerated and the potential of bone resorption is increased in the hemiplegic bone marrow in the early stage of stroke. We randomly divided white female Sprague-Dawley (SD) rats (n = 30) into two groups, stroke (n = 15) and sham group (n = 15). On the 7th day after stroke, after cutting away the epiphyses of the femurs and tibias, diaphyseal channels were flushed using alpha-minimum essential medium (alpha-MEM) and bone marrow cells were collected. Bone marrow stem cells, which were extracted from the femur and tibia, were cultured on the 7th day after middle cerebral artery occlusion. We then estimated the ratio of non-adherent cells to total bone marrow cells that included osteoclast precursor cells. After culturing these cells separately, cells that tested positive on the tartrate resistant acid phosphatase (TRAP) were counted and bone resorption was evaluated by using the OAAS(TM) plate. In comparison to the control group, the stroke group showed a higher increase of non-adherent cells in the hemiplegic side bone marrow. In addition, after the primary culture, the stroke group showed an increased number of TRAP positive cells and a higher degree of bone resorption estimated by OAAS(TM) plate. As a result, osteoclastogenesis and osteoclast differentiation are accelerated and the potential of bone resorption is increased in the hemiplegic bone marrow and these changes are detected as early as within the first week after middle cerebral artery occlusion in SD rats.