Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis

Abstract Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. Objectives The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. Material and Methods Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. Results Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. Conclusion Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Abstract Objective: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. Material and Methods: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD). Results: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). Conclusion: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Análise histológica, imunoistoquímica e morfométrica de biópsias de tecidos ósseo de pacientes hipertensos compensados / Histological, molecular and morphometric analysis of bone tissue biopsies in compensated hypertensive patients

Objetivo: O presente estudo objetivou avaliar as características morfométicas, histológicas e imunoistoquímicas do tecido ósseo coletado de pacientes portadores de hipertensão arterial sistêmica compensada pelo uso de medicamentos antagonistas do sistema renina-angiotensina-aldoesterona (SRAA). Materiais e Métodos: Trinta pacientes com indicação para reabilitação por meio de implantes instalados na região posterior de mandíbula foram divididos em dois grupos, seguindo os critérios de inclusão e exclusão previamente estabelecidos. O primeiro grupo não apresentava alterações sistêmicas (GSA) e não fazia uso de qualquer medicação e, o segundo grupo foi composto por pacientes hipertensos diagnosticados e medicados por antagonistas do SRAA (GAS). Durante o procedimento cirúrgico para instalação dos implantes osseointegráveis com superfície texturizada, foram coletados blocos ósseos por meio de biópsia com broca trefina de 3,0mm de diâmetro nos locais de instalação dos implantes. As biópsias coletadas foram separadas para avaliação por microtomografia computadorizada, sendo avaliados os seguintes parâmetros: volume ósseo (BV/TV), percentual de volume ósseo (BV/TV), espessura de trabéculas (Tb.Th), número de trabéculas (Tb.N), separação entre as trabéculas (Tb.S) e porosidade total (Po-tot). Também foi realizada a análise dos cortes histológicos corados por hematoxilina e eosina, bem como a avaliação imunoistoquímica de proteínas que caracterizam as células da linhagem osteoblástica: Runx2, Osteopontina e Osteocalcina Resultados: Para todos os parâmetros analisados (BV, BV/TV, Tb.Th, Tb.N, Tb.S e Po-tot), houve similaridade na comparação entre os grupos GAS e GSA (p<0,05, teste t). As imunomarcações para osteopontina e osteocalcina mostraram-se semelhantes nos dois grupos. Vale destacar importante marcação observada no grupo GAS para o fator de transcrição Runt 2 (Runx2), em comparação a marcação da mesma proteína no grupo GSA. Além disso, a biologia do tecido ósseo do ponto de vista histológico foi semelhante nos dois grupos. Conclusões: Foi possível concluir que indivíduos hipertensos tratados com antagonistas do SRAA apresentam grande similaridade óssea microestrutural e também celular/protéica aos indivíduos normotensos(AU)

Objectives: This study aimed to evaluate the morphometric characteristics, histological and immunohistochemical bone tissue collected from patients with hypertension offset by the use of drugs antagonists of the renin angiotensin system. Material and Methods: 30 patients referred for rehabilitation with implants placed in the posterior mandible were divided into two groups, following the criteria of inclusion and exclusion previously established. The first group showed no systemic changes (GSA) and did not use any medication and the second group was composed of diagnosed hypertensive patients treated by RAAS (GAS) antagonists. During the procedure for installation of dental implants with textured surface, they were collected bone blocks through biopsy trephine drill 3.0mm diameter implants in the installation sites. The collected biopsies were separated for evaluation by microtomography, being evaluated the following parameters: bone volume (BV / TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), separation of the trabecular (Tb.S) and total porosity (Po-tot). Also the analysis of histological sections stained with hematoxylin and eosin staining was performed as well as the immunohistochemical evaluation of proteins that characterize the cells of osteoblast lineage: Runx2, osteopontin and osteocalcin. Results: For all parameters (BV, BV / TV, Tb.Th, Tb.N, Tb.S and E-tot) were similar in the comparison between GAS and GSA (p> 0.05, t test). The biology of bone tissue to analyze by immunohistochemistry presented similar results in both groups, with markings scores in ordinal qualitative analysis for transcription factor related to Runt 2 (Runx2) - GSA (light) and GAS (moderate), osteopontin (OP) - GSA (mild to moderate) and GAS (moderate to intense), osteocalcin (OC) - GSA (intense) and GAS (moderate). Furthermore, the biology of bone tissue was histologically similar in both groups. Conclusions: Therefore, it was concluded that hypertensive subjects treated with renin-angiotensin system antagonists have great bone microstructural similarity and also cell / protein to normotensive individuals(AU)

Análise do processo de reparo de defeitos ósseos críticos em calvária de ratos preenchidos com osso autógeno ou Bone Ceramic®: um estudo histométrico e imunoistoquímico / Analysis of repair of critical rats calvarial deffects after reconstruction with autogenous bone or Bone Ceramic®: a histometric and immunohistochemical study

Avaliar por meio da análise histométrica e imunoistoquímica, o potencial osteocondutor de grânulos de hidroxiapatita e beta- tricálcio fosfato (Bone Ceramic - Straumann®) no processo de reparo de defeitos ósseos críticos em calvária de ratos. (2) Métodos: Foram utilizados ratos divididos em três grupos (n=8), submetidos à eutanásia aos 14 dias e 28 dias pós-cirúrgicos. Em cada animal foi realizado um defeito ósseo de 5mm na calvária, sendo o Grupo Coágulo (GC) com o defeito preenchido somente com coágulo; Grupo Osso Autógeno (GA), preenchido com osso autógeno e Grupo Bone Ceramic (GBC), com osso aloplástico (Straumann®). Foi avaliada a área de tecido ósseo presente na região central dos defeitos ósseos. Para a comparação entre os valores obtidos, foi realizado o teste ANOVA e como pós-teste, Tukey. Foi adotado como nível de significância p<0,05. Foi realizada análise imunoistoquímica, com os anticorpos primários contra OC, RUNX 2, TRAP e VEGF, para a avaliação dos diferentes estágios do processo de reparo ósseo. Como análise adicional, foram obtidas imagens 3D das cálvarias em microtomografia. (3) Resultados: O local do defeito ósseo originalmente tratado com BC foi totalmente preenchido por um conglomerado de biomateriais e osso neoformado, o qual foi estatisticamente superior ao GC, em ambos os períodos analisados (p<0,05). Remanescentes de BC eram visíveis e estavam em íntimo contato com o tecido ósseo. Além disso, no grupo GA as observações foram semelhantes, porém foi notado fechamento total do defeito aos 28 dias e houve maior área de neoformação óssea em todos os períodos analisados, comparando-se aos demais biomateriais (p<0,05). Defeitos que foram preenchidos com CO apresentaram apenas um tecido conjuntivo delgado fechando o defeito ósseo. A proteína TRAP foi imunomarcada de forma leve. Já a imunomarcação da VEGF foi moderada. A imunomarcação da osteocalcina se mostrou presente em todos os períodos analisados (14 e 28 dias). As imagens...

To evaluate by histometric and immunohistochemical analysis, the osteoconductive potential of hydroxyapatite granules and beta-tricalcium phosphate (Bone Ceramic - Straumann®) in the repair of critical bone defects in rat calvaria process. (2)Methods: The rats were divided into three groups (n = 8) and submitted to euthanasia at 14 days and 28 days post-surgery. In each animal a 5 mm calvaria bone defect was performed. In Blood Clot Group (CG) the defect was filled only with clot; in the Autogenous Bone Group (AG) the defect was filled with autogenous bone and in Bone Ceramic Group (BC), with alloplastic bone (Straumann®).The bone tissue area was evaluated in the central region of bone defects. The results were submitted to ANOVA and Tukey’s test at 5% level of significance. For the evaluation of the different stages of the bone healing process, immunohistochemical analysis was performed with primary antibodies against OC, RUNX 2, TRAP and VEGF. As an additional analysis, calvaria’s 3D images were obtained in microtomography. (3)Results: The bone defect treated with BC was filled with a conglomerate of biomaterials and bone formation, which was statistically higher than CG in both periods analyzed. Remnants of BC were visible and were in intimate contact with bone tissue. Furthermore, the AG group observations were similar, but it was observed a complete defect closure after 28 days and there was a greater area of bone formation in all periods analyzed, comparing to other biomaterials (p <0.05). The defects filled with CO showed only a slender conjunctive tissue closing the bone defect. The TRAP protein was lightly immunomarked, while immunostaining of VEGF was moderate. The osteocalcin immunostaining was present in all analyzed periods (14 and 28 days). The AG group´s 3D image showed full compatibility bone formation at 28 days. (4)Conclusions: The supplementation of tested biomaterial (BC) was favorable to the bone defect filling until...

Tumor odontogênico queratocístico - relato de caso / Odontogenic keratocyst tumor - a case report

Introdução: O Tumor Odontogênico Queratocístico (TOQ)deriva dos restos lâmina dentária com particularidades easpectos histológicos específicos, com alto índice de recidiva ecomportamento clínico agressivo. Apresenta certa predileçãopara o sexo masculino, acometendo a mandíbula de 60% a 80%dos casos, podendo estar relacionado a dente incluso de 25 a45% dos casos. Objetivo: evidenciar as características clínicas,imaginológicas e histopatológicas do TOQ, bem como discutirsobre o tratamento desta lesão. Relato de Caso: Paciente de 10anos de idade que ao procurar o ortodontista para correção demordida aberta anterior, observou-se na ortopantomografia árearadiolúcida, na região do corpo de mandíbula, associada à inclusãopatológica do pré-molar inferior. Foi realizada biópsia incisionalda lesão e o laudo histopatológico foi de tumor odontogênicoqueratocístico. Realizou-se uma tomografia computadorizadapara avaliar a extensão da lesão e sua relação com as estruturasanatômicas. Como conduta, optou-se pela extração do molarinferior decíduo e enucleação da lesão, preservando o pré-molarincluso. O mesmo segue em controle clínico-radiográfico de 18meses, após a remoção do TOQ obtendo-se a erupção do prémolarque estava envolvido na lesão. Comentários Finais: Épreciso adotar protocolos de atenção odontológica que incluemo conhecimento de diagnóstico bucal, anamnese e avaliaçãoclínica criteriosa sem esquecer a necessidade de confirmaçãohistopatológica.

Smile analysis following orthognathic surgery

Aim: This study compared the different views between orthodontists and oral maxillo facial surgeons,as for smile analysis in patients subjected to orthognathic surgery. Methods: Thirty individuals who had undergone orthognathic surgery and had a minimum postoperative period of 6 months were selected. Post treatment frontal smile photographs were obtained and examined. Smile features were recorded by 4 professionals (2 orthodontists and 2 surgeons) and the agreement between them was assessed. Results: The subjective analysis of smile as well as the observation of incisal and gingival exposure showed a statistically significant agreement percentage between the two groups. Nevertheless, no agreement was seen between the surgeons, while evaluating the buccal corridor and the parallelism between the incisal edge of antero-superior teeth and the lower lip. Significant agreement percentage (60%) was seen only between the orthodontists regarding the smile arch parallelism. Conclusions: Professionals must be alert as for facial analysis, mainly in terms of smile harmony, so that the orthognathic surgery will satisfactorily reestablish the facial esthetics in all the parameters outlined.