Reconstruction of parietal bone defects with adiposederived mesenchymal stem cells. Experimental study

Abstract Purpose: This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration. Methods: Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter. Results: There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05. Conclusions: Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.

Reconstrução de calota craniana com prótese customizada de PMMA após craniectomias descompressivas / Skull reconstruction with PMMA customized prostheses after decompressive craniectomies

Introdução: A craniectomia descompressiva é uma cirurgia indicada no tratamento da hipertensão intracraniana em situações graves de traumas cranioencefálicos. Esta cirurgia confere uma aparência bizarra ao paciente, como se "parte da cabeça" houvesse sido retirada. Após a regressão do edema cerebral e quando o paciente reunir boas condições clínicas, a reconstrução craniana está indicada. A reconstrução da calota craniana poderá ser realizada com osso autólogo ou com materiais aloplásticos. Este estudo objetiva apresentar a experiência do autor com reconstruções de calota craniana utilizando próteses customizadas de PMMA. Métodos: Foram selecionados 14 pacientes submetidos à craniectomia descompressiva que, após serem liberados clinicamente pela Neurocirurgia, realizaram a reconstrução da calota craniana com próteses de PMMA customizadas por prototipagem entre os anos de 2014 e 2015 e com, no mínimo, 6 meses de pós-operatório. Sinais e sintomas de síndrome do Trefinado, tomografia computadorizada e aparência estética dos pacientes foram analisadas no pré e no 6º mês pós-operatório. Resultados: Todos os pacientes apresentaram melhora sintomatológica, melhora estética e expansão cerebral após a cirurgia. Conclusão: A reconstrução da calota craniana com prótese customizada de PMMA promoveu a melhora dos sinais e sintomas e da aparência estética de todos os 14 pacientes operados. A utilização de protótipos para customizar próteses cranianas facilitou a técnica operatória e possibilitou a recuperação de um contorno craniano muito próximo da normalidade.

Introduction: Decompressive craniectomy is indicated for the treatment of intracranial hypertension in cases of serious traumatic brain injury. This surgery results in a bizarre appearance, as if "part of the head" had been. After regression of cerebral edema and when the patient is in good clinical condition, the reconstruction of the skull is indicated. Reconstruction of the skull can be performed with autologous bone or with alloplastic materials. This study sought to present the experience of the author with skull reconstructions using custom PMMA prostheses. Methods: In between 2014 and 2015, fourteen patients with previous (longer than 6 months) decompressive craniectomies were selected after Neurosurgery medical clearance and underwent skull reconstruction with customized PMMA prototyped prostheses. Signs and symptoms of syndrome of the trephined, computed tomography, and aesthetic appearance of the patients were analyzed preoperatively and at 6 months after reconstruction. Results: All patients presented with improved symptomatology, aesthetic improvement and expansion of the brain after surgery. Conclusion: Reconstruction of the skull with customized prototyped PMMA prostheses improved the signs and symptoms and the aesthetic appearance in all 14 patients of this series. The use of prototypes to customize cranial prostheses facilitates the operative technique and enables patients to develop a nearly normal cranial contour.

Effects of cigarette smoke inhalation and coffee consumption on bone formation and osseous integration of hydroxyapatite implant / Os efeitos do cigarro e do consumo de café sobre a formação óssea e a integração óssea de implantes de hidroxiapatita

The present study aims to assess the effects of cigarette smoke inhalation and/or coffee consumption on bone formation and osseous integration of a dense hydroxyapatite (DHA) implant in rats. For this study, 20 male rats were divided into four groups (n = 5): CT (control) group, CE (coffee) group, CI (cigarette) group and CC (coffee + cigarette) group. During 16 weeks, animals in the CI group were exposed to cigarette smoke inhalation equivalent to 6 cigarettes per day; specimens in the CE group drank coffee as liquid diet; and rats in the CC group were submitted to both substances. In the 6th week a 5 mm slit in the parietal bone and a 4 mm slit in the tibia were performed on the left side: the former was left open while the latter received a DHA implant. As soon as surgeries were finished, the animals returned to their original protocols and after 10 weeks of exposure they were euthanised (ethically sacrificed) and the mentioned bones collected for histological processing. Data showed that exposure to cigarette smoke inhalation and coffee consumption did not interfere in weight gain and that solid and liquid diet consumption was satisfactory. Rats in the CC group showed a decrease in bone neoformation around the tibial DHA implant (31.8 ± 2.8) as well as in bone formation in the parietal slit (28.6 ± 2.2). On their own, cigarette smoke inhalation or coffee consumption also led to diminished bone neoformation around the implant and delayed the bone repair process in relation to the CT group. However, reduction in the bone repair process was accentuated with exposure to both cigarette smoke inhalation and coffee consumption in this study.

O presente estudo teve como objetivo avaliar os efeitos do tabagismo e do consumo de café, isolada ou concomitantemente, sobre a formação óssea e a osseointegração de implantes hidroxiapatita densa. Foram utilizados 20 ratos machos, divididos em quatro grupos (n = 5): grupo CT (controle); grupo CA (café); grupo CI (cigarro), e grupo CC (cigarro + café). Durante 16 semanas, os animais do grupo CI foram expostos à fumaça de seis cigarros/dia; os animais do grupo CA consumiram café como dieta líquida, e os animais do grupo CC, ambas as substâncias. Após seis semanas de exposição, uma falha óssea de 5 mm foi produzida no osso parietal esquerdo e de 4 mm, na tíbia esquerda dos animais. A falha do parietal foi mantida aberta, enquanto na tíbia corpos cerâmicos de hidroxiapatita densa (HAD) foram implantados em cavidade produzida cirurgicamente. Após as cirurgias, os animais retornaram aos protocolos experimentais e, ao término de dez semanas, foram eutanasiados, sendo as tíbias e os parietais coletados para processamento histológico. A exposição à fumaça do cigarro e o consumo de café não interferiram no ganho de peso dos animais, e os consumos de dieta líquida e sólida foram satisfatórios entre os grupos. Os animais do grupo CC apresentaram menor volume de osso neoformado ao redor do implante de HAD na tíbia (31,8 ± 2,8) e menor osteogênese na falha produzida no osso parietal (28,6 ± 2,2). O café e o cigarro consumidos isoladamente provocam a diminuição do volume de osso ao redor do implante e o atraso no processo de reparação óssea. Observou-se que o consumo de café associado à exposição à fumaça do cigarro reduziu de forma acentuada o processo de reparação óssea, no presente estudo.

Exploring anorganic bovine bone granules as osteoblast carriers for bone bioengineering: a study in rat critical-size calvarial defects

It is known that current trends on bone bioengineering seek ideal scaffolds and explore innovative methods to restore tissue function. In this way, the objective of this study was to evaluate the behavior of anorganic bovine bone as osteoblast carrier in critical-size calvarial defects. MC3T3-E1 osteoblast cells (1x10(5) cells/well) were cultured on granules of anorganic bovine bone in 24-well plates and after 24 h these granules were implanted into rat critical-size calvarial defects (group Biomaterial + Cells). In addition, other groups were established with different fillings of the defect: Blood Clot (negative control); Autogenous Bone (positive control); Biomaterial (only granules) and Cells (only MC3T3-E1 cells). After 30 days, the animals were euthanized and the calvaria were technically processed in order to allow histological and morphometric analysis. It was possible to detect blood vessels, connective tissue and newly formed bone in all groups. Particularly in the Biomaterial + Cells group, it was possible to observe a profile of biological events between the positive control group (autogenous bone) and the group in which only anorganic bovine granules were implanted. Altogether, the results of the present study showed that granules of anorganic bovine bone can be used as carrier to osteoblasts and that adding growth factors at the moment of implantation should maximize these results.

Sabe-se que uma das atuais tendências na bioengenharia óssea é procurar um carreador ideal e explorar métodos inovadores para restaurar a função do tecido. Desta forma, nosso objetivo foi avaliar o comportamento do osso bovino inorgânico como carreador de osteoblastos em defeitos ósseos de tamanho crítico em calvária de ratos. Osteoblastos da linhagem MC3T3-E1 (1x10(5) células/poço) foram cultivadas em grânulos de osso bovino inorgânico sob placas de 24 poços e após 24 h esses grânulos foram implantados em defeitos ósseos de tamanho crítico em calvária de ratos. Além deste grupo experimental (Biomaterial + Células), foram estabelecidos outros grupos com diferentes preenchimentos do defeito crítico: coágulo sanguíneo (controle negativo); osso autógeno (controle positivo); Biomaterial (apenas grânulos) e Células (apenas células MC3T3-E1). Após 30 dias, os animais foram eutanasiados e as calvárias foram processadas histotecnicamente, a fim de permitir a análise histológica e morfometria. Nossos resultados mostraram que em todos os grupos avaliados foi possível detectar vasos sanguíneos, tecido conjuntivo e osso neoformado. Em especial para o grupo tratado com Biomaterial + Células, foi possível observar um perfil de eventos biológicos intermediário ao grupo controle positivo (osso autógeno) e o grupo de biomaterial (apenas grânulos inorgânico bovino). Ao todo, nossos resultados mostraram que os grânulos de osso bovino inorgânico podem ser usados como carreador de osteoblastos e que a adição de fatores de crescimento no momento em que ocorre o implante deve maximizar os resultados.

Histomorphometric evaluation of calcium phosphate bone grafts on bone repair / Avaliação histomorfométrica de enxertos ósseos de cimento fosfato de cálcio no processo de reparo ósseo

Because of its biocompatibility and osteoconductive properties, calcium-phosphate cement has been used as bone surrogate. OBJECTIVE: The purpose of this study was to do a histomorphometric comparison of bone regeneration using hydroxyapatite biphasic ceramic, calcium-phosphate cement and autogenous bone graft. STUDY DESIGN: Prospective and laboratorial experiment. MATERIALS AND METHODS: Two 5mm in diameter cavities (left and right - test and control) were made in the parietal bone of 72 rats. The GI, GII, GIII and GIV test cavities were filled with calcium-phosphate cement, biphasic ceramic hydroxyapatite, autogenous bone graft and blood. The animals were killed at 30, 60 and 90 days and the specimens underwent histomorphometric analysis. RESULTS: The results showed that autogenous bone graft treated defects had significantly more new bone at 30 days compared to other test groups. Within 60 and 90 days, bone formation was more significant in the test groups GI, GII and GIII; GI and GII encompassed larger areas. Throughout the evaluation periods, GII tests showed more bone formation when compared to GI. CONCLUSIONS: Biomaterials depicted a significantly increase in bone content, when compared to autogenous bone graft, concerning bone regeneration.

Os materiais de fosfato de cálcio, pelas características de biocompatibilidade e osteocondução, estão sendo estudados como substitutos ósseos. OBJETIVO: Comparar histomorfometricamente o reparo ósseo promovido pela cerâmica bifásica de hidroxiapatita, cimento fosfato de cálcio e enxerto ósseo autógeno. FORMA DE ESTUDO: Prospectivo e experimental em laboratório. MATERIAL E MÉTODO: Foram criadas duas cavidades (esquerda e direita - teste e controle) de 5mm de diâmetro nos ossos parietais de 72 ratos Wistar. As cavidades testes GI, GII, GIII e GIV foram preenchidas com cimento fosfato de cálcio, cerâmica bifásica de hidroxiapatita, enxerto ósseo autógeno e coágulo sanguíneo. Os animais foram sacrificados aos 30, 60 e 90 dias e os espécimes avaliados histomorfometricamente. RESULTADOS: Os resultados mostraram maior formação óssea no período de 30 dias para o GIII quando comparado aos outros grupos testes. Nos períodos de 60 e 90 dias, a neoformação óssea foi mais acentuada nos grupos testes GI, GII e GIII, alcançando maiores áreas em GI e GII. Em todos os períodos de avaliação, as cavidades testes GII apresentaram maiores áreas frente às GI. CONCLUSÃO: Os biomateriais foram superiores ao enxerto autógeno no reparo ósseo.

Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats

Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. OBJECTIVES: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. MATERIAL AND METHODS: Five adult male rats weighing 200-300 g were used. The animals received two 5-mm-diameter bone defects bilaterally in each parietal bone with a trephine bur under general anesthesia. Two groups of defects were formed: a control group (n=5), in which the defects were filled with blood clot, and a graft group (n=5), in which the defects were filled with autogenous bone block, removed from the contralateral defect. The fluorochromes calcein and alizarin were applied at the 7th and 30th postoperative days, respectively. The animals were killed at 35 days. RESULTS: The mineralization process was more intense in the graft group (32.09 percent) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66 percent). CONCLUSIONS: The fluorochromes showed to be appropriate to label mineralization areas. The interfacial areas between fluorochrome labels are important sources of information about the bone regeneration dynamics.

An experimental model for the study of craniofacial deformities / Modelo experimental para o estudo de deformidades craniofaciais

PURPOSE: To develop an experimental surgical model in rats for the study of craniofacial abnormalities. METHODS: Full thickness calvarial defects with 10x10-mm and 5x8-mm dimensions were created in 40 male NIS Wistar rats, body weight ranging from 320 to 420 g. The animals were equally divided into two groups. The periosteum was removed and dura mater was left intact. Animals were killed at 8 and 16 weeks postoperatively and cranial tissue samples were taken from the defects for histological analysis. RESULTS: Cranial defects remained open even after 16 weeks postoperatively. CONCLUSION: The experimental model with 5x8-mm defects in the parietal region with the removal of the periosteum and maintenance of the integrity of the dura mater are critical and might be used for the study of cranial bone defects in craniofacial abnormalities.

OBJETIVO: Desenvolver um modelo experimental em ratos para o estudo de deformidades craniofaciais. MÉTODOS: Foram realizados defeitos ósseos de espessura total com diâmetro de 5 x 8 mm e 10 x 10mm na calota craniana em 40 ratos, machos, NIS Wistar, com peso de 320 a 420 g divididos igualmente em dois grupos. O periósteo foi retirado e a dura-máter mantida intacta. Os animais foram sacrificados na 8ª e 16ª semana de pós-operatório e amostras de tecido ósseo foram extraídas para realização da análise histológica. RESULTADOS: Os defeitos cranianos permaneceram abertos mesmo após 16 semanas após a cirurgia. CONCLUSÃO: O modelo experimental com defeitos de 5x8mm na região parietal, com remoção do periósteo e manutenção da integridade da dura-máter são considerados críticos, e poderá ser utilizado para o estudo dos defeitos ósseos cranianos nas anomalias craniofaciais.

[Histological evaluation of the effects of human bone matrix gelatin [BMG] with autogenous bone graft in the reconstruction of parietal bone defect in rats]

Autogenous bone grafts are commonly used for the reconstruction of bone defects in surgical procedures. The complication of preparing bone grafts and their application are important factors that have encouraged investigators to use human bone matrix gelatin human [BMG] which is one of the most popular graft materials. Because of the worldwide need for reconstruction of bone defects and its difficulty the aim of this study was to evaluate and compare the effects of BMG and auto graft on the reconstruction of bone defects in parietal bone of rats. In this experimental study, data was collected through microscopic observations. Human BMG produced using human Humorous bone based on Urist technical method. 12 healthy male Sprague dawley rats randomly assigned into 4 groups [3 rats in each group] and sacrificed in 7, 14, 24 and 60[th] days after surgery. Two defects were made in the left and right sides of parietal bone of all rats. Human BMG placed randomly in one side and auto graft in the other side and then all specimens in each group were assessed and compared histologically to each other. Assessments included amount, rate and type of bone formation, inflammation signs, fibrous tissue and cartilage formation to analyze the histologic findings, Wilcoxon-single rank test was used. The results showed a reduction of inflammation and also increase in new bone formation in both groups during 7, 14, 24 and 60th day after surgery. Bone formation percentage in human BMG cases in 24th day was more than autograft. There was no significant difference between two groups in 60th day. The findings suggested that although human BMG has the same effects as autograft, the rate of reconstruction with human BMG is more

Bone regeneration in cranioplasty and clinical complications in rabbits with alloxan-induced diabetes

This research evaluated the bone repair process in surgical defects created on the parietal bones of diabetic rabbits using the guided bone regeneration technique to observe the effects of alloxan in the induction of diabetes mellitus. Twenty-four adult rabbits were divided into three study groups: control (C), diabetic (D) and diabetic associated to polytetrafluoroethylene (PTFE) membrane (D-PTFE). For diabetes induction the animals received one dose of monohydrated alloxan (90 mg/kg) by intravenous administration in the auricular or femoral vein. In group D-PTFE the membrane covered both the floor and the surface of the bone defect. In groups D and C, the bone defect was filled up with blood clot. The specimens were fixed in 10 percent formol and prepared for histomorphometric analysis. The results showed that the 90 mg/kg dose of monohydrate alloxan was sufficient to promote diabetes mellitus when administered in the auricular vein. Bone regeneration was slower in the diabetic group when compared with the control and diabetic-PTFE groups, but there was no significant statistical difference between the two experimental groups (D and D-PTFE). The oral and general clinical complications among the diabetics were weight loss, polyuria, polyphagia and severe chronic gingivitis.

Optical density of bone repair after implantation of homogenous demineralized dentin matrix in diabetic rabbits

This research evaluated the bone repair process after implantation of homogenous demineralized dentin matrix (HDDM) in surgical defects in the parietal bone of rabbits with alloxan-induced diabetes, using a polytetrafluorethylene (PTFe) barrier for guided bone regeneration. Thirty-six rabbits were used and divided into four groups: control (C, n = 12), diabetic (D, n = 12, left parietal bone), diabetic with PTFe (D-PTFe, same 12 rabbits, right parietal bone), and diabetic with PTFe associated to HDDM (D-PTFe+HDDM, n = 12). Bone defects were created in the parietal bone of the rabbits and the experimental treatments were performed, where applicable. The rabbits were sacrificed after 15, 30, 60 and 90 days. The bone defects were examined radiographically and by optical density (ANOVA and Tukey test, p < .05). The radiographic findings showed that the D-PTFe+HDDM group presented greater radiopacity and better trabecular bone arrangement when compared to that of the C, D and D-PTFe groups. The statistical analysis showed significant differences in the optical density of the newly formed bone among the studied groups. It was possible to conclude that HDDM was biocompatible in diabetic rabbits.

Avaliaçäo da atividade osteoindutora da matriz dentinária autógena descalcificada em defeitos ósseos cirúrgicos obtidos por craniotomia e tratados pela técnica de regeneraçäo óssea guiada / Evaluation of the osteoinductive property of autogenous deminerilized dentin matrix on surgical bone defects obtained for craniotomy and treated by the guided bone regeneration technique

O propósito deste trabalho foi avaliar a atividade osteoindutora da matriz dentinária autógena descalcificada (MDAD), em defeitos ósseos cirúrgicos experimentais no osso parietal de coelho, associada à regeneraçäo óssea guiada com o uso de Membrana Amniótica Humana (MAH) e Membrana de Politetrafluoretileno (MP). Nesta pesquisa, foram empregados 72 coelhos adultos com peso médio de aproximadamente 4,5Kg e divididos em dois grupos controles, MAH e MP, e dois grupos experimentais, MAH associada à MDAD e MP associada à MDAD. Após a confecçäo do defeito ósseo, nos grupos controles, as respectivas membranas foram colocadas na superfície e no assoalho da loja cirúrgica e a cavidade foi preenchida pelo coágulo sanguineo. Nos grupos experimentais, implantou-se fatias de MDAD na periferia do defeito ósseo e colocou-se membrana na superfície e no assoalho do defeito ósseo. Em seguida, procedeu-se à sutura do periosteo sobre as membranas e da pele. Decorridos 15, 30, 45, 60, 90 e 120 dias, três coelhos de cada grupo foram sacrificados. As peças contendo os defeitos ósseos foram removidas em bloco, fixadas em formol a 10 por cento e submetidas a análise macroscópica, análise radiográfica com radiografia digital direta, sistema DIGORA, e a análise microscópica. Os resultados obtidos possibilitaram concluir que a MAH e a MP näo interferiram no processo de reparo ósseo, a MP permaneceu na regiäo de implantaçäo durante todos os períodos estudados e a MAH foi reabsorvida. As fatias de MDAD estimularam a neoformaçäo óssea de forma direta, sendo rapidamente incorporadas ao osso neoformado e reabsorvidas durante o processo de remodelaçäo óssea

Fratura com afundamento craniano em crianças com menos de dois anos de idade / Depressed skull fractures in children under 2 years of age

As fraturas com afundamento da calota craniana (FAC) säo relativamente frequentes e seu tratamento neurocirúrgico está bem estabelecido, porém pouca atençäo tem sido dada a esta patologia na faixa etária de 0 a 2 anos de idade. Este estudo baseia-se na análise retrospectiva de 43 pacientes com FAC e idade entre 0 e 2 anos. As principais causas da FAC foram as quedas, seguidas pelos atropelamentos. A maioria apresentava FAC tipo I, isto é, aquela na qual o osso deprimido permanece conectado à calota craniana. Tratamento cirúrgico foi instituído em 69,8 por cento dos casos. A incidência de lesöes encefálicas associadas foi mais baixa do que a relatada na literatura

Tratamento de perdas de substancia ossea da regiao frontal com enxerto autogeno de tabua externa / Treatment of losses of bone substance of the frontal region with autogenic graft of outer table

Foram operados dez pacientes com perda de substancia na regiao frontal utilizando-se enxerto de tabua externa da regiao parietal, obtidos sem craniotomia. Em todos os casos foi restaurado o contorno da regiao frontal, sem sequela na area doadora. Os resultados avaliados clinica e radiologicamente mantiveram-se no acompanhamento de um ano. A utilizacao do enxerto de tabua externa da regiao parietal permite correcao dos defeitos da regiao frontal, com bons resultados esteticos. A morbidade na area e menor que na regiao da crista iliaca e ha menor reabsorcao ossea do enxerto.

Cisto epidermóide em osso parietal: excisäo e cranioplastia / Epidermoid cyst of the parietal bone: excision and cranioplasty

É apresentado um caso invulgar de cisto epidermóide intradiplóico de osso parietal, com seus aspectos clínicos, radiológicos, cirúrgicos e histológicos. Alerta-se quanto às possíveis repercussöes de uma abordagem cirúrgica simplificada, análoga à dos cistos epidermóides da pele, uma vez que importantes conseqüências clínicas estäo relacionadas à sua topografia