In situ endoscopic analysis of bone microstructure and vascularization in post-extraction sites immediately after a minimally invasive vertical tooth extraction in teeth with different periodontal status / Análisis endoscópico in situ de la microestructura ósea y vascularización en alvéolos post-extracción inmediatamente después de una extracción dental mínimamente invasiva en dientes con diferente estado periodontal

SUMMARY: The aim of this study was to perform an in situ endoscopic analysis of the vascularization of post-extraction sites immediately after a non-traumatic extraction in terms of the number of blood vessels per field (NBV), relative area of blood vessels (RABV) and relative area of unmineralized bone (RAUB) in teeth with different periodontal status (PS). This assessment was performed using short distance support immersion endoscopy (SD-SIE). Ten patients (4 men/ 6 women, aged between 25 and 44) were selected. From them, 10 teeth were extracted due to periodontal reasons or other motives. These teeth were then categorized into 2 groups according to their PS, either as periodontally compromised (PC) (clinical attachment loss (CAL) > 7 mm and probing depth (PD) > 5 mm) or periodontally healthy (PH) (CAL < 7 mm and PD < 5 mm, without bleeding or suppuration during periodontal probing), and mobile (M) (> 1 mm horizontally) or immobile (I) (< 1 mm horizontally). The minimally invasive vertical tooth extractions were performed using the Benex ® extractor. Immediately after extraction, a rigid immersion endoscope with a diameter of 2.7 mm was introduced, and a video-alveoloscopy was carried out. This video was analyzed by ImageJ software for the quantification of NBV, RABV and RAUB per field of the post-extraction sites with different PS (PC, PH, M, I) were quantified. In the PC group, significantly greater values for RAUB were observed (33.45 %) compared to those from the PH group (19.65 %). Compared with the M group, the I group did not show significant differences in terms of RAUB or RABV. There were also no differences in NBV in both groups (Means: 33.8 vs. 30.5, respectively).

RESUMEN: El objetivo de este estudio fue realizar un análisis endoscópico in situ de la vascularización de los alvéolos post-extracción inmediatamente después de una extracción atraumática en términos de número de vasos sanguíneos por campo de observación (NBV), área relativa de vasos sanguíneos (RABV) y el área relativa de espacios no mineralizados (RAUB) en dientes con diferente estado periodontal (PS). Esta evaluación se realizó mediante endoscopía de inmersión de corta distancia (SD-SIE). Se seleccionaron diez pacientes (4 hombres / 6 mujeres, con edades comprendidas entre 25 y 44). De ellos, se extrajeron 10 dientes debido a razones periodontales u otros motivos. Estos dientes se clasificaron en 2 grupos según su PS, ya sea como periodontalmente comprometidos (PC), los que presentaban un nivel de inserción clínica (CAL) ≥ 7 mm y una profundidad de sondaje (PD) ≥ 5 mm; o periodontalmente sanos (PH) (CAL <7 mm y PD <5 mm, sin sangramiento o supuración durante el sondaje periodontal). También se categorizaron según su movilidad como móvil (M) (≥ 1 mm horizontalmente) o inmóvil (I) (<1 mm horizontalmente). Las extracciones verticales mínimamente invasivas se realizaron con el extractor Benex ®. Inmediatamente después de la extracción, se introdujo un endoscopio rígido de inmersión con un diámetro de 2.7 mm, con el cual se realizó una video-alveoloscopía. Este video fue analizado por el software ImageJ para la cuantificación de NBV, RABV y RAUB por campo, de los alvéolos post-extracción con diferente estado periodontal. En el grupo de dientes PC, se observaron valores significativamente mayores para RAUB (33.45%) en comparación con los del grupo PH (19.65 %). En comparación con el grupo M, el grupo I no mostró diferencias significativas en términos de RAUB o RABV. Tampoco hubo diferencias en el NBV en ambos grupos (Media: 33.8 frente a 30.5, respectivamente).

Bone health in type 1 diabetes.

PURPOSE OF REVIEW: This article reviews recent publications on the effect of type 1 diabetes (T1D) on fracture risk, bone mineral density (BMD), bone structure, and bone tissue quality. Possible fracture prevention strategies for patients with T1D have also been reviewed. RECENT FINDINGS: T1D is associated with substantially elevated fracture risk and modestly low BMD at the femoral neck. However, BMD alone does not explain higher observed fracture risk in T1D. T1D also affects bone macro- and microstructure, characterized by thinner cortices and trabecular bone changes such as thinner and more widely spaced trabeculae. Structural bone deficit is pronounced in the presence of microvascular complications. Tissue-level changes, such as accumulation of advanced glycation endproducts, detrimental alterations of the mineral phase because of low bone turnover, and occlusion of vascular channels in bone by mineralized tissue, are implicated in pathophysiology of bone fragility in T1D. There are no guidelines on screening and prevention of osteoporotic fractures in T1D. SUMMARY: More studies are needed to understand the influence of T1D on structural bone quality and tissue material properties. There is a need for a prospective study to evaluate better screening strategies for diagnosis and treatment of osteoporosis in T1D.

Effectiveness of ultrasonography in detecting intraosseous vascularization: an in-vitro study

A ultrassonografia é um recurso de imagem para a finalidade de diagnosticar lesões e para avaliar o grau de vascularização intraóssea de tumores. No entanto, lesões intraósseas podem representar um desafi o devido à espessura de osso circundante que poderá impedir a captura do sinal de ultrassom. O objetivo deste estudo foi avaliar a infl uência da espessura óssea na captura do sinal de eco dos vasos utilizando a ultrassonografi a. Hemimandíbulas maceradas suínas (n = 20) com espessuras ósseas diferentes foram adaptadas para receber tubos de borracha tipo CFlex ligados a um capilar de vidro, por onde água foi conduzida por meio de uma bomba para simular a vascularização sanguínea. A ultrassonografi a Doppler foi usada para avaliar o fl uxo de sangue na região do canal mandibular ao nível dos dentes molares. O teste t de Student foi utilizado para avaliar as diferenças entre as espessuras de osso das hemimandíbulas por meio de sinal negativo e sinal positivo do ultrassom. A reprodutibilidade e a confi abilidade foram confi rmadas para as análises. O sinal de fl uxo simulado foi capturado em ossos corticais com espessura na faixa de 0,2 a 1,0 mm (0.59 0.42 mm), mas não foi capturado a uma espessura superior a 1,0 mm (1.39 0.59 mm). Concluindo, a ultrassonografi a pode ser usada para investigar a vascularização intraóssea em áreas mandibulares com uma espessura óssea vestibular de até 1,0 mm.

Ultrasonography is useful to diagnose lesions, insofar as it detects the type of injury, and to assess the degree of vascularization of tumors. However, intraosseous lesions may represent a challenge, since the surrounding bone thickness could prevent ultrasound signal capture. The aim of this study was to evaluate the infl uence of surrounding bone thickness on the ability of ultrasonography in capturing the echo signal of blood vessels. Macerated porcine hemimandibles (n = 20) with different buccal bone thicknesses were prepared and adapted to receive CFlex-type rubber tubes connected to a glass capillary through which pump-driven water was conducted to simulate blood vasculature. Doppler ultrasonography was used to assess the blood fl ow in the region of the mandibular canal at the level of the molar teeth. Student’s t-test was used to assess differences between the bone thicknesses of hemimandibles with a negative and with a positive ultrasound signal. The presence of the echo signal in the simulated vasculature was assessed by ultrasonography. Reproducibility and reliability were confi rmed for the analyses. The simulated fl ow signal was captured in cortical bones with a thickness in the 0.2–1.0 mm range (0.59 ± 0.42 mm), but was not captured in those with a thickness greater than 1.0 mm (1.39 ± 0.59 mm). In conclusion, ultrasonography can be used to investigate intraosseous vascularization in mandibular areas with a buccal bone thickness up to 1.0 mm.

Endothelial differentiation of human stem cells seeded onto electrospun polyhydroxybutyrate/polyhydroxybutyrate-co-hydroxyvalerate fiber mesh.

Tissue engineering is based on the association of cultured cells with structural matrices and the incorporation of signaling molecules for inducing tissue regeneration. Despite its enormous potential, tissue engineering faces a major challenge concerning the maintenance of cell viability after the implantation of the constructs. The lack of a functional vasculature within the implant compromises the delivery of nutrients to and removal of metabolites from the cells, which can lead to implant failure. In this sense, our investigation aims to develop a new strategy for enhancing vascularization in tissue engineering constructs. This study's aim was to establish a culture of human adipose tissue-derived stem cells (hASCs) to evaluate the biocompatibility of electrospun fiber mesh made of polyhydroxybutyrate (PHB) and its copolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHB-HV) and to promote the differentiation of hASCs into the endothelial lineage. Fiber mesh was produced by blending 30% PHB with 70% PHB-HV and its physical characterization was conducted using scanning electron microscopy analysis (SEM). Using electrospinning, fiber mesh was obtained with diameters ranging 300 nm to 1.3 µm. To assess the biological performance, hASCs were extracted, cultured, characterized by flow cytometry, expanded and seeded onto electrospun PHB/PHB-HV fiber mesh. Various aspects of the cells were analyzed in vitro using SEM, MTT assay and Calcein-AM staining. The in vitro evaluation demonstrated good adhesion and a normal morphology of the hASCs. After 7, 14 and 21 days of seeding hASCs onto electrospun PHB/PHB-HV fiber mesh, the cells remained viable and proliferative. Moreover, when cultured with endothelial differentiation medium (i.e., medium containing VEGF and bFGF), the hASCs expressed endothelial markers such as VE-Cadherin and the vWF factor. Therefore, the electrospun PHB/PHB-HV fiber mesh appears to be a suitable material that can be used in combination with endothelial-differentiated cells to improve vascularization in engineered bone tissues.

Early osseous tissue formation associated to submerged and non-submerged dental implants: a histomorphometric animal study / Formación temprana de tejido óseo asociado a implantes dentales sumergidos y no sumergidos. Un estudio histomorfométrico animal

The purpose of this research was to compare the bone formation around submerged and non-submerged implants installed in a mandible of dog. Seven beagle dogs were used in this protocol; initially, was performed extraction of posterior teeth of mandible and after 3 month healing were installed two dental implants with surface treatment (subtraction of titanium via acidification) in each hemimandible. A transmucosal healing screw of 7 mm without oclusal contact was installed at the anterior implant as a model of non-submerged implant; in the posterior implant were installed a cover screw, using the submerged technique. After six weeks of healing, histomorphometric analysis of osseous tissue between the threads was performed. Was analyzed the implant unit as well as the cervical, meddle and apical region of implant. Student t test with 5 percent significance was used. The non-submerged implant model showed more bone formation than submerged implant without statistically significance (p=0.106); for regional analyses, cervical area shows more osseous formation than middle and apical areas. The regional analyses did not present statistical difference between areas for comparative analysis of submerged and non-submerged implant model. Non-submerged implant model it's not an obstacle for osseous formation.

El objetivo de esta investigación fue comparar la formación ósea alrededor de implantes dentales sumergidos y no sumergidos instalados en mandíbula de perro. Siete perros Beagle fueron utilizados en este protocolo; inicialmente fueron realizadas las exodoncias de dientes posteriores de mandíbula y luego de 3 meses de recuperación fueron instalados dos implantes dentales con tratamiento de superficie en cada hemimandíbula (substracción de titanio vía acidificación). En el implante anterior fue instalado también un conector transmucoso de 7 mm sin contacto oclusal y en el implante posterior fue instalado el tornillo de cierre. Luego de 6 semanas de recuperación, se realizó un análisis histomorfométrico del tejido óseo presente entre las roscas. Se analizó el implante como unidad así como también sus sectores cervical, medio y apical. Se utilizó la prueba estadística t de student con 5 por ciento de significancia estadística. El implante no sumergido presentó mayor formación ósea sin diferencias estadísticamente significativa (p=0.106); en los análisis regionales, el área cervical presentó mayor formación ósea que las áreas medianas y apicales. El análisis regional no presentó diferencias estadísticamente significativas entre ambos tipos de implante. El modelo de implante no sumergido no es un obstáculo para la formación ósea.

Efecto de la terapia láser de baja potencia sobre el hueso alveolar dañado / The low level laser therapy effect on alveolar bone damaged

La terapia con láser de baja potencia ha demostrado tener propiedades analgésicas antiinflamatorias, bioestimulantes y promotoras de la respuesta tisular al daño. El propósito de este estudio fue determinar el efecto que el láser de baja potencia tiene sobre el hueso alveolar dañado. Se utilizaros 13 ratas Sprage Dawley, en las cuales se realizó una lesión estandarizada del hueso alveolar, posterior a lo cual una muestra aleatoria de 7 ratas fue sometida a un protocolo de irradiación de 6 J/cm2, tres veces por semana durante cuatro semanas. Las muestras obtenidas del sitio lesionado en ratas expuestas y no expuestas a la terapia fueron procesadas para hematoxilina eosina, contabilizándose el número de osteonas al microscopio óptico con aumento de 40x. Los resultados muestran un aumento en el número de osteonas en el grupo irradiado, diferencia que resultó estadísticamente significativa (p<0,01), con una alta fuerza de asociación estadística (O.R=5,6 ). Estos resultados sugieren que la terapia láser de baja potencia favorece la respuesta del hueso alveolar dañado.

The Low Level Laser Therapy (LLLT) has demostrated to have analgesic, antiinflamatory, bioestimulant and promoters from the tissues responses properties to the damage. The purpose of this study was determinate the Low Level Laser Therapy effect in the damaged alveolar bone. Thirteen Sprage Dawley rats were used. Total number of animals alveolar bones a standarized lesion was made, later an aleatory sample of seven rats was subjected to the irradiation protocol 6 J/cm², three times per week during four weeks. The obtained samples of the injured area, of exposed and not exposed rats to the laser therapy were processed for hematoxilin & eosin, being the osteon number count by optic microscope with increase of 40x. The result show an increase in the osteon number in the irradiated group, this differentiated was statistically significant (p<0.01), whit a high strength of statistical association (OR=5.6). These result suggest that the therapy laser of low power favors the answer of the damaged alveolar bone.

Revascularization of autogenous block grafts with or without an e-PTFE membrane.

PURPOSE: The aim of this study was to describe the revascularization process of autogenous bone block grafts placed with or without an expanded polytetrafluoroethylene (e-PTFE) membrane. MATERIALS AND METHODS: Thirty Wistar male rats had their mandibles augmented by either an autogenous bone block graft (group A) or an autogenous bone block graft covered with an e-PTFE membrane (group B). The animals were sacrificed by perfusion at baseline, 3, 7, 14, and 21 days after surgery. RESULTS: After 3 days, the presence of vascular sprouts derived from the recipient bed was observed in group A; more discrete sprouts were also observed in group B. After 7 days, revascularization continued, with vessels derived from both the recipient bed and the surrounding connective tissue in group A but only from the recipient bed in group B. At 14 days, group A showed penetration of vessels at the periphery of the graft; the vessels reached varying distances inside it. In group B, revascularization of the graft occurred mainly near its perforation, its borders, and at the recipient bed-graft interface. After 21 days, graft vascular penetration could be observed throughout the extent of the graft in group A but only approximately halfway through the graft in group B. DISCUSSION: The results emphasized the importance of the vascular network and of the revascularization process of the autogenous bone graft in new bone formation. Early vascular penetration and nutrition of the graft are key factors in its integration with the recipient bed. CONCLUSIONS: Revascularization of the bone graft occurred in both A and B. However, vascular sprouts originated only from the recipient bed in group A, while in group B the graft was penetrated by vessels from both the recipient bed and the surrounding connective tissue. The revascularization took place more promptly and was more intense and extensive in group A than in group B for all periods.

Histiocitoma fibroso maligno sobre infarto ósseo e calo de fratura / Malignant fibrous histocytoma on bone infarction and callus frasture

Os autores relatam caso de histiocitoma fibroso maligno que se instalou sobre calo de fratura, em zona onde havia infarto ósseo, em fêmur distal. O tumor surgiu 14 meses após a fratura, tratada conservadoramente em sua cidade. O quadril foi desarticulado com 17 meses de fratura. Apresentam detalhes do exame anatomopatológico e lembram a raridade da associaçao malignidade x infarto ósseo. Nao encontraram relato na literatura de língua inglesa da tríplice associaçao.

The effect of venous occlusion on the integration of vascularized cortical bone graft.

The biologic phenomena involved in the healing process of vascularized, cortical bone grafts, vascularized grafts with venous occlusion, and conventional cortical bone grafts, were studied in rabbits. The middle third of the radial diaphysis was the donor site, with a 1.6-cm-long bone cylinder delimited by double transverse osteotomies. The vascularized grafts were raised by extraperiosteal dissection, with preservation of their vascular pedicle, while the conventional grafts were obtained by subperiosteal dissection. The vascularized graft with venous occlusion had its draining vein ligated. Radiologic, scintigraphic, and histologic studies were undertaken at days 7, 15, 30, and 60 postoperatively. Results demonstrated that the vascularized graft healed earlier than the corresponding vascularized graft with venous occlusion and than the conventional graft, respectively. The vascularized graft with venous occlusion suffered some degree of impairment of its irrigation, probably due to retrograde block of the arterial blood flow. It underwent a degree of bone necrosis, followed by resorption and creeping substitution, which delayed its integration. This seemed to be a temporary effect, for it healed earlier than the conventional graft.

The "double barrel" free vascularized fibular bone graft.

A further modification of the free vascularized fibular bone graft is described in which a transverse osteotomy is made from the anterolateral aspect of the fibular shaft just distal to the entry of the nutrient artery. This produces two vascularized bone struts that may be folded parallel to each other but that remain connected by the periosteum and muscle cuff surrounding the peroneal artery and vein. The proximal strut is vascularized by both a periosteal and an endosteal blood supply, whereas the distal strut is vascularized by a periosteal blood supply alone. This so-called "double barrel" free vascularized fibular graft has been employed in three patients with segmental bone defects of the distal femur and in one patient with adjacent bony defects of the radius and ulna.

Particularidades da reparaçäo de fratura experimental do colo da mandíbula de rato `a microscopia óptica e eletrônica de varredura / Peculiarities of healing of experimental fracture of the mandibular neck in rats, under light and scanning electron microscopy

O processo de reparaçäo óssea após fratura condilar experimental foi estudada em 50 ratos. Os resultados demonstram que: 1) a participaçäo da cápsula fibrosa da articulaçäo no reparo ósseo do processo ondilar foi evidente no período inicial, através do preenchimento da área fraturada por tecido conjuntivo frouxo celularizado e vascularizado; 2) a presença acentuada da cartilagem neste processo, durante os primeiro 10 días, decorre da necessidade de alcançar mais rapidamente um equilíbrio morfouncional; 3) o processo de reparo ósseo de fratura ao nível do colo da mandíbula desenvolveu-se normalmente, demonstrando a capacidade do processo condilar de se adaptar `as novas condiçöes funcionais; 4) o reparo ósseo da fratura do processo condilar se faz mediante a formaçäo intensa de tecido conjuntivo, dispondo-se paralelamente `a fratura, e é constituído de fibras colágenas dispostas em diferentes direçöes sempre se conectando com as margens da fratura; 5) a área com uma constituiçäo estrutural complexa, mostra intensa neoformaçäo tecidual, com o preenchimento da área fraturada por espessos feixes de fibras colágenas, alguns forames vasculares e áreas de reabsorçäo; 6) o processo de reparaçäo óssea, no período examinado, se faz através de uma mudança gradual nas caracterísicas da superfície da área fraturada, mediante a organizaçäo de espessos feixes de fibras colágenas, dando maior definiçäo `a sua orientaçäo, acompanhado pela presença cada vez maior de espaços e orifícios com características morfológicas mais definidas

Scintigraphic differentiation of bone infarction from osteomyelitis in children with sickle cell disease.

Bone scans or bone marrow scans or both were obtained during 42 episodes of bone pain in 40 children with sickle cell disease, and the usefulness of these procedures was compared. On the basis of the subsequent clinical course, a diagnosis of bone infarction was made in 34 episodes, and osteomyelitis in eight. Among 22 patients with bone infarction, uptake on bone scan was increased in 14, decreased in three, and normal in five. Seven of eight patients with osteomyelitis had increased uptake on bone scan; one had normal uptake. In contrast, marrow scan uptake was markedly decreased in 15 of 16 patients with bone infarction, and was normal in five of five patients with osteomyelitis. Thus, decreased uptake on bone marrow scan in a patient with sickle cell disease and bone pain almost invariably indicates infarction, whereas normal uptake strongly suggests the diagnosis of osteomyelitis. We found marrow scans more useful than bone scans for this differential diagnosis.

Histological analysis of undecalcified thin sections of archeological bone.

Archeological bone often lends itself to histological analysis. Sections from bone samples approximately one thousand years old may show as much structural preservation as those only a few hundred years old; hence, it appears that the degree of preservation is not necessarily affected by time. Enough structure may be preserved to permit the diagnosis of metabolic disorders of bone which might go undetected by other methods. This type of analysis can be utilized to accept or reject individual remains suspected of being pathological on the basis of other less precise diagnostic techniques.