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).

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.

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.

Tissue Engineered Vascularized Bone Formation Using in vivo Implanted Osteoblast-Polyglycolic acid Scaffold

Repair of skeletal defects with vascularized bone grafts has many advantages over non-vascularized free grafts, but the availability of these grafts is extremely limited. This study was designed to determine whether new vascularized bone could be engineered by transplantation of osteoblasts around existing vascular pedicles using biodegradable, synthetic polymer as a cell delivery vehicle. Cells were isolated from the periosteum of fetal bovine humerus, and then seeded onto non-woven multifilament, polyglycolic acid polymer. The polymers provided three dimensional support during in vitro culture. The cell-polymer constructs were maintained in vitro for two weeks and then implanted around the right femoral vessels of twelve athymic nude rats. The polymer templates without the cells were implanted around left femoral vessels of each mouse as a control. Twelve rats were sacrificed at the following intervals: three rats at six, and nine rats at nine weeks. New bone formation was evident in 10 out of the 12 periosteal-derived cell seeded implants. At six weeks, the tissue was primarily composed of what appeared both grossly and histologically to be cartilage enveloping small islands of osteoid. The degree of osteoid and bone formation progressed with time, as blood vessels invaded the tissue. This tissue ultimately underwent morphogenesis to become an organized trabeculated bone with a vascular pedicle. We believe that this technique may prove to be useful in the reconstruction of bony defect.

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.

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

Bone and Joint Circulation Physiological Basis for Clinical Practice

No abstract available.