Cuantificación de la distorsión presente en la radiografía posteroanterior de cráneo / Quantification of the distortion present in the postero-anterior cephalogram

RESUMEN Introducción: Universalmente se acepta que la radiografía postero-anterior de cráneo presenta menor grado de distorsión que otras imágenes radiográficas, por lo que las mediciones en ella son consideradas confiables. Objetivo: Determinar el porcentaje de distorsión que se presenta en las diferentes regiones faciales de la radiografía posteroanterior de cráneo. Métodos: Treinta cráneos humanos con sus mandíbulas fueron divididos por tres planos horizontales y cuatro verticales en quince cuadrantes; resultaron diez en el cráneo y cinco en la mandíbula. En cada uno de ellos se colocó un alambre de acero en posiciones vertical y horizontal y se midió su longitud (medida real). A cada conjunto se le tomó una radiografía en proyección postero-anterior y se midió la longitud de los alambres en la imagen (medida radiográfica). Resultados: No fue posible medir en los cuadrantes laterales del cráneo. La medida horizontal en los cuadrantes intermedios inferiores derecho e izquierdo del cráneo y en los cuadrantes intermedio y lateral de ambos lados de la mandíbula no es confiable; en el cuadrante mediano de la mandíbula se minimiza; en los cuadrantes medianos superior e inferior e intermedios superiores derecho e izquierdo del cráneo se magnifica. Las medidas verticales en todos los cuadrantes son confiables; en los cuadrantes intermedios superiores derecho e izquierdo del cráneo y en los intermedios y laterales derechos e izquierdos de la mandíbula se magnifica; en los cuadrantes intermedios inferiores y medianos superior e inferior del cráneo y mediano de la mandíbula se minimiza. La menor distorsión para ambas medidas se presenta en el cuadrante mediano superior del cráneo. Se reportan los porcentajes de distorsión para cada cuadrante. Conclusiones: Se presenta distorsión en la radiografía postero-anterior de cráneo y esta varía de una región a otra de la cara(AU)

ABSTRACT Introduction: Universally, it has been accepted that the postero-anterior cephalogram presents less distortion than any other x-ray radiograph; for this reason, the measurements taken on it are considered reliable. Objective: To determine for a postero-anterior cephalogram, what percentage of distortion is present in different regions of the skull and mandible. Methods: Thirty human skulls with their mandibles were divided by three horizontal and four vertical planes in fifteen quadrants, resulting ten in the skull and five in the mandible. In each quadrant, one vertical and one horizontal steel wire were fixed and their lengths were measured (real value). To each set, a postero-anterior cephalogram was taken and the wire images were measured (radiograph value). Results: No measurement could be taken in the lateral quadrants of the skull. The horizontal measurement in the right and left intermediate inferior quadrants of the skull and in the right and left intermediate and lateral quadrants of the mandible is not reliable; in the median quadrant of the mandible it is minimized; in the median superior and inferior and intermediate superior right and left quadrants of the skull it is magnified. The vertical measurement in all the quadrants is reliable; in the right and left intermediate superior quadrants of the skull and right and left intermediate and lateral quadrants of the mandible it is magnified; in the right and left intermediate inferior and median superior and inferior quadrants of the skull and median quadrant of the mandible it is minimized. The minimum distortion for both measurements is present in the median superior quadrant of the skull. The percentage of distortion in each quadrant for both measurements is reported. Conclusions: Distortion is present in the postero-anterior cephalogram and it varies from one region to another of the face(AU)

Demineralized bone matrix and calcium-phosphate cement in bone regeneration in rats

Abstract Purpose: To compare bone regeneration in critical-sized defects in rat calvarium using demineralized bone matrix and calcium phosphate cement. Methods: Thirty Wistar rats were divided into 3 groups of 10 animals each. Two defects of 5-mm were made in the parietal bones of each animal. Group I had calcium phosphate cement placed in the experimental defect, Group II had filled with demineralized bone matrix and Group III had with the combination of the matrix and cement in equal parts. All animals had one defect left unfilled to serve as controls. Five animals in each group were sacrificed at 4 and 8 weeks. Histomorphometric analysis was used to quantify the amount of new bone within the defects. Results: The results showed that demineralized bone matrix-treated defects had significantly more new bone at 4 weeks compared to calcium phosphate cement-treated defects (p=0.03) and also had significantly more new bone at 8 weeks compared to unfilled defects (p=0.04). Conclusions: The demineralized bone matrix was superior to calcium phosphate cement in bone regeneration. It seems that calcium phosphate cement acted by inhibiting the osteogenesis when associated with a demineralized bone matrix and this combination should not be recommended.

Evaluation of photobiomodulation therapy associated with guided bone regeneration in critical size defects. In vivo study

Abstract The repair of bone defects raises the interest of investigators in several health specialties. Grafting techniques with bone substitutes and laser therapies have been investigated to replace autogenous bone and accelerate the bone healing process. Objective To evaluate the effect of photobiomodulation therapy (PBMT) associated with guided bone regeneration (GBR) in critical size defects. Material and Methods The study was conducted on 80 male rats (Rattus norvegicus albinus, Wistar) submitted to surgical creation of a critical size defect on the calvaria, divided into eight study groups: group C (control - only blood clot); group M (collagen membrane); group PBMT (photobiomodulation therapy); group AB (autogenous bone); group AB+PBMT; group AB+M; group PBMT+M; group AB+PBMT+M. The animals were killed 30 days postoperatively. After tissue processing, bone regeneration was evaluated by histomorphometric analysis and statistical analyses were performed (Tukey test, p<0.05). Results All groups had greater area of newly formed bone compared to group C (9.96±4.49%). The group PBMT+M (achieved the greater quantity of new bone (64.09±7.62%), followed by groups PBMT (47.67±8.66%), M (47.43±15.73%), AB+PBMT (39.15±16.72%) and AB+PBMT+M (35.82±7.68%). After group C, the groups AB (25.10±16.59%) and AB+M (22.72±13.83%) had the smallest quantities of newly formed bone. The area of remaining particles did not have statistically significant difference between groups AB+M (14.93±8.92%) and AB+PBMT+M (14.76±6.58%). Conclusion The PBMT utilization may be effective for bone repair, when associated with bone regeneration techniques.

Platelet Rich Plasma (PRP) Produces an Atherofibrotic Histophenotype During Craniofacial Bone Repair Due to Changes of Immunohistochemical Expression of Erk1/2, p38α /β, Adiponectin and Elevated Presence of Cells Exhibiting B-scavenger Receptor (CD36+)

Abstract The platelet-extracellular matrix interaction in platelet rich plasma (PRP) through thrombospondin receptor-CD36 induces the secretion of growth factors responsible for cellular proliferation and differentiation during the repair process. Since CD36 also acts as a class B-scavenger-receptor for development of foam-like cells and mitogen-activated kinases, such as Erk1/2 and p38α/β, are important proteins activated by platelet growth factor, the aim of this study was to evaluate the immunohistochemical presence of CD36, Erk1/2, p38α/β during the bone repair treated and non-treated with PRP and to compare these results with the histomorphometry of repair. Simultaneously, the immunopresence of adiponectin was analyzed, which may contribute to osteogenesis at the same time it inhibits fibrosis and impairs adipogenesis and foam cell formation in the medullary area. An artificial bone defect measuring 5×1 mm was produced in the calvaria of 56 Wistar rats. The defects were randomly treated with autograft, autograft+PRP, PRP alone and sham. The animals were euthanized at 2 and 6 weeks post-surgery. Data were analyzed by ANOVA followed by non-parametric test Student Newman-Keuls (p<0.05) for histomorphometric and immunohistochemical interpretation. The results revealed that in specimens that received PRP the immunopositivity for Erk1/2, p38α/β and CD36 proteins increased significantly while the immunohistochemical expression of adiponectin decreased simultaneously. There was also an accentuated reduction of bone matrix deposition and increase of the medullary area represented by fibrosis and/or presence of foam-like cells, which exhibited immunophenotype CD36+adiponectin. The findings of this study suggest that PRP acted as an inhibitor of osteogenesis during the craniofacial bone repair and induced a pathological condition that mimics an atherofibrotic condition.

Resumo A interação da matriz extracelular-plaquetas no plasma rico em plaquetas (PRP) através de receptor trombospondina CD36 induz a secreção de fatores de crescimento responsáveis pela proliferação e diferenciação celular durante o processo de reparo. Uma vez que o CD36 também age como receptor scavenger de classe B para o desenvolvimento de células do tipo espuma, e as quinases ativadas por mitógenos, tais como ERK1/2 e p38α/β, são importantes proteínas ativadas por fator de crescimento das plaquetas, o objetivo deste estudo foi avaliar a presença imunoistoquímica de CD36, ERK1/2, p38α/β durante o reparo ósseo tratado e não-tratado com PRP e comparar estes resultados com a histomorfometria do reparo. Simultaneamente, analisou-se a imunopresença da adiponectina, que pode contribuir para osteogênese ao mesmo tempo que inibe a fibrose e prejudica a formação de células tipo espuma/xantomatosas na área medular. Um defeito artificial de osso medindo 5×1 mm foi produzido na calvária de 56 ratos Wistar. Os defeitos foram tratados aleatoriamente com auto-enxerto, enxerto autógeno+PRP, PRP apenas e sham. Os animais foram sacrificados 2 e 6 semanas pós-cirurgia. Os dados foram examinados por meio de ANOVA, seguido pelo teste não-paramétrico Student Newman-Keuls (p<0,05) para a interpretação histomorfométrica e imunoistoquímica. Os resultados revelaram que as amostras que receberam PRP aumentaram significativamente a imunopositividade para as proteínas ERK1/2, p38α/β e CD36, simultaneamente à diminuição de expressão imunoistoquímica da adiponectina. Houve também expressiva redução de deposição de matriz óssea e aumento da área medular representada por fibrose e/ou presença de células do tipo espuma que apresentaram imunofenótipo CD36 + adiponectina. Estes resultados sugerem que o PRP atuou como um inibidor da osteogênese durante o reparo ósseo craniofacial e induziu uma condição patológica que mimetiza uma condição aterofibrótica.

Avaliação das citocinas TNF-α, RANKL e OPG e do número de osteoclastos no reparo de defeito ósseo em calvária de ratos diabéticos tratados com matriz óssea desmineralizada / Evaluation of cytokines TNF-α, RANKL and OPG and the number of osteoclasts on repair of bone defects in skulls of diabetic rats treated with demineralized bone matrix

Neste trabalho, foi avaliado a participação dos osteoclastos bem como a ação das citocinas RANKL, OPG e TNF-α durante a formação e remodelação óssea em defeitos ósseos de tamanho crítico em ratos normoglicêmicos e diabéticos tratados ou não com a MAOD. Para isso, foram utilizados 250 ratos machos Wistar. Trinta ratos foram utilizados para coleta dos fêmures e tíbias, os quais foram processados para obtenção da MAOD. Os demais 220 ratos foram divididos em Grupo Não Diabétido (CTL, n=110) e Grupo Diabético (DIAB, n= 110) induzido pela aplicação de uma dose única de 47 mg/Kg de massa corporal de estreptozotocina. Um defeito transósseo de 8 mm de diâmetro foi realizado nos ossos parietais dos ratos, sendo que, nos subgrupos CTL MAOD e DIAB MAOD, os defeitos foram preenchidos com MAOD e nos grupos CTL COAG e DIAB COAG apenas com coágulo sanguíneo. Após 0, 7, 14, 21 e 42 dias, as calotas cranianas foram coletadas para determinação da densidade de volume, número de osteoclastos/mm2 na área do defeito, quantificação por imunoistoquimica e expressão do RNAm para as proteínas RANKL, OPG e TNF-α. Os resultados para volume do tecido ósseo neoformado foi maior nos grupos CTL COAG e CTL MAOD, bem como no grupo DIAB MAOD quando comparado com DIAB COAG (CTL MAOD > CTL COAG e DIAB MAOD > DIAB COAG). O número de osteoclastos nos grupos CTL aumentaram significantemente (3,69 osteoclasto/mm2), enquanto que nos grupos MAOD aumentaram gradualmente até os 42 dias (2,8 osteoclasto/mm2). Os resultados para imunomarcação mostraram que a MAOD promove 1,28 vezes maior expressão de OPG, bem como de TNF-α tanto no grupo CTL (1,59 vezes) como no DIAB (1,76 vezes). Os resultados para expressão do RNAm para OPG mostrou que a média dos valores do grupo COAG comparado com a do grupo MAOD foi 1,91 vezes maior no grupo COAG. Já os valores para expressão de RANKL permaneceram constantes no grupo DIAB MAOD, com aumento significativo de 2,57 vezes aos 42 dias, sendo 4,3 vezes maior, quando comparado com a média dos outros grupos no mesmo período. Conclui-se que nos animais normoglicemicos, o tratamento com a MAOD aumenta a expressão de OPG, RANKL e TNF-α, assim como a atividade osteoclástica, promovendo reabsorção da MAOD e formação de tecido ósseo, enquanto que nos animais diabéticos, a atividade osteoclástica foi reduzida, sem alteração nos níveis de OPG e RANKL, reduzindo a reabsorção da MAOD e consequentemente da formação óssea.(AU)

Participation of osteoclasts was evaluated in reabsorption process of demineralized allogenic bone matrix (DABM) as well as the activity of cytokines RANKL, OPG and TNF- α during formation and bone remodeling in critial size defect of normoglycemic and diabetic rats treated or not with DABM. Therefore, 250 male Wistar rats were used. Thirty rats had femurs and tibias collected and processed to obtain DABM. 220 rats were divided into control group (CTL, n=110) and diabetic group (DIAB, n= 110) injected by a single dose of 47 mg/Kg of body weight streptozotocin. Were made 8mm bone defect on skulls of rats, in subgroups CTL DABM and DIAB DABM, defects were filled with DABM and subgroups CTL CLOT and DIAB CLOT were filled with blood clot. After 0, 7, 14, 21 and 42 days, the skulls were collected to determine the volume density, number of osteoclasts/mm2 into defects area, quantification by immunohistochemistry and RNAm expression of RANKL, OPG and TNF-α cytokines. The results of volume density of newly formed bone was higher in CTL CLOT and CTL DABM, as well as in DIAB DABM compared to DIAB CLOT (CTL DABM > CTL CLOT and DIAB DABM > DIAB CLOT). The number of osteoclasts in CTL groups increased to 3,69 osteoclasts/mm2, while in subgroups treated with DABM gradually increased up until 42 days (2,8 osteoclasts/mm2). Immunohistochemistry showed that DABM promotes an increase of 1.28-fold of OPG expression, as well as TNF-a expression in CTL group (1.59-fold) and DIAB group (1.76-fold). The results of RNAm expression of OPG showed that the average values of the CLOT subgroup compared to the average values of DABM subgroup was 1.91- fold higher in CLOT subgroup. The values of RANKL RNAm expression increase 2.57-fold at 42 days, being 4.3-fold higher than the average os the other groups in the same period. In conclusion, in the normoglicemic animals (CTL group), the treatment with DABM increase the expression of OPG, RANKL and TNF-α as the activity of osteoclasts, leading to DABM resorption and bone tissue formation, while in diabetic animals, the osteoclast activity was reduced, without changes in the leves of OPG and RANKL, decreasing DABM resorption and bone formation.(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)

The application of finite element analysis in the skull biomechanics and dentistry.

Empirical concepts describe the direction of the masticatory stress dissipation in the skull. The scientific evidence of the trajectories and the magnitude of stress dissipation can help in the diagnosis of the masticatory alterations and the planning of oral rehabilitation in the different areas of Dentistry. The Finite Element Analysis (FEA) is a tool that may reproduce complex structures with irregular geometries of natural and artificial tissues of the human body because it uses mathematical functions that enable the understanding of the craniofacial biomechanics. The aim of this study was to review the literature on the advantages and limitations of FEA in the skull biomechanics and Dentistry study. The keywords of the selected original research articles were: Finite element analysis, biomechanics, skull, Dentistry, teeth, and implant. The literature review was performed in the databases, PUBMED, MEDLINE and SCOPUS. The selected books and articles were between the years 1928 and 2010. The FEA is an assessment tool whose application in different areas of the Dentistry has gradually increased over the past 10 years, but its application in the analysis of the skull biomechanics is scarce. The main advantages of the FEA are the realistic mode of approach and the possibility of results being based on analysis of only one model. On the other hand, the main limitation of the FEA studies is the lack of anatomical details in the modeling phase of the craniofacial structures and the lack of information about the material properties.

Biomechanics of the human canine pillar based on its geometry using finite element analysis / Biomecánica del pilar canino en el cráneo humano basada en la geometría utilizando análisis de elementos finitos

This study evaluated the stress distribution based on the canine pillar geometry in human skull, using a finite element analysis. Computed tomography of human skull was used to build a finite element model, which was composed by all bony structures of canine pillar: canine eminence, canine fossa, frontal process of maxilla, glabellum and superciliary arch. A support on the bite contact of maxillary canine tooth and a resultant force of the masticatory muscles was applied in the simulation. Equivalent Von-mises and maximum principal stresses were analyzed along the structures that compose the canine pillar geometry. Von-mises stress presented high stress concentrated at the canine fossa and frontal process of maxilla. Maximum principal stress showed compression areas at the canine fossa and part of frontal process and tensile stress at canine eminence and part of the frontal process. In conclusion, the different stress areas means different force concentrations transmitted along the canine pillar geometry during a peak canine bite.

Este estudio evaluó la distribución de la tensión sobre la geometría del pilar canino en el cráneo humano, utilizando análisis de elementos finitos. Se usó la tomografía computarizada de cráneo humano para construir un modelo de elementos finitos compuesto por todas las estructuras óseas del pilar canino: eminencia canina, fosa canina, proceso frontal del maxilar, glabela y arco superciliar. Se aplicó en la simulación un soporte ubicado sobre el contacto de mordida del diente canino maxilar y una fuerza resultante de los músculos de la masticación. Tensiones Equivalentes de Von-Mises y tensiones principales máximas fueron analizadas a lo largo de las estructuras que componen la geometría de pilar canino. La tensión de Von-Mises fue alta y concentrada en la fosa canina y proceso frontal del maxilar. La tensión principal máxima mostró áreas de compresión en la fosa canina y parte del proceso frontal y la tensión de tracción en la eminencia canina y parte del proceso frontal. Las diferentes áreas de tensión significan diferentes concentraciones de tensiones transmitida a lo largo de la geometría del pilar canino durante una mordedura canina máxima.

Relación entre índice facial superior e índice nasal en cráneos Chilenos adultos / Relation between superior facial index and nasal index in Chilean adult crania

La cara es el sello principal de la identidad, lo que nos define como individuos en los contactos interpersonales. Las características métricas aportadas por la craneometría nos permiten caracterizar cráneos y caras por medio de los índices. Se realizó un estudio craneométrico en 32 cráneos de individuos adultos de ambos sexos. En ellos se midieron diámetros faciales y se determinaron sus índices según Bidegain & Carvalho de Mello. La altura facial superior (n-pr) promedio fue de 66,20mm (DE +/- 5,26), con límite máximo de 76,68mm y mínimo de 51,22mm. El ancho facial máximo (zy-zy) promedio fue de 127,05mm (DE +/- 6,85), con límite máximo 139,08mm y mínimo de 112,77mm. El ancho nasal (al-al) promedio fue de 23,99 mm (DE +/-2,81), con límite máximo de un 35,13mm y mínimo de 18,97 mm. La altura nasal (n-ns) promedio fue de 50,97 mm (DE +/- 3,58), con límite máximo de 55,96 mm y mínimo de 39,58mm. El Índice Facial Superior promedio fue de 52,20 (DE +/- 4,54), con límite máximo de 62,29 y mínimo de 43,92 determinando la tendencia meseno en cráneos de género masculino y femenino. El Índice Nasal promedio fue de 47,30 (DE +/- 6,28) con límite máximo de 67,14 y mínimo de 36,23 determinando características leptorrinas tanto en cráneos masculinos como femeninos. Los datos obtenidos permitirán a los profesionales del área salud contar con nuevos antecedentes para estudios antropométricos y antropológicos.

The face is the main symbol of identity which defines us as individuals as well as in the process of interpersonal contacts. Metric characteristics contributed by craniometry allow us to characterize crania and faces by means of indexes. A craniometric study was carried out in 32 crania of adult subjects of both sexes. Facial diameters were measured using indexes according to Bidegain & Carvalho de Mello. Facial height average (n-pr) was 66.20 mm (SD +/- 5.26) with maximum boundary of 76.68 mm and minimum of 51.22 mm. Facial maximum width on average (zy ­ zy) was 127.05 mm. (SD +/- 6.85), with maximum boundary of 139.08 mm and minimum of 112.7 mm. Average Nasal width was 23.99 mm (SD +/- 2.81), with maximum boundary of 35.13 mm and minimum of 18.97mm. Nasal height average (n-ns) was 50.97 mm (SD +/- 3.58) with maximum boundary of 55.96 mm and minimum of 39.58 mm. Facial Superior Index on average was of 52.20 (SD +/- 4.54) with maximum boundary of 62.29 mm and minimum of 43.92 determining the mesorrhine tendency in male and female crania. Nasal average index was 47.30 (SD +/- 6.28) with maximum boundary of 67.14 and minimum of 36.23 thereby determining leptorrhine characteristics in male as well as female crania. The information obtained will afford health care professionals access to new data for anthropometric and anthropological studies.

Establishment of a 3D finite element model of human skull using MSCT images and mimics software / 法医学杂志

OBJECTIVE@#To establish a human 3D finite element skull model, and to explore its value in biomechanics analysis.@*METHODS@#The cadaveric head was scanned and then 3D skull model was created using Mimics software based on 2D CT axial images. The 3D skull model was optimized by preprocessor along with creation of the surface and volume meshes. The stress changes, after the head was struck by an object or the head hit the ground directly, were analyzed using ANSYS software.@*RESULTS@#The original 3D skull model showed a large number of triangles with a poor quality and high similarity with the real head, while the optimized model showed high quality surface and volume meshes with a small number of triangles comparatively. The model could show the local and global stress changes effectively.@*CONCLUSION@#The human 3D skull model can be established using MSCT and Mimics software and provides a good finite element model for biomechanics analysis. This model may also provide a base for the study of head stress changes following different forces.

Avaliação do reparo de defeito ósseo em calvária de ratos diabéticos tratados com matriz óssea desmineralizada / Evaluation of repair of bone defects in skulls of diabetic rats treated with demineralized bone matrix

O objetivo deste trabalho foi avaliar as atividades osteoindutoras e osteocondutoras da matriz alogênica óssea desmineralizada (MAOD) frente à diabetes no reparo de defeito de tamanho crítico em calvárias de ratos diabéticos. Para isso, 100 ratos machos Wistar foram divididos em 2 grupos: no grupo diabético (DIAB, n=50) foi injetado 47 mg/Kg de massa corporal de estreptozotocina, enquanto que no grupo controle (CTL, n=50) foi injetado solução fisiológica a 0,9%. A MAOD foi obtida de 50 ratos, cujo fêmur e tíbia foram retirados, desmineralizados com HCl a 0,6M por 24 horas, particulados em 1-2mm³, neutralizados com soro fisiológico e armazenados em álcool. Após a anestesia, foram realizados defeitos ósseos de 8 mm nas calvárias dos animais, sendo os grupos CTL COAG (n=25) e DIAB COAG (n=25) preenchidos com coágulo e os grupos CTL MAOD (n=25) e DIAB MAOD (n=25) preenchidos com MAOD. Após os períodos de 0, 7, 14, 21 e 42 dias, as calvárias foram coletadas. A análise radiográfica mostrou que houve formação de ilhas radiodensas no interior dos defeitos nos grupos CTL e DIAB tratados com MAOD, enquanto que nos grupos tratados com coágulo houve formação de áreas mais radiodensas somente nas bordas do defeito, corroborando com os resultados morfológicos, que mostraram nos grupos tratados com coágulo que o reparo ósseo teve início nas bordas do defeito, enquanto que nos grupos tratados com MAOD, a neoformação óssea ocorreu também nas áreas de reabsorção nas partículas de MAOD. De acordo com os resultados morfométricos, o volume de tecido ósseo aumentou gradativamente em todos os grupos, porém, esse aumento foi maior nos grupos CTL em relação aos seus respectivos tratamentos nos grupos DIAB (CTL COAG > DIAB COAG e CTL MAOD > DIAB MAOD) e maior quando comparados os grupos tratados com MAOD versus os respectivos grupos tratados com COAG (CTL MAOD > CTL COAG e DIAB MAOD > DIAB COAG). Assim, ao término de 42 dias, o volume de tecido ósseo no grupo CTL MAOD foi...

The aim of this work was to evaluate the osteoinductive and osteoconductive activities of demineralized allogeneic bone matrix (DABM) against diabetes in repairing critical size defects in diabetic rats skulls. Therefore, 100 male Wistar rats were shered into two groups: in the diabetic group (DIAB, n=50) was 47 mg/Kg of body weight streptozotocin, while in the control group (CTL, n=50) was injected saline 0.9%. The DABM was obteined using 50 rats which were removed their femur and tibia bones, demineralized in 0.6 N HCl during 24 hours, cut into 1-2mm³ pieces, neutralized in saline and stored in alcohol. After anesthesia, were made 8 mm bone defects on skulls of rats, being the CTL CLOT group (n=25) and DIAB CLOT group (n=25) filled with blood clot and the CTL DABM group (n=25) and DIAB DABM group (n=25) filled with DABM. After 0, 7, 14, 21 and 42 days, the skulls were collected. The radiographic analysis showed radiodense islets inside the defects filled with DABM in CTL and DIAB groups, while groups filled with blood clot showed radiodense areas near the defect border, which is in agreement to the morphologic results, that had showed the begining of bone healing was near the defects border in groups filled with blood clot, while groups filled with DABM showed new bone formation also in resorption DABM areas. According to morphometric results, the volume of bone tissue had increased in all groups, however, this increase was more accentuated in CTL groups when compared to DIAB groups with respected treatments (CTL CLOT > DIAB CLOT and CTL DABM > DIAB DABM) and bigger when groups treated with DABM are compared to respestive groups treated with CLOT (CTL DABM > CTL CLOT e DIAB DABM > DIAB CLOT). Thereby, at the end of 42 days, the CTL DABM bone tissue volume was 3.24 greater than the other groups, the CTL CLOT and DIAB DABM groups didnt show any significant differenceand the DIAB DABM was 1,81 greater than DIAB CLOT. From these results, the conclusion...

Device for craniocervical isolation in rabbits / Dispositivo para isolamento crânio-cervical em coelhos

PURPOSE: To evaluate the craniocervical isolation collar, for use in rabbits, with regard to the following aspects: effectiveness of the craniocervical attachment for up to 120 hours; ease of handling; freedom of the animal to move about and ingest food; and the physical integrity of the animal during and after use of the device. METHODS: Starting from an Elizabethan collar, a craniocervical collar was prepared for use in rabbits with the following modifications: a wide cut in the device in the shape of a half-moon, coinciding with the animal's mouth; inner division of the device into two compartments to individually isolate and immobilize the ears; multiple perforations in the upper compartment for better ventilation; adaptation of the cervical-thoracic band to attach the collar to the cervical region, keeping the fasteners on the animal's back. The device was used on 18 male New Zealand rabbits for up to 120 consecutive hours. RESULTS: The device was effective in the craniocervical isolation and separation of ears in rabbits without interfering with the animals' respiration, ability to swallow food, or causing physical trauma, while allowing the animals to move about freely and rest comfortably. Attaching and removing the device was easy and quick and it remained in place for up to 120 hours without the need to reposition it. CONCLUSION: The modified craniocervical isolation collar made it possible to conduct the experiment with isolation of the rabbits' ears, ease of handling, and without causing limitations in relation to the animals' ability to eat and move about freely.

OBJETIVO: Avaliar um colar de isolamento crânio-cervical, para uso em coelhos, quanto aos seguintes aspectos: eficácia da fixação crânio-cervical em até 120 h; facilidade de manuseio; liberdade do animal para deambular e ingerir alimentos; integridade física do animal durante e depois do uso do dispositivo. MÉTODOS: A partir do colar elizabetano confeccionou-se um colar de isolamento crânio-cervical para uso em coelhos, com as seguintes modificações: amplo corte no aparelho, em forma de meia lua, coincidindo com a boca do animal; divisão interna do dispositivo em dois compartimentos, para isolar e imobilizar as orelhas, individualmente; perfurações múltiplas no compartimento superior para melhor ventilação; adaptação de correia cérvico-torácica, para fixar o colar na região cervical, mantendo-se as presilhas de fechamento no dorso do animal. O dispositivo foi utilizado em 18 coelhos machos da raça Nova Zelândia, por período de até 120 horas consecutivas. RESULTADOS: O aparelho foi eficaz no isolamento crânio-cervical e das orelhas de coelhos, não interferiu nas funções respiratórias do animal, na deglutição de alimentos e não causou trauma físico, permitindo a livre deambulação e conforto no repouso. Foi de fácil e rápido manuseio na colocação e retirada, permanecendo no local sem necessidade de reposicionamento por até 120 horas. CONCLUSÃO: O colar de isolamento crânio-cervical modificado possibilitou a realização do experimento com isolamento das orelhas dos coelhos, com facilidade no manuseio, sem causar limitações ao animal em relação à ingestão de alimentos e deambulação.

Bone repair process in calvarial defects using bioactive glass and calcium sulfate barrier / Processo de reparo ósseo em defeitos experimentais de calotas cranianas frente a utilização do vidro bioativo e da barreira de sulfato de cálcio

PURPOSE: To analyze bone repair process in Wistar rats' calvaria, with the use of two different biomaterials. METHODS: Forty two male Wistar rats were used, and four bicortical cranial cavities were created in each animal. The cavities were filled with: bioactive glass (BG); calcium sulfate barrier (CSB); bioactive glass covered with calcium sulfate barrier (BG/CSB); and autogenous blood clot (control). The animals were euthanized 7, 14, 21, 30, 60, 90, e 120 days after surgery. The scalps were removed and submitted to a routine process for histological preparation: staining with Haematoxylin and Eosin (HE). RESULTS: The BG was not completely resorbed; however, after 60 days, a decrease in size as well as a change in the morphological granule were observed. CSB was not observed in the last group (after 120 days). CONCLUSIONS: In Wistar rat calvaria bioactive glass, in an isolated form, negatively interfered in the bone repair process; the calcium sulfate barrier, in an isolated form, presented the capacity to maintain space, allowing the flow of osteogenic cells; the bioactive glass covered with calcium sulfate barrier association presented a better osteoconductive capacity when compared to isolated materials; calcium sulfate barrier was completely resorbed after 90 days; control cavities did not completely heal until 120 days after surgery.

OBJETIVO: Analisar o processo de reparo ósseo em calotas cranianas de ratos Wistar, frente ao uso de diferentes biomateriais. MÉTODOS: Foram quatro cavidades, bicorticais, nas calotas cranianas de quarenta e dois ratos Wistar machos. As cavidades foram preenchidas com: vidro bioativo (VB); barreira de sulfato de cálcio (BSC); vidro bioativo coberto com barreira de sulfato de cálcio (VB/BSC); coágulo sangüíneo (controle). Os animais foram mortos aos 7, 14, 21, 30, 60, 90 e 120 dias após a cirurgia. As calotas foram removidas e submetidas ao processo de rotina para confecções de lâminas coradas com Hematoxilina e Eosina (HE). RESULTADOS: O VB não foi totalmente reabsorvido, contudo, a partir dos 60 dias, observaram-se alterações no tamanho e forma dos grânulos. A BSC não foi observada no último grupo (120 dias). CONCLUSÕES: Em calotas cranianas de ratos Wistar, o vidro bioativo na forma isolada interferiu negativamente no processo de reparo ósseo. A barreira de sulfato de cálcio na forma isolada apresentou a capacidade de manutenção do espaço preenchido, permitindo a migração de células osteogênicas. A associação vidro bioativo coberto com barreira de sulfato de cálcio apresentou uma maior capacidade osteocondutora quando comparada aos materiais nas formas isoladas. A barreira de sulfato de cálcio foi totalmente reabsorvida após 90 dias; As cavidades utilizadas como controle não cicatrizaram completamente até o período de 120 dias.

Padrão mastigatório em crianças de 5 a 7 anos: suas relações com crescimento craniofacial e hábitos alimentares / Mastication pattern in children between 5 to 7-year old: their relations with the craniofacial growth and feed habits

Objetivo: identificar o padrão mastigatório, o crescimento craniofacial e os hábitos alimentares de crianças de 5 a 7 anos e verificar as possíveis relações entre as variáveis. Métodos: participaram desta pesquisa 26 crianças de ambos os gêneros, na faixa etária de 5 a 7 anos. Foram realizadas entrevistas com os pais, avaliação ortodôntica e fonoaudiológica relacionando a mastigação, crescimento craniofacial e hábitos alimentares. Resultados: em relação ao padrão mastigatório o padrãobilateral alternado foi o mais encontrado; em relação aos terços da face, a média encontrada foi de52,05mm e a respeito dos hábitos alimentares, foi observado predominância de ingestão de alimentossólidos. Houve associação estatisticamente significante entre a ocorrência ou não de vedamentolabial durante a mastigação. Conclusão: o padrão mastigatório mais encontrado foi o bilateral alternado. As crianças apresentaram uma média dos terços da face que não revelou discrepância significativa quando comparados ao padrão mastigatório e hábitos alimentares. Em relação aos hábitos alimentares foi possível constatar que, apesar da maioria ingerir alimentos sólidos ainda há uma grande predominância de crianças que fazem uso de alimentos pastosos.

Purpose: to identify the chewing pattern, the craniofacial growth and the children feed habit between 5(five) to 7(seven) years. Methods: 32 children of both genders, from 5 to 7-year old, participated in this research. Interviews were carried out with parents, orthodontic and phonologic and estimation of relationship with chewing, craniofacial growth and feed habits. Results: the relation of chewing pattern,the alternate bilateral standard was the most found; the relationship of the third part of face, the average found was 52.05mm and about feed habits. The predomination of the solid food swallow was observed. There was significant statistical association among the occurrence or nonoccurrence of labial hinder during the mastication. Conclusion: the chewing pattern most found was the alternate bilateral standard. The children show a middle of third part of face that did not reveal significant discrepancy when comparedto chewing pattern and food habits. In relation to feed habits it was possible to verify, that in spite of the majority swallowing solid food there yet exist a great predominance of children that make use of pasty food.

Monitoreo del tratamiento ortodóncico. Modelo biológico y mecánico de la oclusión / Monitoring of orthodontic treatment. A biological and mechanical model of occlusion

El tratamiento ortodóncico es diagnóstico desde el principio al fin, pues no siempre la mecanoterapia opera exactamente como lo hemos previsto; además, la variación en el tiempo de los factores biológicos que determinan la organización de la oclusión operan en la forma y momento previstos, por ello hay que llevar un control continuo (monitoreo), especialmente en lo que se relaciona con el balance morfofuncional, para lograr resultados estables. El modelo que tiene que tener en mente el profesional es el biológico con consideraciones mecánicas, pero nunca el estrictamente mecánico, porque la boca no es un typodont. Se expone un método reglado para un control sistemático de la organización morfofuncional que da más probabilidades de estabilidad

Cranial bone mineral density in yuong hypogonadal patients and menopausal women

Bone mineral density (BMD) is reduced in the distal radius, proximal femur and lumbar spine of hypogonadal individuals. The objective of the present cross-sectional study was to assess cranial BMD by dual energy X-ray absorptiometry in patients with hypogonadism arising during the first two decades of life, submitted or not to hormone replacement, as well as in menopausal women not submitted to hormone replacement. Cranial BMD was significantly lower in hypogonadal without treatment (1.656 + 0.24 g/cm2; mean + SD) when compared to normal young individuals (1.996 + 0.17). The cranial bone mass did not differ significantly between untreated and treated young hypogonadal individuals (1.779 + 0.32 g/cm2). The values detected in both groups were significantly lower than those detected in the menopausal women (2.146 + 0.29 g/cm2; p<0.01). The cranial BMD of patients with primary hypogonadism did not differ from that of patients with central hypogonadism and confirmed growth hormone deficiency (1.654 + 0.23 versus 1.601 + 0.16 g/cm2). We conclude that hypogonadism of early onset is associated with a marked reduction in cranial BMD, a finding probably due to the high sensitivity of trobecular bone to sex steroid deficiency and to the interference of this deficiency with the achievement of bone mass peak.

Effect of diphenylhydantoin administration on the growth of the functional components of rat skull

With the purpose of studying the effect of diphenylhydantoin (DPH) administration on the growth of the functional components of the rat skull, male Wistar rats weighing 61.6 + 0.6g were assigned to 1 out of 4 different groups. One of them received saline and was taken as normal control. The others were injected once daily with 25,50 or 100 mg/Kg of b.w. of DPH i.p. for 20 days. Another group of rats was put under a restricted diet (RD) (20 percent of normal intake) for the same time for evaluation of the cranial dimensions. On day 21, the rats were killed by ether overdose and fifteen cranial dimensions were evaluated as peviously described employing Pucciarelli's method. The body weight gain of DPH injected rats was up to 20.7 percent lower independently of drug dose. The rats of the RD group showed a similar reduction. The amount of food consumed by DPH rats was 16 percent lower than that consumed by controls independently of drug doses. The concentration of alkaline phosphatase and hemoglobin in rats treated with 50 or 100 mg/kg b.w. of DPH was lower than in controls and RD-animals. However, urea and total calcium in plasma were unchanged in DPH-treated rats as compared to controls. Mean appetite quotient, efficiency of protein and energy utilization did not appear to change in response to the treatment with DPH or maintained under a restricted diet. That cranial dimensions of rats, injected with 25mg/kg b.w. of DPH were not statistically different from those of the control and RD-groups. When the dose of DPH injected was 50 mg/kg b.w. the neurocranial width an height and the spachnocranial length were significantly lower than controls and RD-values. Moreover, all the dimensions corresponding to neurocranium and splachnocranium (width, height and length) of the rats injected with 100 mg/kg b.w. of DPH were significantly lower than those of control and RD-groups. The disharmonius growth of the skull do not appear to be dependent on suboptimal energy intake, efficiency of protein, energy utilization renal failure and anemia.

Relaciones biomecánicas de las regiones craneales, cervicales e hioideas / Biomechanic relations of the cranial, cervical and hyoid regions

Las relaciones entre las regiones craneales, cervicales e hioideas pueden ser modificadas por aparatos ortopédicos removibles instalados por el odontólogo y por las técnicas ortopédicas manuales aplicadas a la columna cervical por el fisioterapeuta. Sin embargo, cada una de estas disciplinas evalúan y tratan de acuerdo a los síntomas de los pacientes y varios criterios objetivos que son los que primariamente limitan este campo. El autor sugiere que estas dos opciones para normalizar aquellas relaciones pueden ser coordinadas. El presenta un método objetivo de evaluación por radiografía para determinar el impacto de ambas disciplinas, y sugiere que esto puede ayudar a determinar las relaciones biomecánicas normales de estas estructuras. El también discute la importancia de estos puntos en cuanto a su método se refiere: 1. La posición del hueso hioideo para determinar la curvatura apropiada de la columna cervical. 2.- La distancia entre el occipital y el atlas y su relevancia con el sindrome de dolor de cabeza. 3. La relación angular del cráneo y la columna cervical