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1.
Dental press j. orthod. (Impr.) ; 27(1): e222098, 2022. tab, graf
Article in English | LILACS, BBO | ID: biblio-1364784

ABSTRACT

ABSTRACT Introduction: Orthodontic mini-implants (MI) are a reliable alternative to provide temporary orthodontic anchorage. Prior to miniscrew insertion, the best approach would be to evaluate each possible insertion site and measure the cortical bone thickness, and verify whether it would provide adequate primary stability. Objective: This study aimed to evaluate the difference in cortical bone thickness in areas of mini-implants insertion in patients of different ages, by means of cone beam computed tomography (CBCT). Methods: The sample of this retrospective study was composed of 123 CBCT scans, which were used to measure cortical bone thickness in the buccal and palatal inter-radicular space in the mesial region of the first permanent molars. These measures were compared by using the Student's t-test, ANOVA/Tukey tests, and Linear regression between male and female subjects, from 12 to 30 years old. Results: No significant difference was found in cortical bone thickness between sex, race and sagittal facial patterns. Significantly higher measurement values were observed in patients older than 12 years of age at all sites evaluated. The coefficient β at the adjusted linear regression analysis showed that at each increment in age, mean cortical thickness values increased by 0.06mm in the mandible, 0.03mm in the buccal region and 0.02mm in the palatal region of the maxilla. Conclusions: The increase in cortical bone thickness was positively associated with age; that is, the more advanced the patient's age was, the less chance there was of failure due to primary stability.


RESUMO Introdução: Os mini-implantes ortodônticos (MI) são uma alternativa confiável para fornecer ancoragem esquelética temporária. Antes da inserção do mini-implante, a melhor abordagem seria avaliar cada local de inserção possível, medir a espessura do osso cortical e verificar se proporcionaria uma adequada estabilidade primária. Objetivo: O presente estudo teve como objetivo avaliar a diferença na espessura do osso cortical em áreas de inserção dos mini-implantes em pacientes de diferentes idades, por meio da tomografia computadorizada de feixe cônico. Métodos: A amostra desse estudo retrospectivo foi composta por 123 tomografias computadorizadas de feixe cônico, que foram utilizadas para medir a espessura do osso cortical nos espaços inter-radiculares vestibular e palatino na região mesial dos primeiros molares permanentes. Essas medidas foram comparadas por meio dos testes t de Student, ANOVA/Tukey e regressão linear entre os sexos masculino e feminino, de 12 a 30 anos. Resultados: Não houve diferença estatisticamente significativa na espessura cortical, quando comparados sexo, cor da pele e padrão facial sagital. Foram verificadas medidas significativamente maiores em pacientes com idade superior a 12 anos em todos os sítios avaliados. O coeficiente β da análise de regressão linear ajustada mostrou que, a cada incremento da idade, os valores médios da espessura cortical aumentaram 0,06 mm na mandíbula, 0,03 mm na região vestibular e 0,02 mm na região palatina da maxila. Conclusão: O aumento da espessura do osso cortical teve associação positiva com a idade, ou seja, quanto mais avançada a idade do paciente, menor a chance de falha, devido à estabilidade primária.


Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Young Adult , Dental Implants , Orthodontic Anchorage Procedures/methods , Retrospective Studies , Cone-Beam Computed Tomography/methods , Cortical Bone/diagnostic imaging , Mandible/surgery , Mandible/diagnostic imaging , Maxilla/diagnostic imaging
2.
Int. j. morphol ; 39(3): 907-914, jun. 2021. ilus, tab, graf
Article in English | LILACS | ID: biblio-1385389

ABSTRACT

SUMMARY: This study was performed to identify optimal microimplant sites in the mandibular retromolar area by measurement and analysis of cortical bone thickness and density. Forty-nine records of cone-beam computed tomography were selected from 173 patients. Invivo 5.2 software was used to measure the thickness and density of 25 sites on a mesh in the mandibular retromolar area. Pearson correlation, Spearman correlation, and binary logistic regression analyses were performed to explore correlations between retromolar measurements and patient characteristics. The LSD test was used to identify optimal microimplant sites in this area. One-way ANOVA, with post hoc SNK test, was used to compare optimal microimplant sites among the retromolar area, the distobuccal bone of the second molar, and a location between the first and second molars. The mean thickness and density of mandibular retromolar cortical bone were 2.35 ± 0.76 mm and 530.49 ± 188.83 HU, respectively. In the mandibular retromolar area, the thickness and density of cortical bone increased from the lingual to buccal sides, and from the distal to mesial. Among 25 sites, S5C1 had the greatest thickness and density; it exhibited greater thickness and density, compared with the distobuccal bone of the second molar and the site between the first and second molars. For distal uprighting of mesially tipped molars, we recommend placement of microimplants into the retromolar distobuccal site; for distalization of mandibular dentition, we recommend placement of microimplants into the retromolar mesiobuccal site (S5C1) or 2 mm from the mesial direction of the second molar distobuccal site (B).


RESUMEN: Este estudio se realizó para identificar los sitios óptimos de microimplantes en el área retromolar mandibular mediante la medición y el análisis del grosor y la densidad del hueso cortical. Se seleccionaron 49 registros de tomografía computarizada de haz cónico de 173 pacientes. Se utilizó el software Invivo 5.2 para medir el grosor y la densidad de 25 sitios en una malla en el área retromolar mandibular. Se realizaron análisis de correlación de Pearson, correlación de Spearman y regresión logística binaria para explorar las correlaciones entre las mediciones retromolares y las características del paciente. La prueba de LSD se utilizó para identificar los sitios óptimos de microimplantes en esta área. Se utilizó ANOVA unidireccional, con prueba SNK post hoc, para comparar los sitios óptimos de microimplante entre el área retromolar, el hueso distobucal del segundo molar y una ubicación entre el primer y el segundo molar. El grosor y la densidad medios del hueso cortical retromolar mandibular fueron 2,35 ± 0,76 mm y 530,49 ± 188,83 HU, respectivamente. En el área retromolar mandibular, el grosor y la densidad del hueso cortical aumentaron desde el lado lingual al bucal y desde el distal al mesial. Entre los 25 sitios, S5C1 se determinó el mayor espesor y densidad; presentó mayor grosor y densidad, en comparación con el hueso distobucal del segundo molar y el sitio entre el primero y el segundo molar. Para rectificación distal de molares con punta mesial, recomendamos la colocación de microimplantes en el sitio retromolar bucal; para la distalización de la dentición mandibular, recomendamos la colocación de microimplantes en el sitio retromolar mesiobucal (S5C1) o 2 mm desde la dirección mesial del sitio distobucal del segundo molar (B).


Subject(s)
Humans , Cone-Beam Computed Tomography , Cortical Bone/diagnostic imaging , Mandible/diagnostic imaging , Prostheses and Implants , Regression Analysis , Analysis of Variance , Cortical Bone/anatomy & histology , Mandible/anatomy & histology , Molar
3.
Braz. dent. j ; 32(1): 9-15, Jan.-Feb. 2021. graf
Article in English | LILACS, BBO | ID: biblio-1180725

ABSTRACT

Abstract Aiming to evaluate cortical bone microarchitecture and osteonal morphology after irradiation, twelve male New Zealand rabbits were used. The animals were divided: control group (no radiation-NIr); and 3 irradiated groups, sacrificed after: 7 (Ir7d); 14 (Ir14d) and 21 (Ir21d) days. A single radiation dose of 30 Gy was used. Computed microtomography analyzed the cortical microarchitecture: cortical thickness (CtTh), bone volume (BV), total porosity (Ct.Po), intracortical porosity (CtPo-cl), channel/pore number (Po.N), fractal dimension (FD) and degree of anisotropy (Ct.DA). After scan, osteonal morphology was histologically assessed by means: area and perimeter of the osteons (O.Ar; O.p) and of the Haversian canals (C.Ar; C.p). Microtomographic analysis were performed by ANOVA, followed by Tukey and Dunnet tests. Osteon morphology analyses were performed by Kruskal-Wallis, and test Dunn's. Cortical thickness was significant difference (p<0.010) between the NIr and irradiated groups, with thicker cortex at Ir7d (1.15±0.09). The intracortical porosity revealed significant difference (p<0.001) between irradiated groups and NIr, with lower value for Ir7d (0.29±0.09). Bone volume was lower in Ir14d compared to control. Area and perimeter of the osteons were statistically different (p<0.0001) between NIr and Ir7d. Haversian canals also revealed lower values (p<0.0001) in Ir7d (80.57±9.3; 31.63±6.5) compared to NIr and irradiated groups. Cortical microarchitecture was affected by radiation, and the effects appear to be time-dependent, mostly regarding the osteons morphology at the initial days. Cortex structure in Ir21d revealed similarities to control suggesting that microarchitecture resembles normal condition after a period.


Resumo Com o objetivo de avaliar a microarquitetura óssea cortical e a morfologia dos osteons após irradiação, foram utilizados doze coelhos machos da Nova Zelândia. Os animais foram divididos: grupo controle (sem radiação-NIr); e 3 grupos irradiados, sacrificados após: 7 (Ir7d); 14 (Ir14d) e 21 (Ir21d) dias. Foi utilizada uma dose única de radiação de 30 Gy. A microtomografia computadorizada analisou a microarquitetura cortical: espessura cortical (CtTh), volume ósseo (BV), porosidade total (Ct.Po), porosidade intracortical (CtPo-cl), número de canal/ poro (Po.N), dimensão fractal (DF) e grau de anisotropia (Ct.DA). Após a varredura, a morfologia dos osteosn foi avaliada histologicamente por meio de: Área e perímetro do osteon (O.Ar; O.p) e dos canais de Havers (C.Ar; C.p). A análise microtomográfica foi realizada por ANOVA, seguida pelos testes de Tukey e Dunnet. As análises morfológicas do osteon foram realizadas por Kruskal-Wallis e testadas por Dunn. A espessura cortical foi diferente (p<0,010) entre os grupos controle e irradiados, com córtex mais espesso no Ir7d (1,15±0,09). A porosidade intracortical revelou diferenças significativas (p<0,001) entre os grupos irradiados e o controle, com menor valor para Ir7d (0,29±0,09). O volume ósseo foi menor no Ir14d em relação ao controle. Área e perímetro do osteon foi diferente (p<0,0001) entre o controle e Ir7d. Os canais haversianos também revelaram valores mais baixos (p<0,0001) em Ir7d (80.57±9.3; 31.63±6.5) em relação ao controle e demais grupos irradiados. A microarquitetura cortical é afetada pela radiação e os efeitos parecem ser dependentes do tempo, principalmente em relação à morfologia dos osteons nos dias iniciais. A estrutura cortical em Ir21d revelou semelhanças com o controle, sugerindo que a microarquitetura se assemelha à condição normal após um período.


Subject(s)
Animals , Male , Rabbits , Cortical Bone/diagnostic imaging , Haversian System , Bone and Bones , Porosity , Fractals
4.
Dental press j. orthod. (Impr.) ; 26(1): e211965, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1154060

ABSTRACT

ABSTRACT Objective: The aim of this study was to evaluate the thickness of the zygomatic-maxillary cortical bone using computed tomography in different skeletal patterns. Methods: A total of 54 patients of both sexes, divided into three groups according to the vertical skeletal pattern, were evaluated for cortical bone thickness of the anterior slope of the zygomatic process of the maxilla, using cone beam computed tomography. Measurements were made at 2mm, 4mm, 6mm, 8mm and 10mm above from first molar mesial root apex. Vertical skeletal pattern was determined by Frankfurt mandibular angle (FMA). Results: The hyperdivergent pattern had the lowest cortical thickness value, nevertheless, no patient in the hyperdivergent group presented cortical thickness exceeding 2mm, and no patient in the hypodivergent group presented cortical thickness less than 1mm. However, the correlation between cortical thickness and mandibular plane angle was weak and not significant. Conclusion: Although higher prevalence of thick cortical was observed in the hypodivergent patients, and thin cortical groups in the hyperdivergent group, the vertical skeletal pattern could not be used as determinant of the zygomatic-maxillary cortical thickness.


RESUMO Objetivo: O objetivo do presente estudo foi avaliar a espessura da cortical óssea zigomático-maxilar por meio de tomografia computadorizada em diferentes padrões esqueléticos. Métodos: Um total de 54 pacientes de ambos os sexos, divididos em três grupos, de acordo com o padrão esquelético vertical, foi avaliado quanto à espessura da cortical óssea na vertente anterior do processo zigomático da maxila, por meio de tomografia computadorizada de feixe cônico. As medidas foram feitas a 2mm, 4mm, 6mm, 8mm e 10mm acima do ápice da raiz mesial do primeiro molar. O padrão esquelético vertical foi determinado pelo Ângulo do Plano Mandibular (FMA). Resultados: O padrão hiperdivergente apresentou o menor valor de espessura de cortical. No entanto, nenhum paciente do grupo hiperdivergente apresentou espessura cortical superior a 2mm e nenhum paciente do grupo hipodivergente apresentou espessura cortical inferior a 1mm. No entanto, a correlação entre a espessura da cortical e o ângulo do plano mandibular foi fraca e não significativa. Conclusão: Embora tenha havido uma maior prevalência de cortical espessa no grupo hipodivergente e cortical fina no grupo hiperdivergente, o padrão esquelético vertical não pode ser utilizado como determinante da espessura cortical zigomático-maxilar.


Subject(s)
Humans , Male , Female , Cephalometry , Mandible , Maxilla , Cone-Beam Computed Tomography , Cortical Bone/diagnostic imaging , Mandible/diagnostic imaging , Maxilla/diagnostic imaging
5.
Dental press j. orthod. (Impr.) ; 25(6): 33-42, Nov.-Dec. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1154050

ABSTRACT

ABSTRACT Introduction: Controversial reports suggest a relationship between growth pattern and cortical alveolar bone thickness, and its effect in the use of mini-implants. Objective: The main purpose of this study was to assess the influence of the growth pattern on the cortical alveolar bone thickness and on the stability and success rate of mini-implants. Methods: Fifty-six mini-implants were inserted in the buccal region of the maxilla of 30 patients. These patients were allocated into two groups, based on their growth pattern (horizontal group [HG] and vertical group [VG]). Cortical thickness was measured using Cone Beam Computed Tomography. Stability of mini-implants, soft tissue in the insertion site, sensitivity during loading and plaque around the mini-implants were evaluated once a month. Intergroup comparisons were performed using t tests, Mann-Whitney tests, and Fisher exact tests. Correlations were evaluated with Pearson's correlation coefficient. Results: The cortical bone thickness was significantly greater in the HG at the maxillary labial anterior region and at the mandibular buccal posterior and labial anterior regions. There was a significant negative correlation between Frankfort-mandibular plane angle (FMA) and the labial cortical thickness of the maxilla, and with the labial and lingual cortical bone thicknesses of the mandible. No significant intergroup difference was found for mini-implant mobility and success rate. No associated factor influenced stability of the mini-implants. Conclusions: Growth pattern affects the alveolar bone cortical thickness in specific areas of the maxilla and mandible, with horizontal patients presenting greater cortical bone thickness. However, this fact may have no influence on the stability and success rate of mini-implants in the maxillary buccal posterior region.


RESUMO Introdução: Relatos controversos sugerem uma relação entre o padrão de crescimento e a espessura do osso alveolar cortical e seu efeito no uso de mini-implantes. Objetivo: Avaliar a influência do padrão de crescimento na espessura do osso cortical alveolar e na estabilidade e taxa de sucesso dos mini-implantes. Métodos: Cinquenta e seis mini-implantes foram inseridos na região vestibular da maxila de trinta pacientes. Esses pacientes foram alocados em dois grupos, com base em seu padrão de crescimento (grupo horizontal [GH] e grupo vertical [GV]). As espessuras corticais foram medidas por meio de tomografias computadorizadas de feixe cônico. A estabilidade dos mini-implantes, tecido mole no local de inserção, sensibilidade durante a carga e o acúmulo de placa ao redor dos mini-implantes foram avaliados uma vez por mês. As comparações intergrupos foram realizadas por testes t de Student, testes de Mann-Whitney e testes exatos de Fisher. As correlações foram avaliadas com o coeficiente de correlação de Pearson. Resultados: A espessura do osso cortical foi significativamente maior no GH na região vestibular anterior da maxila e nas regiões vestibulares posterior e anterior da mandíbula. Houve uma correlação negativa significativa entre o ângulo do plano mandibular (FMA) e a espessura da cortical vestibular da maxila, e com a espessura das corticais vestibular e lingual da mandíbula. Nenhuma diferença significativa entre os grupos foi encontrada com relação à mobilidade do mini-implante e taxa de sucesso. Nenhum fator associado influenciou a estabilidade dos mini-implantes. Conclusões: O padrão de crescimento afeta a espessura da cortical óssea alveolar em áreas específicas da maxila e mandíbula, com pacientes horizontais apresentando maior espessura da cortical óssea. No entanto, esse fato pode não ter influência na estabilidade e na taxa de sucesso dos mini-implantes na região vestibular posterior da maxila.


Subject(s)
Humans , Dental Implants , Cone-Beam Computed Tomography , Cortical Bone/diagnostic imaging , Mandible , Mandible/diagnostic imaging , Maxilla/diagnostic imaging
6.
Actual. osteol ; 16(1): 26-34, Ene - abr. 2020. ilus, graf
Article in Spanish | LILACS | ID: biblio-1130074

ABSTRACT

La expansión modeladora de la geometría cortical de un hueso inducida por su entorno mecánico podría ser difícil de modificar por estímulos ulteriores con diferente direccionalidad. Este estudio, que por primera vez combina datos tomográficos del peroné (pQCT) y dinamométricos de la musculatura peronea lateral, intenta demostrar que, en individuos jóvenes no entrenados, el entrenamiento en fútbol produce cambios geométricos peroneos expansivos, similares a los del rugby, que podrían interferir en los efectos de un entrenamiento ulterior direccionalmente diferente (carrera larga). Confirmando la hipótesis, los resultados indican, con evidencias originales, 1) la relevancia creciente del uso del pie (rotación externa y eversión provocadas por los peroneos laterales) para la determinación de la geometría peronea (incremento del desarrollo de los indicadores de masa y de diseño óseos), evidenciada por la secuencia creciente de efectos: carrera < fútbol < rugby; 2) la predominancia de esos efectos sobre el desarrollo centro-proximal del peroné para resistir a la flexión lateral, y en la región distal para resistir el buckling (principal sitio y causa de fractura del hueso) y 3.) la relevancia de la anticipación de esos efectos para interferir en la manifestación de los cambios producidos por un entrenamiento ulterior (carrera), cuando los del primero (fútbol) afectan la modelación cortical de modo expansivo. Esta última deducción demuestra, en forma inédita, que un cambio modelatorio expansivo tempranamente inducido sobre la estructura cortical ósea 'delimitaría el terreno'para la manifestación de cualquier otro efecto ulterior por estímulos de distinta direccionalidad. (AU)


The modeling-dependent, geometrical expansion of cortical bone induced by the mechanical environment could be hard to modify by subsequent stimulations with a different directionality. The current study aimed to demonstrate that in young, untrained individuals, training in soccer or rugby enhances the geometric properties of the fibula cortical shell in such a way that the geometrical changes could interfere on the effects of a second training in which the loads are induced in a different direction, e.g. long-distance running. The original findings reported herein confirm our hypothesis and support 1) The relevance of the use of the foot (external rotation and eversion produced by peroneus muscles) to determine fibula geometry (improved development of indicators of bone mass and design) as evidenced by the increasing nature of the effects induced by running < soccer < rugby trainings; 2) The predominance of those effects on the ability of the fibula to resist lateral bending in the centralproximal region (insertion of peroneus muscles), and to resist buckling in the distal region (the main cause and site of the most frequent bone fractures), and 3) The interaction of the effects of a previous training with those of a subsequent training with a different orientation of the loads when the former induced a modeling-dependent expansion of the cortex. Our results support the proposed hypothesis with original arguments by showing that a first, expansive effect induced on cortical bone modeling would set the stage the manifestation of any subsequent effect derived from mechanical stimuli. (AU)


Subject(s)
Humans , Male , Adolescent , Adult , Young Adult , Exercise/physiology , Fibula/growth & development , Running/physiology , Soccer/physiology , Sports/physiology , Tomography , Bone Density , Fractures, Bone/prevention & control , Muscle Strength/physiology , Muscle Strength Dynamometer , Fibula/diagnostic imaging , Cortical Bone/diagnostic imaging , Foot/growth & development , Foot/physiology , Foot/diagnostic imaging , Football/physiology
7.
J. appl. oral sci ; 28: e20190435, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1056593

ABSTRACT

Abstract Objective To quantify the bone volume that can be safely withdrawn from 3 donor sites: (1) the mandibular symphysis, (2) the oblique mandibular line and (3) the skullcap. Methodology For the symphysis, 200 tomographic exams were evaluated by the extension of the anterior loop of mental foramen, by the nerve, by the distance of the foramens, by the distance between the vestibular cortical and the lingual plates and by the distance between the apexes, or lower anterior teeth, and the mandibular base, using the "distance" tool of the I-CAT Vision, in the panoramic and parasagittal reformations. For the oblique line, 70 TCFC exams were analyzed retrospectively in panoramic and parasagittal reformations, evaluating the thickness of the vestibular cortical and the distance between the cortical and the mandibular canal. For the cranial bone, a hexagonal donor site located in parietal area was considered. Results The average dimensions of the bone blocks that can be safely removed from the region of the mandibular symphysis are: 32.27 mm in length, 4.87 mm in height and 4 mm in thickness, providing a volume of 628.61 mm3 available for grafting. In the oblique line, the available bone volume for grafting was 859.61 mm3. In the region of the cranial vault, multiplying the average bone thickness by the area of the hexagon, an average volume of 2,499 mm3 was obtained. Conclusions Comparing the donor sites, the bone availability in the cranial vault is 3 times greater than in the mandibular posterior region, and at least 2 times greater than in the mandibular symphysis.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Skull/transplantation , Bone Transplantation/methods , Cone-Beam Computed Tomography/methods , Transplant Donor Site , Mandible/transplantation , Skull/diagnostic imaging , Retrospective Studies , Anatomic Landmarks , Transplant Donor Site/diagnostic imaging , Cortical Bone/transplantation , Cortical Bone/diagnostic imaging , Mandible/diagnostic imaging , Medical Illustration
8.
Int. j. morphol ; 36(3): 1002-1006, Sept. 2018. tab, graf
Article in English | LILACS | ID: biblio-954222

ABSTRACT

Cone Beam Computed Tomography (CBCT) measurement of cortical bone thickness and implantation angle in the maxillary posterior region was used to provide reference for the safety of Micro-Implanted-Anchorage (MIA) implantation in skeletal class II malocclusion. Twenty samples of CBCT images were collected from orthodontics patients (ages, 12-40 years) in Shanxi Medical University Stomatological Hospital, the thickness of cortical bone was measured at 45°, 60° and 90° from the alveolar crest, being at 4 mm, 6 mm and 8 mm, respectively. SPSS17.0 statistical software was used to analyze the data, and the one-way ANOVA and LSD method were compared. There was a significant difference in the thickness of the cortical bone obtained by implanting MIA at the same height of different angle (P≤0.05). The greater the inclination angle of the implanted MIA, the thicker the cortical bone. Also, the higher the implant site, the thicker the cortical bone thickness. Finally, the greater the thickness of the cortical bone in the maxillary posterior region of skeletal class II malocclusion, the greater the thickness of the cortical bone. At the same implantation height, implanted MIA with a tilt angle of 45º to 60º, 90º to obtain the best cortical bone thickness.


La medición del grosor del hueso cortical y del ángulo de implantación en la región posterior del maxilar por tomografía computarizada de haz cónico (TCHC) se utilizó para proporcionar una referencia para la implantación y el anclaje seguros de un Micro-Implante de Anclaje (MIA) en la maloclusión de clase esquelética tipo II. Veinte muestras de imágenes de TCHC fueron obtenidas de pacientes de ortodoncia (12-40 años) en el Hospital Estomatológico de la Universidad Médica de Shanxi. Se midió el grosor del hueso cortical a 45°, 60° y 90° de la cresta alveolar, encontrándose a 4 mm, 6 mm y 8 mm, respectivamente. Se utilizó el software estadístico SPSS 17.0 para analizar los datos, y se compararon con los métodos ANOVA y LSD de un factor. Hubo una diferencia significativa en el grosor del hueso cortical obtenido al implantar el MIA a la misma altura en diferentes ángulos (P <0,05). Cuanto mayor es el ángulo de inclinación del MIA implantado, más grueso es el hueso cortical. También, cuanto más alto es el sitio del implante, más grueso es el grosor del hueso cortical. Finalmente, cuanto mayor sea el grosor del hueso cortical en la región posterior del maxilar, en la maloclusión de clase esquelética tipo II, mayor será el grosor del hueso cortical.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Orthodontic Anchorage Procedures , Cortical Bone/anatomy & histology , Cortical Bone/diagnostic imaging , Malocclusion, Angle Class II , Cone-Beam Computed Tomography
10.
Clinics ; 71(11): 657-663, Nov. 2016. tab, graf
Article in English | LILACS | ID: biblio-828545

ABSTRACT

OBJECTIVE: To compare ultrasound propagation velocity with densitometry in the diaphyseal compact cortical bone of whole sheep metatarsals. METHODS: The transverse ultrasound velocity and bone mineral density of 5-cm-long diaphyseal bone segments were first measured. The bone segments were then divided into four groups of 15 segments each and demineralized in an aqueous 0.5 N hydrochloric acid solution for 6, 12, 24 or 36 hours. All measurements were repeated after demineralization for each time duration and the values measured before and after demineralization were compared. RESULTS: Ultrasound velocity and bone mineral density decreased with demineralization time, and most differences in the pre- and post-demineralization values within each group and between groups were significant: A moderate correlation coefficient (r=0.75956) together with a moderate agreement was determined between both post-demineralization parameters, detected by the Bland-Altman method. CONCLUSION: We conclude that both ultrasound velocity and bone mineral density decrease as a result of demineralization, thus indicating that bone mineral content is of great importance for maintaining the acoustic parameters of cortical bone, as observed for cancellous bone. Ultrasound velocity can be used to evaluate both compact cortical bone quality and bone mineral density.


Subject(s)
Animals , Osteoporosis/diagnostic imaging , Ultrasonography/methods , Bone Demineralization Technique , Densitometry , Cortical Bone/diagnostic imaging , Osteoporosis/physiopathology , Time Factors , Sheep , Metatarsal Bones/physiopathology , Metatarsal Bones/diagnostic imaging , Bone Density , Cortical Bone/physiopathology
11.
Rev. argent. radiol ; 80(2): 127-135, jun. 2016. ilus
Article in Spanish | LILACS | ID: biblio-843215

ABSTRACT

La ecografía es el método de elección para la evaluación inicial de las partes blandas y el sistema muscular, siendo una técnica accesible, portátil y de bajo costo. Sin embargo, ha sido excluida de la exploración y evaluación de las patologías óseas debido a la idea de que es incapaz de penetrar la superficie del hueso. De hecho, muchos radiólogos admiten que esta es una de las pocas localizaciones donde la ecografía no resulta efectiva. Si bien algunos de estos conceptos son ciertos, este método puede aportar valiosa información diagnóstica sobre el estado del hueso, principalmente sobre la cortical ósea, en variadas circunstancias. La ecografía de la cortical ósea es posible por el artefacto de reflexión hiperecogénico lineal y regular que esta genera. En manos experimentadas, el reconocimiento y exploración de la superficie ósea permiten obtener datos muy útiles. Los tumores óseos generan reacciones periósticas fácilmente observables y caracterizables por ultrasonido, con la ventaja adicional de que el Doppler color identifica la vascularización del tumor. Las fracturas se observan como disrupciones de la cortical y la patología degenerativa se puede sospechar ante irregularidades corticales. Asimismo, es posible reconocer patologías como avulsiones, callos óseos de procesos previos e incluso fracturas por estrés. En este ensayo iconográfico mostramos diferentes casos de ecografías de partes blandas que evidenciaron hallazgos patológicos en la cortical ósea, permitiendo arribar a un diagnóstico o guiando en la elección de un estudio adicional.


Ultrasound is the best choice to evaluate soft tissues and the muscular system because of its accessibility, low cost and portability. Historically, the assumption has been that because ultrasound waves cannot penetrate bone, it is not useful in the evaluation of the skeletal system and its diseases. Radiologists admit that one of the very few tissue types which ultrasound cannot evaluate is bone. There is, of course, much truth in this, but recent studies suggest that ultrasound can provide valuable diagnostic information regarding the state of bone in some circumstances. The high reflectivity of sound at the bone-soft tissue interface is what allows the bone surface to be visualised. Valuable diagnostic information can be obtained by exploring bone surface in detail. The fact that bone tumours manifest themselves as periosteal reactions makes them easily recognisable by ultrasound, with the additional advantage if using Doppler colour. Bone fractures could be seen as interruptions of the bone continuity, and degenerative diseases should be suspected when an irregular surface is observed. Likewise, other pathologies such as avulsion fractures, bone callus stemming from previous processes, and even stress fractures can be identified. In this pictorial essay different cases are presented of musculoskeletal ultrasound in which bone surface was evaluated and abnormalities discovered, making a diagnosis or suggesting an additional test.


Subject(s)
Humans , Ultrasonography , Cortical Bone/diagnostic imaging , Soft Tissue Neoplasms , Ultrasonography, Doppler, Color , Ultrasonography, Doppler , Hand/diagnostic imaging
12.
Braz. oral res. (Online) ; 30(1): e49, 2016. tab, graf
Article in English | LILACS | ID: biblio-952050

ABSTRACT

Abstract The aim of this study was to assess the presence, location and, multiplanar distance of the canalis sinuosus (CS) between the incisive foramen and the anterior maxillary alveolar ridge using cone beam computed tomography (CBCT). Therefore, 500 CBCT maxillary images obtained from male and female patients aged 20 to 80 years were selected to assist in the dental treatment. Low-quality tomographic images were discarded. All images were captured with the i-CATTM Classic tomograph and assessed using the XoranCatTM software. The axial sections were analyzed at the incisive foramen in order to verify the CS presence in laterality and location. Furthermore, linear measurements of the nasal cavity floor, buccal cortical bone, and alveolar ridge crest were made. All the collected data were statistically analyzed. Results show a variation of the CS in relation to the classification and distance of anatomical structures, but no significant difference between the right and left sides. It should be highlighted that CBCT is necessary before invasive procedures in order to preserve important anatomical structures. In conclusion, the location of the CS varies in relation to the alveolar ridge crest and buccal cortical bone, assuming that it is going to be located by the upper lateral incisor palatine.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Cone-Beam Computed Tomography/methods , Alveolar Process/anatomy & histology , Alveolar Process/diagnostic imaging , Maxilla/anatomy & histology , Maxilla/diagnostic imaging , Maxillary Nerve/anatomy & histology , Maxillary Nerve/diagnostic imaging , Reference Values , Image Processing, Computer-Assisted , Sex Factors , Retrospective Studies , Palate, Hard/anatomy & histology , Palate, Hard/diagnostic imaging , Diagnostic Errors , Anatomic Variation , Cortical Bone/anatomy & histology , Cortical Bone/diagnostic imaging , Incisor/anatomy & histology , Incisor/diagnostic imaging , Middle Aged , Odontometry/methods
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