Bone turnover markers, hip bone geometry parameters and metabolic syndrome in community overweight postmenopausal women / 中华内分泌代谢杂志

Objective:To explore the changes of bone turnover markers and geometric parameters of hip bone in overweight postmenopausal women with metabolic syndrome(MS), as well as the influence of MS components. To analyze the association of these factors with the risk of fracture.Methods:A total of 505 overweight postmenopausal female patients who underwent health check-up in Lianhu Community Service Center, Danyang City, Jiangsu Province from January to December 2017 were selected. According to the MS diagnostic criteria of the International Diabetes Federation(2009), the patients were divided into MS group( n=331)and non-MS group( n=174). Blood samples were collected to determine the level of procollagen type 1 N-terminal propeptide(P1NP)and carboxy-terminal cross-linked telopeptide of type 1 collagen(CTX). Bone mineral density and hip bone geometry parameters were tested with dual-energy X-ray absorptiometry and hip structural analysis software. Results:The incidence of osteoporotic fracture and hip fracture in MS group was significantly higher than that in non-MS group(21.1% vs 13.8%, 4.8% vs 1. 1%, P<0.05). However, the bone mineral density of lumbar vertebra 1-4, femoral neck, and total hip in MS group was significantly higher than that in non-MS group, which remained after adjusting for age( P<0.05), but the difference disappeared after further adjustment for body mass index( P>0.05). The P1NP, CTX, femur strength index(FSI), section modulus(SM), and cross-sectional area(CSA)of MS group were significantly lower than those of non-MS group, the buckling ration(BR)was significantly higher than that in non-MS group, and the differences were still statistically significant after adjusting for age and body mass index( P<0.05). There was no significant difference in bone mineral density of lumbar vertebra 1-4, femoral neck, total hip, P1NP, and CTX between fracture group and non-fracture group in patients with MS. But FSI, SM, cross-sectional moment of inertia(CSMI), and CSA were significantly lower, BR was significantly higher( P<0.05) and femur strength decreased in patients with fracture. Regression analysis showed that high BR was an independent risk factor for fracture risk, while high FSI, SM, CSMI, and CSA were protective factors. Multivariate linear regression analysis showed that wasit circumference, diastolic blood pressure, and fasting plasma glucose were the main MS components affecting bone mineral density, bone turnover indexes, and hip bone geometry parameters. Conclusions:Overweight postmenopausal MS patients had decreased bone turnover rate, femoral strength, and relatively poor bone quality. Hip bone geometry parameters can be used as one of the methods to assess fracture risk in MS patients. Waist circumference, diastolic blood pressure, and fasting blood glucose are the important MS components affecting bone mass and bone quality.

Digital panoramic radiography as a tool for analyzing the quality of trabecular bone microarchitecture / Radiografia panorâmica digital como ferramenta de análise da qualidade da microarquitetura óssea trabecular

Abstract Introduction Osteoporosis is a metabolic disease characterized by reduced bone mineral density, often accompanied by loss of quality of trabecular bone microarchitecture. Objective To assess the quality or degradation of trabecular bone microarchitecture in digital panoramic radiography to better predict the risk of fragility fractures. Material and method The sample included 68 female patients, age-matched, and divided into three groups according to densitometric results. Trabecular Bone Score values were measured and digital panoramic radiographs were taken. Fractal analysis with box counting was conducted in the region of premolars and angle of the mandible, with regions of interest measuring 64×64 and 80×120 pixels. In the statistical analysis, Pearson's correlation was applied between the Trabecular Bone Score and fractal analysis results obtained in each group, using age as a control variable and assigning individualized age ranges within groups. Result A moderate correlation was identified in the regions of interest of 64×64 and 80×120 pixels at the angle of the mandible in the osteoporosis group and in the normal group. A moderate correlation was also obtained using age as a control variable in the 64x64 pixel regions of interest in the premolar region. Considering age range, the within-group analysis presented a strong correlation in the osteoporosis group and moderate correlation in the osteopenia and normal groups. Conclusion Fractal analysis in digital panoramic radiographs was shown to be a promising predictive instrument of bone microarchitecture quality.

Resumo Introdução A osteoporose é uma doença metabólica caracterizada pela redução da densidade mineral óssea, muitas vezes acompanhada da perda de qualidade da microarquitetura óssea trabecular. Objetivo Avaliar a qualidade da microarquitetura óssea trabecular em radiografia panorâmica digital a fim de identificar precocemente a sua degradação, possibilitando melhor predição do risco de fraturas por fragilidade. Material e método A amostra consistiu de 68 pacientes do sexo feminino, pareadas por idade, e divididas em 3 grupos conforme resultado densitométrico. Foram aferidos os valores de Trabecular Bone Score e realizadas radiografias panorâmicas digitais. A análise fractal com box counting foi feita na região de pré-molares e ângulo da mandíbula, com regiões de interesse medindo 64x64 e 80x120 pixels. Na análise estatística utilizou-se a correlação de Pearson entre os resultados de Trabecular Bone Score e de análise fractal obtidos em cada grupo, utilizando-se a idade como variável de controle e através de atribuição de grupos etários individualizados intragrupos. Resultado Identificou-se correlação moderada nas regiões de interesse de 64x64 e 80x120 pixels, em ângulo da mandíbula no grupo Osteoporose e no grupo normal. Também se obteve correlação moderada utilizando a idade como variável de controle nas regiões de interesse de 64x64 pixels, em região de pré-molares. A análise intragrupos, considerando a faixa etária, resultou em correlação forte, no grupo osteoporose e moderada nos grupos osteopenia e normal. Conclusão A análise fractal em radiografias panorâmicas digitais se mostrou promissora como instrumento preditivo da qualidade de microarquitetura óssea.

Bone quality and fracture line morphology of the posterior medial humeral calcar in proximal humerus fractures / 中华骨科杂志

Objective:To investigate the relationship between fracture line morphology, bone quality and fracture type in the posterior medial humeral talus of proximal humerus fractures.Methods:Retrospective analysis of CT data of patients with proximal humeral fractures diagnosed in our hospital from June 2020 to June 2021. Based on 3D reconstruction, the fracture line of the posterior medial humeral calcar was described, substituted into the proximal humeral template to depict the fracture map;and the coordinates of the turning point of the posterior medial fracture line were recorded, and the most concentrated coordinate interval was displayed using Matlab heat mapscript, substituted into the proximal humeral template to mark the area of concentration of the turning point of the fracture line. And according to the inclination angle of the humeral head to establish internal and external rotation and normal group, three groups of humeral distance posterior medial bone density, bone thickness and fracture horizontal line angle were performed and recorded by unordered multicategorical Logistic regression analysis.Results:A total of 62 patients with proximal humeral fractures were included; 21 (34%) were internally turned, 24 (39%) were externally turned and 17 (27%) were normal. Inversion: bone density 0.59±0.12 g/cm 3, bone thickness 2.33±0.48 mm, fracture horizontal line angle 4.54°±14.13°. Normal: Bone density 0.57±0.15 g/cm 3, bone thickness 2.60±0.33 mm, fracture level angle -1.87°±9.98°. Ectropion: bone density 0.62±0.11 g/cm 3, bone thickness 2.69±0.54 mm, fracture horizontal angle -5.64°±20.03°. Epiphyseal extension occurs most often posteriorly and medially, with the fracture line turning point located posterior to the greater tuberosity. Unordered multicategorical Logistic regression of the data showed that: inversion fracture horizontal line angle ( β=0.06, P=0.018), statistically significant, OR=1.06 [95% CI (1.00, 1.12)]; bone thickness ( β=-2.02, P=0.041), statistically significant, OR=0.13 [95% CI (0.03, 0.71)]; bone density ( β=-0.43, P=0.887), not statistically significant; none of the ectropion patterns were statistically significant ( P>0.05). Conclusion:The trend of the fracture line and bone thickness of the posterior medial humeral calcar are factors that influence internal rotation of the humeral head. The incidence of internal rotation is positively correlated with the upward trend of the fracture line and negatively correlated with the thickness of the bone. The fracture line turning point is most often located posterior to the greater tuberosity.

Effects of rosin diglucoside on bone metabolism in young rats / 中国药理学通报

Aim To research the effect of PDG on bone metabolism in young rats. Methods The experimental rats were randomly divided into contro group, PDG-25 group and PDG-50 group. PDG-25 group and PDG-50 group were given PDG at the dose of 25 mg·kg

Effect of advanced glycation end products on metabolism of bone tissue cells / 中国组织工程研究

BACKGROUND: With the research and development of bone tissue engineering, it has been found that advanced glycation end products can accumulate in bone tissue and affect the structure and biomechanical properties of bone. At present, many researchers have discovered that advanced glycation end products/receptor for advanced glycation end products can induce pathological changes of osteoblasts, osteoclasts and osteocytes through special mechanisms, thereby leading to imbalance of bone reconstruction, decrease of bone strength and increase of fracture incidence. OBJECTIVE: To review the effects of advanced glycation end products on bone biomechanics and the mechanism of advanced glycation end products/receptor for advanced glycation end products on bone tissue cells. METHODS: The first author searched the relevant articles regarding the effect of advanced glycation end products/receptor for advanced glycation end products on metabolism of bone tissue cells published in PubMed, Web of Science and Medline database from January 2005 to July 2019. The results were limited to English literatures. RESULTS AND CONCLUSION: Finally, 54 representative literatures were selected for summary. The effects of advanced glycation end products on collagen cross-linking can significantly reduce bone strength. Advanced glycation end products/receptor for advanced glycation end products affects bone metabolism through pathological mechanism changes of bone tissue cells, which results in essential changes of bone tissue cells. Finally, it will lead to imbalance of bone metabolism and increase of bone fragility. The osteoporosis is directly related to the activity change of bone tissue cells, but the specific mechanism needs further study. The change of this special mechanism may provide a unique pathological mechanism, diagnosis methods, treatment and prevention strategies for osteoporosis in the future.

Diabetes and bone

Bone disease is a serious complication to diabetes. Patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) suffer from an increased risk of fracture, most notably at the hip, compared with patients without diabetes. Confounders such as patient sex, age, body mass index, blood glucose status, fall risk, and diabetes medications may influence the fracture risk. Different underlying mechanisms contribute to bone disease in patients with diabetes. Bone quality is affected by low bone turnover in T1D and T2D, and furthermore, incorporation of advanced glycation end-products, changes in the incretin hormone response, and microvascular complications contribute to impaired bone quality and increased fracture risk. Diagnosis of bone disease in patients with diabetes is a challenge as current methods for fracture prediction such as bone mineral density T-score and fracture risk assessment tools underestimate fracture risk for patients with T1D and T2D. This review focuses on bone disease and fracture risk in patients with diabetes regarding epidemiology, underlying disease mechanisms, and diagnostic methods, and we also provide considerations regarding the management of diabetes patients with bone disease in terms of an intervention threshold and different treatments.

Bone quality evaluation of experimental osteometabolic disease in Pantanal alligators (Caiman yacare) by High Resolution Computerized Microtomography (µCT) / Avaliação da qualidade óssea de doença osteometabólica experimental em jacarés do pantanal (Caiman yacare) por Microtomografia Computadorizada (µCT)

Computerized microtomography is the gold standard examination for the evaluation of the three-dimensional bone structure. This experiment was developed to evaluate the structure and bone quality of Caiman yacare with metabolic bone disease using high resolution computerized microtomography (μCT). The animals were distributed into four groups: G1 - hyperphosphatemic diet with sun exposure deprivation (n=4), G2 - hyperphosphatemic diet with sun exposure (n=4), G3 - balanced diet with sun exposure deprivation (n=4), and G4 - balanced diet with exposure to sunlight (n=4). The parameters for the trabecular bone (Trabecular Number, Trabecular Thickness, Trabecular Separation, Bone Pattern Factor, Fractal Dimension, Euler Number, Structural Model Index, Degree of Anisotropy, Eigenvalues 1, 2 and 3, and Centroides X, Y and Z), and cortical bone (Number of Closed Pores, Volume of Closed Pores, Surface of Closed Pores, Closed Porosity, Volume of Open Pores, Open Porosity and Total Porosity). The overall results showed that the structure and bone quality of group G3 and G4 were better than those of groups G1 and G2, and that the diet factor influenced more than the sun exposure factor. The computerized microtomography allowed to evaluate the quality of the cortical and trabecular bones of the Pantanal alligator tibia with osteometabolic disease. The diet and sun exposure factors influenced individually the results of the μCT parameters between the groups, demonstrating the functional and structural complexity. Thus, these parameters can contribute to the interpretation of the mechanical behavior of bones and correlate them with the risk of lesions and fractures associated with osteometabolic diseases.(AU)

Microtomografia computadorizada é o exame padrão-ouro para a avaliação da estrutura tridimensional do osso. Este estudo experimental foi desenvolvido para avaliar a estrutura e a qualidade óssea de jacarés-do-pantanal (Caiman yacare) com doença óssea metabólica utilizando a microtomografia computadorizada (μCT) de Alta Resolução. Os animais foram distribuídos em quatro grupos, G1 - dieta hiperfosfatêmica com privação de luz solar (n=4), G2 - dieta hiperfosfatêmica com exposição à luz solar (n=4), G3 - dieta balanceada com privação de luz solar (n=4) e G4 - dieta balanceada com exposição à luz solar (n=4). Avaliaram-se os parâmetros para o osso trabecular (Número de Trabéculas, Espessura Trabecular, Separação Trabecular, Fator do Padrão Ósseo, Dimensão Fractal, Número de Euler, Índice do Modelo Estrutural, Grau de Anisotropia, Autovalores 1, 2 e 3 e Centroides X, Y e Z) e osso cortical (Número de Poros Fechados, Volume dos Poros Fechados, Superfície de Poros Fechados, Porosidade Fechada, Volume de Poros Abertos, Porosidade Aberta e Porosidade Total). Os resultados gerais evidenciaram que a estrutura e a qualidade óssea dos grupos G3 e G4 foram superiores aos dos grupos G1 e G2, sendo que o fator dieta influenciou mais do que o fator exposição solar. A Microtomografia Computadorizada permitiu avaliar a qualidade dos ossos cortical e trabecular da tíbia de jacarés do pantanal com doença osteometabólica. Os fatores dieta e exposição solar influenciaram individualmente no resultado dos parâmetros do μCT entre os grupos, demonstrando a complexidade funcional e estrutural. Assim, esses parâmetros podem contribuir na interpretação do comportamento mecânico dos ossos e correlacioná-los com o risco de lesões e fraturas associadas às doenças osteometabólicas.(AU)

Various bio-mechanical factors affecting heat generation during osteotomy preparation: A systematic review

As implant site preparation and bone are critical precursors to primary healing, thermal and mechanical damage to the bone must be minimized during the preparation of the implant site. Moreover, excessively traumatic surgery can adversely affect the maturation of bone tissue at the bone/implant interface and consequently diminish the predictability of osseointegration. So, this study was carried out to evaluate the various biological and mechanical factors responsible for heat generation during osteotomy site preparation to reduce the same for successful osseointegration of dental implants. Study Design: A broad search of the dental literature in PubMed added by manual search was performed for articles published between 1992 and December 2015. Various bio-mechanical factors related to dental implant osteotomy preparation such as dental implant drill designs/material/wear, drilling methods, type of irrigation, and bone quality were reviewed. Titles and abstracts were screened and articles which fulfilled the inclusion criteria were selected for a full-text reading. Results: The initial database search yielded 123 titles, of which 59 titles were discarded after reading the titles and abstracts, 30 articles were again excluded based on inclusion and exclusion criteria, and finally 34 articles were selected for data extraction. Many biological and mechanical factors responsible for heat generation were found. Conclusion: Literatures of this review study have indicated that there are various bio-mechanical reasons, which affect the temperature rise during osteotomy and suggest that the amount of heat generation is a multifactorial in nature and it should be minimized for better primary healing of the implant site.

Dual-Energy X-Ray Absorptiometry: Beyond Bone Mineral Density Determination

Significant improvements in dual-energy X-ray absorptiometry (DXA) concerning quality, image resolution and image acquisition time have allowed the development of various functions. DXA can evaluate bone quality by indirect analysis of micro- and macro-architecture of the bone, which and improve the prediction of fracture risk. DXA can also detect existing fractures, such as vertebral fractures or atypical femur fractures, without additional radiologic imaging and radiation exposure. Moreover, it can assess the metabolic status by the measurement of body composition parameters like muscle mass and visceral fat. Although more studies are required to validate and clinically use these parameters, it is clear that DXA is not just for bone mineral densitometry.

Osteoporosis management in patient with renal function impairment / Manejo da osteoporose no paciente com função renal comprometida

Aging is associated with decreases in bone quality and in glomerular filtration. Consequently, osteoporosis and chronic kidney disease (CKD) are common comorbid conditions in the elderly, and often coexist. Biochemical abnormalities in the homeostasis of calcium and phosphorus begin early in CKD, leading to an increase in fracture risk and cardiovascular complications since early stages of the disease. The ability of DXA (dual energy X-ray absorptiometry) to diagnose osteoporosis and to predict fractures in this population remains unclear. The management of the disease is also controversial: calcium and vitamin D, although recommended, must be prescribed with caution, considering vascular calcification risk and the development of adynamic bone disease. Furthermore, safety and effectiveness of osteoporosis drugs are not established in patients with CKD. Thus, risks and benefits of antiosteoporosis treatment must be considered individually.

O envelhecimento associa-se tanto ao declínio da qualidade óssea quanto da filtração glomerular. Consequentemente, osteoporose e doença renal crônica (DRC) são comorbidades frequentes em idosos, e muitas vezes coexistem. Anormalidades bioquímicas na homeostase do cálcio e do fósforo surgem precocemente na DRC, causando aumento do risco de fraturas e de complicações cardiovasculares desde fases precoces da doença. A capacidade da densitometria (DXA) em diagnosticar osteoporose e predizer fraturas nessa população é questionável. O manejo da doença é também controverso; cálcio e vitamina D são recomendados com cautela, devido ao risco de calcificações vasculares e de doença óssea adinâmica. Além disso, a segurança e a eficácia dos medicamentos para osteoporose ainda não estão estabelecidas em pacientes com DRC. Assim, riscos e benefícios do tratamento para osteoporose devem ser considerados individualmente nesses pacientes.

Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (µCT)

INTRODUCTION: Trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. METHODS: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freezed at - 20 °C before carrying out the microCT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). RESULTS: The Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transverserly isotropic symmetry. DISCUSSION: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (∝CT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases.

Teriparatide (recombinant human parathyroid hormone 1-34) for the treatment of osteoporosis: a review / 中华内分泌代谢杂志

Teriparatide is an injectable recombinant human parathyroid hormone (1-34) [rhPTH(1-34)],which has been approved for the treatment of osteoporosis worldwide,including China since 2011.In pre-clinical studies,teriparatide was shown to exhibit anabolic effects on bone with a unique mechanism of action that is distinct from that of antiresorptive agents,including bisphosphonates,selective estrogen receptor modulators (SERMs),calcitonin,and estrogen.This bone-building effect has been supported by clinical trials in men and postmenopausal women,with reductions in fracture risk,and increases in bone turnover markers,including serum osteocalcin and procollagen type Ⅰ N-terminal propeptide (PINP),and bone mineral density (BMD),and improvements in bone quality.Recent studies in Asian patient populations show similar results and support the findings for bone markers and BMD when compared with current antiresorptive medications.

Calidad del hueso en mujeres de edad mediana con hipertiroidismo subclínico farmacológico / Bone quality in middle age women presenting with pharmacological subclinical hyperthyroidism

Las hormonas tiroideas en niveles suprafisiológicos y el hipoestrinismo son factores que pueden inducir baja masa ósea. Objetivo: determinar la calidad de hueso en mujeres en etapa de climaterio que reciben tratamiento con dosis supresivas con hormonas tiroideas. Mètodos: estudio de casos y controles realizado entre marzo de 2006 y diciembre de 2008. Incluye 113 mujeres con edades entre 40-59 años que asisten a la consulta externa de los Institutos Nacionales de Endocrinología y Oncología y Radiobiología, de ellas 43 recibían tratamiento con hormonas tiroideas (grupo estudio) y 70 no (grupo control). Mediante absorciometría dual de rayos x de columna lumbar y antebrazo, se precisó la densidad mineral ósea en g/cm² y el puntaje T, a fin de identificar la presencia de osteopenia o baja masa ósea y osteoporosis. La densidad mineral ósea de columna lumbar y antebrazo fue de 0,9229 vs. 0,8856 (p>0,05) y de 0,536 vs. 0,6226 (p<0,05) para las pacientes de los grupos de estudio y control. A mayor tiempo de tratamiento con hormonas tiroideas se encontró menor contenido mineral en ambos sitios anatómicos, aunque la afectación es mayor en antebrazo (p<0,05). El riesgo para fractura osteopenia+osteoporosis) en columna lumbar fue de 44,1 por ciento y de 50 por ciento, y en antebrazo de 44,8 y 42,7 por ciento respectivamente para las mujeres de los grupos de estudio y control (p>0,05 entre grupos). El uso de hormonas tiroideas en dosis supresiva disminuyó el contenido mineral óseo del antebrazo, sin incrementar el riesgo de fractura(AU)

Thyroid hormones at supraphysiological levels and the hypothyroidism are factors that may to induce a low bone mass. Objetive: to determine the bone quality in climacteric women under treatment with suppressive doses with thyroid hormones. Methods: the case-control study conducted between March, 2006 and December, 2008 includes 113 women aged 40-59 seen in external consultation of National Institutes of Endocrinology, Oncology and Radiobiology where 43 of them were under treatment with thyroid hormones (study group) and 70 not (control group). Using dual beam absorptiometry of lumbar spine and the forearm, it was possible to determine the bone mineral density in g/cm² and the T pointing to identify the presence of osteopenia or a low bone mass and osteoporosis. The bone mineral density of lumbar spine and forearm was of 0,9229 vs. 0,8856 (p<0,05) and of 0,536 vs. 0,6226 (p<0,05) for patients of study group. With treatment using thyroid hormones there was less mineral content in both anatomical sites, although the involvement if greater in the forearm (p<0,05). Fracture risk (osteopenia+osteoporosis) in lumbar spine was of 44,1 percent and of 50 percent and in the forearm was of 44,8 and 42,7 percent, respectively for women from both groups. The use of thyroid hormones in suppressive doses decreased the bone mineral content in forearm with no increase of facture risk(AU)

Comparison of implant stability after different implant surface treatments in dog bone

OBJECTIVES: The purpose of this investigation was to evaluate the effects of different implant surface treatments on implant stability in dog mandibles. MATERIAL AND METHODS: A total of 30 implants (Dentium Co, Seoul, Korea) were placed in 5 dog mandibles. Bone quality was assessed at each site. Implant stability was evaluated using 2 different methods. An OsstellTM resonance frequency analyzer (RFA) was used to determine the stability at baseline (day 1), and 3, 6 and 10 weeks after surgery. Animals were euthanized 10 weeks after implant installation. Specimens were obtained and submitted to the laboratory processing. Sections were stained with hematoxylin and eosin for histologic and histomorphometric analyses. All implantation sites in dog mandibles demonstrated bone types II and III. RESULTS AND CONCLUSIONS: All implants showed good primary stability at baseline in terms of insertion torque. The results of this study suggest that surface treatment may have significant effects on biological stability 3 weeks after implant placement. Further studies are needed to confirm these initial observations in poor quality bone.

Bone quality and osteoporosis therapy / Qualidade óssea e tratamento da osteoporose

Although BMD measured by DXA is a useful clinical tool for osteoporosis diagnosis, changes resulting from osteoporosis treatment only partially explain the observed reduction in fractures. Several other bone properties that influence its resistance to fractures and explain this discrepancy have been defined as "bone quality". Bone quality is determined by its structural and material properties and orchestrated by bone turnover, a continuous process of renewal through which old or damaged bone is replaced by a mechanically healthy bone and calcium homeostasis is maintained. Bone structural properties include its geometry (size and shape) and microarchitecture (trabecular architecture and cortical porosity), while bone material properties include its mineral and collagen composition as well as microdamage and its repair. This review aims to update concepts surrounding bone quality and how drugs employed to treat osteoporosis might influence them.

Embora a DMO, medida por DEXA, seja um recurso clínico útil para o diagnóstico da osteoporose, mudanças resultantes do tratamento da osteoporose explicam apenas parcialmente a redução de fraturas. As demais propriedades ósseas que influenciam sua resistência a fraturas, que não se referem à massa óssea e explicam a discrepância entre os valores de DMO e o risco de fratura, têm sido definidas como "qualidade óssea". A qualidade óssea é determinada por suas propriedades estruturais e materiais e orquestrada pela remodelação óssea, um processo contínuo de renovação por meio do qual o osso velho ou danificado é substituído por um osso mecanicamente saudável e a homeostase do cálcio é mantida. As propriedades estruturais ósseas incluem suas geometria (tamanho e formato) e microarquitetura (arquitetura trabecular e porosidade cortical), enquanto as propriedades materiais referem-se à sua composição mineral e colágena assim como ao microdano e seu reparo. O objetivo desta revisão é uma atualização sobre qualidade óssea e como os medicamentos empregados no tratamento da osteoporose podem modificá-la.

Diabetes Mellitus and the Risk of Fracture / 대한골다공증학회지

The bone mass is known to be decreased in patients with type 1 diabetes, and this is primarily due to osteoblastic dysfunction. A number of epidemiologic studies have consistently shown a significantly higher risk of fractures in type 1 diabetic patients as compared to that of healthy subjects. The data on bone mineral density (BMD) in patients with type 2 diabetes has been inconsistent. However, many recent epidemiologic studies have shown that the osteoporotic fracture risk, and especially at the hip, is also increased in patients with type 2 diabetes, and even in patients with normal or higher BMD. Meanwhile, several studies have shown higher bone mass and a lower fracture risk in subjects with recent onset type 2 diabetes or impaired glucose tolerance with hyperinsulinemia. Poor bone quality and an increased risk of falling are thought to be important contributing factors for the higher fracture risk in patients with type 2 diabetes. Collagen overglycosylation by accumulation of advanced glycation end products (AGE) is thought to be one of the possible mechanisms underlying poor bone quality. The risk of falling in patients with diabetes is increased due to hypoglycemia, visual impairment from retinopathy and cataracts, altered balance, gait problems due to neuropathy and foot ulcers, associated cardiovascular diseases and medication use. Insulin-sensitizing agents, such as thiazolidinediones, are also associated with a higher fracture risk through an increase in bone marrow adiposity and a decrease in osteoblastogenesis. Because diabetes and osteoporosis are highly prevalent chronic diseases in the aging population and the incidences are increasing worldwide, understanding the risk factors that predispose patients to such conditions is very important. On considering the potential mechanisms associated with bone metabolism, adequate glycemic control while minimizing the episodes of hypoglycemia is the most important first step in the medical management to prevent osteoporotic fractures in patients with diabetes.

Analysis of Biological Apatite Orientation in Rat Mandibles / Oral Science International

Recently, significant progress has been made in medical techniques for regenerating bone. However, bone evaluation techniques generally assess bone quantity as opposed to bone quality. The use of <i>c</i>-axis crystallite orientation of biological apatite (BAp) as a bone quality index has recently generated great interest. BAp demonstrates strong crystallographic anisotropy, and preferential alignment of BAp in each bone varies depending on the shape and stress conditions <i>in vivo</i>. In the mandible, complicated bone shape and stress conditions <i>in vivo</i> might be associated with both bone quantity and quality. In this study, we aimed to elucidate changes in the bone microstructure in the mandible using crystallographic orientation of BAp as a bone quality index. Using Crj: CD (SD) IGS female rats, we observed changes in the dentulous mandible during bone growth. Measuring points on the mandible were determined based on its positional relationship with the teeth. For analysis of bone quantity, the area and bone mineral density of cortical bone were evaluated using peripheral quantitative computed tomography (pQCT), while the orientation of the BAp <i>c</i>-axis, as analyzed by a micro-beam X-ray diffraction system, was used to assess bone quality. The results of both bone quantity and quality assessments indicated that changes during bone growth varied depending on the presence of teeth. We concluded that the microstructure (especially the texture) of BAp crystallite changes in correlation with variations in stress distribution <i>in vivo</i> resulting from changes in chewing conditions designed to optimize the dynamic chewing function.

Influence of implant diameter and length changes on initial stability / 대한치과보철학회지

STATEMENT OF PROBLEM: Adequate bone quality and quantity were important to achieve initial stability and to prevent early failures. However there were few published data available regarding the actual effect of dimensional change in implant geometry on initial stability. PURPOSE: The purpose of the current study was to investigate the influence of diameter and length changes on initial stability of implants. MATERIAL AND METHODS: Four types of dummy bone (D1, D2, D3 and D4) consisted of cortical and cancellous layers with different thickness were simulated. Implants which had similar surface area to each other (3.5 x 13.0-mm, 4.0 x 11.5-mm, 4.5 x 10.0-mm, 5.0 x 8.5-mm) were inserted in dummy bones. Implant stability as a function of peak insertion torque and resonance frequency values were recorded for each implant. RESULTS: 1. Bone quality was a major influential factor to achieve initial stability (P .05), however insertion torques were increased with wider and shorter implants (P < .05). 3. In D4 dummy bone, implant stability quotient values and insertion torques were decreased with wider and shorter implants (P <. 05). CONCLUSION: From a point of view of initial stability, it is suggested that use of wide and short implant may be helpful in avoiding bone augmentation procedures in area of adequate bone quality.

A comparison of the implant stability among various implant systems: clinical study

PURPOSE: To determine the change in stability of single-stage, three different design of implant systems in humans utilizing resonance frequency analysis for early healing period (24 weeks), without loading. MATERIAL AND METHODS: Twenty-five patients were included into this study. A total of 45 implants, three different design of implant systems (group A,C,R) were placed in the posterior maxilla or mandible. The specific transducer for each implant system was used. ISQ (implant stability quotient) reading were obtained for each implant at the time of surgery, 3, 6, 8, 10, 12, 24 weeks postoperatively. Data were analyzed for different implant type, bone type, healing time, anatomical locations. RESULTS: For each implant system, a two-factor mixed-model ANOVA demonstrated that a significant effect on ISQ values (group A = 0.0022, C = 0.017, R = 0.0018). For each implant system, in a two-factor mixed model ANOVA, and two-sample t-test, the main effect of jaw position (P > .005) on ISQ values were not significant. CONCLUSIONS: All the implant groups A, C and R, the change patterns of ISQ over time differed by bone type. Implant stability increased greatly between week 0 and week six and showed slow increase between week six and six months (plateau effect).