Particulated bone grafts--effectiveness of bone cell supply

OBJECTIVE: The objective of this study was to measure the amount of viable bone cells present in different types of bone graft. MATERIAL AND METHODS: Bone chips were harvested from the trabecular or cortical bone of the mandible or the iliac crest and either milled or not. The average size of unmilled bone particles was 5 x 5 x 5 mm and that of milled was 2 x 2 x 2 mm. Drill sludge was obtained using either a ball reamer, a diamond ball or an implant drill (the latter from mandibular bone and of average dimension 1 x 1 x 1 mm). A measure of 0.5 g of each category was cultured in Dulbecco's modified Eagle's medium with additives for four weeks. Cell counts were performed. An analysis of the osteocalcin synthesis, the alkaline phosphatase (ALP) activity, the collagen types and the concentration of bone-specific collagen cross-links in medium supernatants was performed. RESULTS: Cells stained positively for osteocalcin and ALP in all groups. Bone-specific collagen cross-links could be quantified and collagen of types I and V was present with no difference in all groups. Unmilled spongy bone chips revealed greater cell counts than milled (P<0.05). Spongy bone chips revealed greater cell counts than cortical bone chips (P<0.05). Drill sludge obtained by hard alloy ball reamer showed the least amount of viable cells (P<0.05). CONCLUSIONS: Bone milling reduces the quantity of osteoblasts. Bone obtained by the ball reamer supplies a smaller number of cells than bone obtained by other methods. Unmilled spongy bone chips appear to offer the greatest amount of viable osteoblasts.     

Aneurysmal bone cyst of the sphenoid bone

Aneurysmal bone cyst (ABC) is an uncommon benign lesion that rarely presents in the craniofacial region. Aneurysmal bone cysts represent nearly 1.4% of all bone tumors, and among those, only 3% are located in the cranium. In this study, we report on an ABC located in the sphenoid bone with superior nasal cavity and ethmoid extension. The presenting symptom of our patient was headache, followed by diplopia, loss of visual accuracy, and abduction restriction. We successfully resected the lesion by a combined subcranial-midfacial degloving approach without any complications or recurrence.     

Aneurysmal bone cyst of the zygomatic bone

Aneurysmal bone cysts are a rare finding in the facial bones and jaws. Only one previous case of this entity affecting the malar bone could be found in the literature. Ultrasound and isotope scan features of this entity are described.     

Oncological treatment of bone tumours and bone metastases

The majority of patients with a malignant bone lesion will have bone metastases from a distant primary tumour. This could be apparent at diagnosis or develop later in the course of the disease. Some primary tumour types are more likely than others to develop bone secondaries. This common clinical problem requires a multidisciplinary approach in order to reduce patient suffering and maintain quality of life. Almost all patients with metastatic bone disease will have incurable cancer and this needs to be acknowledged when considering treatment options. Conversely primary malignant bone tumours are relatively rare conditions and thus need to be managed by specialist centres. Multimodality, multiprofessional treatment is required which may last for many months and can be associated with considerable toxicity. Patients with localized disease can be cured but there remains a high risk of both local recurrence and metastases.     

可吸收性引导骨再生胶原膜治疗骨缺损的实验研究

本研究是对国产吸收性胶原膜的骨引导再生,在骨缺损上应用的有效性方面进行实验研究。方法在实验动物成年犬的颌骨左右侧形成骨缺损,实验侧的骨缺损上覆盖吸收性胶原膜,对照侧没有覆盖,实验期间分别为２周、６周、１２周的取出下颌骨;     

HA人工骨修复较大颌骨囊肿骨腔的临床探讨

本文对近10年来应用HA修复颌骨囊肿186例，及其中较大颌骨囊肿34例，进行了较系统的临床研究。手术切口一期愈合、外形满意27例（79．5％），较明显颗粒逸漏21例（61.7%），迟发性血清肿4例（2.9％）。并对4例单囊性角化囊肿用液氮冷冻后HA修复，经3年以上随访无复发。     

Relationship between bone mineral density and bone stiffness in bone fracture

Objectives Using cancellous bone blocks of racehorses, the relationship between bone mineral density (BMD), which indicates bone strength, and stiffness in bone fracture occurrences was studied.Methods Two groups of cancellous bone blocks were prepared: a fractured group, using the first phalangeal bones of seven racehorses with sagittal fractures; and a nonfractured group, using the first phalangeal bones of nine autopsied racehorses without any fractures. By a peripheral quantitative computed tomography scan, the BMD values were shown as color images and evaluated. In addition, the BMD values obtained from the fractured and nonfractured groups were compared with the stiffness values obtained from a compression test.Results The difference between the average BMD values of the fractured and nonfractured groups was easily observed on the BMD color-conversion display image. The average BMD of the fractured group (472.1 mg/cm³) was significantly higher than that of the nonfractured group (284.5 mg/cm³, P = 0.005). Moreover, the average stiffness of the fractured group (5564.5 N/cm) was significantly higher than that of the nonfractured group (3808.6 N/cm, P = 0.008).Conclusion These results suggest that the occurrence of a fracture does not depend on the BMD or the bone stiffness value.     

The effcct of eel bone powder on bone mineral density in mouse femoral bone

Improvement in bone mineral density (BMD) in the femur after administration of eel bone powder (EBP) was evaluated in ovariectomized (OVX) mice. Female ICR mice were given ovariectomies or sham operations at 9 weeks of age, then housed for 2 weeks during which they were allowed free access to a normal diet. Subsequently, the mice were divided into 3 groups: sham-operated mice fed a normal diet, OVX mice fed a normal diet, and OVX mice fed a diet containing EBP. After the mice in these 3 groups had been housed for 2 months (during which time they were allowed free access to their respective diets), they were dissected and analyzed. The BMD values in the removed femurs were measured by peripheral quantitative computed tomography (pQCT). Femoral total and femoral cancellous BMD values were higher in the EBP-treated group than in the nontreated group. Total BMD: the value in the EBP-treated group was 573 mg/cm³, and that in the non-treated group was 451 mg/cm³ (p<0.05). Cancellous BMD: the value in the EBP-treated group was 242 mg/cm³, and that in the non-treated group was 143 mg/cm³ (p<0.05). However, cortical BMD values did not significantly differ between the EBP-treated group and the non-treated group. Cortical BMD: The value in the EBP-treated group was 1891 mg/cm³, and that in the non-treated group was 1900 mg/cm³. pQCT was used to measure the cortical and cancellous BMD in the long bones. By use of a color conversion technique to display BMD, regional changes in the long bones can be expressed and easily measured. It has been well documented that EBP is effective for improvement or prevention of BMD reduction associated with OVX.     

Microscopy of bone cells, bone tissue, and bone healing around implants.

Newer methods of scanning microscopy using both light and electrons are particularly relevant to the study of bone cells, bone matrix organization, matrix mineralization, bone modeling and remodeling, and the adaptation of cells and matrix to implants. Most of such studies are conducted on retrieved implants, at least after the death of the related tissue. Because the retention of the tissue-implant relationship in such preserved tissue is crucial for critical evaluation of the implant, methods based on the study of flat surfaces of embedded tissue blocks are very important. Using electrons, the backscattered electrons in a scanning electron microscope can be employed to evaluate mean atomic number (density) and cathodoluminescence can identify polymers and fluorescent labels. Using light, confocal microscopical techniques permit the examination of layers deep to the block face. Confocal reflected and fluorescence methods allow the study of cell behavior upon both transparent and opaque substrates in the laboratory. Examples of the above are presented and interpretation problems discussed. Current experiments are aimed at enabling the study of bone wound healing and bone adaptation to implanted materials in vivo, through the implantation of optical quality windows and/or newly conceived and designed microscopical objective lenses.     

骨微环境相关细胞对肿瘤细胞骨转移的作用及机制

肿瘤骨转移是肿瘤转移的重要组成部分。肿瘤骨转移的过程往往会经历肿瘤细胞的定植、休眠及活化等。从肿瘤细胞定植到骨微环境中,再到其休眠激活往往经历一段较长的潜伏期。肿瘤骨转移过程中,骨微环境中的成骨细胞、破骨细胞、骨髓基质细胞、免疫细胞及血管内皮细胞对肿瘤细胞的定植、休眠及活化过程有重要影响。在这个过程中,肿瘤细胞除自身调节外,还通过与骨微环境中的各种细胞发生相互作用。本文针对骨微环境中的相关细胞对肿瘤细胞骨转移的作用及机制研究的现状及进展作一综述。     

颌骨动脉瘤样骨囊肿的临床分析

目的：探讨颌骨动脉瘤样骨囊肿的临床表现、治疗方法及预后特点。方法收集8例颌骨动脉瘤样骨囊肿患者的临床资料,包括性别、年龄、病程、症状、影像学检查、治疗及预后等,并对患者的临床资料进行回顾性分析。结果8例患者中,女性5例,男性3例,年龄5～48岁;发生于上颌骨3例,下颌骨5例,均为原发性病变;颌骨CT扫描显示为多囊性膨胀性占位病变,内见分隔、残留骨嵴及液?液平面形成,增强后病灶周围可显示迂曲扩张的小血管影。所有患者均经病理检查明确诊断,光镜下观察,可见囊壁由梭形纤维细胞、组织细胞、破骨样多核巨细胞及慢性炎症细胞构成,呈飘带样结构,囊腔由含骨及类骨碎片的纤维组织分隔,见有出血及含铁血黄素沉积。8例患者均以病灶根治性切除为主要治疗手段。经1～6年的随访,均无复发。结论颌骨动脉瘤样骨囊肿的影像学表现具有其自身特点,确诊依靠病理诊断,治疗以病灶根治性切除为主。多数病例在病灶彻底切除后能够获得较好的预后。     

Bio-Oss骨粉联合富血小板纤维蛋白在牙槽骨缺损种植引导骨再生后的骨量变化

目的：探讨Bio-Oss骨粉联合富血小板纤维蛋白在牙槽骨缺损种植引导骨再生后骨量的变化。方法：选择106例单颗前牙缺失伴唇侧骨缺损患者,进行种植体种植同期引导骨再生。按随机数字表法随机分为2组,实验组（53例）采用Bio-Oss骨粉联合富血小板纤维蛋白+生物膜引导骨再生,对照组（53例）采用Bio-Oss骨粉联合生物膜引导骨再生。评价2组种植成功率、术后并发症率、种植体唇侧骨壁厚度、骨缺损再生情况。采用SPSS 25.0软件包对数据进行统计学分析。结果：2组种植体种植成功率差异无统计学意义（96.23%:88.68%,P>0.05）。种植后12个月,实验组种植体唇侧骨壁厚度显著大于对照组[（2.72±0.43） mm:（2.51±0.36） mm,P<0.05],不同位点种植体唇侧骨壁厚度大于对照组（P<0.05）,出血指数[（0.32±0.02）:（0.42±0.03）]、探诊深度[（3.31±0.69） mm:（4.32±0.95） mm]、附着丧失[（3.06±0.52） mm:（5.24±1.35） mm]均显著小于对照组（P<0.05）,植骨高度[（2.61±0.52） mm:（2.31±0.35） mm]、成骨高度[（2.59±0.32） mm:（2.01±0.16） mm] 显著大于对照组（P<0.05）。2组患者并发症发生率相比差异无统计学意义（1.89%:5.66%, P>0.05）。结论：Bio-Oss骨粉联合富血小板纤维蛋白可减少骨缺损种植引导骨再生后骨量丢失,促进骨缺损再生。     

Prefabrication of vascularized bone flap by demineralized bone matrix

Demineralized bone matrix (DBM) has been reported to have osteoconductive and osteoinductive properties and has been clinically used as a bone graft alternative. In the present study we attempted to generate a vascularized bone flap by subcutaneous implantation of DBM with a vascular loop to provide blood supply in a rat model. Thirty male Sprague-Dawley rats were divided into two groups according to the presence or absence of blood supply. In the experimental group, the bone flap was created by application of 0.4 mL of DBM onto two pieces of gelatin sponge sheets between which a vascular loop was sandwiched. A prefabricated flap without a vascular loop served as the control. The flaps were biopsied at three different time intervals postoperatively (2, 4, and 6 weeks). The results showed that DBM induced subcutaneous bone formation in both of the groups. However, in the nonvascularized group, the amount of bony tissue had decreased at four postoperative weeks and continued to do so afterwards. In contrast, bone formation was active at four weeks in the vascularized group. Our study indicated that implantation of DBM can prefabricate a bone flap. Blood supply to the flap is considered a key factor of the success of this prefabrication.     

Histologic analysis of alveolar bone following guided bone regeneration

BACKGROUND: Questions on new bone quality following guided bone regeneration (GBR) with various graft materials and its importance in osseointegration have been raised. This study reports histologic analysis of bone sections from future implant sites at upper and lower jaws that were augmented with bovine porous bone mineral graft material plus a porcine collagen membrane. METHODS: Due to severe atrophy of the alveolar crest, GBR prior to implant placement was indicated in 11 patients (mean age 45.5 years). Following an average of 7 months of healing, implant placement surgery was performed. Bone sections from implant beds were fixed in formalin, decalcified in sodium citrate and formic acid, and placed in paraffin. Sections 5 to 7 microm thick were prepared, stained with hematoxylin and eosin, and analyzed under light microscopy. Results for 27 implant sites are presented. RESULTS: Compared to the lower jaw, segments from the upper jaw had a lower percentage of bone and higher percentage of residual material and vascularization. CONCLUSIONS: Within the limits of this study, we concluded that osteogenesis is completed and the rate of vascularization and osteoclastic activity was reduced by 7 months. Also, the upper jaw significantly differed from the lower jaw in bone formation, vascularization, and the amount of residual material. Thus, the anatomical location of the defect may be as important as the properties of the graft material used in obtaining successful osteogenesis using guided bone regeneration techniques.     

以管状脱矿骨基质支架构建组织工程骨的实验研究

目的：探讨应用脱矿管状骨基质支架复合骨髓基质成骨细胞在动物体内构建组织工程骨的方法。方法：体外培养的新西兰兔骨髓基质细胞，经地塞米松诱导后，与藻酸钙凝胶混合，置入长约1-1.5cm，管径约0.2-0.5cm的脱矿管状骨基质内，以自体细胞移植方式，将脱矿管状骨基质/骨髓基质成骨细胞复合物异位植入新西兰兔皮下组织，分别于4、8周取材进行大体，X线摄片显示呈点状阻射影。结果：4周时可见复合物中有类骨组织和新骨形成，X线摄片显示呈点状阻射影，8周时，新生骨组织类似正常成熟骨组织，呈板层结构，细胞椭圆形，位于陷宣传员中，排列规律，X线摄片显示呈均一阻射影，对照组仅有少量类骨组织形成。结论：脱矿管状骨基质为骨髓基质成骨细胞提供了外部支架，藻酸钙为骨髓基质成骨细胞提供了三维的立体载体结构。细胞在其中生长，分泌细胞外基质，最终形成新生骨组织。     

A comparative study of anorganic xenogenic bone and autogenous bone implants for bone regeneration in rabbits

The aim of this study was to investigate the possible use and ultimate fate of anorganic xenogenic bone for the restoration of defects in the maxillae and mandibles of adult rabbits. Furthermore, anorganic xenogenic bone was compared with implanted autogenous bone particles with regard to the response of the surrounding connective tissue and possible resorption of these implants by multinucleated cells. Results showed that after 12 weeks, the implanted autogenous bone was actively resorbed by multinucleated cells, and new bone was formed in close apposition to the particles. In contrast, implanted anorganic xenogenic bone was degraded to a much lesser extent, and new bone was seen adjacent to the anorganic bone particles without signs of resorption. Further long-term studies are needed to determine whether anorganic xenogenic bone may be regarded as a resorbable material and whether any side effects occur as a result of this material's tendency to linger on in the recipient bed.     

Effects of cortical bone perforation on experimental guided bone regeneration

This study was designed to evaluate the effects of cortical bone perforation histologically and histomorphometrically on guided bone regeneration (GBR) in rabbits. After elimination of the periosteum, cortical bone defects of two sizes were made in the external cortical plate of the frontal bone (Group A: 1 x 15 mm; Group B: 3 x 15 mm). A non-resorbable membrane filled with autogenous blood was placed in the experimental area and secured with titanium pins. After 1 and 2 weeks, vascularized connective tissue and new bone were generated in the space surrounding the defects in both the groups. The amount of vascularized connective tissue generated in Group B was greater than that in Group A at 1 week. Alkaline phosphatase (ALP) was expressed on the bone surrounding the perforation. The expression of ALP was more extensive in Group B than in Group A and was proportional to the breadth of perforation. At 2 weeks, the perforated region was almost covered with new bone in Group A. ALP was expressed at the periphery of newly formed bone. The expression of ALP was proportional to the breadth and height of perforation. At 6 weeks, semicircular outgrowth of bone towards the periphery of the perforated region was observed in both the groups. Newly formed bone volume and ALP expression in Group B were more extensive than those in Group A. At 12 weeks, the space was filled with bone and connective tissue in both the groups. There was no difference in ALP expression between Groups A and B. Histomorphometric analysis showed significant differences between both the groups (two-way ANOVA, P<0.01). We conclude that a larger perforation is associated with prompter bone formation in the secluded space during GBR.     

The effect of platelet-rich plasma combined with autogenous bone graft for bone regeneration in bone defects

The objective of the present study was to evaluate the effect of PRP on bone healing both quantitatively and qualitatively using histomorphometrical methods in a rabbit model. The examined materials were autogenous bone, PRP alone, a mixture of autogenous bone and PRP, and whole blood (as a control). These materials were implanted into artificial defects prepared in rabbit tibiae. The observation period was set at 1, 2, 3, and 4 weeks. All specimens were used for histologic evaluation and 2- and 4-week specimens were used for histomorphometrical evaluations. The bone quantity increased when autogenous bone was applied but the percentage of mature bone in the autogenous bone site was smaller than in the PRP applied site. The results of this study suggested that the quantity of newly formed bone increased when autogenous bone was applied, but not when PRP only was applied. However, PRP might accelerate bone maturation by activating bone remodeling. According to this study, the bone quality could be altered by the application of PRP.