The treatment of 3D-printed metal prostheses on bone defect of malignant bone tumors in lower limbs / 中华骨科杂志

Objective:To investigate the early and middle term clinical efficacies of 3D-printed metal prostheses in the reconstruction of bone defects after osteotomy in malignant bone tumors.Methods:A total of 34 patients with malignant bone tumors of lower extremity femur and tibia who underwent 3D printing individualized metal prosthesis replacement surgery in the Department of Bone and Soft Tissue of Affiliated Cancer Hospital of Zhengzhou University from March 2019 to March 2022 were retrospectively analyzed. There were 23 males and 11 females, with an average age of 19.1±15.2 years (range, 7-80 years). There were 22 children and adolescents younger than 18 years old. There were 3 cases in the proximal femur, 15 cases in the middle and distal femur, 10 cases in the proximal tibia and 6 cases in the distal tibia. According to the final pathological diagnosis, 24 cases of osteosarcoma, 6 cases of Ewing's sarcoma, 2 cases of undifferentiated sarcoma, 1 case of osteosarcoma, and 1 case of malignant giant cell tumor of bone were enrolled in this study. Postoperative complications, wound healing, periprosthetic fracture and aseptic loosening, tumor outcome (evaluated by tumor control evaluation criteria), and length difference of lower limbs were recorded. Response evaluation criteria in solid tumor (RECIST) was used to evaluate tumor outcomes. Prosthetic-bone interface healing was evaluated postoperatively, and the function was evaluated based on Musculoskeletal Oncology Society (MSTS) 93.Results:The length of lesions was 70-240 mm in 34 patients, with an average of 125.5±35.4 mm. The length of osteotomy was 80-275 mm, with an average of 160.2±33.9 mm. No tumor was found on the osteotomy surface. The customized prosthesis was firmly installed and closely matched with the side of the preserved articular surface. There were 2 patients with local incision fat liquefaction and 4 patients with superficial wound infection, which healed after debridement and antibiotic treatment. One distal tibia osteosarcoma case developed severe periprosthetic infection 2 months after surgery, resulting in prosthesis implantation failure, limb movement pain and poor ankle function. After removal of the prosthesis, infection control and osteogenesis with the Ilizarov technique, the infection was completely controlled and local osteogenesis was possible. The remaining 33 patients had a good prosthetic-bone interface union. One case was found to have localized bone resorption on the contact surface of the prosthesis 7 months after operation, but the metal prosthesis and screws were not loose. The incisions healed well in other patients, without infection, prosthesis loosening, fracture or other complications. All patients survived and were followed up for 13.8±5.6 months (range, 7-27 months). During the follow-up, there was no recurrence of tumor at the osteotomy end in all patients, but 5 patients developed lung metastasis. At the end of the last follow-up, all patients survived. Among them, 16 patients had unequal length of lower limbs, including 10 cases within 2 cm, 3 cases between 2-5 cm, and 3 cases over 5 cm. With the exception of one patient whose prosthesis was removed due to infection, the MSTS 93 of the other patients was 24.9±2.2 (range, 19-28), and were rated as excellent in 26 cases and good in 7 cases. According to the RECIST evaluation criteria, 26 of 34 patients had complete response, 5 had disease progression, and 3 had stable disease.Conclusion:3D printed metal prosthesis is one of the effective methods for the treatment of bone defects after resection of malignant bone tumors in lower limbs, which is safe, reliable and has satisfactory early curative effect.

Value of 3D printed polyether ether ketone prosthesis in the treatment of scapular tumors / 中华骨科杂志

Polyetheretherketone (PEEK) as a new type of thermoplastic engineering plastic, has good biological activity, elastic modulus close to human cortical bone and radiation permeability, and has been widely used in medical field. This study aims to explore the safety and clinical efficacy of using 3D printing personalized PEEK materials to repaire scapular bone defects after bone tumor resection. A total of 6 patients who underwent the implantation of 3D printed PEEK scapular prosthesis from January 2020 to December 2021 in Yunnan Cancer Hospital were retrospectively analyzed. There were 3 males and 3 females, with age ranged from 14 to 52 years. There were 1 case of synovial sarcoma, 1 of Ewing's sarcoma, and 4 of chondrosarcoma. PEEK prosthesis was designed and fabricated based on CT data before surgery. Tumor resection and prosthesis replacement were performed under the premise of ensuring safe surgical boundaries, including 2 cases of total scapular prosthesis replacement and 4 cases of partial scapular prosthesis replacement. The operation time was 90-170 min, and the intraoperative blood loss was 100-400 ml. All 6 patients received satisfactory follow-up, with a tumor progression free survival time of 16-28 months. No tumor recurrence or metastasis was observed, and all patients survived tumor free. At last follow-up, the Constant-Murley shoulder joint score was a minimum of 62 points and a maximum of 68 points. The Japanese Orthopaedic Association's shoulder joint score was 63 points minimum and 78 points maximum. Computer-aided design 3D printing PEEK material prosthesis has certain advantages in the treatment of scapular tumor limb salvage. It has light weight, well adapted, relatively simple installation, good histocompatibility, and can obtain a better appearance and function of the shoulder joint after operation. It can become one of the options for limb salvage treatment of scapular tumor.

Research progress on an autophagy-mediating AMPK pathway involving bone metabolism-related cells that regulate bone homeostasis in periodontitis / 口腔疾病防治

@#Osteoclasts are the only cells responsible for bone resorption in the body, and osteoblasts are the main cells responsible for bone regeneration in the body. Under physiological conditions, these cells maintain a dynamic balance to maintain bone homeostasis. It was widely believed that the imbalance of bone metabolism is mainly affected by the expression of related inflammatory factors. However, with the gradual expansion of related studies in recent years, autophagy has been shown to be closely related to the differentiation, apoptosis and functions of osteoclasts and osteoblasts. AMP-activated protein kinase (AMPK) is an important regulator of energy metabolism in vivo and is involved in the regulation of autophagy and bone homeostasis in bone metabolism-related cells. Periodontitis is a chronic infectious disease, and its typical symptoms are alveolar bone resorption. At present, controlling the level of periodontal inflammation and alveolar bone resorption more effectively in clinical practice remains a challenge. The detection of AMPK and autophagy levels in bone metabolism-related cells shows certain prospects for the clinical prevention and treatment of periodontitis in the future. Therefore, this article reviews the regulation of periodontal inflammation levels and bone homeostasis through cell autophagy related to AMPK-mediated bone metabolism.

Research progress on the effect of implant-supported overdentures on residual ridges / 口腔疾病防治

@#With the growing maturity of implant technology, implant overdenture has gradually become a conventional repair method for edentulous patients to restore beauty and function, which improves the quality of life of edentulous patients. This paper reviews the effects of implant factors, attachment factors, occlusal factors and patients' own factors on residual alveolar ridge. Existing studies suggest that when designing denture, doctors first need to consider the oral mucosa and jaw conditions of patients before operation, and select the appropriate size of implant to ensure that sufficient bone remains around the implant; Secondly, when choosing the type of attachment, the number, location and A-P distance of implants should be fully considered, and the inclination of cusp should be properly reduced to avoid the harm of excessive lateral force to alveolar ridge; Finally, regular reexamination should be carried out after operation to maintain longer service time of denture and more sufficient bone mass of edentulous patients. However, there are many factors affecting jaw absorption. In the future, we should further explore many factors, such as patients' habit and frequency of wearing dentures, oral health and nutritional status, systemic diseases and medication.

Análise do potencial do reparo ósseo através da reconstrução de ressecções segmentares por meio da associação de scaffolds de Polidioxanona ou malha de titânio e rhBMP-2: estudo in vivo / Bone potential analysis through segmental resection reconstruction using Polydioxanone or Titanium Mesh scaffolds and rhBMP-2: in vivo study

O objetivo deste trabalho foi analisar o potencial bioativo de um "scaffold" de Polidioxanona (PDO) com associação da rhBMP-2, nas reconstruções após simulação de ressecção óssea em fêmures de ratos. Para tanto, 24 ratos, machos, adultos, com 6 meses de idade, foram submetidos a ressecção e reconstrução dos fêmures bilateralmente. Inicialmente foi realizada a estabilização com fixação de placas e parafusos de titânio do sistema 1.5mm e em seguida a confecção de um "gap" de 2mm. A reconstrução foi realizada com rhBMP-2 (Infuse) carreada em esponja de colágeno (3,25 µg), tendo uma malha de titânio, para o grupo Titânio (n=24 fêmures) (grupo controle), atuando como um arcabouço. E para o grupo PDO (n=24 fêmures) (grupo teste), a reconstrução foi realizada também com a rhBMP-2 carreada em uma esponja de colágeno (3,25 µg), envolvido por um "scaffold" de PDO. Desses animais, 16 (2 por tempo) receberam em seu dorso, no plano subcutâneo, um fragmento do mesmo material testado em seu fêmur, para análise de biocompatibilidade, que foram removidos sob anestesia local, junto de fragmento do tecido subcutâneo adjacente, aos 3, 5, 7 e 10 dias para análise. Os animais foram submetidos à eutanásia (n=6 por grupo) nos períodos de 14 e 60 dias após a cirurgia de reconstrução tiveram seus órgãos de metabolização (cérebro, rim, fígado e músculo) removidos para análise anatomopatológica e seus fêmures também foram removidos, reduzidos, radiografados para análise da densitometria radiográfica posteriormente os fêmures passaram por descalcificação e em seguida todas as peças foram submetidas ao processamento para obtenção de lâminas com cortes de 5 µm de espessura, para avaliação histológica, com avaliação da área óssea neoformada e perfil inflamatório e para análise imunohistoquimica através das proteínas Runx2, OPG, RANKL, OCN e BMP2. Todos os dados quantitativos foram submetidos ao teste ANOVA-2 fatores e quando p< 0,05, o pós-teste Tukey foi realizado. Os resultados da densitometria radiográfica demonstraram maior densidade para o grupo PDO, especialmente no período de 14 dias (p< 0,05). Na análise histológica observou-se reparo mais favorável para o grupo PDO, especialmente aos 60 dias quando comparado ao Titânio, com diferença estatística significativa (p = 0.002) bem como menor infiltrado inflamatório e maior número de vasos sanguíneos aos 14 dias. Com relação as imunomarcações, BMP-2 não apresentou marcações para Titânio e dados expressivos para PDO, com diferença significativamente estatística aos 60 dias (p< 0.05). OPG e RANKL mostraram maior marcação para titânio, principalmente aos 60 dias (p< 0.05). Já Runx2 e OCN apresentaram resultados superiores para PDO aos 14 dias, entretanto, aos 60 dias titânio demonstrou maior expressão. A análise de biocompatibilidade mostrou maior processo inflamatório para o grupo titânio. Os órgãos de metabolização apresentaram aspectos de higidez dentro da normalidade para ambos grupos. Os resultados deste trabalho demonstram um padrão reparacional mais favorável à associação do "Scaffold" de PDO com a rhBMP-2, quando comparado a reconstrução com malha de titânio(AU)

The objective of this work was to analyze the bioactive potential of a Polydioxanone (PDO) scaffold with rhBMP-2 association, in reconstructions after simulating bone resection in rat femurs. Therefore, 24 male, adult rats, aged 6 months, underwent resection and reconstruction of the femurs bilaterally. Initially, stabilization was performed with fixation of titanium plates and screws of the 1.5mm system and then a 2mm gap was created. The reconstruction was performed with rhBMP-2 (Infuse) loaded in a collagen sponge (3.25 µg), with a titanium mesh, for the Titanium group (n=24 femurs) (control group), acting as a scaffold. And for the PDO group (n=24 femurs) (test group), the reconstruction was also performed with rhBMP-2 carried in a collagen sponge (3.25 µg), surrounded by a PDO scaffold. Of these animals, 16 (2 per time) received on their back, in the subcutaneous plane, a fragment of the same material tested in their femur, for biocompatibility analysis, which was removed under local anesthesia, together with a fragment of the adjacent subcutaneous tissue, at 3, 5, 7 and 10 days for analysis. The animals were euthanized (n=6 per group) in the periods of 14 and 60 days after the reconstruction surgery, had their metabolizing organs (brain, kidney, liver, and muscle) removed for anatomopathological analysis and their femurs were also removed, reduced, radiographed for analysis of radiographic densitometry later the femurs underwent decalcification and then all the pieces were submitted to processing to obtain 5 µm thick slices for histological evaluation, with the evaluation of the newly formed bone area and inflammatory profile and for immunohistochemical analysis through Runx2, OPG, RANKL, OCN, and BMP2 proteins. All quantitative data were submitted to the 2-way ANOVA test and when p< 0.05, the Tukey post-test was performed. The results of radiographic densitometry showed higher density for the PDO group, especially in the 14-day period (p< 0.05). In the histological analysis, a more favorable repair was observed for the PDO group, especially at 60 days when compared to Titanium, with a statistically significant difference (p = 0.002), as well as a lower inflammatory, infiltrate and a greater number of blood vessels at 14 days. Regarding immunostaining, BMP-2 did not show staining for Titanium and expressive data for PDO, with a statistically significant difference at 60 days (p< 0.05). OPG and RANKL showed higher staining for titanium, mainly at 60 days (p< 0.05). On the other hand, Runx2 and OCN showed superior results for PDO at 14 days, however, at 60 days titanium showed greater expression. The biocompatibility analysis showed a greater inflammatory process for the titanium group. The metabolizing organs presented aspects of health within the normal range for both groups. The results of this work demonstrate a more favorable repair pattern for the association of the PDO scaffold with rhBMP-2, when compared to reconstruction with titanium mesh(AU)

Research progress on micro-osteoperforation-assisted orthodontic treatment / 口腔疾病防治

@#As a minimally invasive procedure, micro-osteoperforations (MOPs) achieve desired therapeutic effect with minimal surgical intervention. The operation is relatively simple, and the effect of assisted orthodontic treatment is obvious. However, due to the lack of long-term follow-up studies, there is no unified consensus on the long-term stability of the procedure. This article reviews the research status of MOPs, biological and biomechanical mechanisms, clinical applications and limitations. MOPs can shorten orthodontic treatment time and accelerate tooth movement by exerting regional acceleratory phenomena (RAP). At the same time, this procedure will not damage the health of the periodontal tissue, and the postoperative bleeding and postoperative reaction are minor. In addition, the pain and discomfort of patients were relatively mild and acceptable. However, it also has limitations, mainly including the limited time of the RAP effect of MOPs. Although this procedure is a minimally invasive surgery, there is still a risk of treating regional bone defects. At present, it is still necessary to increase the sample size and extend the follow-up time to evaluate the long-term stability of MOPs.

Application of dentin in bone tissue engineering / 口腔疾病防治

@#Defects in oral hard tissue caused by various factors have a negative impact on the functional and aesthetic results of prosthetic treatment. In recent years, the usage of bone tissue engineering for bone reconstruction has drawn widespread attention. Bone tissue engineering exhibits significant advantages, including the abundance of building materials and few side effects. In this paper, the composition and structure of dentin and its application in bone tissue engineering are reviewed, providing a new way to further optimize its performance. The results of a literature review show that the structure of dentin is very similar to that of autogenous bone. The inorganic component is mainly hydroxyapatite (HA), while the organic component is mainly collagen I, noncollagenous proteins (NCPs) and growth factors. Because of its unique composition, dentin can act as a scaffold and/or growth factor source through different processing methods. The deproteinization process removes most of the organic substances and creates a HA-based scaffold material with high porosity, which allows for vascularization and cellular infiltration. Demineralization increases dentin porosity by reducing the crystallinity of the mineralized components, so that part of HA, collagen fibers and growth factors are preserved. Demineralized dentin possesses various regulation functions ranging from differentiation, adhesion and proliferation of primitive cells and bone forming cell lineage. Extracted NCPs, as bioactive molecules, have been proved to play important roles that control cell differentiation, crystal nucleation and mineralization in bone formation. NCPs could be combined with variety of scaffold materials and modify their properties.

Discussion on hot topics of skeletal sternal reconstruction / 中华外科杂志

Sternum is an important constituent of the thoracic cage, and a pivotal part of the anterior chest wall. When a considerable portion of the sternum needs to be resected, in order to protect the vital organs beneath, restore the anatomical structure and physiological function, reconstruction is unavoidable. Sternal reconstruction consists of two related parts: skeletal and soft tissue reconstruction. Skeletal reconstruction uses materials such as autograft or allograft of bones, metallic plates, sandwich patch, non-rigid patches, bio-synthetic patches and three-dimensional printing prosthesis. Each has its advantages and disadvantages. For example, autogenous bone transplantation is limited by the source of donor bones and surgical trauma; allograft bone transplantation demands cryopreservation and is susceptible to infection; titanium plate cannot be placed overlapped; "sandwich" patch is susceptible to local fluid accumulation and infection; non-rigid patches cannot provide enough mechanical support; the design and manufacture of three-dimensional printing prosthesis is complicated, time consuming and expensive, and cannot be adjusted due to change of extent of resection during operation. The modularized prosthesis system is a promising new technique developed on the basis of titanium plate. It is divided into standard components of different sizes that can be selected according to operational requirement and easily assembled. Until now, no perfect method or material has been found to imitate the autogenous sternum. Soft tissue reconstruction is a prerequisite to the success of large scale skeletal reconstruction of the sternum.

Restoration of long bone defects of infected tibia with induced membrane technique / 中华创伤骨科杂志

Objective To evaluate the induced membrane technique (Masquelet technique) used for restoration of long bone defects of infected tibia.Methods This retrospective study evaluated 44 patients with long bone defect of infected tibia who had been treated at Department of Orthopedics,The Second Affiliated Hospital by the induced membrane technique between January 2004 and January 2017.They were 31 males and 13 females,aged from 18 to 71 years (mean,43.7 years).Of them,17 were complicated with diabetes,13 with primary hypertension,and 12 with more than two basic diseases.Their bone defects ranged from 6 to 17 cm (average,11 cm).Their postoperative fracture healing and complications were observed.Results This cohort received from 2 to 5 operations on average (average,3.7 operations).All the patents obtained bony union after 9 to 13 months (average,11.3 months).Their follow-ups ranged from 16 months to 11 years (average,3.1 years).Nineteen complications related to the surgery occurred in 15 cases.Skin healing problem after implantation of bone cement was found in 5 cases which called for operative intervention,infection relapsed in 8 patients after the first phase of cement implantation which necessitated further surgical debridement for successful management,local haematoma appeared after bone grafting in one case of 17 cm bone defect,implant failure occurred in one case,leg length discrepancy larger than 2 cm was observed in 3 cases,and a discharging sinus developed in one case 2 years after successful healing of a tibial defect.Conclusions The induced membrane technique appears to be a good alternative management for large tibial defects secondary to infection.The technique should be considered in the surgeon's armamentarium and patients conditions as it is effective and associated with a low rate of complications.

The preliminary research for the corticosterone to the femoral head microenvironment of rat 11 beta HSD1 expression and the influence of bone reconstruction / 重庆医学

Objective To study the endogenous glucocorticoid on rat femoral head microenvironment of 11 hydroxysteroid dehydrogenase expression ,and to discuss the influence of combined with femoral head pathological changes of the corresponding mechanism .Methods Sixty SD rats were divided into control group ,1‐month group ,3‐months group ,each 20 rats in group .1‐month group and 3‐months group inject cortisone acetate in the abdominal cavity intraperitoneal for 1‐month or 3‐months each .Im‐munohistochemical ,immunofluorescence ,Real‐time qPCR ,HE staining were employed in this study .Results From immunohisto‐chemical ,immunofluorescence ,Real‐time qPCR ,the 11 hydroxysteroid dehydrogenase content of 1‐month group and 3‐months group were higher than that of the control group(P<0 .05) .From HE staining we detected 1‐month group in the bone marrow cavity in‐creased in fat cells ,3‐months group subchondral trabecular bone density decreased ,compared with the control group(P< 0 .05) . Conclusion Supplement of corticosterone could promote rat femoral head microenvironment 11 hydroxysteroid dehydrogenase ex‐pression and subchondral trabecular bone density decrease .

Aumento da espessura do rebordo ósseo com um novo enxerto sintético particulado. Caso clínico com avaliação microtomográfica / Horizontal alveolar ridge augmentation with a new particulate bone substitute: a case report with micro-CT evaluation

As limitações anatômicas do rebordo alveolar residual podem impedir a instalação de um implante osseointegrado. Nesses casos, procedimentos de regeneração óssea guiada são necessários para proporcionar osso alveolar suficiente em altura e/ou espessura para a inserção de implantes dentais. Este relato piloto de caso clínico apresenta um procedimento de aumento horizontal do rebordo ósseo usando um novo substituto ósseo aloplástico para proporcionar volume ósseo necessário para a colocação de um implante, avaliando também por meio de microtomografia o osso neoformado. O paciente do sexo masculino, 58 anos, não fumante, sem condições sistêmicas que pudessem afetar o procedimento cirúrgico, apresentava a ausência de um dente (primeiro pré-molar superior direito) e optou por instalar um implante para a reabilitação cirúrgico-protética desta área. A tomografia computadorizada pré-operatória mostrou que o osso residual tinha espessura insuficiente para a instalação de um implante, sendo necessária a realização de um procedimento cirúrgico para aumento ósseo horizontal. O paciente assinou um consentimento informado autorizando a realização dos procedimentos bem como a documentação científica do caso. Foi realizada cirurgia de regeneração óssea guiada (ROG) utilizando substituto ósseo particulado (Reprobone®) e uma membrana colágena (Biomend), para aumentar a espessura óssea vestíbulo-palatal. O paciente foi apropriadamente medicado e a cicatrização ocorreu sem intercorrências. Após 6 meses, a área foi reaberta e antes da instalação do implante uma biópsia óssea foi coletada para análise microtomográfica. A técnica de ROG proporcionou volume ósseo adequado para a colocação do implante. A análise microtomográfica da biópsia óssea resultou em 40,85% de volume ósseo cortical e 17,08% de biomaterial residual...

Anatomic limitations of the residual alveolar bone may impair implant placement. Alveolar ridge augmentation procedures are required in such cases to provide alveolar bone width and/or height for dental implant placement. This case report presents a horizontal ridge augmentation procedure using a new alloplastic bone substitute providing bone volume for implant placement, with micro-CT analysis of the newly formed bone. The patient was a 58-year-old male, non-smoker, with no systemic health conditions that could affect the surgical procedure, and reported the willingness of rehabilitating the edentulous area corresponding to the tooth 14 with an osseointegrated implant. The CBCT analysis revealed that residual alveolar bone width was too narrow for implant insertion, and therefore a bone augmentation procedure was necessary. The patient signed an informed consent form authorizing all procedures and scientific documentation. Guided bone regeneration was performed using ReproBone® granules and a collagen membrane (BioMend®) to increase the buccal-palatal bone width. The patient was properly medicated and healing was uneventful. After 6 months, the area was reopened and before placing an implant a bone biopsy was collected for micro-CT analysis. The bone augmentation procedure provided adequate bone volume for implant placement. The micro-CT results of the bone biopsy showed 40% of bone volume and 17% of remnant particles of the biomaterial after 6 months. It was concluded that this biomaterial may be used in such clinical situations as an alternative to autogenous bone blocks and still avoiding patient morbidity...

Estudio morfométrico del seno maxilar mediante tomografías computadorizadas: evaluación de la reconstrucción total de piso sinusal / Morphometric study of maxillary sinus by computed tomography: assessment of sinus floor bone reconstruction

La rehabilitación con implantes dentales en maxila posterior es compleja debido a la presencia del seno maxilar con sus diferentes variaciones anatómicas; el objetivo de este trabajo fue determinar el volumen óseo intrasinusal necesario para realizar la instalación de uno o mas implantes dentarios sin invadir la membrana sinusal. En 22 cráneos fueron evaluados 40 senos maxilares mediante tomografías computadorizadas (TC) realizando mediciones en los cortes axiales, coronales y sagitales. Se clasificaron los senos maxilares según el remanente de hueso alveolar y se instalo un implante de forma virtual en el lugar del primer molar superior, mediante el software implant view. Con estas medidas volumétricas finales se estableció las indicaciones reconstructivas intra sinusales a partir de los sitios donantes intrabucales mas frecuentemente evaluados en la literatura mundial. El grupo I (1mm a 4mm de reborde alveolar remanente) presentaba déficit óseo de hasta 1,98 cm3, el grupo II (4mm a 7mm) presentaba déficit de 1,06cm3; el grupo III (7mm a 10mm) presentaba un déficit de 0,67 cm3; a partir de estos resultados podemos concluir que los sitios intrabucales pueden ser utilizados en la mayoría de los grupo estudiados, incluyendo las reconstrucciones bilaterales.

Rehabilitation with dental implants in posterior maxilla is difficult because of the presence of maxillary sinus with anatomical variations. The aim of this research was to evaluate the sinus volume to install one or more implants without invading the sinus membrane. Forty (40) maxillary sinuses were evaluated in 22 skulls by computed tomography measuring in the axial, coronal and sagittal slice. The sinus were classified according to the remaining alveolar bone and a dental implant in the place of the upper first molar was virtually installed by implant view software. With this final volumetric measurement the surgical indications were established for inlay reconstruction from intra oral donor sites frequently evaluated in world literature. Group I (1mm to 4mm of alveolar ridge) showed a bone deficit of 1.98 cm3, group II (4mm to 7mm) showed a deficit of 1.06 cm3; group III (7mm to 10mm) showed a 0.67 cm3 deficit. In view of these results we concluded that intra oral donor site can be used for the three study groups and in some cases in bilateral reconstruction.

Análise das intercorrências e complicações em instalação de implantes dentais: um estudo retrospectivo / Analysis of intercurrences and complications in the placement of dental implants: a retrospective study

Intrinsecamente, todo procedimento cirúrgico apresenta um certo índice de intercorrências e/ou complicações associadas. Hemorragias, infecções, parestesias ou disestesias e perda primária dos implantes são algumas das intercorrências e complicações mais comuns relacionadas a procedimentos cirúrgicos para implantodontia. Este estudo avaliou retrospectivamente o índice de intercorrências e complicações após cirurgia para a instalação de implantes dentais osteointegráveis. Foram avaliados, retrospectivamente, 660 prontuários clínicos de pacientes submetidos à instalação de implantes osteointegráveis no período de 8 anos, atendidos na Área de Cirurgia Buco-Maxilo-Facial da Faculdade de Odontologia de Piracicaba - Unicamp. Os resultados demonstraram que houve um maior índice de intercorrências e complicações quando os pacientes eram atendidos por alunos de especialização (p= 0,015) e quando o exame por imagem realizado era somente a radiografia panorâmica convencional (p= 0,011). Os resultados demonstraram também um maior índice de intercorrências e complicações nos pacientes quando estes eram submetidos a procedimentos cirúrgicos de reconstrução óssea alveolar (p< 0,0001). A presença de infecção pós-operatória influenciou significativamente para o aumento no índice de perda primária de implantes (p< 0,0001).

Intrinsically, every surgical procedure presents a certain rate of associated intercurrences and/or complications. Hemorrhages, infections, paresthesias or dysesthesias and primary loss of implants are some of the most common intercurrences and complications related to surgical procedures in implant dentistry. This study conducted a retrospective evaluation of the rate of intercurrences and complications related to patients submitted to osseointegratable dental implant placement. A retrospective evaluation was made of 660 clinical record charts of patients submitted to osseointegratable dental implants in the period of 8 years, attended in the Oral and Maxillofacial Surgery Department of Piracicaba Dental School - Unicamp. The results showed that there was a higher rate of intercurrences and complications when patients were attended by residents (p= 0.015) and when the panoramic radiograph was the only preoperative image exam requested (p= 0.011). The results also showed a higher rate of intercurrences and complications in patients when they were submitted to surgical procedures of alveolar bone reconstruction (p< 0.0001). The presence of post-operative infection had a significant influence on the increase in the primary loss of implants (p< 0.0001).

THE APPLICATION OF RAPID PROTOTYPING IN THE ORTHOGNATHIC SURGERY / 解剖学报

Objective To construct a geometric skull model by using three-dimensional reconstruction, computer tomography scanning and rapid prototyping technology and evaluate its significance in treatment of complex oral and maxillofacial deformities. Methods A cranial and a goldenhar syndrome patient with complex oral and maxillofacial deformities bone received continuous volumetric scanning of skull and the data acquisition was done by an electron computed tomography, by which reconstruction was performed and the obtained images saved as STL files. Then the data were input into rapid prototyping machine to make three-dimensional geometric model. Direct measurement, designation and surgery simulation could be done on this three-dimensional model. Then the mandibular mirror physical model was manufactured using rapid prototyping according to the normal side. Results A computer-aided model according to CT data could represent the three-dimensional anatomic structures and their relationships precisely. The replica exhibited dimensional errors ranging 0.02 mm to 0.53 mm. Which provided strong basis for accurate understanding of disease status and reasonable surgical plans and helped improve the curative effect of surgery. Conclusion Rapid prototyping can help surgeons in many ways for therapy of the complex oral and maxillofacial deformities.

Tissue Engineering with rhBMP-2: Bone Reconstruction in Implant Dentistry / 대한치주과학회지

The preclinical and clinical studies reviewed herein show that rhBMP-2 induces normal physiologic bone in relevant defects in the craniofacial skeleton. The newly formed bone assumes characteristics of the adjacent resident bone, and allows placement and osseointegration of dental implants. Clearly, the bone inducing capacity of rhBMP-2 is carrier and site dependent. rhBMP-2 in an absorbable collagen sponge carrier induces relevant bone formation in space providing defects. Space providing carries extends this possibility to nonspace providing sites. Notably, some ceramic and polymeric biomaterials may substantially interfere with rhBMP-2 induced osteogenesis.

Reconstruction of Thumb Associated with Defect of Metacarpal Bone / 中华创伤杂志

86 cases of defect of thumb with defect of metacarpal bone were operated by the second toe transfer to reconstruction of the thumb, of which 82 cases were successful occuping 95. 6% of total cases. The metacarpal-phalangal arthral reconstruction of the thumb was completed by the hemi-arthral and full-arthral transplantation of metatarsal-phalangee joint of second toe. The results of follow-ups after operation revealed that the degree of movement of the joint was 26 in the former, 36% in the latter. The reconstruction of the first web by means of the local flap of the dasalis manual; dasalis pealical flap and groin flap. Fair results were obtainded with 63.2 %; 87. 1% and 100%. respectively. The disadvantages of groinflap method are timeconsuming, and incomfortable in position. The operative methods vary with the degree of the defect of the matacarpal bone and the condition of the web space