Material For Reconstruction Research Articles

粘性ダンパーを有する構造の広帯域振幅規定問題における形状最適設計

It is efficient to use the modal method for shape design of structures considering vibrations in a wide frequency range. However, when there are viscous dampers in the structure, it is difficult to use the modal method because the equation of motion cannot be decoupled. In this paper, we propose an efficient shape optimization analysis method using the modal method for the displacement regulation problem in a wide frequency range with a viscous damper. The shape gradient function is derived analytically, and is given as a modal solution. In addition, the H1 gradient method was used for shape modification analysis. Using a simple numerical model, it was shown that this method can be applied not only to the shape-optimal design of structures, but also to the shape-optimal design of the materials for eardrum reconstruction.

Иноземное население Санкт-Петербурга первой половины XVIII столетия: опыт статистической реконструкции

The article systematizes data about the number of St. Petersburg foreign population in the first half of the 18th century, for the first time cites quantitative and qualitative indicators characterizing the religious, national and social composition of its foreign diaspora. The materials for the statistical reconstruction were the results of the analysis of the St. Petersburg Catholic and Protestant parish registers and the foreigners' databases created on the basis of these church books. To identify demographic structures, the authors used the methods of descriptive statistics and comparative analysis of statistical indicators, and to determine the number of foreigners (“inozemtsy”), they used the method of reconstructing values using constant coefficients expressing the ratio of the adult believers' number to the sum of church rites for a certain time period. As a result, they found that the greatest concentration of foreigners (at the level of 10-13%) in St. Petersburg was observed in the Petrine era, and under Anna Ioannovna and Empress Elizabeth Petrovna their share fell to 6-7%. The number of foreigners was a relatively constant value and amounted to about 4 thousands adult men and women at the end of the reign of Peter the Great, and about 4-5 thousand people of both sexes in the 1730s and 1740s. As parts of the foreign population, the authors separately took into account groups of Germans, French, Italians, Poles, Dutch people, Finns, Swedes, Armenians, Tatars, and other nationalities. The authors publish the results of a special study, during which the size of various religious groups of St. Petersburg residents was determined - such as Catholics, Lutherans, Calvinists, believers of the Armenian Apostolic Church. They substantiate the conclusion that initially it was not Germans, as is traditionally considered, but Swedes and Finns that prevailed among the foreigners of St. Petersburg, and only by the middle of the 18th century the Germans became the most common group of foreigners, accounting for about half of their number. The largest social stratum of the foreign population in the city was the craft-working (future petty-bourgeois), they included masters and apprentices of the guild craft, artisans, all kinds of civilian specialists and persons who were in service. In the 1730s, this layer of Petersburgians incorporated about three thousand foreigners of both sexes, they made up a significant percentage of the commercial and industrial population of the city and strengthened the stratum of Posadsky residents. Turning to the questions of the socioprofessional composition of the St. Petersburg foreign society of the first half of the 18th century, the authors came to the conclusion that the confessional factor affected the choosing of the type of activity by foreigners.

Biologic Shaping in Periodontal Therapy

This article focuses on biologic shaping during periodontal treatment. This is especially important if there is concavity or unevenness of the enamel near the edge of the crown. This can create an unmanageable situation and increase the risk of further loss of bone support. The point is that biologic shaping in periodontal therapy limit unnecessary bone removal and create a biocompatible environment. Biologic shaping preserve bone, creating the biologic width necessary for tooth restoration. However, putting biological shaping into practice requires a team approach with a deep understanding of fundamentals, anatomy, surgical and reconstructive procedures, materials, and final reconstructive contours. When performed correctly, it can improve the long-term prognosis of dental health.

Innovative materials for reconstruction and restoration

Innovative materials for reconstruction and restoration

Comparison between autologous and artificial graft ossiculoplasty in canal wall down tympanomastoidectomy: A 10 year's personal experience

Background: Ossiculoplasty is the reconstruction of ossicular chain: Malleus, incus, and stapes. This procedure attempts to reestablish the continuity between the tympanic membrane and the oval window. Different materials were used in ossiculoplasty; whether to use autologous grafts or synthetic prosthesis. Aims: This study aimed to evaluate hearing changes in patients' undergone ossiculoplasty as a part of Tympanomastoidectomy. Also, to appraise the autologous reconstruction materials used in ossiculoplasty at Jordan University Hospital (JUH) in comparison to other materials. Materials and Methods: A retrospective study done for a total of 100 patients underwent ossiculoplasty using autologous and artificial graft during canal wall down tympanomastoidectomy at JUH from 2009 to 2019. Results: Overall average mean of air-bone gap (ABG) closure (Hearing Gain) for Group A was 11.07 dB, while for Group B was 7.5 dB; this decrease was found to be highly significant (P = 0.002). In Group A, ABG mean was (34.44 dB) preoperative and reduced to 23.37 dB postoperative, while in Group B was (32.95 dB) preoperative and reduced to 25.45 dB postoperative. Conclusions: Autologous grafts can be used safely in reconstruction of middle ear with favorable outcome. Our study is one of the few reports that compare outcome between artificial and autologous graft in ossiculoplasty.

The proximal fibular free flap - an ideal material for reconstructing distal radius defect after Giant tumor cell resection. A case report

Giant cell tumors (GCT) of the distal end of radius are relatively common tumors, representing approximately 5% of all primary bone tumors. It is the third most common location for GCT following distal femur and proximal tibia. In general, treatment includes thorough tumor excision, reconstruction of the defect, and wrist joint rehabilitation. The proximal fibular free flap is an ideal material for distal radius reconstruction after giant cell tumor excision. We present a case of a 57-year-old female, admitted to the hospital due to painful and limited proper wrist movement. Based on X-ray and Magnetic resonance imaging (MRI) images and histopathology findings, the patient was diagnosed with a stage 3 giant cell tumor of the distal radius. The patient underwent a one-step surgery of tumor excision and distal radius reconstruction by a vascularized proximal fibular free flap. 2 years follow-up post-surgery showed that the patient had no pain of the wrist, improved wrist joint function, no sign of recurrence, and good flap vitality and the knee joint remains normal. In conclusion, the surgery was successful with no further prolonged pain, improvement of the wrist joint function and overall improvement of the patient quality of life.

A Narrative Review of u-HA/PLLA, a Bioactive Resorbable Reconstruction Material: Applications in Oral and Maxillofacial Surgery.

The advent of bioresorbable materials to overcome limitations and replace traditional bone-reconstruction titanium-plate systems for bone fixation, thus achieving greater efficiency and safety in medical and dental applications, has ushered in a new era in biomaterial development. Because of its bioactive osteoconductive ability and biocompatibility, the forged composite of uncalcined/unsintered hydroxyapatite and poly L-lactic acid (u-HA/PLLA) has attracted considerable interest from researchers in bone tissue engineering, as well as from clinicians, particularly for applications in maxillofacial reconstructive surgery. Thus, various in vitro studies, in vivo studies, and clinical trials have been conducted to investigate the feasibility and weaknesses of this biomaterial in oral and maxillofacial surgery. Various technical improvements have been proposed to optimize its advantages and limit its disadvantages. This narrative review presents an up-to-date, comprehensive review of u-HA/PLLA, a bioactive osteoconductive and bioresorbable bone-reconstruction and -fixation material, in the context of oral and maxillofacial surgery, notably maxillofacial trauma, orthognathic surgery, and maxillofacial reconstruction. It simultaneously introduces new trends in the development of bioresorbable materials that could used in this field. Various studies have shown the superiority of u-HA/PLLA, a third-generation bioresorbable biomaterial with high mechanical strength, biocompatibility, and bioactive osteoconductivity, compared to other bioresorbable materials. Future developments may focus on controlling its bioactivity and biodegradation rate and enhancing its mechanical strength.

EPISTOLARY HERITAGE OF N.I. ILMINSKY AS A SOURCE ON THE HISTORY OF EDUCATING NON-RUSSIAN PEOPLES OF EASTERN RUSSIA (in the last third of the XIX century)

The article is devoted to the analysis of epistolary sources on the history of educating non-Russian peoples of eastern Russia. The correspondence gives an opportunity to present the work of N.I. Ilminsky on education, methods of his activity, difficulties encountered along the way. The correspondence focuses on the development of Orthodox education among non-Russian peoples. The specific composition of letters is diverse. By correspondents, the sources are divided into the following groups: letters to senior statesmen, to figures of the Russian Orthodox Church, to local education figures. By the content, the correspondence is divided into groups of materials: about translation and publishing activities, about organizing the network of non-Russian schools, about training and appointment of teachers and priests, about introducing church worship in native languages. The letters significantly complement our understanding of N.I. Ilminsky’s personality and his educational activities. Currently, many scientists believe that it is necessary to conduct a deeper study and interpretation of historical events concerning educating the population of the country, including non-Russian peoples of the eastern part of Russia, taking into account their diversity. Epistolary sources provide rich material for historical reconstruction, their information potential is rich and diverse. The research methodology is based on historical methods: historical-genetic and historical-comparative. The historical-genetic method enables to trace the course of events in their chronological sequence, the dynamics of processes related to the history of educating non-Russian peoples of eastern Russia. The comparative historical method, which puts the fait accompli as the basis of all arguments and conclusions, was an important method in the historical reconstruction of educational process of the non-Russian peoples of the region under study on the basis of Orthodox education. A variety of epistolary sources made it possible to conduct a holistic historical reconstruction of the period under study in the history of education and to formulate analytical conclusions on the research problem. The author managed to analyze the collected material. The analysis performed gives the opportunity to make a conclusion about the diverse activities of N.I. Ilminsky on education.

Application of Hyaluronic Acid as a Biopolymer Material in Reconstruction of Interdental Papilla in Rats

Applying hyaluronic acid, a biopolymer material, in the treatment of interdental papilla reconstruction has become a trend. The main objective of this research is to investigate the histologic effect of hyaluronic acid on interdental papilla over time. Deficient interdental papilla models were surgically created in sixty-two Sprague-Dawley (SD) rats and were randomly treated with the injection of hyaluronic acid (HA group) or phosphate-buffered saline (sham control group) or left untreated (control group). After 2, 4, and 8 weeks, the rats were sacrificed in batches to observe the histological changes. A fluorochrome label was used to monitor bone formation in 8 weeks. Immunohistochemical analyses were performed to evaluate the expression of potentially relevant cytokines, vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2), and Wnt-induced secreted protein 1 (WISP1) in the gingival tissue in 8 weeks. A preliminary study of HA degradation after 24 weeks was performed in two rats. Following the HA injection, no inflammation or granulomatous foreign body reaction was observed. HA was able to promote collagen fiber and alveolar bone regular formation in the reconstruction site. HA also enhanced VEGF, BMP-2, and WISP-1 expression in gingival tissue (p＜0.05). After 24 weeks, there was no HA filler observed in the interdental papilla. In conclusion, our study suggested that HA is an effective way to reconstruct deficient interdental papilla.

Challenges Hindering the Resourcing for Post-Disaster Housing Reconstruction in Gaza

Resourcing post-disaster housing reconstruction (PDHR) entails many drawbacks creating bottlenecks to reconstruction projects. Understanding these vulnerable issues is of utmost to identify the appropriate interventions to mitigate their effects. The devastating aggression in 2014 in Gaza Strip served as a typical example of resources hampers. Based on the quantitative approach, the research employed a self-administrated questionnaire survey to identify the most significant challenges hindering the resourcing for post-2014 aggression housing reconstruction. The questionnaire targeted 55 of the key people in the implementing agencies of post-2014 aggression housing reconstruction. The data collected was analysed using descriptive statistics, through frequency distribution and effect index (EI); and using inferential statistics through one sample Wilcoxon signed rank test. Findings indicated that the challenges related to political issues have the most significant effect on resourcing the PDHR. The main key challenges are: (1) Difficulties to obtain permits from the Israeli side to flow the reconstruction materials into the Gaza Strip, (2) Insufficient funds for reconstruction efforts and (3) Refusal of the international community to contact the local de facto government. This research fills the knowledge gap relating to Gaza and provides the basis for more research on resourcing problems. This research has also extended, updated and confirmed the current knowledge regarding challenges hindering the resourcing for PDHR. The results draw attention of the implementing agencies in Gaza to the factors that creating bottlenecks to resource the reconstruction projects in order to overcome them and to mitigate their negative effects.

Double-Modified Bacterial Cellulose/Soy Protein Isolate Composites by Laser Hole Forming and Selective Oxidation Used for Urethral Repair.

In this study, a double-modified bacterial cellulose/soybean protein isolate (DMBC/SPI), a new type of urethral tissue engineering scaffold with good biocompatibility, biodegradability, and cell-oriented growth, was prepared. Bacterial cellulose (BC) was physically and chemically modified by laser hole forming and selective oxidation to obtain the double-modified bacterial cellulose (DMBC). The soybean protein isolate (SPI) was compounded on DMBC to obtain DMBC/SPI with better biocompatibility. DMBC/SPI was used to repair the damaged urethra in rabbits. The results showed that DMBC/SPI was beneficial to heal the damaged urethra and did not cause a milder inflammatory response. The repaired urethra was smooth and continuous. DMBC/SPI has a good urethral repair effect and is expected to be used as a new urethral reconstruction material in clinical applications. In addition, FT-IR spectroscopy, SEM, static contact angle measurements, mechanical property investigation, and cell experiments were also performed to characterize the properties of DMBC/SPI composites.

Can plastic be better than biological? What is the best material for reconstruction of the aortic arch in the Norwood procedure?

Can plastic be better than biological? What is the best material for reconstruction of the aortic arch in the Norwood procedure?

The Significance of Biomechanics and Scaffold Structure for Bladder Tissue Engineering

Current approaches for bladder reconstruction surgery are associated with many morbidities. Tissue engineering is considered an ideal approach to create constructs capable of restoring the function of the bladder wall. However, many constructs to date have failed to create a sufficient improvement in bladder capacity due to insufficient neobladder compliance. This review evaluates the biomechanical properties of the bladder wall and how the current reconstructive materials aim to meet this need. To date, limited data from mechanical testing and tissue anisotropy make it challenging to reach a consensus on the native properties of the bladder wall. Many of the materials whose mechanical properties have been quantified do not fall within the range of mechanical properties measured for native bladder wall tissue. Many promising new materials have yet to be mechanically quantified, which makes it difficult to ascertain their likely effectiveness. The impact of scaffold structures and the long-term effect of implanting these materials on their inherent mechanical properties are areas yet to be widely investigated that could provide important insight into the likely longevity of the neobladder construct. In conclusion, there are many opportunities for further investigation into novel materials for bladder reconstruction. Currently, the field would benefit from a consensus on the target values of key mechanical parameters for bladder wall scaffolds.

Developing of Load-bearing Bones Replacement Based on Cerium Compounds/Nano-hydroxyapatite Composites

The importance of implantable biomaterials is growing up in recent days for modern medicine, especially fixation, replacement, and regeneration of load-bearing bones. Through the past several years, metals, ceramics, polymers, and their composites, have been used for the reconstruction of hard tissues. Special standards such as adequate mechanical and biocompatible properties are required to avoid rejection reactions of the tissues. Recently, a number of novel advanced biomaterials are developed as promising candidates. Amongst those, cerium-based biomaterials acquired attention as a substitution material for hard tissues reconstruction because of cerium antioxidative properties, which enabled it to be used to decrease mediators of inflammation. In addition, the eminent mechanical properties, as well as the perfect chemical and biological compatibilities, make cerium-based biomaterials attractive for biomedical application.

Performance of different osteosynthesis materials in microvascular fibula free flap reconstruction

Fibular free flap (FFF) is the main reconstructive choice for large mandibular defects. Recent improvements have been made regarding planning and surgical procedure, but choice of osteosynthesis material (OSM) for segment-fixation remains controversial. A retrospective cohort study obtained clinical and radiological data from FFF-patients. Data were screened for OSM, surgical procedure and complications as OSM fractures, loosening, exposure, or insufficient osseous consolidation. Eighty patients with FFF were included. Planning was CAD/CAM (n=29), Recon Guide (n=26) or without planning (n=25). OSM was 2.0mm-miniplates in standard (n=26), preformed (n=6), CAD/CAM (n=14) or ReconGuide (n=23) variation and 2.3mm-reconstruction-plates in standard (n=5) or CAD/CAM (n=6) variation. Complications were observed in 21 cases, fractures occurred 10 times overall, but with low rates for preformed (n=1), ReconGuide (n=3) and none for CAD/CAM. Analysis detected significant correlations between used OSM and plate exposure (p = 0.000), but none regarding fracture (p = 0.275), loosening (p = 0.714) or insufficient osseous consolidation (p = 0.208). No correlations were observed between complications and OSM (p = 0.609) or diagnosis (p = 0.716). Fixation of FFF segments for reconstruction is possible with various OSM providing good clinical outcome. No significant differences were detected regarding prevention of complications by any osteosynthesis material (miniplate vs. macroplate). Although no differences were detected, miniplate usage is advocated whenever clinically reasonable, due to easier reintervention possibilities and reduced implanted foreign material. Nevertheless, decision for ideal OSM must remain patient-specific and cannot be generalised.

Biomaterials and Meniscal Lesions: Current Concepts and Future Perspective.

Menisci are crucial structures for knee homeostasis. After a meniscal lesion, the golden rule, now, is to save as much meniscus as possible; only the meniscus tissue that is identified as unrepairable should be excised, and meniscal sutures find more and more indications. Several different methods have been proposed to improve meniscal healing. They include very basic techniques, such as needling, abrasion, trephination and gluing, or more complex methods, such as synovial flaps, meniscal wrapping or the application of fibrin clots. Basic research of meniscal substitutes has also become very active in the last decades. The aim of this literature review is to analyze possible therapeutic and surgical options that go beyond traditional meniscal surgery: from scaffolds, which are made of different kind of polymers, such as natural, synthetic or hydrogel components, to new technologies, such as 3-D printing construct or hybrid biomaterials made of scaffolds and specific cells. These recent advances show that there is great interest in the development of new materials for meniscal reconstruction and that, with the development of new biomaterials, there will be the possibility of better management of meniscal injuries

A bifunctional MXene-modified scaffold for photothermal therapy and maxillofacial tissue regeneration

Abstract Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumours in the oral and maxillofacial regions and is highly malignant and prone to recur despite the development of various effective treatments, including surgery and chemoradiotherapy. Actually, it is difficult to ensure the complete elimination of tumour cells, and maxillofacial bone defects caused by surgery are hard to heal by themselves. In addition, chemoradiotherapy can bring serious side effects. Therefore, it is imperative to develop a postoperative therapy to kill residual squamous cancer cells and repair bone defects without any side effects. Here, we prepared a three-dimensional (3D) scaffold by a 3D printing technique and freeze-drying method, which contained collagen, silk and hydroxyapatite (CSH) and was functionalized with MXene nanosheets (M-CSH). The considerable photothermal effect with long-term stability can significantly kill squamous CAL-27 cancer cells in vitro and inhibit tumour growth in vivo, increasing the probability of the M-CSH scaffold being applied in the photothermal therapy of OSCC. Moreover, the cell proliferation- and osteogenic-related protein expression of mouse embryonic osteogenic precursors (MC3T3-E1) indicated excellent biocompatibility and osteogenic activity of M-CSH scaffolds. The good compression modulus (52.83 ± 2.25 kPa) and in vivo bone formation performance made it possible to be used as reconstructive materials for bone defects. This scaffold is likely promising in future tissue engineering, especially for the multifunctional treatment of maxillofacial tumours.

Autologous dura mater grafts in reconstructive surgeries for breast cancer patients

Reconstructive surgeries have long been considered as an essential part of rehabilitation of breast cancer patients. The majority of patients tend to choose one-stage reconstruction, because this type of surgery ensures rapid emotional and physical recovery. Due to the lack of subcutaneous fat in a substantial proportion of cases, which leads to postoperative complications, the most common surgical tactics now is simultaneous reconstruction after subcutaneous mastectomy with subpectoral implant location and strengthening of the lower breast slope using different materials. So far, there has been no gold standard material for secure covering of the lower pole of the implant. Autologous acellular dura mater grafts are a promising material for breast reconstruction. Studies evaluating biointegration, compatibility, inertness, reactivity, and cost effectiveness of autologous acellular dura mater grafts have determined feasibility of using these grafts in reconstructive surgeries.

The morphological changes of thorax in pediatric microtia patients after costal cartilage harvesting

BackgroundThe surgical treatment of microtia generally starts in childhood, and costal cartilage is the most widely used material for auricular reconstruction. However, multiple costal cartilage harvests lead to local cartilage defects, which may influence the growth of the hemithorax, that need close attention by doctors. In this study, morphological changes of the thorax were measured and analyzed in different follow-up groups. MethodsTwenty-eight adolescent microtia patients underwent auricular reconstruction using 6th-8th costal cartilage. Thoracic computed tomography (CT) with three-dimensional reconstruction was performed preoperatively and during follow-up. Comparison of the hemithorax on the operated and unoperated sides was performed by measuring several thoracic parameters using Mimics software (Materialise, Belgium). The data were further analyzed by a paired-samples t-test. ResultsIn the operated hemithorax, the costochondral junction midpoints moved medially (6th-8th), posteriorly (6th-7th) and descended less (6th-9th) with significant differences as P < 0.05 compared to the unoperated hemithorax. In addition, height differences indicated local depressions in the chest wall in the areas of cartilage defects (6th-9th, P < 0.05). Following local depression of the chest wall and migration of the ribs, the operated hemithorax also had a smaller area than the unoperated hemithorax (6th-9th, P < 0.05). The differences in the hemithorax were more significant in the midterm group (5–10 y) than in the other follow-up groups, while most parameters showed no significant differences in the long-term group (10–15 y). No significant differences were found in the modified Haller index. ConclusionMultiple costal cartilage harvests caused morphological changes and asymmetry of the thorax in adolescent patients. As indicated by thoracic CT, significant changes occurred in the local area of cartilage defects, which did not affect the overall thorax. In the long term, more than 10 years after harvesting, the differences in the hemithorax between the operated and unoperated sides decreased significantly. This study provides an important reference for thoracic changes when applying auricular reconstruction in the pediatric microtia patients.

Characterization of Cryopreserved Canine Amniotic Membrane.

Amniotic membrane is an effective corneal reconstruction material in veterinary surgery. Cryopreserved amniotic membrane is widely used in practice. Properties of cryopreserved canine amniotic membranes are currently not well studied. This study aimed to compare three properties between canine amniotic membranes cryopreserved for 7 days and 30 days, including tensile strength, transparency, and cell viability. After their respective cryopreservation time, stress–strain curves of the cryopreserved membranes’ tensile strength were assessed using a universal testing machine. Both groups produced J-shaped stress–strain curves with statistically comparable parameters, including maximum stress, strain, and Young’s modulus. The percentage of cell viability was observed by trypan blue staining under a light microscope. Membrane transparency was tested with a spectrophotometer. Transparency tests showed high levels of light transmission and low haze, with no statistical difference between groups. Cell viability was statistically lower in the 30-day cryopreserved group. Tensile strength and transparency of cryopreserved CAM were not significantly impeded for up to 30 days. For CAM to be used as an alternative corneal transplant material in veterinary and regenerative medicine, further research on cell biology, biomechanical properties of the membrane, and cell viability should be conducted.