• Title/Summary/Keyword: Model Surgery

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Freeze-dried bovine amniotic membrane as a cell delivery scaffold in a porcine model of radiation-induced chronic wounds

  • Oh, Daemyung;Son, Daegu;Kim, Jinhee;Kwon, Sun-Young
    • Archives of Plastic Surgery
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    • v.48 no.4
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    • pp.448-456
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    • 2021
  • Background Locoregional stem cell delivery is very important for increasing the efficiency of cell therapy. Amnisite BA (Amnisite) is a freeze-dried amniotic membrane harvested from bovine placenta. The objective of this study was to investigate the retention of cells of the stromal vascular fraction (SVF) on Amnisite and to determine the effects of cell-loaded Amnisite in a porcine radiation-induced chronic wound model. Methods Initially, experiments were conducted to find the most suitable hydration and incubation conditions for the attachment of SVF cells extracted from pig fat to Amnisite. Before seeding, SVFs were labeled with PKH67. The SVF cell-loaded Amnisite (group S), Amnisite only (group A), and polyurethane foam (group C) were applied to treat radiation-induced chronic wounds in a porcine model. Biopsy was performed at 10, 14, and 21 days post-operation for histological analysis. Results Retaining the SVF on Amnisite required 30 minutes for hydration and 1 hour for incubation. A PKH67 fluorescence study showed that Amnisite successfully delivered the SVF to the wounds. In histological analysis, group S showed increased re-epithelialization and revascularization with decreased inflammation at 10 days post-operation. Conclusions SVFs had acceptable adherence on hydrated Amnisite, with successful cell delivery to a radiation-induced chronic wound model.

Mixed-reality simulation for orthognathic surgery

  • Fushima, Kenji;Kobayashi, Masaru
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.38
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    • pp.13.1-13.12
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    • 2016
  • Background: Mandibular motion tracking system (ManMoS) has been developed for orthognathic surgery. This article aimed to introduce the ManMoS and to examine the accuracy of this system. Methods: Skeletal and dental models are reconstructed in a virtual space from the DICOM data of three-dimensional computed tomography (3D-CT) recording and the STL data of 3D scanning, respectively. The ManMoS uniquely integrates the virtual dento-skeletal model with the real motion of the dental cast mounted on the simulator, using the reference splint. Positional change of the dental cast is tracked by using the 3D motion tracking equipment and reflects on the jaw position of the virtual model in real time, generating the mixed-reality surgical simulation. ManMoS was applied for two clinical cases having a facial asymmetry. In order to assess the accuracy of the ManMoS, the positional change of the lower dental arch was compared between the virtual and real models. Results: With the measurement data of the real lower dental cast as a reference, measurement error for the whole simulation system was less than 0.32 mm. In ManMoS, the skeletal and dental asymmetries were adequately diagnosed in three dimensions. Jaw repositioning was simulated with priority given to the skeletal correction rather than the occlusal correction. In two cases, facial asymmetry was successfully improved while a normal occlusal relationship was reconstructed. Positional change measured in the virtual model did not differ significantly from that in the real model. Conclusions: It was suggested that the accuracy of the ManMoS was good enough for a clinical use. This surgical simulation system appears to meet clinical demands well and is an important facilitator of communication between orthodontists and surgeons.

Characteristics of Women Who Have Had Cosmetic Breast Implants That Could Be Associated with Increased Suicide Risk: A Systematic Review, Proposing a Suicide Prevention Model

  • Manoloudakis, Nikolaos;Labiris, Georgios;Karakitsou, Nefeli;Kim, Jong B.;Sheena, Yezen;Niakas, Dimitrios
    • Archives of Plastic Surgery
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    • v.42 no.2
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    • pp.131-142
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    • 2015
  • Literature indicates an increased risk of suicide among women who have had cosmetic breast implants. An explanatory model for this association has not been established. Some studies conclude that women with cosmetic breast implants demonstrate some characteristics that are associated with increased suicide risk while others support that the breast augmentation protects from suicide. A systematic review including data collection from January 1961 up to February 2014 was conducted. The results were incorporated to pre-existing suicide risk models of the general population. A modified suicide risk model was created for the female cosmetic augmentation mammaplasty candidate. A 2-3 times increased suicide risk among women that undergo cosmetic breast augmentation has been identified. Breast augmentation patients show some characteristics that are associated with increased suicide risk. The majority of women reported high postoperative satisfaction. Recent research indicates that the Autoimmune syndrome induced by adjuvants and fibromyalgia syndrome are associated with silicone implantation. A thorough surgical, medical and psycho-social (psychiatric, family, reproductive, and occupational) history should be included in the preoperative assessment of women seeking to undergo cosmetic breast augmentation. Breast augmentation surgery can stimulate a systematic stress response and increase the risk of suicide. Each risk factor of suicide has poor predictive value when considered independently and can result in prediction errors. A clinical management model has been proposed considering the overlapping risk factors of women that undergo cosmetic breast augmentation with suicide.

Development of an easy-to-handle murine model for the characterization of radiation-induced gross and molecular changes in skin

  • Chang, Hsien Pin;Cho, Jae Ho;Lee, Won Jai;Roh, Hyun;Lee, Dong Won
    • Archives of Plastic Surgery
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    • v.45 no.5
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    • pp.403-410
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    • 2018
  • Background Radiation-induced skin injury is a dose-limiting complication of radiotherapy. To investigate this problem and to develop a framework for making decisions on treatment and dose prescription, a murine model of radiation-induced skin injury was developed. Methods The dorsal skin of the mice was isolated, and irradiation was applied at single doses of 15, 30, and 50 Gy. The mice were followed for 12 weeks with serial photography and laser Doppler analysis. Sequential skin biopsy samples were obtained and subjected to a histological analysis, immunostaining against transforming growth factor beta (TGF-${\beta}$), and Western blotting with Wnt-3 and ${\beta}$-catenin. Increases in the levels of TGF-${\beta}$, Wnt, and ${\beta}$-catenin were detected after irradiation. Results All tested radiation doses caused progressive dermal thickening and fibrosis. The cause of this process, however, may not be radiation alone, as the natural course of wound healing may elicit a similar response. The latent appearance of molecular and histological markers that induce fibrosis in the 15 Gy group without causing apparent gross skin injuries indicates that 15 Gy is an appropriate dose for characterizing the effects of chronic irradiation alone. Thus, this model best mimics the patterns of injury that occur in human subjects. Conclusions This animal model can be used to elucidate the gross and molecular changes that occur in radiation-induced skin injury and provides an effective platform for studying this adverse effect without complicating the process of wound healing.

Development of a Chronic Skin Wound Defect: A Swine Model (돼지를 이용한 만성피부결손상처의 모델)

  • Sohn, Hyung Bin;Son, Dae Gu;Kim, Jun Hyung;Han, Ki Hwan;Ryoo, Nam Hee;Kwon, Sun Young
    • Archives of Plastic Surgery
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    • v.33 no.5
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    • pp.606-611
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    • 2006
  • Purpose: Animal models of a chronic wound are yet to be fully developed, and animal studies on this subject has yet to take place. The purpose of this study is to create the foundation for research on chronic wound healing based on a swine model, the most similar to that of a human. Methods: Three female 2-3 month old 'yolkshires' were used. Total of eight full thickness skin defects, $6{\times}3cm$ sized, were created on the back of each pigs. Three groups were created for comparison; Group I (n=4) was left as they were after full skin thickness excision, while the excised tissues of Group II (n=3) were turned inside out and sutured so that the epidermis would come in contact with the fascia. Group III (n=3) were excised full skin thickness in depth and silicone blocks were implanted in them. Dressing was not practised so that the wounds would be vulnerable to infection. Results: In Group III, the skin contraction rate was the least among the three groups for each three weeks of observation respectively. Also during the three weeks, bacteral colonization was at the highest among the comparison. On the third week, inflammatory cells were still active, but the generations of epidermis and collagen synthesis were detected minimally. Conclusion: The Group III was relatively the most similar model of chronic wounds. and modification of the silicone blocks, could provide us with a very effective chronic skin wound model similar to human.

Comprehensive Analysis of Chicken Vessels as Microvascular Anastomosis Training Model

  • Kang, Bo Young;Jeon, Byung-Joon;Lee, Kyeong-Tae;Mun, Goo-Hyun
    • Archives of Plastic Surgery
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    • v.44 no.1
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    • pp.12-18
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    • 2017
  • Background Nonliving chickens are commonly used as a microvascular anastomosis training model. However, previous studies have investigated only a few types of vessel, and no study has compared the characteristics of the various vessels. The present study evaluated the anatomic characteristics of various chicken vessels as a training model. Methods Eight vessels-the brachial artery, basilic vein, radial artery, ulnar artery, ischiatic artery and vein, cranial tibial artery, and common dorsal metatarsal artery-were evaluated in 26 fresh chickens and 30 chicken feet for external diameter (ED) and thicknesses of the tunica adventitia and media. The dissection time from skin incision to application of vessel clamps was also measured. Results The EDs of the vessels varied. The ischiatic vein had the largest ED of $2.69{\pm}0.33mm$, followed by the basilic vein ($1.88{\pm}0.36mm$), ischiatic artery ($1.68{\pm}0.24mm$), common dorsal metatarsal artery ($1.23{\pm}0.23mm$), cranial tibial artery ($1.18{\pm}0.19mm$), brachial artery ($1.08{\pm}0.15mm$), ulnar artery ($0.82{\pm}0.13mm$), and radial artery ($0.56{\pm}0.12mm$), and the order of size was consistent across all subjects. Thicknesses of the tunica adventitia and media were also diverse, ranging from $74.09{\pm}19.91{\mu}m$ to $158.66{\pm}40.25{\mu}m$ (adventitia) and from $31.2{\pm}7.13{\mu}m$ to $154.15{\pm}46.48{\mu}m$ (media), respectively. Mean dissection time was <3 minutes for all vessels. Conclusions Our results suggest that nonliving chickens can provide various vessels with different anatomic characteristics, which can allow trainees the choice of an appropriate microvascular anastomosis training model depending on their purpose and skillfulness.

Development of an experimental model for radiation-induced inhibition of cranial bone regeneration

  • Jung, Hong-Moon;Lee, Jeong-Eun;Lee, Seoung-Jun;Lee, Jung-Tae;Kwon, Tae-Yub;Kwon, Tae-Geon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.40
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    • pp.34.1-34.8
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    • 2018
  • Background: Radiation therapy is widely employed in the treatment of head and neck cancer. Adverse effects of therapeutic irradiation include delayed bone healing after dental extraction or impaired bone regeneration at the irradiated bony defect. Development of a reliable experimental model may be beneficial to study tissue regeneration in the irradiated field. The current study aimed to develop a relevant animal model of post-radiation cranial bone defect. Methods: A lead shielding block was designed for selective external irradiation of the mouse calvaria. Critical-size calvarial defect was created 2 weeks after the irradiation. The defect was filled with a collagen scaffold, with or without incorporation of bone morphogenetic protein 2 (BMP-2) (1 ㎍/ml). The non-irradiated mice treated with or without BMP-2-included scaffold served as control. Four weeks after the surgery, the specimens were harvested and the degree of bone formation was evaluated by histological and radiographical examinations. Results: BMP-2-treated scaffold yielded significant bone regeneration in the mice calvarial defects. However, a single fraction of external irradiation was observed to eliminate the bone regeneration capacity of the BMP-2-incorporated scaffold without influencing the survival of the animals. Conclusion: The current study established an efficient model for post-radiation cranial bone regeneration and can be applied for evaluating the robust bone formation system using various chemokines or agents in unfavorable, demanding radiation-related bone defect models.

Use of 3D Printing Model for the Management of Fibrous Dysplasia: Preliminary Case Study

  • Choi, Jong-Woo;Jeong, Woo Shik
    • Journal of International Society for Simulation Surgery
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    • v.3 no.1
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    • pp.36-38
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    • 2016
  • Fibrous dysplasia is a relatively rare disease but the management would be quite challenging. Because this is not a malignant tumor, the preservation of the facial contour and the various functions seems to be important in treatment planning. Until now the facial bone reconstruction with autogenous bone would be the standard. Although the autogenous bone would be the ideal one for facial bone reconstruction, donor site morbidity would be the inevitable problem in many cases. Meanwhile, various types of allogenic and alloplastic materials have been also used. However, facial bone reconstruction with many alloplastic material have produced no less complications including infection, exposure, and delayed wound healing. Because the 3D printing technique evolved so fast that 3D printed titanium implant were possible recently. The aim of this trial is to try to restore the original maxillary anatomy as possible using the 3D printing model, based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. And we molded Titanium mesh to reconstruct three-dimensional maxillary structure during the operation. This prefabricated Titanium-mesh implant was then inserted onto the defected maxilla and fixed. Three dimensional printing technique of titanium material based on the computer simulation turned out to be successful in this patient. Individualized approach for each patient could be an ideal way to restore the facial bone.

Reconstruction of temporal hollowing deformities using silicone implants made using a toy-clay model: a report of three cases

  • Kim, Min Wook;Kim, Seung Hyun;Nam, Su Bong;Lee, Jae Woo;Jeong, Dae Kyun;Kim, Young Ha
    • Archives of Craniofacial Surgery
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    • v.23 no.1
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    • pp.34-38
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    • 2022
  • Severe temporal hollowing deformities can occur in patients who undergo craniectomy after intracranial hemorrhage. Reconstruction surgery for cosmetic purposes using silicone implants in patients with temporal hollowing deformities after craniectomy is advantageous because the procedure is simple and rapid, with a short recovery time, resulting in lower overall treatment costs. Of paramount importance, this option yields highly satisfactory results for patients. The authors present three cases of simple and fast surgery using silicone implants where highly satisfactory outcomes were obtained.

Lack of Association between the hOGG1 Ser326Cys Polymorphism and Gastric Cancer Risk: a Meta-analysis

  • Li, Bai-Rong;Zhou, Guo-Wu;Bian, Qi;Song, Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1145-1149
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    • 2012
  • Aim: To clarify any association between the hOGG1 Ser326Cys polymorphism and susceptibility to gastric cancer. Methods: A meta-analysis based on 11 eligible case-control studies involving 5,107 subjects was carried out to summarize the data on the association between hOGG1 Ser326Cys polymorphism and gastric cancer risk. Results: No association was found between hOGG1 Ser326Cys polymorphism and gastric cancer risk (dominant model: OR = 0.95, 95% CI: 0.83-1.09, p = 0.486, ph (p values for heterogeneity) = 0.419; additive model: OR = 1.02, 95% CI: 0.81-1.30, p = 0.850, ph = 0.181; recessive model: OR = 1.09, 95% CI: 0.80-1.48, p = 0.586, ph = 0.053). Subgroup analysis based on ethnicity (Asian and Caucasian) and smoking status (ever smoker and never smoker) did did notpresent any significant association. Sensitivity analysis did not perturb the results. Conclusions: This study strongly suggested there might be no association between the hOGG1 Ser326Cys polymorphism and gastric cancer risk. However, larger scale studies are needed for confirmation.