• Title/Summary/Keyword: bone exposure

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Preliminary Application of Synthetic Computed Tomography Image Generation from Magnetic Resonance Image Using Deep-Learning in Breast Cancer Patients

  • Jeon, Wan;An, Hyun Joon;Kim, Jung-in;Park, Jong Min;Kim, Hyoungnyoun;Shin, Kyung Hwan;Chie, Eui Kyu
    • Journal of Radiation Protection and Research
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    • v.44 no.4
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    • pp.149-155
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    • 2019
  • Background: Magnetic resonance (MR) image guided radiation therapy system, enables real time MR guided radiotherapy (RT) without additional radiation exposure to patients during treatment. However, MR image lacks electron density information required for dose calculation. Image fusion algorithm with deformable registration between MR and computed tomography (CT) was developed to solve this issue. However, delivered dose may be different due to volumetric changes during image registration process. In this respect, synthetic CT generated from the MR image would provide more accurate information required for the real time RT. Materials and Methods: We analyzed 1,209 MR images from 16 patients who underwent MR guided RT. Structures were divided into five tissue types, air, lung, fat, soft tissue and bone, according to the Hounsfield unit of deformed CT. Using the deep learning model (U-NET model), synthetic CT images were generated from the MR images acquired during RT. This synthetic CT images were compared to deformed CT generated using the deformable registration. Pixel-to-pixel match was conducted to compare the synthetic and deformed CT images. Results and Discussion: In two test image sets, average pixel match rate per section was more than 70% (67.9 to 80.3% and 60.1 to 79%; synthetic CT pixel/deformed planning CT pixel) and the average pixel match rate in the entire patient image set was 69.8%. Conclusion: The synthetic CT generated from the MR images were comparable to deformed CT, suggesting possible use for real time RT. Deep learning model may further improve match rate of synthetic CT with larger MR imaging data.

BUCCAL FAT PAD TRANSFER AS A PEDICLED FLAP FOR FACIAL AUGMENTATION (외상성 안면 함몰부에 협지방대 유경 피판을 사용한 재건술)

  • Chung, Sang-Chul;Ann, Heui-Yong;Choi, Hong-Sik;Um, In-Woong;Kim, Chang-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.13 no.2
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    • pp.153-159
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    • 1991
  • The use of the autogenous free fat is a well-known procedure to fill in superficial depressions resulting from the traumatic or congenital defects. The major donor site for this procedure was the abdominal subcutaneous fat or buttocks. In 1977, Egyedi was the first to report the use of the buccal fat pad as a pedicled graft. The buccal fat pad is a structure usually considered to be a nuisance when encountered in intraoral procedures such as facial bone osteotomies, elevation of buccal falp, or procedures on Stensen's duct. In these operations, appearance of the buccal fat pad complicates surgical exposure. The buccal fat pad is a lobulated convex mass of fatty tissue covered by a very delicate membrane, and is described as having a body from which four processes extend. These projection serve as a filling material between the various muscular structures in the area. Recently malar depression was augmented with the pedicled buccal fat pad in 3 cases, and it was used for the reconstruction of the nasolabial fold in one case.

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A STUDY ON THE ORTHODONTIC TOOTH MOVEMENT UNDER HALF SINE-WAVE PULSED ELECTROMAGNETIC FIELDS (Half sine-wave pulsed electromagnetic fields 내에서 교정력에 의한 치아 이동에 대한 연구)

  • Kim, Young-Joon;Ryu, Young-Kyu
    • The korean journal of orthodontics
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    • v.24 no.4 s.47
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    • pp.897-916
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    • 1994
  • The biologic potential, which is different from the piezoelectric signals, relates tooth movement at least in part to changes in bone metaboliosm in bioelectric theory. The purpose of this experiment was to determine wheather the application of half sine-wave pulsed electromagnetic fields (HSPEMF) could increase both the rate and amount of orthodontic tooth movement. Forty-three male Hartley guinea pigs, weighting approximately 255g, were utilized in this study. The animals were 35 days old at the start of the study. Laterally directed orthodontic force was applied to the maxillary central incisors of 40 Hartley guinea pigs (20 experimental, 20 control). According to the amount of orthodontic force (6g, 12g), they were divided into two sub-groups (10 experimental I, 10 experimental II, 10 control I, 10 control II). During the experimental period, experimental animals were placed in plastic animal holders with their heads positioned in an area of uniform electromagnetic field. Control animals were placed in similar plastic holders that did not carry the electric apparatus. The results were as follows : 1. The application of a HSPEMF to the experimental groups significantly increase the final amount of orthodontic tooth movement observed over a 10-day experimental period. 2. The application of a HSPEMF to the experimental groups significantly increase the velocity of orthodontic tooth movement observed over a 10-day experimental period. 3. There was no significant difference in the final amount of orthodontic tooth movement at the fourth day to the eighth day, but there was significant difference in the final amount of orthodontic tooth movement at the nineth, tenth day during a 10-day experimental period. 4. After 10 days of HSPEMF exposure & orthodontic force, the experimental groups demonstrated more osteodasts in the pressure side than control groups.

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Leukocyte- and platelet-rich fibrin as an adjuvant to the surgical approach for osteoradionecrosis: a case report

  • Maluf, Gustavo;Caldas, Rogerio Jardim;Fregnani, Eduardo Rodrigues;da Silva Santos, Paulo Sergio
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.46 no.2
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    • pp.150-154
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    • 2020
  • We present a case of osteoradionecrosis treated with leukocyte- and platelet-rich fibrin (LPRF) and surgery and followed up with clinical and tomographic investigations. A 65-year-old woman presented with pain in the posterior region of the right palate. Her medical history included cardiovascular disease and squamous cell carcinoma in the anterior region of the floor of the mouth that had been treated with intensity-modulated radiation therapy. Measurements of isodose curves showed a full dosage of 6,462.6 cGy in the anterior mandibular region, whereas that in the posterior region on the right side of the maxilla reached 5,708.1 cGy. Osteotomy was performed using rotary instruments, and debridement and placement of two LPRF membranes were also carried out. New gum tissue with no bone exposure was noted 14 days postoperatively. Tissue repair was complete, and the patient had no further complaints. During a 39-month follow-up period, the oral mucosa remained intact, and the patient was rehabilitated with a new upper denture. Since there is no consensus regarding the best protocol to treat osteoradionecrosis, LPRF might be an interesting adjuvant to a surgical approach. The use of LPRF is simple and reduces operational costs, time of handling, probability of technical failure, and associated morbidities for patients with osteoradionecrosis.

Selection of Free Flap for the Reconstruction of Soft Tissue Defect of the Hand (수부의 연부조직 결손 재건을 위한 유리 피판의 선택)

  • Kim, Taek-Kyu;Kim, Han-Su;Choi, Sang-Mook;Chung, Chan-Min;Suh, In-Suck
    • Archives of Reconstructive Microsurgery
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    • v.6 no.1
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    • pp.87-95
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    • 1997
  • Traumatic injury to the hand often leads to soft tissue defects with exposed tendons, bones, or joints. Though many new flap have been introduced, the choice of flap that would be best for the patient depends on such factors as the site, size, and degree of wounds. Additionally the selected surgical method should be yielded cosmetic and functional superiority by the one-staged reconstruction. In our experience, small to medium sized soft tissue defect with bone and tendon exposure of hand can be resurfaced with an arterialized venous free flap from the volar aspect of distal forearm. Wide and deep defects of the hand can be covered with a sensory cutaneous free flap such as the medial plantar free flap, dorsalis pedis free flap, and radial forearm free flap. Specialized flap such as wrap-around flap, toe-to-finger transfer, onychocutaneous free flap can be used for the recontruction of defect on the thumb and finger. Based on the above considerations and our clinical experience of 60 free flap cases of the hand, the various methods for the proper repair of soft tissue defects of the hand are described. And we obtained satisfactory functional and cosmetic results with 95% success rate of free flap.

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Repairing Facial Soft Tissue Defects by Swelling Anesthesia after Tumor Resection with Narrow Pedicle Flaps

  • Huang, Chun-Hui;Qian, Han-Gen;Zhao, Xiao-Yu;Shen, Guo-Liang;Lin, Wei;Qi, Qiang
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6761-6763
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    • 2015
  • Aims: To investigate the role of swelling anesthesia in repairing facial soft tissue defects after tumor resection and temporal superficial artery frontal branch of narrow pedicle flap. Materials and Methods: From January 2008 to June 2008, 16 patients from Department of Ophthalmology with eye or eyelid tumors after eyeball removal of eye and part resection of surrounding soft tissue, undergoing postoperative swelling anesthesia with superficial temporal artery flap repair to prevent facial soft tissue defect formation and bone exposure, were recruited. Results: In all 16 patients facial soft tissue defect repair had good effects, with limited bleeding, and short operation times. Seven days after surgery, all flaps were in good repair. On postoperative follow-up after 3 months, flaps showed a similar appearance as with facial tissue. Conclusions: Swelling anesthesia for superficial temporoparietal artery frontal branch of narrow pedicle flap to repair soft tissue defect after facial tumor resection is feasible, and is linked with good analgesic effects, high postoperative survival of skin flaps, and good cosmetic effects.

Modified Approach in Reduction Malarplasty for Repositioning and Fixation (광대뼈 축소술에 있어서 재배치와 고정)

  • Hwang, So-Min;Song, Jennifer Kim;Baek, Se-Min;Baek, Rong-Min
    • Archives of Plastic Surgery
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    • v.38 no.3
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    • pp.273-278
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    • 2011
  • Purpose: It has always been an aspiration for Asians to look more balanced and feminine, considering their facial features regarding relatively flat midface with marked prominences of the zygoma. Many studies have been dealt in this subject. However, the authors would like to emphasize the concept and introduce the technique of repositioning of the malar complex to a cosmetically beneficial point and stationing it on proper position by fixation on zygoma body and arch. Methods: From January 1998 to December 2007, this method was performed in 50 patients of mild to moderate prominence and malposition of the malar complex. A simplified technique of lateral orbital osteotomy and oblique osteotomy on zygomatic arch through intraoral and preauricular incision was developed. Then, liberal malar complex can be moved to a supero-posterior direction and repositioned to a more cosmetically beneficial point. To maintain the stationed position and to protect from vector affected by the attached masticating muscle to zygomatc bone, fixation was done on both zygoma body and arch. Results: We have obtained satisfactory results using this procedure without any observable complications. The advantages of this procedure are proper exposure, inconspicuous scar, safe, more natural contour, improved stability, and shorter healing time. Conclusion: The authors suggest that reduction malarplasty should be approached with underlying concept of repositioning and fixation. In mild moderate malar prominent cases, our technique will provide with maintenance of aesthetic concept, equal to the malar reduction performed under coronal approach and provide with more natural facial contour with stability even with less invasive surgical approach.

Mechanisms of Cadmium Carcinogenicity in the Gastrointestinal Tract

  • Bishak, Yaser Khaje;Payahoo, Laleh;Osatdrahimi, Alireza;Nourazarian, Alireza
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.1
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    • pp.9-21
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    • 2015
  • Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer-related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.

Second-look Arthroscopy after Surgical Treatment for Osteochondral Lesion of Talus - Comparison of Mosaicplasty with Microfracture - (거골 골연골 병변의 수술적 치료 후 이차 관절경술 -자가 골연골 이식술과 미세 골절술의 결과 비교-)

  • Choi, Jin;Lee, Keun-Bae;Cho, Seong-Beom;Jung, Sung-Taek;Park, Gi-Heon
    • Journal of Korean Foot and Ankle Society
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    • v.10 no.2
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    • pp.133-139
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    • 2006
  • Purpose: To evaluate the results of mosaicplasty and microfracture after surgical treatments for symptomatic osteochondral lesion of talus (OLT) by second-look arthroscopy. Materials and Methods: 7 cases of mosaicplasty and 7 cases of microfracture were reviewed who undertook second-look arthroscopy at 6 months or one year after undertaking mosaicplasty or microfracture for OLT between December 2004 and October 2005. The mean age at first operation was 43.6 years (Range, 20-59) (Mosaicplasty; 43.9 years, Microfracture; 43.4 years). The mean size of cartilage defect was $15.0{\times}7.7\;mm$ in mosaicplasty and $7.1{\times}6.6\;mm$ in microfracture. Clinical outcomes were evaluated by Freiburg ankle score. Cartilage healing state was evaluated by Insall's classification for chondromalasia during second-look arthroscopy. Results: By the Freiburg ankle score, 9 ankles (6 in mosaicplasty, 3 in microfracture) had excellent and 5 (1 in mosaicplasty, 4 in microfracture) had good results at the times of second-look arthroscopy. By Insall's classification, consistency of the osteochondral grafts and congruity between grafts and native cartilage (Grade I) were shown in 9 (6 ankles in mosaicplasty, 3 ankles in microfracture), a fissuring (Grade II) in one ankle of mosaicplasty, a fasciculation (Grade III) in one ankle of microfracture, and partial exposure of subchondral bone (Grade IV) in 3 ankles of microfractures. Conclusion: Mosaicplasty was more excellent in consistency and hardness of cartilage than microfracture. In some cases of microfracture, cartilage healing was incomplete at 6 months postoperatively, so second-look arthroscopy is necessary to identify. If incomplete cartilage healing was shown, additional procedure such as microfracture or mosaicplasty was needed.

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Effectiveness of the ultrasonography in the evaluation following orbit wall reconstruction (안와벽 재건술 시행 후 평가방법으로서 초음파의 효용성)

  • Kim, Chang Yun;Yang, Jeong Yeol;Cheon, Ji Seon;Moon, Jae won
    • Archives of Plastic Surgery
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    • v.36 no.4
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    • pp.428-431
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    • 2009
  • Purpose: Blow out fracture resulting from facial trauma is of high frequency among facial bone fractures, and can cause severe complications. So, proper management and close observation after operation are needed. So far, Computed tomography has been the best choice in the evalution following orbit wall reconstruction. However, cost - effectiveness, accessibility to patients and hazard of radiation exposure of computed tomography require supplementary measure for the evaluation following orbit wall reconstruction. This study was performed to describe the effectiveness of ultrasonography in the evalution following orbit wall reconstruction. Methods: A retrospective study was performed on 40 patients who underwent orbit wall reconstruction from June, 2008 to July, 2008. The patients' ages ranged from 13 to 65 years (mean 27.5 years), and this group was compsoed of 27 male and 13 female patients. The follow up period ranged from 2 weeks to 28 weeks (mean 11weeks). Preoperatively, all fractures were diagnosed using computed tomography. Ultrasonography for all cases, and computed tomography for 2 cases were performed for evaluation following orbit wall reconstruction. Results: Reduction of herniated orbital soft tissue and orbit implant was identified by using ultrasonography in 38 cases out of 40 cases. In other cases which we could not identify the orbit implant, computed tomography was performed. Con clusion: Compared to computed tomography, ultrasonography is simple, inexpensive and convenient method. Ultrasonography can be used as supplementary measure to computed tomography in the evaluation following orbit wall reconstruction for elective patients.