• Archives of Plastic Surgery
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• v.48 no.3
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• pp.246-253
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• 2021

In order to provide a physiological solution for patients with breast cancer-related lymphedema (BCRL), the surgeon must understand where and how the pathology of lymphedema occurred. Based on each patient's pathology, the treatment plan should be carefully decided and individualized. At the authors' institution, the treatment plan is made individually based on each patient's symptoms and relative factors. Most early-stage patients first undergo decongestive therapy and then, depending on the efficacy of the treatment, a surgical approach is suggested. If the patient is indicated for surgery, all the points of lymphatic flow obstruction are carefully examined. Thus a BCRL patient can be considered for lymphaticovenous anastomosis (LVA), a lymph node flap, scar resection, or a combination thereof. LVA targets ectatic superficial collecting lymphatics, which are located within the deep fat layer, and preoperative mapping using ultrasonography is critical. If there is contracture on the axilla, axillary scar removal is indicated to relieve the vein pressure and allow better drainage. Furthermore, removing the scars and reconstructing the fat layer will allow a better chance for the lymphatics to regenerate. After complete removal of scar tissue, a regional fat flap or a superficial circumflex iliac artery perforator flap with lymph node transfer is performed. By deciding the surgical planning for BCRL based on each patient's pathophysiology, optimal outcomes can be achieved. Depending on each patient's pathophysiology, LVA, scar removal, vascularized lymph node transfer with a sufficient adipocutaneous flap, and simultaneous breast reconstruction should be planned.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.121-126
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• 2021

Background Despite the wide demand for thin flaps for various types of extremity reconstruction, the thin elevation technique for anterolateral thigh (ALT) flaps is not very popular because of its technical difficulty and safety concerns. This study proposes a novel perforator-centralizing technique for super-thin ALT flaps and analyzes its effects in comparison with a skewed-perforator group. Methods From June 2018 to January 2020, 41 patients who required coverage of various types of defects with a single perforator-based super-thin ALT free flap were enrolled. The incidence of partial necrosis and proportion of the necrotic area were analyzed on postoperative day 20 according to the location of superficial penetrating perforators along the flap. The centralized-perforator group was defined as having a perforator anchored to the middle third of the x- and y-axes of the flap, while the skewed-perforator group was defined as having a perforator anchored outside of the middle third of the x- and y-axes of the flap. Results No statistically significant difference in flap thickness and dimension was found between the two groups. The arterial and venous anastomosis patterns of patients in both groups were not significantly different. Only the mean partial necrotic area showed a statistically significant difference between the two groups (centralized-perforator group, 3.4%±2.2%; skewed-perforator group, 15.8%±8.6%; P=0.022). Conclusions The present study demonstrated that super-thin ALT perforator flaps can be elevated safely, with minimal partial necrosis, using the perforator-centralizing technique.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.69-74
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• 2021

Background In inferomedially rotated zygomatic fractures sticking in the maxillary sinus, it is often difficult to achieve complete reduction only by conventional intraoral reduction. We present a new intraoral reduction technique using a Kirschner wire and its clinical outcome. Methods Among 39 inferomedially impacted zygomatic fractures incompletely reduced by a simple intraoral reduction trial with a bone elevator, a Kirschner wire (1.5 mm) was vertically inserted from the zygomatic body to the lateral orbital rim in 17 inferior-dominant rotation fractures and horizontally inserted to the zygomatic arch in nine medial-dominant and 13 bidirectional rotation fractures. A Kirschner wire was held with a wire holder and lifted in the superolateral or anterolateral direction for reduction. Following reduction of the zygomaticomaxillary fracture, internal fixation was performed. Results Fractures were completely reduced using only an intraoral approach with Kirschner wire reduction in 33 cases and through an additional lower lid or transconjunctival incision in six cases. There were no surgical complications except in one patient with undercorrection. Postoperative 6-month computed tomography scans showed complete bone union and excellent bone alignment. Four patients experienced difficulty with upper lip elevation; however, these problems spontaneously resolved after manual tissue lump massage and intralesional steroid (Triamcinolone) injection. Conclusions We completely reduced infraorbital rim fractures, zygomaticomaxillary buttresses, and zygomaticofrontal suture fractures in 84% of patients through an intraoral approach alone. Intraoral Kirschner wire reduction may be a useful option by which to obtain effective and powerful reduction motion of an inferomedially rotated zygomatic body.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.7
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• pp.935-941
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• 2020

People estimation is important to provide IoT services. Most people counting technologies use camera or sensor data. However, the conventional technologies have the disadvantages of invasion of privacy and the need to install extra infrastructure. This paper proposes a method for estimating the number of people using a Wi-Fi AP. We use channel state information of Wi-Fi and analyze that using deep learning technology. It can be achieved by pre-installed Wi-Fi infrastructure that reduce cost for people estimation and privacy infringement. The proposed algorithm uses a k-binding data for pre-processing process and a 1D-CNN learning model. Two APs were installed to analyze the estimation results of six people. The result of the accurate number estimation was 64.8%, but the result of classifying the number of people into classes showed a high result of 84.5%. This algorithm is expected to be applicable to estimate the density of people in a small space.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.81-94
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• 2005

Recently, wireless LAN circumstance is being widely deployed in Public spots. Many People use Portable equipments such as PDA and laptop computer for multimedia applications, and also demand of mobility support is increasing. However, handoff latency is inevitably occurred between both APs when clients move from one AP to another. To reduce handoff latency. in this paper, we suggest WFH(Weighted Frequent Handoff) using effective data structure. WFH improves cache hit ratio using a new cache replacement algorithm considering the movement pattern of users. It also reduces unessential duplicate traffics. Our algorithm uses FHR(Frequent Handoff Region) that can change pre-authentication lesion according to QoS based user level, movement Pattern and Neighbor Graph that dynamically captures network movement topology.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.137-148
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• 2021

Purpose: This study aimed to assess the computer monitors used for analysis and interpretation of digital radiographs within the clinics of the Oral Health Centre of Western Australia. Materials and Methods: In total, 135 computer monitors(3 brands, 6 models) were assessed by analysing the same radiographic image of a combined 13-step aluminium step wedge and the Artinis CDDent 1.0^® (Artinis Medical Systems B.V.^®, Elst, the Netherlands) test object. The number of steps and cylindrical objects observed on each monitor was recorded along with the monitor's make, model, position relative to the researcher's eye level, and proximity to the nearest window. The number of window panels blocked by blinds, the outside weather conditions, and the number of ceiling lights over the surgical suite/cubicle were also recorded. MedCalc^® version 19.2.1 (MedCalc Software Ltd^®, Ostend, Belgium, https://www.medcalc.org; 2020) was used for statistical analyses(Kruskal-Wallis test and stepwise regression analysis). The level of significance was set at P<0.05. Results: Stepwise regression analysis showed that only the monitor brand and proximity of the monitor to a window had a significant impact on the monitor's performance (P<0.05). The Kruskal-Wallis test showed significant differences (P<0.05) in monitor performance for all variables investigated, except for the weather and the clinic in which the monitors were placed. Conclusion: The vast performance variation present between computer monitors implies the need for a review of monitor selection, calibration, and viewing conditions.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.3-9
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• 2021

Background For an attractive and natural tip contour in Asian rhinoplasty, insertion of a nasal implant and reinforcement of the cartilaginous framework are essential. However, scar contracture, which often results from augmentation with implant insertion and inadequate soft tissue coverage of the framework, is one of the most common causes of alar retraction. This study reports a novel method of redraping soft tissue along the alar rim to prevent alar retraction in Asians. Methods Twenty young Asian men who underwent primary rhinoplasty with septoplasty were retrospectively reviewed. After the usual rhinoplasty procedures, alar rim redraping was conducted for the soft tissue along the transcolumellar and bilateral infracartilaginous incisions. The longest axis of the nostril (a) and the height of the nostril from that axis (b) were measured in anterior-posterior and lateral views. The preoperative and postoperative ratios (b/a) were analyzed using the paired t-test. Results All 20 patients showed natural contours of the nasal tip, nostrils, and alae after a mean follow-up of 53.6 weeks (range, 52-60 weeks). The ratio of the nostril axes significantly decreased postoperatively in all patients except one, by an average of 11.08%±6.52% in the anterior-posterior view and 17.74%±8.49% in the lateral view (P<0.01). There were no complications, including asymmetry, contracture, subdermal plexus injury, flap congestion, or infection. Conclusions A quantitative analysis of alar retraction by evaluating the ratio of nostril axes showed that alar rim redraping is a simple and effective adjuvant technique for preventing alar retraction in rhinoplasty for young Asian men.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.33-43
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• 2021

Background Acellular dermal matrices (ADMs) have become an essential material for implant-based breast reconstruction. No previous studies have evaluated the effects of sterility of ADM under conditions of radiation. This study compared sterile (irradiated) and aseptic (non-irradiated) ADMs to determine which would better endure radiotherapy. Methods Eighteen male Balb/C mice were assigned to the control group with no irradiation (group 1) or one of two other groups with a radiation intensity of 10 Gy (group 2) or 20 Gy (group 3). Both sterile and aseptic ADMs were inserted into the back of each mouse. The residual volume of the ADM (measured using three-dimensional photography), cell incorporation, α-smooth muscle actin expression, and connective tissue growth factor expression were evaluated. The thickness and CD3 expression of the skin were measured 4 and 8 weeks after radiation. Results In groups 2 and 3, irradiated ADMs had a significantly larger residual volume than the non-irradiated ADMs after 8 weeks (P<0.05). No significant differences were found in cell incorporation and the amount of fibrosis between irradiated and non-irradiated ADMs. The skin was significantly thicker in the non-irradiated ADMs than in the irradiated ADMs in group 3 (P<0.05). CD3 staining showed significantly fewer inflammatory cells in the skin of irradiated ADMs than in non-irradiated ADMs in all three groups after 4 and 8 weeks (P<0.05). Conclusions Under radiation exposure, irradiated ADMs were more durable, with less volume decrease and less deposition of collagen fibers and inflammatory reactions in the skin than in non-irradiated ADMs.

• Archives of Plastic Surgery
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• v.48 no.2
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• pp.208-212
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• 2021

Background There are currently no guidelines for the postoperative wound management of the hard-palate donor site in cases involving mucosal harvesting. This study describes our experiences with the use of an artificial dermis for early epithelialization and transparent plate fixation in cases involving hard-palate mucosal harvesting. Methods A transparent palatal plate was custom-fabricated using a thermoplastic resin board. After mucosal harvesting, an alginic acid-containing wound dressing (Sorbsan) was applied to the donor site, which was then covered with the plate. After confirming hemostasis, the dressing was changed to artificial dermis a few days later, and the plate was fixed to the artificial dermis. The size of the mucosal defect ranged from 8×25 to 20×40 mm. Results Plate fixation was adequate, with no postoperative slippage or infection of the artificial dermis. There was no pain at the harvest site, but a slight sense of incongruity during eating was reported. Although the fabrication and application of the palatal plate required extra steps before and after harvesting, the combination of the artificial dermis and palatal plate was found to be very useful for protecting the mucosal harvest site, and resulted in decreased pain and earlier epithelialization. Conclusions The combination of artificial dermis and a transparent palatal plate for wound management at the hard-palate mucosal donor site resolved some of the limitations of conventional methods.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.49-54
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• 2021

Background Reconstruction after removal of a malignant tumor in the head and neck region is crucial for restoring tissue integrity, function, and aesthetics. We retrospectively analyzed patients who underwent intraoral reconstruction surgery using radial forearm free flaps (RFFF) and anterolateral thigh free flaps (ALT) at a single institution to provide more information supporting the choice of a reconstruction method after removal of head and neck cancer. Methods The charts of 708 patients who underwent head and neck reconstruction between 1998 and 2018 at the Department of Plastic and Reconstructive Surgery at our institution were retrospectively reviewed. Patients' age, sex, and history of radiation therapy, diabetes mellitus, and smoking were retrieved. The primary cancer site, types of defects, and complications were investigated. Results Overall, 473 and 95 patients underwent reconstruction surgery with RFFF and ALT, respectively. RFFF was more often used in patients with cancers of the pharynx, larynx, esophagus, or tonsil, while ALT was more frequently used in patients with cancers of the mouth floor with tonsil or tongue involvement. The proportion of patients undergoing ALT increased gradually. Flap failure and donor site morbidities did not show significant differences between the two groups. Conclusions RFFF and ALT flaps resulted in similar outcomes in terms of flap survival and donor site morbidity. ALT can be an option for head and neck reconstruction surgery in patients with large and complex defects or for young patients who want to hide their donor site scars.