• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.86-91
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• 2009

The success of implants essentially depends on a sufficient volume of healthy bone at the recipient site during implant placement. In patients who have the severe alveolar bone resorption or pneumatized maxillary sinus, it should be performed that bone regeneration procedure before implant placement. Development of barrier membrane makes it possible that predictable result of alveolar bone reconstruction. Many kind of materials used for barrier membrane technique are introduced, non-absorbable or absorbable membranes. But, when operation site was ruptured with membrane exposure, bacterias can be grow up at the bone graft site. Then morphology and migration of fibroblast will be changed. It works as a negative factor on healing process of bone graft site. In oral and maxillofacial department of Chonbuk national university dental hospital, we use variable suture technique like as subgingival suture, vertical mattress suture, simple interrupted suture, if need, tenting suture after GBR or block bone graft. Within these suture technique, wound healing was excellent without complication, so now we take a report of suture technique in reconstruction of alveolar bone surgery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.608-616
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• 2018

If a general nonlinear system is linearized by the successive multiplication of the 1st and 2nd order systems, then there are four types of poles in this linearized system: the pole of the 1st order system and the equal poles, two distinct real poles, and complex conjugate pair of poles of the 2nd order system. Linear Quadratic (LQ) control is a method of designing a control law that minimizes the quadratic performance index. It has the advantage of ensuring the stability of the system and the pole placement of the root of the system by weighted matrix adjustment. LQ control by the weighted matrix can move the position of the pole of the system arbitrarily, but it is difficult to set the weighting matrix by the trial and error method. This problem can be solved using the characteristic equations of the Hamiltonian system, and if the control weighting matrix is a symmetric matrix of constants, it is possible to move several poles of the system to the desired closed loop poles by applying the control law repeatedly. The paper presents a method of calculating the state weighting matrix and the control law for moving the equal poles with Jordan blocks to two real poles using the characteristic equation of the Hamiltonian system. We express this characteristic equation with a state weighting matrix by means of a trigonometric function, and we derive the relation function (${\rho},\;{\theta}$) between the equal poles and the state weighting matrix under the condition that the two real poles are the roots of the characteristic equation. Then, we obtain the moving-range of the two real poles under the condition that the state weighting matrix becomes a positive semi-finite matrix. We calculate the state weighting matrix and the control law by substituting the two real roots selected in the moving-range into the relational function. As an example, we apply the proposed method to a simple example 3rd order system.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.61-70
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• 2020

In this study, the IOT-based desk layout method was proposed to complement the existing seating method and to improve the work efficiency. The IoT system for the desk layout needs determining the function, type and network protocol of the sensor to find out the working status of the desk to reasonably assist the worker's seat placement. A collection method was proposed. The algorithm used in Block Stacking was used when deciding how to allocate seats using the acquired data. As a result, we could suggest an arithmetic basis for rational desk layout in IoT environment and show that it can be applied to an advanced flexible seating system based on working type in addition to the preferences of employees in the future.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.340-345
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• 2009

Purpose: The purpose of this study was to evaluate the surgical success of bone reconstruction of the severely atrophic maxilla using autogenous block bone onlay graft from the ramus and ilium prior to dental implantation. And we measured the amount of vertical height change Material and Methods: 26 partially edentulous patients(32 case) who needed block onlay bone graft before implant placement in posterior maxillary area from 2002 to 2009 were selected for this study. Patients consisted of 20 males & 6 females and the average of their age was 54.2. Patients who were treated with ramal bone were 19 case and patients who were treated with iliac bone were 11 case. Digital panoramic X-ray was taken at the day of surgery, 3 months and 6 months later after the surgery. Vertical height change & resorption rate of grafted bone were measured with the same X-rays and compared Results: Two out of 32 bone grafts had to be removed because of inflamation at the grafts area(97.3%). The mean of radiographic vertical height change(change rate) of post-op. 3 month was 0.54mm(8.5%)and 6 month was 0.99mm(15.9%). Compairing to intraoral donor site(ramus), iliac bone had more vertical height change(1.18mm) at 6 month after surgery. Conclusions: Within the limit of this study, autogenous block onlay grafts can be considered a promising treatment for severely atrophic maxilla.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.21.1-21.6
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• 2017

Background: The purposes of the present study were to compare implant stabilities of mandibular block bone graft and bovine bone graft and to evaluate influencing factors for implant stability in mandibular block bone (MBB) graft. Methods: This retrospective study investigated 1224 cases and 389 patients treated by one surgeon in the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital (Yangsan, Korea) between January 2010 and December 2014. Proportions that MBB graft cases constitute in all implant restoration cases and in all bone graft cases were measured. Implant stability quotient (ISQ) values were achieved by the same surgeon before loading. The average ISQ values of the experimental groups were compared. In addition, ISQ values of influencing factors, such as age, sex, implant size, and implant placement site, were compared within the MBB group using $Osstell^{TM}$ Mentor ($Osstell^{(R)}$, $G{\ddot{o}}teborg$, Sweden). Paired t test and ANOVA were conducted for statistical analysis with a significance level of 0.05. Results: Fifty-five percent of all implant restoration cases performed bone graft while MBB cases constituted 34% of all implant restoration cases and 61% of all bone graft cases. Comparing ISQ values according to bone graft materials, the MBB group manifested sufficient implant stability by presenting comparable ISQ value to that of the experimental group without bone graft. Among the reviewed factors, females, mandibular molar regions, and implants in larger diameter displayed greater implant stabilities. Conclusions: Satisfactory implant stability was accomplished upon administration of MBB graft. Within the limitation of this study, gender, implant site, and implant diameter were speculated to influence on implant stability in MBB graft.

• The Korean Journal of Pain
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• v.20 no.1
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• pp.40-45
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• 2007

Background: Caudal block is useful when anesthesia for surgery or treatment for chronic pain is needed, but this procedure has a failure rate of up to 25% even when it performed byan experienced physician. This high failure rate is usually due to improper needle placement. Methods: After gaining approval of the ethics committee, 46 patients received caudal blocks under ultrasound guidance; these were performed after the anatomical structures in the sacral hiatus had been measured with ultrasound. All these procedures were performed by the same anesthesiologist. The position and direction of the needle were identified using fluoroscopy by injecting a radio-opaque contrast through the needle. The time taken from thelidocaine injection to verification of the needle was measured and the planned nerve block was then carried out. Results: All cases of needle insertion into the sacral canal under ultrasound guidance were successful. The average duration of the procedure and the trial count were $134.1{\pm}10.1seconds$ and $1.2{\pm}0.1$, respectively. In 12 of the 46 cases (26%), the needle deviated either left or right in the sacral canal, so the direction of the needle had to be adjusted. The distance between two cornua, the depth of the sacral hiatus and the thickness and length of the sacrococcygeal ligament were $17.1{\pm}0.4$, $3.9{\pm}0.3$, $2.3{\pm}0.1$ and $24.9{\pm}0.9mm$, respectively. Conclusions: Ultrasound guidance can increase the success rate of inserting a needle into the sacral canal. However, even when ultrasound is used, the needle can deviate either left or right in the sacral canal.

• Journal of The Korean Dental Society of Anesthesiology
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• v.13 no.2
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• pp.39-44
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• 2013

Most of the dental treatments have been routinely performed under the local anesthesia and the effectiveness has also been proved safe. However, even not frequently dentists face some complications associated with the local anesthesia. In this report, the experience of the paresthesia after mental nerve block anesthesia for an implant placement of the mandibular premolar was presented to raise awareness of the complications related with local anesthetic procedure and to discuss about the causes, the proper treatments and the preventive approach of the paresthesia.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3071-3095
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• 2013

Configuring optimization of wireless sensor networks, which can improve the network performance such as utilization efficiency and network lifetime with minimal energy, has received considerable attention in recent years. In this paper, a cross layer optimal approach is proposed for multi-source linear network and grid network under Rayleigh block-fading channels, which not only achieves an optimal utility but also guarantees the end-to-end reliability. Specifically, in this paper, we first strictly present the optimization method for optimal nodal number $N^*$, nodal placement $d^*$ and nodal transmission structure $p^*$ under constraints of minimum total energy consumption and minimum unit data transmitting energy consumption. Then, based on the facts that nodal energy consumption is higher for those nodes near the sink and those nodes far from the sink may have remaining energy, a cross layer optimal design is proposed to achieve balanced network energy consumption. The design adopts lower reliability requirement and shorter transmission distance for nodes near the sink, and adopts higher reliability requirement and farther transmission distance for nodes far from the sink, the solvability conditions is given as well. In the end, both the theoretical analysis and experimental results for performance evaluation show that the optimal design indeed can improve the network lifetime by 20-50%, network utility by 20% and guarantee desire level of reliability.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.483-489
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• 2011

Introduction: This study examined the cumulative resorption of implants placed in a severely atrophic mandible and analyzed the radiologic bone resorption in the marginal bone, after an autogenous bone graft including both block and particulates that had been harvested from the ramus and iliac crest. Materials and Methods: A retrospective study was performed on patients who had bone grafts for augmentation followed by implant installation in the mandible area from 2003 to 2008. Twelve patients (6 men and 6 women) who received 34 implants in the augmented sites were evaluated. Cumulative radiologic resorption around the implants was measured immediately, 3 months, 6 months and 12 months after implant installation surgery. Results: The installed implant in grafted bone showed 0.84 mm marginal bone resorption after 3 months and 50% total cumulative resorption after 1 year. The mean marginal bone resorption around the implant installed in the grafted bone was 0.44 mm after 3 months, 0.52 mm after 1 year, after which it stabilized. The implant survival rate was 97% (failed implant was 1/34). Marginal bone resorption of the installed implant in the autogenous onlay block bone grafts was 0.98 mm after 3 months, which was significantly higher than that of a particulated bone graft (0.74 mm) (P <0.05). Conclusion: An autogenous graft including block type and particulate type is a predictable procedure for the use of dental implants in a severely atrophic mandible. Implant placement in augmented areas show a relatively high survival and minimal bone loss, as revealed by a radiologic evaluation.

• The Korean Journal of Pain
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• v.35 no.4
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• pp.403-412
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• 2022

Background: Most pain management techniques for challenging procedures are still performed under the guidance of the C-arm fluoroscope although it is sometimes difficult for even experienced clinicians to understand the modified three-dimensional anatomy as a two-dimensional X-ray image. To overcome these difficulties, the development of a virtual simulator may be helpful. Therefore, in this study, the authors developed a virtual simulator and presented its clinical application cases. Methods: We developed a computer program to simulate the actual environment of the procedure. Computed tomography (CT) Digital Imaging and Communications in Medicine (DICOM) data were used for the simulations. Virtual needle placement was simulated at the most appropriate position for a successful block. Using a virtual C-arm, the authors searched for the position of the C-arm at which the needle was visualized as a point. The positional relationships between the anatomy of the patient and the needle were identified. Results: For the simulations, the CT DICOM data of patients who visited the outpatient clinic was used. When the patients revisited the clinic, images similar to the simulated images were obtained by manipulating the C-arm. Transforaminal epidural injection, which was difficult to perform due to severe spinal deformity, and the challenging procedures of the superior hypogastric plexus block and Gasserian ganglion block, were successfully performed with the help of the simulation. Conclusions: We created a pre-procedural virtual simulation and demonstrated its successful application in patients who are expected to undergo challenging procedures.