• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.203-209
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• 2000

Objective : The authors retrospectively analysed the factors affecting the favorable outcomes in the treatment of the Failed Back Surgery Syndrome(FBSS) or six years. Method : From March 1991 to December 1996, seventy-five patients were diagnosed as FBSS and its incidence was 3.4% of admitted patients with back pain in our department. We analysed the demographic data, etiologies, clinical menifestations, outcomes according to methods of operation, numbers of previous surgery, and time intervals between initial operation and final operation. Result : The most common etiology and previous surgical method of FBSS were insufficient surgery(54.7%) and partial laminectomy(53.3%). Patients were managed as followings ; Total laminectomy and spinal fusion with instrument in 41 cases(54.7%), total laminectomy without fusion in 23 cases(30.7%), and only partial laminectomy in 11 cases(14.7%). The overall treatment outcome was satisfactory in 48 cases(64%). Satisfactory results were observed in those patients who were treated by spinal fusion after complete laminectomy(34 cases), who had underwent only one operation previously(45 cases), and when the time interval between the initial operation and reoperation is shorter than 12 months(43 cases). Conclusion : The treatment outcome in FBSS was favorable in cases of the complete total laminectomy and spinal fusion with instrument, only one previous back surgery, and short time interval between initial and final operations.

• Journal of Trauma and Injury
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• v.33 no.2
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• pp.104-111
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• 2020

Purpose: Although exchange nailing is a standard method of treating femoral shaft nonunion, various rates of healing, ranging from 72% to 100%, have been reported. The purpose of this study was to evaluate the efficacy of exchange nailing in femoral shaft nonunion. Methods: We retrospectively reviewed 30 cases of aseptic femoral shaft nonunion after intramedullary nailing. The mean postsurgical period of nonunion was 66.8 weeks. A nail at least 2 mm larger in diameter was selected to replace the previous nail after reaming. Distal fixation was performed using at least two interlocking screws. The success of the procedure was determined by the finding of union on simple radiographs. Possible reasons for failure were analyzed, including the location of nonunion, the type of nonunion, and the number of screws used for distal fixation. Results: Of the 30 cases, 27 achieved primary healing with the technique of exchange nailing. The average time to achieve union was 23.1 weeks (range, 13.7-36.9 weeks). The three failures involved nonunion at the isthmic level (three of 15 cases), not at the infraisthmic level (zero of 15 cases). Of eight cases of oligotrophic nonunion, two (25%) failed to heal, and of 22 cases of hypertrophic nonunion, one (4.5%) failed to heal. Of 11 cases involving two screws at the distal fixation, two (18.2%) failed to heal, and of 19 cases involving three or more screws, one (5.3%) failed to heal. None of these findings was statistically significant. Conclusions: Exchange nailing may enable successful healing in cases of aseptic nonunion of the femoral shaft. Although nonunion at the isthmic level, oligotrophic nonunion, and weaker distal fixation seemed to be associated with a higher chance of failure, further study is needed to confirm those findings.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.4
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• pp.337-343
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• 2010

Purpose: By reviewing literature on the subject, we compared the survival rate of implants placed in various graft materials used for maxillary sinus augmentation. Materials and Methods: The search protocol used the Pubmed electronic database, with a time limit from 1998 to 2009. Keywords such as 'sinus lift,' 'sinus augmentation,' 'sinus floor elevation,' 'sinus graft,' 'bone graft,' 'implants,' 'oral implants,' and 'dental implants' were used, alone and in combination, to search the database. We selected articles and divided them into three groups by type of graft materials: Group 1. Autogenous bone group: autogenous bone alone; Group 2. Combined bone group: autogenous bone in combination with bone substitutes; and Group 3. Substitute group: bone substitutes alone or bone substitute combinations. Results: We selected 37 articles concerning a total of 2,257 patients and 7,282 implants; 417 implants failed. The total implant survival rate (ISR, %) was 94.3%. In Group 1, 761 patients and 2,644 implants were studied; 179 implants failed and the ISR was 93.2%. In Group 2, 583 patients and 1,931 implants were studied; 126 implants failed and the ISR was 93.5%. In Group 3, 823 patients and 2,707 implants were studied; 112 implants failed and the ISR was 95.9%. Conclusion: Implants inserted in grafts composed of bone substitutes alone or in grafts composed of autogenous bone in combination with bone substitutes may achieve survival rates better than those for implants using autogenous bone alone (P<0.05).

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.149-156
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• 1994

Failure of in vitro fertilization may occur even though oocyte and semen parameters seem satisfactory. Quantified ultrastructural study of spermatozoa was performed in three cases of failed in vitro fertilization. The results were compared to those of four fertile men. Quantification was achieved by cataloguing cell defects of the spermatozoon heads and mid/principal pieces of the flagella. Using the data from each specimen, the percentages of total cellular abnormalities in the head/mid/principal pieces were established. The percentages of anomalies of the midpiece and of the principal piece were not significantly different between failed cases and controls. The percentage of cell alterations of the head (96-100 vs 75${\pm}$3,4%), the percentage of combined anomalies of the head (80-86 vs 52.5${\pm}$1.9%), and the percentages of nuclear shape deformation (68-86 vs 47.5${\pm}$6.3%), acrosomal defects (86-96 vs 50${\pm}$4.3%), and postacrosomal sheath defects (78-88 vs 44.5${\pm}$7.2%) of the head were significantly different between failed cases and controls. Due to the cost and time involved in processing semen samples for electron microscopy, the widespread application of this technique to all couples presenting for IVF certainly is not warranted. However, in selected instances electron microscopy may play a crucial role in identifying an occult male factor.

• Journal of Digital Convergence
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• v.16 no.2
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• pp.461-469
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• 2018

This study focuses on the influence of interpersonal relationship in suicidal ideation and mediation effect of depression in the case of psychiatric inpatients. The subject group was consisted of 109 psychiatric inpatients. Interpersonal relationship was classified into 'perceived burdensomeness' and 'failed belongingness' Findings were as follows: Perceived burdensomeness directly influence depression and through depression also indirectly influences suicidal ideation. In contrast, failed belongingness, though directly influencing depression, do not influence suicidal ideation. In accordance with these findings, this study argues that when intervening in the suicidal ideation of psychiatric inpatients, methods that could influence the factors related to interpersonal relationship would be effective.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.2
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• pp.84-89
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• 2015

We report the eventually successful treatment of a huge bone defect and peri-implantitis following reconstruction of a previously failed intra-mobile cylinder implant system (IMZ) implant site using distraction osteogenesis (DO). In the anterior mandible, two IMZ implants failed and surgical debridement was performed in accordance to the patient's needs. Thereafter, mobility and suppuration were decreased and the patient visited the dental clinic on a regular basis for oral health maintenance. However, the inflammation did not resolve, and the bone destruction around the implants progressed for 4 years. Finally, the implants failed and a severe bone defect remained after implant removal. To reconstruct the bone defects, we attempted bone graft procedures. Titanium mesh was unsuccessfully used to obtain bone volume regeneration. However, DO subsequently was used to obtain sufficient bone volume for implant placement. The new implants were then installed, followed by prosthetic procedures. In conclusion, progression of peri-implantitis could not be arrested despite surgical intervention and repeated maintenance care for 3 years. Reconstruction of the peri-implantitis site was complicated due to its horizontal and vertical bone defects. Lesions caused by implant failure require an aggressive regenerative strategy, such as DO. DO was successful in reconstruction of a peri-implantitis site that was complicated due to horizontal and vertical bone defects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1684-1691
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• 2016

Erasure codes have recently been applied to distributed storage systems due to their high storage efficiency. Regenerating codes are a kind of erasure codes, which are optimal in terms of minimum repair bandwidth. An (n,k,d)-regenerating code consists of n storage nodes where a failed node can be recovered with the help of the exactly d numbers of surviving nodes. However, if node failures occur frequently or network connection is unstable, the number of helper nodes that a failed node can contact may be smaller than d. In such cases, regenerating codes cannot repair the failed nodes efficiently since the node repair process of the codes does not work when the number of helper nodes is less than d. In this paper, we propose an operating method of regenerating codes where a failed node can be repaired from ${\bar{d}}$ helper nodes where $$k{\leq_-}{\bar{d}}{\leq_-}d$$.

• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.16.1-16.9
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• 2018

Objectives: Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods: This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results: Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions: Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment.

• The Korean Journal of Pain
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• v.25 no.2
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• pp.94-98
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• 2012

Background: An intravenous infusion of lidocaine has been used on numerous occasions to produce analgesia in neuropathic pain. In the cases of failed back surgery syndrom, the pain generated as result of abnormal impulse from the dorsal root ganglion and spinal cord, for instance as a result of nerve injury may be particularly sensitive to lidocaine. The aim of the present study was to identify the effects of IV lidocaine on neuropathic pain items of FBSS. Methods: The study was a randomized, prospective, double-blinded, crossover study involving eighteen patients with failed back surgery syndrome. The treatments were: 0.9% normal saline, lidocaine 1 mg/kg in 500 ml normal saline, and lidocaine 5 mg/kg in 500 ml normal saline over 60 minutes. The patients underwent infusions on three different appointments, at least two weeks apart. Thus all patients received all 3 treatments. Pain measurement was taken by visual analogue scale (VAS), and neuropathic pain questionnaire. Results: Both lidocaine (1 mg/kg, 5 mg/kg) and placebo significantly reduced the intense, sharp, hot, dull, cold, sensitivity, itchy, unpleasant, deep and superficial of pain. The amount of change was not significantly different among either of the lidocaine and placebo, or among the lidocaine treatments themselves, for any of the pain responses, except sharp, dull, cold, unpleasant, and deep pain. And VAS was decreased during infusion in all 3 group and there were no difference among groups. Conclusions: This study shows that 1 mg/kg, or 5 mg/kg of IV lidocaine, and palcebo was effective in patients with neuropathic pain attributable to FBSS, but effect of licoaine did not differ from placebo saline.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.92-100
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• 1986

Results of reoperation for tissue valve failure were presented with review of current knowledge. Through January 1986, 19 patients required reoperation: 18 had undergone mitral, 2 aortic, and 1 tricuspid valve. Primary tissue failure was the main cause of tissue valve failure: it occurred in 18 valves [15 mitral, 2 aortic, and 1 tricuspid] at a mean postoperative interval of 54-25 months [range 29-120]. During the same period, 2 patients required reoperation for prosthetic valve endocarditis, 1 for paravalvular leakage. The types of valves failed were 12 lonescu-Shiley valves, 5 Hancock valves, and 1 Carpentier-Edwards valve. All 6 patients younger than 15 years of age at first operation had been implanted with lonescu-Shiley valves and failed after a mean interval of 35 months. In contrast, 11 patients older than 15 years had been implanted with 5 Hancock, 6 lonescu-Shiley, and 1 Carpentier-Edwards valve initially, and eventually failed after mean intervals of 81, 53, 47 months each other. The kinds of valves used at reoperation were 8 lonescu-Shiley, 4 Bjork-Shiley, and 6 St. Jude Medical valves for primary tissue failure cases and 3 lonescu-Shiley valves for the other 3 cases. Overall mortality at reoperation was 10%: 5.6% for primary tissue failure, 50% for prosthetic valve endocarditis. In 15 cases [all mitral] primary tissue failure were caused by calcification associated with or without leaflet destruction or fibrous ingrowth, and in 2 cases [all aortic] caused by cusp perforation and tearing without any evidence of calcification. In conclusion: 1 primary tissue failure is the main cause of reoperation in patients with tissue valve failure; 2. the majority of the failed valves is in mitral position; 3. leaflet calcification is the leading pathology of primary tissue failure; 4, reoperation for tissue valve failure may be a major concern, although the mortality is low; 5. the limited durability of tissue valve suggests its use be restricted to selected cases.