• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.237-249
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• 2007

This study was performed to evaluate the effect of membrane exposure on new bone formation when guided bone regeneration with perforated titanium membrane on atrophic alveolar ridge. The present study attempted to establish a GBR model for four adult beagle dog premolar. Intra-marrow penetration defects were created on the alveolar ridge(twelve weeks after extraction) on the mandibular premolar teeth in the beagle dogs. Space providing perforated titanium membrane with various graft material were implanted to provide for GBR. The graft material were demineralized bovine bone(DBB), Irradiated cancellous bone(ICB) and demineralized human bone powder(DFDB). The gingival flap were advanced to cover the membranes and sutured. Seven sites experienced wound failure within 2-3weeks postsurgery resulting in membrane exposure. The animals were euthanized at 4 weeks postsurgery for histologic and histometric analysis. The results of this study were as follows: 1. There was little new bone formation at 4 weeks postsurgery. irrespectively of membrane exposure. 2. There was significant relationship between membrane exposure and bone graft resorption(P<0.05), but no relation between membrane exposure and infiltrated connective tissue. 3. There was much bone graft resorption on DFDB than ICB and DBB. 4. The less exposure was on the perforated titanium membrane, the more dense infiltrated connective tissue was filled under the membrane when grafted with ICB and DBB. but there was no relationship between the rate of membrane exposure and the percentage of infiltrated connective tissue area and no relationship between the percentage of the area in the infiltrated connective tissue and in the residual bone graft. Within the above results, bone formation may be inhibited when membrane was exposed and ICB and DBB were more effective than DFDB as a bone graft material when guided bone regeneration.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.37-44
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• 1999

Because of bone resorption, wear of ultra-high molecular weight polyethylene(UHMWPE) in total knee arthroplasty has been recognized as a major factor in long-term failure of knee implant. The surface damage and the following harmful wear debris of UHMWPE is largely related to contact stress. Most of the previous studies focused on the contact condition only at the articulating surface of UHMWPE. Recently, contact stress at the metal-backing interface has been implicated as one of major factors in UHMWPE wear. Therefore, the purpose of the is study is to investigate the effect of the contact stress for different thickness, conformity friction coefficient, and flexion degree of the UHMWPE component in total knee system, considering the contact conditions at both interfaces. In this study, a two-dimensional non-linear plane strain finite element model was developed. The results showed that the maximum value of von-Mises stress occurred below the articulating surface and the contact stress was lower for the more conforming models. All-polyethylene component showed lower stress distribution than the metal-backed component. With increased friction coefficient on the tibiofemoral contact surface, the maximum shear stress increased about twofold.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.4
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• pp.260-269
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• 2019

The prolonged neglect of the posterior teeth missing area may cause mesial drift, extrusion, unexpected movement of the adjacent teeth and alveolar bone loss with occlusion collapse. Therefore it is recommended to treat that area by the prosthesis as soon as possible after tooth missing. However, if orthodontic treatment is applied to move the remained teeth, it can create improved biomechanical dentoalveolar environment. The use of the third molars in teeth missing area provides advantages as optimizing of prosthesis size. However, crown shape, location, soundness of the third molar and possible of eruption failure should be considered. In this case report, two patients closed a second teeth missing site and reduced the size of the first and second teeth missing area for an implant by protraction of impacted third molars. This case reports the considerations for closing or reducing the posterior teeth space with protracting the third molars by comparing two patients.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.167-172
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• 2009

Purpose: We wanted to evaluate the results of treating acromioclavicular joint dislocation using an AO hook plate. Materials and Methods: Between February 2008 and September 2009, 10 patients underwent implant removal after surgical treatment of acromioclavicular joint dislocation using a AO hook plate. The Constant-Murley scoring system was administered postoperatively for evaluating the clinical results, and simple X-ray was taken for evaluating the state of reduction. Results: All cases showed satisfactory results on the clinical and radiological study. The mean Constant-Murley score at follow-up was 90.5 (range: 84~95). Three patients had some degree of discomfort with the hook plate, but these symptoms were relieved on removal of the plate. The radiological evaluation showed restoration of the vertical displacement of the clavicle in all the patients. No complications occurred such as infection, plate failure or redislocation after removal of the plate. Conclusion: The short term follow-up results of treating acromioclvicular joint dislocation using an AO hook plate were satisfactory both clinically and radiologically.

• Journal of Korean society of Dental Hygiene
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• v.6 no.4
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• pp.283-294
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• 2006

The purpose of this study was to examine the state of smoking among some college students, the smoking motivation of smoker students, what made them quit smoking and how they got ready for giving up smoking, as smoking had a huge impact on national health and there was a desperate necessity for preventive antismoking education programs to let students keep away from smoking. After a survey was conducted with self-administered questionnaires from October 1 through November 1, 2006, the responses from 400 students were gathered, and 384 answer sheets were analyzed except 16 incomplete ones. The findings of the study were as follows: 1. By gender, 62.4% of the male students and 28.6% of the female students were smokers, and the state of smoking was statistically significantly different according to their gender(p<0.05). 2. The largest number of the male students, which accounted 44.1%, started smoking in their high school days, and 39.5% of the females did that in middle school. As for a daily mean amount of smoking, 41.8% of the male students, the greatest percentage, smoked 10 to 19 cigarettes a day, and one to nine cigarettes were most common among the females, which represented 57.9 %. But the gap between the two was insignificant(p>0.05). As many as 83.6% of the males and 86.8% of the females had ever attempted to quit it. 3. Concerning awareness of antismoking policies, they felt that a raise in cigarette price would lead to less smoking, and that antismoking advertisement or posters through television or newspaper would deliver the same results as well. There was a statistically significant difference among their awareness(p<0.05). 4. Regarding preparation stage for quitting smoking, 31.3% of the male smokers had no intention to give it up, and 23.2% considered it. 36.7%, the largest percentage, got ready to refrain from it. Among the female smokers, 34.2% had no plans to abstain from smoking, and 36.8% took it into consideration. 23.7% got ready to do that. The females who got ready for that were outnumbered the males who did. 5. As to connections between the state of smoking and relevant knowledge, the students didn't have a good knowledge on that, and a statistically significant difference existed between the smokers and nonsmokers in smoking knowledge. 6. As for knowledge about oral diseases, they were highly cognizant of the relationship of smoking to tooth discoloration, nicotine stomatitis and bad breath, but they didn't know well about its relationship to delayed recovery from dental treatment, implant failure and ozena. Their smoking condition made a statistically significant difference to their knowledge(p<0.05). In the future, sustained research efforts should be channeled into determining how much smoking affects health and concerns oral diseases, and antismoking counseling programs should be prepared to bolster people's awareness of oral health.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.523-526
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• 2014

Three dogs were admitted for repair of bone fracture. Case 1 (Maltese, 1.8 kg, intact female, 5-month-old) and case 2 (poodle, 3.0 kg, intact female, 6-month-old) had non-weight bearing lameness in the left pelvic limb, and case 3 (mixed, 3.3 kg, intact female, age unknown) had non-weight-bearing lameness in the left thoracic limb. On orthopedic examination, there was pain, crepitus, palpable instability and substantial soft tissue swelling on the affected side. No neurological deficits were identified. Radiographs revealed left proximal metaphyseal tibial and fibular fractures in cases 1 and 2, and left proximal metaphyseal radial and ulnar fractures in case 3. All cases had closed long-bone fractures with short juxta-articular fracture segments. Under fluoroscopic guidance, proper placement of the ring fixation elements was confirmed during surgery. Two or three rings were used to stabilize fractures with traditional circular external skeletal fixators (CESF). Postoperative radiographs showed acceptable alignment and apposition of the previously identified fracture. Time to radiographic union ranged from 5 to 14 weeks and there were no signs of implant failure or pin tract infection. Functional outcomes were excellent in all cases. CESF can be successfully used to reduce short juxta-articular fractures in which bone plates or external skeletal fixation cannot be applied.

• Journal of the Korean Orthopaedic Association
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• v.55 no.6
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• pp.534-539
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• 2020

The management of severe scoliosis remains a challenge to spine surgeons. The rapid intraoperative correction of severe scoliosis may increase the risk of perioperative complications, such as neurological compromise and implant failure. To minimize these risks, various preoperative traction methods have been employed to achieve partial correction before performing definitive corrective surgery. On the other hand, some studies have shown that one of the complications associated with halo traction could lead to cranial nerve palsy, with the sixth nerve (abducens nerve) being most commonly affected. To reduce the complications, gradual increases in the traction weight and detailed neurological examinations are needed, particularly for patients who have previously undergone brain or cervical surgery. The authors report a case of sixth cranial nerve palsy by preoperative halo-pelvic traction in patients with severe scoliosis who underwent previous decompression surgery for a Chiari I malformation with a review of the relevant literature.

• Journal of Oral Medicine and Pain
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• v.36 no.4
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• pp.225-234
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• 2011

Tobacco smoking is a major risk factor of systemic health and also impairs oral health, which is related to development of oral cancers, periodontitis, delayed wound healing, tooth loss, failure of implant, etc. Aside from smoking, many other risk factors can be related to oral health and long-term effects of smoking on salivary flow and taste threshold are still in controversy. Authors considered dental students to be an appropriate group with good oral hygiene for a long-term study to reveal effects of smoking on oral health. This study was performed to compare smoking patterns and current oral health conditions between smokers and nonsmokers in dental students prior to long-term evaluation. 192 volunteers (85.7%) of 224 male dental students in Dankook University were evaluated through questionnaires and clinical examination in 2010. Questionnaires included smoking pattern, alcohol use, nicotine dependence, preventive care, psychological profile and clinical examinations comprised assessment of teeth or periodontal status, nicotine pigmentation, salivary flow, electrical taste thresholds and halitosis. From the study, (current) smokers were older, and drank more frequently with more alcohol intake compared to former smokers and nonsmokers(p<0.05). There was no significant difference among them in salivary flow rate, halitosis and electrical taste threshold. However, there was significant difference in DMFT rate, periodontal treatment need, nicotinic pigmentation between smokers and nonsmokers(p<0.05), irrespective of their levels of preventive care. The smokers in this study, who are young dental students with relatively shorter duration of smoking, less use of cigarettes and low level of nicotine dependence, did not reveal significant impairment of oral health. However, their oral health was found to be relatively impaired compared to nonsmokers', which suggests negative effect of smoking on the oral health and a need of smoking cessation.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.1
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• pp.119-133
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• 1997

In spite of much progress in vitro fertilization and embryo transfer (IVF-ET) program, the pregnancy rate remains at 20-30%, and the endometrial implantation rate per embryo transferred at 10-15%. As a result, about 90% of embryos may fail to implant to the endometrium, and many attempts such as optimization of follicular development, improvement of in vitro culture system including coculture, and micromanipulation of zona pellucida have been made to improve embryonic implantation after IVF-ET. Recently, several procedures of assisted hatching (AH) using micromanipulation have been introduced, and pregnancies and births have been obtained after AH. To develop and establish AH as an effective procedure to improve embryonic implantation, AH with partial zona dissection (PZD) was performed in 116 cycles of 89 infertile couples who had previous repeated failures of standard IVF-ET more than two times (Group I: 71 cycles in 54 patients), or who had implantation failure of embryos with good quality (Group II: 15 cycles in 13), or who had undergone AH without specific indication (Group III: 30 cycles in 22) from January, 1995 to Februry, 1996, and the outcomes of AH were analyzed according to pregnancy rate. The number of oocytes retrieved after controlled ovarian hyperstimulation (COH) was $9.9{\pm}7.1$ in Group I, $11.5{\pm}4.5$ in Group II, and $7.9{\pm}6.4$ in Group III. The number of embryos transferred after AH was $4.7{\pm}1.8$ in Group I, $5.3{\pm}1.3$ in Group II, and $3.5{\pm}2.4$ in Group III. The mean cumulative embryo score (CES) was $56.8{\pm}30.0$ in Group I, $76.1{\pm}35.9$ in Group II, and $38.5{\pm}29.9$ in Group III. The overall clinical pregnancy rate per cycle and per patient was 12.7% (9/71) and 16.7% (9/54) in Group I, 33.3% (5/15) and 38.5% (5/13) in Group II, and 6.7% (2/30) and 9.1% (2/22) in Group III, respectively. There were significant differences in the numbers of oocytes retrieved and embryos transferred, CES, and the clinical pregnancy rate per cycle among three groups. There was a significant inverse correlation between basal serum FSH level and CES, and no pregnancy occurred in patients with CES less than 20. In conclusion, AH of human embryos with PZD prior to ET has improved the implantation and pregnancy rates in IVF-ET patients with the past history of repeated failures, especially in spite of transfer of embryos with good quality, and AH will provide a range of novel techniques which may contribute much to effective management of infertile couples.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.22-27
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• 2015

We evaluated outcomes of dogs surgically treated for grade 2 or 3 medial patellar luxation (MPL) with and without trochleoplasty. A retrospective study of 63 dogs with grade 2 or 3 MPL surgically treated with or without trochleoplasty was performed. Results of radiographic evaluation were expressed numerically as degenerative joint disease score and were compared between the groups with and without trochleoplasty. The study included 7 (7/68, 10.3%) cases of reluxation and 1 case of tibial tuberosity transposition implant failure. Reluxation and complications requiring additional surgery were confirmed in 3 cases (3/47, 6.4%) in trochleoplasty group and in 1 case (1/21, 4.8%) in nontrochleoplasty group. The nontrochleoplasty group showed a shorter recovery time than the trochleoplasty group (P < 0.05). There was a significant difference in degenerative joint disease scores over time between the groups, with nontrochleoplasty group having lower scores (P < 0.05). This study suggests that surgical treatment without trochleoplasty results in favorable outcomes compared to treatment with trochleoplasty. It is not mandatory to exclude trochleoplasty when performing surgery for grade 2 or 3 MPL, but we propose that surgical treatment without trochleoplasty is one option when choosing a combination of surgical techniques.