• 대한치과보철학회지
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• 제44권4호
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• pp.394-404
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• 2006

Statement of problem: A conventional 3-unit fixed partial denture design with a pontic between two retainers is the most commonly used. However in cases where the mental nerve is in close proximity to the second premolar, a cantilever design can be considered. As such, logical and scientific evidence is lacking for the number and position of implants to be placed for partially edentulous patients, and no clear-cut set of treatment principles currently exist. Purpose : The purpose of this study was to evaluate prognosis of implant-supported fixed partial dentures and to compare changes in bone level which may rise due to the different factors. Material and method : The present study examined radiographical marginal bone loss in patients treated with implant-supported fixed partial dentures (87 prostheses supported by 227 implants) and evaluated the influence of the span of the pontic, type of the opposing dentition. Clinical complications were studied using a retrospective method. Within the limitation of this study. the following result were drawn Result, 1. Seven of a total of 227 implants restored with fixed prostheses failed, resulting in a 96.9% success rate. 2. Complications encountered during recall appointments included dissolution of temporary luting agent (17 cases), porcelain fracture (8 cases), loosened screws (5 cases), gingival recession (4 cases), and gingival enlargement (1 case). 3. Marginal bone loss, 1 year after prosthesis placement, was significant(P<0.05) in the group that underwent bone grafting, however no difference in annual resorption rate was observed afterwards. 4. Marginal bono loss, 1 year post-placement, was greater in cantilever-type prostheses than in centric pontic protheses (P<0.05). 5. Marginal bone loss was more pronounced in posterior regions compared to anterior regions (P<0.05). 6. The degree of marginal bone loss was proportional to the length of the pontic (P<0.05). Conclusion: The success rate of implant-supported fixed partial dentures, including marginal bone loss, was satisfactory in the present study. Factors influencing marginal bone loss included whether bone graft was performed, location of the pontic (s), location of the surgical area in the arch pontic span. Long-term evaluation is necessary for implant-supported fixed partial dentures, as are further studies on the relationship between functional load and the number of implants to be placed.

• 대한치과보철학회지
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• 제55권4호
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• pp.458-466
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• 2017

구강종양을 절제한 경우 악안면 구조의 상실로 인해 발음, 저작, 심미 등 기능장애를 유발하게 되므로 기능회복을 위해 보철 수복이 필요하다. 이때 임플란트를 이용하면 보철물의 효과적인 기능 향상을 기대할 수 있다. 하지만 골절제술을 시행한 후, 이식골의 성공률과는 별개로 연조직이 감염에 취약한 형태를 갖기 쉬우며 이식골은 염증에 이환된 경우 빠른 속도로 파괴가 발생할 수 있다. 성공적인 보철치료를 위해서는 보철치료에 앞서 적절한 연조직 처치와 보철수복 후 잦은 정기검진을 통해 임플란트의 예후와 연관된 각별한 주의가 필요하다.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.191-198
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• 2008

Purpose: Guided bone regeneration(GBR) has emerged as a treatment in the management of osseous defects associated with dental implants. But several studies have reported different degrees of success of guided bone regeneration, depending upon the type of barrier selected, presence or absence of an underlying graft material, types of graft material, feasibility of technique, and clinician's preference. The aim of the present study was to evaluate bone formation following dental implant placement with augmentation materials at dehiscence defects in dogs. Material and Methods: Standardized buccal dehiscence defects($3{\times}5\;mm$) were surgically 2 Mongrel dog's mandibles, each 8 SLA surface, 8 anodizing surface implants. Each buccal dehiscence defect received flap surgery only(no treatment, control), $Cytoflex^{(R)}$ membrane only, Resolut $XT^{(R)}$ membrane only, Resolut $XT^{(R)}+Osteon^{TM}$. Animals were sacrificed at 8 weeks postsurgery and block sections were harvested for histologic analysis. Resuts: All experimental group resulted in higher bone formation than control. Resolut $XT^{(R)}+Osteon^{TM}$ group resulted appeared highest defect resolution. There was no difference between SLA and anodizing surface, nonresorbable and resorbable membrane. Conclusion: GBR results in rapid and clinically relevant bone closure on dehiscence defects of the dental implants.

• Archives of Plastic Surgery
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• 제32권1호
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• pp.100-104
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• 2005

A soft tissue defect of the lower leg or foot presents a challenging problem. Reconstructive surgeon should be armed at all points of wound site, tendon and bone exposure, injury of major vessel and so on in the lower limb. We reconstructed the defects of lower legs and feet of 25 patients between February, 1997 and December, 2003. Applying reversed adipofascial flap with skin graft on a soft tissue defect of the lower leg or foot is challenging. We did a comparative study of 25 reversed adipofascial flaps with 51 free flaps. All 25 cases of reverse adpofascial flap reconstruction were successful except for a partial loss of skin graft in 3 occasions. The reversed adipofascial flap had a merit of a short operation time and hositalization, a high success rate and minimum complications. Besides major vessels in the lower leg are better preserved and donor morbidity is minimal. However, the flap is unmerited in reconstructing a hug hallowed defect and in the leg with poor blood circulation and once previous surgery. The operators may consider the feasible substitution of reversed adipofascial flap for free flap before applying in the lower leg.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권3호
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• pp.242-246
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• 2006

Objective : This is to report the criteria of success of intraoral distraction osteogenesis for alveolar augmentation in the severely atrophied alveolar defects through clinical result of 2 cases. Subjects and Methods : Anterior segmental osteotomy was performed and alveolar distractors (Martin and Leibinger, Germany) were applied each in 2 patients with severely defected anterior maxillary area. The osteomized alveolar segments were distracted by 1mm a day after latency period. After the consolidation period implants were installed with removal of distractor. The implants were evaluated clinically and radiographically. Results : In Case I, the distracted bone was directed to the palatal side, and another augmentation treatment - block bone graft, guided bone regeneration - was needed. In Case II, the successful alveolar bone augmentation was achieved. Dental implant was placed on distracted alveolar bone, and showed good osseointegration and good function without any complication. Conclusion : Distraction osteogenesis can be a good choice for alveolar ridge augmentation of severely atrophied ridges. However, the anterior esthetic prosthetics relies on the control of the vector, the kind of distractor, the healing capacity of patient and the etiology of atrophy. Therefore another study of each category would be needed.

• Journal of Periodontal and Implant Science
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• 제41권2호
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• pp.86-91
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• 2011

Purpose: The aim of this study was to analyze the short-term predictability and reliability of Astra Tech implants according to the demographical distribution of patients and condition of implant sites and location of implants. Methods: Among patients treated with Astra Tech implant (Astra Tech AB) in the Department of Periodontology at the Dental Hospital of Yonsei University of College of Dentisry and K Dental Clinic from May 2004 to March 2009, 195 implants in 98 patients which had been restored more than 6 months ago were reviewed in this study. Following data were reviewed from patient charts and implants success rate was examined: 1) patient type and implant location, 2) bone status at the implant site, 3) diameter and length of the placed implants, 4) presence or absence of bone augmentation and types of the augmentation. Results: The results from this study are as follows: 1) most implants were placed in the molar area, especially 1st molar area of maxilla, 2) most implants were placed at $D_2$ and $D_3$ bone type, 3) most implants were placed in areas of B and C bone quantity, 4) autogenous and alloplastic bone graft and artificial membrane were used for placement of 74 implants. Conclusions: Short-term survival rate of Astra Tech implants was 100%.

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.581-595
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• 2001

In performing implant procedures in the anterior portion of the maxilla, many difficulties exist because of anatomical reasons, such as the proximity of the nasal floor, lateral extension of the incisive canal, and labial concavity. On the other hand, in the posterior region of the maxilla, there is often insufficient recipient bone between the maxillary sinus and alveolar ridge due to alveolar ridge resorption and pneumatization of the maxillary sinus. In order to perform implants in such regions, ridge augmentation procedures such as onlay bone graft, guided bone regeneration, and maxillary sinus grafting are performed. In studies of Caucasians, use of autograft from mandibular symphysis has been reported to be highly successful in maxillary sinus grafting. However, in a clinical study of Koreans, autograft of mandibular symphysis has been reported to have significantly low success rate. It has been hypothesized that this is because of insufficient cancellous bone due to thick cortical bone. In order to test this hypothesis, bone quality and morphology of Koreans can be compared with those of Caucasians. In this study, the bone density and morphology of the cortical bone and cancellous bone in the mandibular symphysis of 35 Korean cadavers were evaluated. The following results were obtained: 1. In terms of bone density, type I, type II, and type III consisted of 1.4%(3/213), 72.3%(154/213), and 26.3%(56/213) of the cross-sectioned specimens, respectively. In general, the bone density tended to change from type II to type III, as cross-sectioned specimens were evaluated from the midline to the canine. Type IV wasn't observed in this study. 2. The distance between the root apex and the lower border of the cancellous bone was 18.34mm-20.59mm. Considering that the bone has to be cut 5mm below the root apex during the procedure, autografts with about 15mm of vertical thickness can be obtained. 3. The thickness of cortical bone on the labial side increased from the root apex to the lower border of the mandible. The average values ranged from 1.43mm to 2.36mm. 4. The labio-lingual thickness of cancellous bone ranged from 3.43mm to 6.51mm. The thickness tended to increase from the apex to the lower border of the mandible and decrease around the lower border of cancellous bone. From the above results, the anatomic factors of the mandibular symphysis (bone density, thickness, quantity and length of the cortical bone and cancellous bone) didn't show any difference from Caucasians, and it cannot be viewed as the cause of failure in autografts in the maxillary sinus for implants.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권5호
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• pp.457-464
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• 2008

Purpose: The aim of this study was to evaluate the clinical results of implants which were installed with maxillary sinus elevation by using lateral window technique. Materials and methods: We performed the maxillary sinus elevation by lateral window technique to 87 patients who visited Dept. of Oral & Maxillofacial Surgery, Chonnam National University Hospital from January, 2003 to January, 2007. When the residual bone height was from 3 mm to 7 mm, the sinus elevation and simultaneous implant installation was mostly performed. When the residual bone height was less than 3 mm, the sinus elevation was performed and the delayed implant installation was done after 5 or 6 months. No artificial membranes were used for coverage of the lateral bony window site and freeze dried fibrin sealant was applied to the grafted bone. The mean follow-up period was 28.5 months (ranged from 10 months to 48 months) Results: 1. Unilateral sinus elevations were performed in 51 patients and bilateral sinus elevations were performed in 36 patients. And the total number of sinus elevation procedure was 123 cases. 2. The sinus elevation and simultaneous implant installation was performed in 89 sinuses and 249 implants were installed. The sinus elevation and delayed implant installation was performed in 44 sinuses and 141 implants were installed. The total number of implants were 390 in 133 sinuses. The average healing period after sinus elevations was 6.1 months in delayed implant installation. 3. Only autogenous bone, autogenous bone mixing with allografts or autogenous bone mixing with xenografts were used as graft materials. 4. The average period from first surgery to second surgery was about 7.2 months. 5. Some patients complications, such as perforation of sinus membrane, swelling, infection and exposure of cover screw. Two implants were removed in the infected sinus. 6. The survival rate of implants with maxillary sinus elevation by lateral window technique was 99.5% and the success rate of implants was 95.1%. Conclusions: These results indicated that the implants which were installed with maxillary sinus elevation by lateral window technique showed high survival and success rates.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권2호
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• pp.41-47
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• 1990

Treatment of infected mandibular fractures is confronted with various difficult problem, e.g. eradication of infection and osseous union even in the presence of devastating infection. To solve this problem various methods were proved including exteranal fixation, IMF and plating with some success. Author treated 3 cases of infected mandibular fractures with champy's miniplate. 1. Satisfactory union was obtained in 3 cases. 2. In One case, pus drainage continued even after internal fixation with miniplate, but it was easily controlled using proper antibiotic therapy & drainage. 3. In Case 3, autogenous bone graft was implanted into the infected fracture site to fill defect.

• Archives of Reconstructive Microsurgery
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• 제18권2호
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• pp.41-48
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• 2009

There are several advantages for groin flap, but its small and unpredictable vessels of pedicle have made it to lose its initial popularity. Although it would be ideal flap when it is focused on its useful advantages such as relative larger size, low donor site morbidity and possible bone graft, there have been few studies for prognostic factors for successful groin flap. Authors intended to determine prognostic factors which are relative with success of free groin flap. From January 1985 to December 2007, 107 patients who underwent groin flap for reconstruction of extremities were selected consecutively. Univariate and multivariate analysis were performed to determine prognostic factors which were related with success of groin flap. Eighty of 107 (74.8%) flaps survived. There was significant difference in success rate according to the recipient site. Nineteen of 20 cases (95%) survived in upper extremities, but 61 of 87 cases (70.1%) survived in lower extremities, which was statistically significant (p=0.022). Univariate analysis showed that mean diameter of donor veins was significantly larger in success group (p=0.021). Groin flap is recommended for reconstruction of upper extremities than lower extremities. It is thought to be critical that surgeons try to match vessel diameters between donor and recipient site.