• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.97-106
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• 2021

Dental implants should be placed at ideal sites for implant-supported restorations. For a patient with insufficient residual ridge, mouth preparation including surgical intervention can be indicated to establish a soft and hard tissue environment favorable for a definitive prosthesis. Prosthodontic design based on computer-guided surgery and computer-aided design-computer-aided manufacturing (CAD-CAM) provides a visual blueprint allowing a clinician to assess the necessity of such a surgical intervention beforehand. In this case, a definitive restoration was planned and made via a CAD-CAM system according to the patient's oral status before treatment, simulated surgical interventions and serial provisional restorations. Based on the planning, a guided template was made and the implants were installed with bone augmentation using the template. Customized abutments, the first and the second provisional restorations were designed and fabricated by CAD-CAM. The definitive restorations were digitally made following the shape of the second provisional prostheses, which were confirmed in the patient's mouth. The patient was satisfied with the masticatory, phonetic and aesthetic functions of these definitive prostheses.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.228-239
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• 2007

Statement of problem: Following tooth loss, the edentulous alveolar process of maxilla is affected by irreversible reabsorption process, with progressive sinus pneumatization leads to leaving inadquate bone height for placement of endosseous implants. Grafting the floor of maxillary sinus by sinus lifting surgery and augmentation of autologous bone or alternative bone material is a method of attaining sufficient bone height for maxillary implants placement and has proven to be a highty successful. Purpose: This study was undertaken to clarify the morphometric characteristics of inferior maxillary sinus and alveolar process for installation of implants. Material and method: Nineteen skulls (37 sinuses, 10M / 9F) obtained from the collection of the department of anatomy and cell biology of Hanyang medical school were studied. The mean age of the deceased was 69.9 years (range 44 to 88 years). The distance between alveolar border and inferior sinus margin at each tooth, the height of alveolar process and the thickness of cortical bone of the outer and inner table of alveolar process and the inferior wall of maxillary sinus were measured. Results and Conclusion: 1. The septum of inferior maxillary sinus were observe 28 sides (76.%) and located at the third molar (52.6%) and the second molar (26.3%). The deepest points of inferior border of maxillary sinus were located the first or second molar. The distance between alveolar margin and the deepest point of inferior maxillary sinus is $9.7{\pm}4.9mm$. 2. The length of the outer table of alveolar process were $4.9\sim28.2mm$ and the shortest point was between the first and the second molors. The thickness of them were $0.9\sim3.2mm$. The length of the inner table of alveolar process were $7.4\sim25.8mm$ and the shortest point was between the first and the second molars. The thickness of the were $0.9\sim4.6mm$. The results of this study are useful anatomical data for installing of maxillary implants.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.324-331
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• 2001

The present study was aimed to investigate the effects of latency period on alveolar ridge distraction using the intraoral distraction device. Nine adult mongrel dogs of either sex, weighing about 15kg, were used. They were divided into 3-day, 5-day, and 7-day groups according to the latency period. The left upper and lower premolars and first molars were extracted. Twelve weeks after the extraction, an osteotomy was performed and the distraction device was applied. After the latency period, the distraction was applied at a rate of 1.2mm for 8 days. The distraction device was left in place for 2 weeks to allow consolidation and was then removed. The animals were sacrified at 8 weeks after completion of distraction and were examined macroscopically, radiographically, and histologically. After completion of the distraction, the alveolar crest protruded prominently, showing the vertical augmentation of the alveolar bone. Soft tissues were broken down after the 6th day of distraction in 3-day latency group, and premature union occurred on the 7th day of distraction in the 7-day latency group. The average distance was $9.40{\pm}0.3mm$ in 3-day latency group, $9.35{\pm}0.1mm$ in 5-day latency group, and $8.85{\pm}0.1mm$ in 7-day latency group. In the radiograph taken at 8 weeks after distraction, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in all groups. Fibrous tissues were present in a part of the buccal cortical bone area of the distraction gap, and the woven and lamellar bones were observed in the distracted gap. There were bony bridges in the distraction gap in all animals examined. These results suggest that optimal time of latency period on alveolar ridge distraction using the intraoral distraction device is about 5 days in dogs, and about 7days in human beings.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.154-165
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• 2006

Objectives : It is difficult to place implants at a severely atrophied edentulous mandible because of vertical and horizontal alveolar defect. The autogenous and allogenic bone graft and guided bone regeneration are useful, but there are some limitations such as the resorption and infection of the grafted bone, and insufficiency of soft tissue. Distraction osteogenesis has recently evolved a challenging technique to overcome major draws of conventional augmentation procedures, we, therefore, report the four applications of implant placement after vertical alveolar distraction osteogenesis. Patients and Methods : Four patients(all female, mean age: $60{\pm}6$ years) with severe alveolar ridge deficiencies at their anterior mandible were treated with vertical alveolar distraction osteogenesis by intraoral device(Track 1.5, 15 mm model, KLS Martin, Tuttlingen, Germany) and placement of implants (Branemark MK III, TiUnite). After the latency periods of 5, 7, 8 days, distraction rhythm and rate were $0.5\;mm{\times}2\;times/day$ in the case of good bone quality, and $0.25\;mm{\times}3\;times/day$ in the case of poor bone quality. After consolidation periods of mean fifteen weeks, five implants for each patients were placed at the interforaminal area. Results : On average, a vertical gain of $11.38{\pm}1.38\;mm$ was obtained by distraction. And all distraction zone showed complete ossification by panoramic radiography. There were no postoperative complications other than numbness of lower lip in one case. Total twenty implants in four patients were placed and their outcomes were satisfactory. Conclusion : It is a useful method to place five implants after vertical distraction osteogenesis of the severely atrophied mandible for the implant-supported fixed prosthesis.

• Journal of Periodontal and Implant Science
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• v.49 no.1
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• pp.14-24
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• 2019

Purpose: To assess the influence of using different combinations of guided bone regeneration (GBR) materials on volume changes after wound closure at peri-implant dehiscence defects. Methods: In 5 pig mandibles, standardized bone defects were created and implants were centrally placed. The defects were augmented using different combinations of GBR materials: xenogeneic granulate and collagen membrane (group 1, n=10), xenogeneic granulate and alloplastic membrane (group 2, n=10), alloplastic granulates and alloplastic membrane (group 3, n=10). The horizontal thickness was assessed using cone-beam computed tomography before and after suturing. Measurements were performed at the implant shoulder (HT0) and at 1 mm (HT1) and 2mm (HT2) below. The data were statistically analysed using the Wilcoxon signed-rank test to evaluate within-group differences. Bonferroni correction was applied when calculating statistical significance between the groups. Results: The mean horizontal thickness before suturing was $2.55{\pm}0.53mm$ (group 1), $1.94{\pm}0.56mm$ (group 2), and $2.49{\pm}0.73mm$ (group 3). Post-suturing, the values were $1.47{\pm}0.31mm$ (group 1), $1.77{\pm}0.27mm$ (group 2), and $2.00{\pm}0.48mm$ (group 3). All groups demonstrated a loss of horizontal dimension. Intragroup changes exhibited significant differences in group 1 (P<0.001) and group 3 (P<0.01). Intergroup comparisons revealed statistically significant differences of the relative changes between groups 1 and 2 (P=0.033) and groups 1 and 3 (P=0.015). Conclusions: Volume change after wound closure was minimized by using an alloplastic membrane. The stability of the augmented horizontal thickness was most ensured by using this type of membrane irrespective of the bone substitute material used for membrane support.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.35-49
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• 2016

With the increasing demand for aesthetic implant dentistry, the importance of implant restoration is emphasized not only in the functional aspect but also in the aesthetic aspect. The aesthetic restoration of dental implants in the anterior maxilla is a challenge for clinicians because it requires proper harmony in three following conditions; reconstruction of hard tissue, soft tissue, and aesthetic prosthesis. The soft tissue aesthetics are dependent upon the condition of the supporting hard tissue because the osseous structure provides a framework for the development of a healthy and aesthetic soft tissue interface. Therefore, the augmentation of hard tissue is a first step and especially, optimal 3-dimensional position of implant is the most important factor in aesthetic implant restoration. The management of soft tissue is a second step, and the final step is a restoration of harmonic prosthesis using provisional restoration with proper emergence profile. This clinical report describes the procedure of bone augmentation in labial dehiscence defect, Vascularized Interpositional Periosteal-Connective Tissue (VIP-CT) flap for aesthetic anterior soft tissue, and the importance of provisional restoration and impression taking stage with customized impression coping.

• Journal of Korean Neurosurgical Society
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• v.46 no.1
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• pp.5-10
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• 2009

Objective: The purpose of this study is to evaluate the effectiveness of unilateral decompression and pedicle screw fixation for the unilateral symptomatic foraminal stenosis. Methods: The study group comprises consecutive 16 patients who underwent unilateral decompression and bone cement augmented pedicle screw fixation from May 2003 to January 2006. The patients were evaluated by visual analog scale (VAS) for pain and the scoring system of the Japanese Orthopedic Association (JOA) for low back pain. The result of surgery was also evaluated with McNab's classification. Excellent or good outcome was considered as successful. The patients were followed at postoperative 1 month, 3 month, 6 month, and 1 year with standing AP and lateral films. Results: The average VAS and JOA score of the 16 patients were 7.8(range, 6-9) and 5.8(range, 3 - 10) before surgery and 2.2(range, 0 - 5)and 12.3(range, 9 - 15) at the time of last follow up. Both VAS and JOA score improved significantly after the surgery (p<0.05, t-test). All patients improved after the operation and no revision surgery was required. No metal failure or pseudoarthrosis was observed during the follow-up. The success rate was 87.5%. Conclusion: Our data suggest that unilateral decompression and pedicle screw fixation for the unilateral symptomatic foraminal stenosis is an effect method for obtaining satisfactory clinical outcome. Its possible advantage is shorter operation time and reduced surgical extent. We believe that the reduced stiffness of unilateral fixation was compensated by pedicle screw augmentation and interbody fusion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.281-285
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• 2011

Sinus floor elevation is a predictable and standard procedure for the treatment of the posterior maxilla before insertion of dental implants. Although overall complication rates are low, complications can occur including sinus membrane perforation, infection of sinus, swelling and hemorrhage. The most common complication is membrane perforation. Recently, various techniques and materials for repair of perforation to the sinus membrane have been proposed. The purpose of this article is to report on various techniques and materials that can be used for repair of perforations to the sinus membrane. The search protocol used was the following electronic database: Pubmed, with a time limit from 1998 to 2009. The key words such as 'sinus lift', 'sinus augmentation', 'sinus floor elevation', 'sinus graft', 'sinus perforation', 'repair of sinus perforation' and 'repair of sinus membrane' were used, alone and in combination, when searching the database. Various techniques have been proposed to manage of perforation of sinus membranes. These include that the use of collagen membranes, demineralized freeze-dried human lamellar bone sheets, processed human allografts, lamella bone, buccal fat pads and suturing. Implant success rate ranges from 69.9% to 98.9%.

• Journal of Periodontal and Implant Science
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• v.46 no.4
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• pp.234-243
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• 2016

Purpose: Immediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws. Methods: A total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1-8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging. Results: A total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading. Conclusions: Within the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws.

• Journal of Periodontal and Implant Science
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• v.44 no.1
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• pp.33-38
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• 2014

Purpose: Autogenous bones are frequently used because of their lack of antigenicity, but good osteoconductive and osteoinductive properties. This study evaluated the biological behavior of perforated and nonperforated cortical block bone grafts. Methods: Ten nonsmoking patients who required treatment due to severe resorption of the alveolar process and subsequent implant installation were included in the study. The inclusion criteria was loss of one or more teeth; the presence of atrophy of the alveolar process with the indication of reconstruction procedures to allow rehabilitation with dental implants; and the absence of systemic disease, local infection, or inflammation. The patients were randomly divided into two groups based on whether they received a perforated (inner surface) or nonperforated graft. After a 6-month healing period, a biopsy was performed and osseointegrated implants were installed in the same procedure. Results: Fibrous connective tissue was evident at the interface in patients who received nonperforated grafts. However, full union between the graft and host bed was visible in those who had received a perforated graft. Conclusions: We found that cortical inner side perforations at donor sites increased the surface area and opened the medullary cavity. Our results indicate an increased rate of graft incorporation in patients who received such perforated grafts.