• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.108-116
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• 2007

Recently, it has been reported that the posterior stabilized implant, which is clinically used for the total knee replacement (TKR), may have failure risk such as wear or fracture by the contact pressure and stress on the tibial post. The purpose of this study is to investigate the influence of the mal alignment of the posterior stabilized implant on the tibial post by estimating the distributions of contact pressure and von-Mises stress on a tibial post and to analyze the failure risk of the tibial post. Finite element models of a knee joint and an implant were developed from 1mm slices of CT images and 3D CAD software, respectively. The contact pressure and the von-Mises stress applying on the implant were analyzed by the finite element analysis in the neutral alignment as well as the 8 malalignment cases (3 and 5 degrees of valgus and varus angulations, and 2 and 4 degrees of anterior and posterior tilts). Loading condition at the 40% of one whole gait cycle such as 2000N of compressive load, 25N of anterior-posterior load, and 6.5Nm of torque was applied to the TKR models. Both the maximum contact pressure and the maximum von-Mises stress were concentrated on the anterior-medial region of the tibial post regardless of the malalignment, and their magnitudes increased as the degree of the malalignment increased. From present result, it is shown that the malalignment of the implant can influence on the failure risk of the tibial post.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.445-446
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.207-208
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• 2007

• Journal of Korean Dental Science
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• v.13 no.2
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• pp.67-72
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• 2020

Purpose: This clinical study presented the effectiveness of 2-stage posterior maxillary segmental osteotomy (PMSO) under local anesthesia in gaining interarch space to restore the posterior mandibular segment with dental implants. Materials and Methods: Nine patients who received two-stage PMSO for mandibular implant placement from 2003 to 2011 were included in the study. Of the 9 patients, 7 were female and 2 were male. Ages ranged form 28 to 72 (mean 46.6). Potential complications were investigated such as sinus infection, survival of bone segment, inflammatory root resorption of adjacent teeth, relapse of bone segment and timing of implant placement, delivery of implant prosthesis and stability of bone segment. Result: None of the patients showed relapse or complication. Bone segments were stabilized by opposed implant prosthesis. Conclusion: Office-based 2-stage PMSO under local anesthesia can be considered a stable and predictable procedure. Also pedicle damage can be avoided by allowing favor of blood supply to the bone segments. From these advantages, it can be concluded that this surgical procedure can decrease post-operative complications.

• Archives of Plastic Surgery
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• v.36 no.2
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• pp.167-173
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• 2009

Purpose: The key points of treatment of cryptotia are the elevation of invaginated ear helix and the correction of deformed cartilage. Prevention of stabilized cartilage contouring from returning to the previous state is also important. The authors carried otoplasty by modified Onizuka's method or Ohmori's method that conchal cartilage graft or high density polyethylene implant(MEDPOR$^{(R)}$) graft served as fixation after spreading posterior aspect of adhered antihelix and a splint for prevention of recurrence of cartilage deformities. The aim of this study is to reveal the availability of the high density polyethylene implant(MEDPOR$^{(R)}$) graft for the correction of cryptotia. Methods: We have repaired 17 cryptotic deformities using cartilage graft from cavum of concha(12 cases) or high density polyethylene implant(5 cases) for correction of deformed cartilage. We investigate the operative time, complications, and satisfaction of postoperative ear shape on both autogenous cartilage graft group and high density polyethylene implant graft group. Results: There was 1 case of reinvagination on autogenous cartilage graft group. Implant exposure was occurred on high density polyethylene implant graft group, as 1 case. These were statistically no differences between autogenous cartilage graft group and high density polyethylene implant graft group to the satisfaction of ear shape. Conclusion: High density polyethylene implant(MEDPOR$^{(R)}$) present an alternative to autogenous material as they allow of fibrovascular ingrowth, leading to stability of the implant and decreased infection rates. The correction of deformed cartilage by using the high density polyethylene implant(MEDPOR$^{(R)}$) is a good option for the treatment of cryptotia.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.367-378
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• 2023

With the recent development of computer-aided design-computer-aided manufacturing technology and 3D printing technology, and the introduction of various digital techniques, the accuracy and efficiency of top-down definitive prosthetic restoration are increasing. In this clinical case, stable occlusion support was obtained through the placement of a total of 9 maxillary and mandibular posterior implants in patient with anterior-posterior crossed occlusion. The edentulous area of the maxillary anterior teeth, which showed a tendency of high resorption of the residual alveolar bone, was restored with a Kennedy Class IV implant assisted removable partial denture to restore soft tissue esthetics. Computed tomography guided surgery was used to place implants in the planned position, double scan technique was used to reflect the stabilized occlusion in the interim restoration stage to the definitive prostheses, and metal 3D printing was used to manufacture the coping and framework. This clinical case reports that efficient and predictable top-down full mouth rehabilitation was achieved using various digital technologies and techniques.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.431-441
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• 2022

The digital facebow device records the trajectory of the mandibular movement where it is then reflected on the computer-aided design software, leading to an improvement on treatment outcomes of prosthetic restorations. In this clinical case, using a digital technology, an implant placement and prosthetic restoration were done in a patient who has lost maxillary and mandibular molars. Following an intraoral scan, a surgical stent for implant surgery was fabricated based on digital diagnostic wax-up, and implants were installed. After six months of sufficient osseointegration, customized abutments and the first temporary prostheses were delivered. Then two months later, at an abutment level, an intraoral scan and digital facebow transfer device were used to mount the intraoral scan data on a virtual articulator, and record the mandibular movements. Once the second temporary prostheses were fabricated and delivered on a basis of the mandibular movement, the definitive zirconia prostheses were designed and delivered based on a stabilized occlusion that was duplicated via double scan technique.

• Journal of Periodontal and Implant Science
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• v.38 no.3
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• pp.557-564
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• 2008

Purpose: Various methods are used in clinical crown lengthening procedure, Esthetic is more important in anterior region than in posterior region. Therefore when performing clinical crown lengthening procedure in esthetic region, clinicians should choose method which doesn't impair esthetic. Surgical extrusion could be a good method to achieve esthetic results. Material and Methods: Two patients were scheduled to clinical crown lengthening procedure in esthetic region. Teeth were extruded with periotome carefully to the intended level. Extruded teeth were anchored with sutures. Sutures are removed after 7day. Restorations were seated after extruded teeth were stabilized. Result: Five to six months later, both cases showed favorable esthetic outcome that were harmonious with adjacent teeth. Conclusion: When clinicians are to do clinical crown lengthening procedure in esthetic region, predictable esthetic outcome could be achieved with surgical extrusion.