• Journal of Periodontal and Implant Science
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• v.38 no.3
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• pp.413-428
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• 2008

Purpose: Given the predictability of dental implant procedure from the studies of successful osseointegration, implant dentistry is often the treatment of choice to replace missing teeth in edentulous patient instead of the fixed prosthesis or removable denture. The $Renova^{(R)}$ dental implant has a RBM(Resorbable Blast Media) surface, internal hex prosthetic connection and a tapered design. At this study gives the analysis of the implant and the short term survival rate of the implant. Material and Methods: In this study, a multilateral analysis was performed on the subjects undergoing placement with $Renova^{(R)}$ implant between August 2006 and February 2008 in Yonsei University dental hospital. 96 implants were placed in 56 patients and they were surveyed for cumulative survival rate. Among them 78 implants in 44 patients were surveyed for the rest analyses. Result: 1. The cumulative survival rate was 96.88% of 96 implants in 56 patients. 2. The mean marginal bone loss was 0.803mm and the marginal bone loss in augmentation group has higher value than the marginal bone loss in non augmentation group. 3. The health scale for the implants were 87% in success group, 9% in satisfactory survival group, 1% in compromised survival group, and 3% in failure group. 4. Two implants placed in poor bone posterior area by 2-stage failed during prosthetic procedure. Conclusion: $Renova^{(R)}$ dental implant showed high cumulative survival rate in installation on partial edentulous ridge and could be a predictable implant system.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.297-306
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• 1991

The purpose of this study is to improve the availabilities of radiographic technics as diagnostic methods to evaluate maxillary sinus in dental clinic. For the morphologic study of maxillary sinus, 20 dry maxillas were used and intraoral standard views, orthopantomograms, and skull P-A views were taken. For measuring the vertical image magnification rates, 5 sites in maxillary molar regions of 5 dry mandibles were selected radndomly and 25 wires of the determined sizes for selected portions were attached to the sites, after then, intraoral radiograms with bisecting technic and orthopantomograms were taken. The acquired results were as follows: 1. The anterior extension of the maxillary sinus on orthopantomogram was the distal side of the canine in 45.45% of subjects, the mesial side of the canine in 27.27%, the lateral incisor in 9.09%, the mesial side of the 1st premolar in 9.09%, and the mesial side of the 2nd pre-molar in 9.09%. 2. The positional relationship between the floor of maxillary sinus and the apex of alveolar socket revealed superimposed type in 58.3% of subjects, approached type in 33.3%, and separated type in 8.4%. 3. The morphology of inferior border of maxillary sinus was simple V or U shape in edentulous stage and V or wide U shape in alveolar socket stage. 4. The vertical image length on intraoral film taken by bisecting technic was magnified by 27.23% on the average and the length on orthopantomogram by 12.35%. 5. The inferior borders of maxillary sinus coinciding with each of the areas bearing the anterior and the posterior teeth on skull P-A view were determined.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.213-220
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• 2014

Purpose: This study was performed to determine the efficacy of observers' prediction for the need of bone grafting and presence of perioperative complications on the basis of cone-beam computed tomography (CBCT) and panoramic radiographic (PAN) planning as compared to the surgical outcome. Materials and Methods: One hundred and eight partially edentulous patients with a need for implant rehabilitation were referred for preoperative imaging. Imaging consisted of PAN and CBCT images. Four observers carried out implant planning using PAN image datasets, and at least one month later, using CBCT image datasets. Based on their own planning, the observers assessed the need for bone graft augmentation as well as complication prediction. The implant length and diameter, the need for bone graft augmentation, and the occurrence of anatomical complications during planning and implant placement were statistically compared. Results: In the 108 patients, 365 implants were installed. Receiver operating characteristic analyses of both PAN and CBCT preoperative planning showed that CBCT performed better than PAN-based planning with respect to the need for bone graft augmentation and perioperative complications. The sensitivity and the specificity of CBCT for implant complications were 96.5% and 90.5%, respectively, and for bone graft augmentation, they were 95.2% and 96.3%, respectively. Significant differences were found between PAN-based planning and the surgery of posterior implant lengths. Conclusion: Our findings indicated that CBCT-based preoperative implant planning enabled treatment planning with a higher degree of prediction and agreement as compared to the surgical standard. In PAN-based surgery, the prediction of implant length was poor.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.254-261
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• 2009

The maxillary sinus bone graft procedure is one of the predictable and successful treatments for the rehabilitation of atrophic and pneumatized edentulous posterior maxilla. Materials used for maxillary sinus floor augmentation include autogenous bone, allogenic bone, xenogenic bone and alloplastic materials. Among them, autogenous bone grafts still represents 'gold standard'for bone augmentation procedures. We selected the mandibular ramus area as a donor site for the autogenous bone graft because of low donor site morbidity. We performed maxillary sinus bone graft procedures with implant placement using particulated ramal autobone and bovine bone mixture, and got good results. This is a preliminary report of the maxillary sinus bone graft using particulated ramal autobone and bovine bone, requires more long-term follow up and further studies.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.178-183
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• 2001

Since the introduction of the concept of osseointegration, the success rate of dental implant has increased dramatically. So, the uses of dental implant in the treatment of partially or fully edentulous patients have played an important role in dental rehabilitation. Regardless of high success rate of dental implant, some amounts of fixtures cannot help failing. We can classify dental implant failure according to timing, causative factor, etc. This study is focused on dental implant fixture failure, occurring during preprosthetic stage. There are various reasons that cause implant failure on this periods, such as improper patient selection, poor bone quality, and periimplantitis, etc. We investigate the survival rate of 1058 fixtures, which installed in 306 patients in our clinic from January 1997 to December 1999, according to type, sex, location, fixture length and width, using Kaplan-Meier product-limit method and to compare each other with log-rank test. Overall survival rate was 96.80%, and 33 implants failed over the preprosthetic stage. Our survey data identified posterior location of mandible as being associated with implant failure(P<0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.539-549
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• 1995

The purpose of this study was to determine the accuracy of 3 implant impression methods by using strain gauge. The models used for this study were partially edentulous mandibular acrylic resin casts Model A, with two abutment analogs in #46,47 extraction site, represented two implant parallel to to the adjacent natural tooth. Model B represent an anterior implant parallel to the adjacene natural tooth and a posterior implant exhibiting a 15-degree lingual inclination. Master framework were fabricated on the master model, and 3 strain gauges were attached to a master framwork to determine the passivity of fit of the framework to sample casts made by the three impression techniques. The master framework was attached to each sample cast with gold screws, which were tightened with the torque driver to ensure a consistent toque application of 10 Ncm. Universal Digital Measuring System UCAM-5BT was used for strain measuring. Impression techniques studid were : 1. unsplinted tapered impression coping, polyvinyl siloxane, stock tray 2. unsplinted squared impression coping, polyether, custom tray 3. squared impression coping splinted with Duralay resin, polyether, custom tray Through analysis on data from this study, the following conclusions were obtained. 1. There were no statistically significant differences between the mean strain recorded from the sample casts made with the tree impression. But only strain values of model A(parallel group) Y-axis was signifcantly differed between Technique 1 and 3(P<0.05). 2. There was no statistically significant difference between model A(parallel group) and model B(15-degree divergent group).

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.2
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• pp.198-204
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• 2017

Maxillofacial defect comes from congenital defect, trauma and surgical resection. Patients with intraoral defect are commonly related to maxillary defect and they need prosthetic rehabilitation. Functional reconstruction of partially edentulous mandible has many limitations. However, if both condyles are intact, maxillofacial prosthesis using partial denture give competent results. In this case, a patient of 58 year-old male has a defect on palate and left mandibular posterior teeth from gunshot. The maxillary defect of this patient is Class IV according to Aramany classification and the mandibular one is Type V according to Cantor and Curtis classification. For retention of the obturator, remaining teeth are fully utilized and artificial teeth are arranged harmoniously to provide stable occlusion. Mandibular RPD covered limited range of deformed soft tissue derived from mandibular resection surgery. With these treatments, the patient in this case showed improvements in mastication, swallowing and speech.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.295-301
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• 2018

To obtain denture retention, support, and stability in Class III edentulous cases with flat alveolar ridges and extensive flabby tissue is very difficult. The patient was a 72-year-old male who wore ill-fitting 20 year old dentures made by non-medical institutions. There was flabby tissue on the maxillary anterior ridge. The patient showed Angle Class III skeletal relationship with severe protruded mandible. First, temporary dentures were fabricated to restore the masticatory function, and final dentures were made through non- pressure impression technique and careful the arrangement of the posterior resin teeth. Improvement of the retention and stability of the denture during the occlusal force application is reported.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.2
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• pp.77-84
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• 2013

Objectives: This study evaluated implant success rate, survival rate, marginal bone resorption of implants, and material resorption of sinus bone graft in cases wherein tapered body implants were installed. Materials and Methods: From September 2003 to January 2006, 20 patients from Seoul National University Bundong Hospital, with a mean age of 54.7 years, were considered. The mean follow-up period was 19 months. This study covered 50 implants; 14 implants were placed in the maxillary premolar area, and 36 in the maxillary molar area; 24 sinuses were included. Results: The success rate was 92%, and the survival rate was 96.0%. The mean amount of sinus augmentation was $12.35{\pm}3.27$ mm. The bone graft resorption rate one year after surgery was $0.97{\pm}0.84$ mm; that for the immediate implantation group was $0.91{\pm}0.86$ mm, and that for the delayed implantation group was $1.16{\pm}0.77$ mm. However, the difference was not statistically significant. The mean marginal bone resorption one year after restoration was $0.17{\pm}0.27$ mm (immediate group: $0.12{\pm}0.23$ mm; delayed group $0.40{\pm}0.33$ mm); statistically significant difference was observed between the two groups. Conclusion: Tapered body implant can be available in the maxillary posterior edentulous ridge which sinus bone graft is necessary.

• Journal of Periodontal and Implant Science
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• v.44 no.2
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• pp.50-56
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• 2014

Purpose: The aims of this study were to measure the distance of the intraosseous vascular anastomosis in the anterolateral wall of the maxillary sinus from different reference points, and to correlate the location of the intraosseous vascular anastomosis with the tooth position and the residual bone height of the maxilla. Methods: Computed tomography (CT) images were taken from 283 patients undergoing dental implants placement in the posterior maxilla. Three horizontal lines were drawn at the ridge crest, maxillary sinus floor, and the position of the anastomosis. A vertical second line at the center of each tooth was drawn perpendicular to the horizontal lines. The distance from the ridge crest to the maxillary sinus floor and the distance from the maxillary sinus floor to the bony canal were measured from the intersections of the horizontal and vertical lines. The residual alveolar bone height was used to categorize three groups: group 1,<4 mm; group 2, between 4 and 8 mm; and group 3, >8 mm. Results: The residual bone height values of different tooth positions were significantly different (P=0.0002). The distance from the maxillary sinus floor to the intraosseous vascular anastomosis was significantly different between groups 1 and 3 (P=0.0039). At the molar sites, a moderate negative correlation was found between the residual bone height and the distance from the maxillary sinus floor to the intraosseous anastomosis. The distances of the alveolar ridge crest and the maxillary sinus from the intraosseous vascular anastomosis were not significantly different between sexes. Conclusions: Within the limitations of this study, sites with a higher residual bone height in the molar regions were at a relatively high risk of artery damage during window osteotomy preparation; therefore, we recommend taking more precautions when using a lateral approach for sinus elevation.