• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.644-651
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• 2000

In cases of severe alveolar bony resorption in the edentulous posterior maxillae, implant placement is limited anatomically due to maxillary sinus. If the ridge is atrophic, the various bone grafting methods are required for the ridge augmentation. But the result of the onlay grafting procedure is not always promising. On the posterior maxilla, maxillary sinus mucosa lifting and bone grafting into the sinus floor, subantral augmentation(SA) technique are recommended. Various SA procedures have been developed for implant installation. We perfer to simultaneous block bone graft and implant installation through the residual alveolar ridge into the grafted block bone to fix the grafted bone and to gain the primary stability of the installed fixture. When a sagittal skeletal discrepancy in present due to the severe alveolar bony resorption of the maxilla, the advancement of the maxilla by Le Fort I osteotomy simultaneously with installation of implant fixtures combined with sinus lifting and interpositional bone graft procedure can be indicated. We applied various SA techniques for implant installtion to the 46 edentulous posterior maxillae, and total 154 implants were installed at our department from 1992 to 1999. Various SA techniques were classified in detail and the indications of each techniques were discussed. The changes of residual bony height following SA procedure were studied. The results were as follows. 1. The SA procedure combined with bone graft and simultaneous fixture installation were performed in 41 cases, 126 fixtures were installed and 5 fixtures were removed out of them. Le Fort I osteotomy procedure combined with sinus lifting and interpositional bone graft simultaneous with fixture installation were performed in 5 cases. Total 28 fixtures were installed and 2 fixtures were removed so far. 2. Autogenous block bone graft into sinus floor were performed in 35 cases, autogenous particulated marrow cancellous bone(PMCB) graft in 9 cases, and demineralized human bone powder in 2 cases. The donor site for bone graft were anterior iliac bone in 39 cases, posterior iliac bone in 3 cases and mandibular symphysis in 1 case and mandibular ramus in 1 case. 3. In 9 cases with which SA procedure had been performed with the block bone graft, the change of pre- and postoperative residual bony height were measured using MPR(multiplanar reformatted)-CT. The mean residual bony height was 8.0mm preoperatively, 20.2mm at 6 months following up operation and we gained average 12.2mm alveolar bony height. So, we can recommend this one-stage subantral augmentation and fixture installation technique as a time conserving, safe and useful method for compromised posterior edentulous maxilla.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.160-167
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• 2022

One of the treatment options for edentulous state patients with residual ridge resorption is implant overdenture using milled bar and attachment. It not only provides improved retention and stability but can also reduce the coverage of palatal surface. In addition, when a small number of implants are used, milled bar has the effect of being splinted between implant fixtures, which makes it mechanically advantageous under functions such as mastication. The patient in this case was a maxillary edentulous state patient with a considerable amount of residual alveolar bone resorption after removing the existing failed implants. Three implants were planted on both sides and an implant overdenture was fabricated using milled bar and ADD-TOC attachment.

• The Journal of the Korean dental association
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• v.56 no.3
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• pp.142-150
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• 2018

In the posterior maxillary area, due to resorption of the ridge after extraction and pneumatization of the maxillary sinus, the height of the alveolar ridge may not be sufficient for placement of implants. To solve this problem, sinus augmentation using both crestal and lateral approaches have been widely used. Jung et al. (2010) introduced the modified lateral approach technique, which is a simplified technique that combines the advantages of crestal and lateral approaches. The purpose of this case report is to report two cases in the posterior maxilla in which simultaneous implant placement with maxillary sinus augmentation has been performed using the modified lateral approach technique. In two female patients, 67 and 74 years old, respectively, simultaneous implant placement was performed using the modified lateral approach technique on the left maxillary second premolar and the first molar. In both patients, the residual bone height on the distal side of the maxillary second premolar was measured to be approximately 5 mm, and the residual bone height of the first molar was measured to be 2-3 mm. After flap elevation, osteotomy of the lateral window was performed in the form of a mesiodistally extended slot above the sinus floor and the Schneiderian membrane was elevated. Sequenced drilling was performed while protecting the membrane with a periosteal elevator. Bone graft and implant placement was performed after preparation of the implant site. Sufficient primary stability was achieved for each implant and sinus membrane was not perforated. After four and five months respectively, implant second surgery was performed. Clinically, the implants were observed to be stable. Implants and surrounding peri-implant mucosa were well maintained after prosthodontic treatment. In conclusion, the modified lateral approach could be a predictable and efficient technique for implant placement in the atrophied posterior maxilla.

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.79-83
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• 2003

Purpose : To assess the relationship between the direction of the indicating rod of the radiographic stent for ideal prosthetic design and the actual possible path of implant fixture placement when residual ridge resorption is considered. Materials and Methods: The study materials consisted of 326 implant sites (male 214 cases and female 112 cases) from a total of 106 patients (male 65 patients and female 41 patients) who desired implant prostheses. Computed tomography of patients were taken and reformatted using ToothPix/sup (R)/ software. Bony defects, bony sclerosis, the change of the direction of indicating rod, and root proximity of the adjacent teeth were examined on the CT-derived images. Results: The rate of the irregular crestal cortex was relatively high on premolar and molar area of maxilla. Mandibular molar area showed relatively high rate of focal sclerosis on the area of implant fixture insertion. The position of the indicating rods were relatively acceptable on the molar areas of both jaws. However, the position of the indicating rods should be shifted to buccal side with lingual rotation of the apical end on maxillary anterior teeth and premolar area. Conclusion: Clinically determined rod direction and position of the indicating rod for implant placement was not always acceptable for insertion according to the reformatted CT images. The pre-operative treatment plan for implant should be determined carefully, considering the state of the alveolar bone using the reformatted CT images.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.266-275
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• 2008

Dental endosseous implants require sufficient alveolar bone volume and quality for complete bone coverage and initial stability. But, atrophy or resorption of alveolar bone height and width according to patient's age and period of tooth loss can prevent ideal implant placement. Bone graft procedure has been proposed before or simultaneously with the placement of dental implants in patients with insufficient alveolar bone volume. While allografts, xenografts, and alloplastic bone grafts have been proposed and studied for alveolar ridge augmentation, the use of autogenous bone grafts represents the 'gold standard' for bone augmentation procedures. Conventional bone grafts are usually harvested from distant sites such as the ilium or ribs. Recently there is a growing use of intraoral bone grafts from intraoral donor sites such as mandibular symphysis, mandibular ramus and maxillary tuberosity. We recommend that the mandibular ramus is a safe autogenous bone graft donor site for bone harvesting with low morbidity. We report various effective autogenous bone graft procedures from mandibular ramus for the implant placement on various atrophic alveolar ridges.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.493-502
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• 2003

Statement of problem : Removable partial denture and complete denture often require denture base relines to improve the fittness against tissue-bearing mucosa because of the gradual change in edentulous ridge contour and resorption of underlyng bony structure. Self-curing hard reline resins offers the immediate and relatively inexpensive means to be recondition the surface of denture base directly However weak bond between denture base resin and reline material can harbor bacteria, promote staining, or result in complete separation of the two materials. Purpose : The purpose of this study was to evaluate the effect of denture cleansers on bond strength and surface hardness of reline resin to denture base resin Denture base resin beams($60.0{\times}15.0{\times}3.0mm$) were made with Lucitone 199. Material and methods : 10mm section was removed from the center of each specimen. The samples were replaced in the molds and the space of l0mm sections were packed with Tokuso Rebase reline material. The specimens were immersed in denture cleansers (Polident, Cleadent) and were evaluated after 1 week, 2 weeks, and 4 weeks. The bond strength and surface hardness of self-curing hard reline materials to heat-curing denture base resin were measured using an UTM (universal testing machine). Results and conclusion : 1) There was no significant difference of usage, kind, and denture cleaner by application time on the bonding strength of self-curing hard reline resin to denture base resin. 2) There was no significant difference of usage, kind, and denture cleaner by application time on the surface hardness, but the surface hardness showed decreasing tendency, as the time of immersion was extended. 3) The failure modes of the specimens was initially adhesive failure and finally cohesive failure of self-curing hard reline resin.

• Journal of Yeungnam Medical Science
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• v.20 no.2
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• pp.169-176
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• 2003

Background: Although dental implantation has become widespread and acceptable treatment for dental prosthodontics, maxillary posterior jaw region is often complicated by the pneumatization of the maxillary sinus and physiological resorption of the alveolar bone. When this occurs, the residual bone between the floor of the sinus and the crestal ridge is inadequate for the placement of implants. The sinus elevation procedure provides a way to increase the amount of available bone and to allow the placement of longer implants. Materials & methods: We studied 11 patients requiring the implant placements and the maxillary sinus elevation simultaneously from 1996 to 2003 in our clinic. Nine patients were males and two patients were females, aged from 39 to 72(mean=51.6). Four patients had medical compromised states; angina pectoris, diabetes, hypertension, hepatitis. Patients didn't show any pathologic findings clinically or radiographically. We studied the success and survival rate of implants, factors increasing the osseointegrating capacity of implants. Results: The success rate of osseointegration of implants was 93%. At least 6 months after loading on implants, the survival rate of implants was 78.5%. Autogenous bone graft and adequate residual bone height(>6mm) increased survival rate of implants. Conclusion: Successful implant placement with maxillary sinus elevation mainly depends on sufficient residual bone height, healthy maxillary sinus, autogenous bone graft.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.5
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• pp.519-526
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• 2000

Osteoporosis has recently been recognized as a major health problem in the elderly population. The disorder is manifested as a loss of bone mass accompanied by structural alteration of bone and increased incidence of fracture. Mandible also may be affected. So, I evaluated panoramic views of 66 postmenopausal women for finding the possibility of useful diagnostic mandibular parmeters of osteoporosis. To know the correlationship between skeleton and mandible, the average of the bone mineral density of lumbar from 2nd to 4th by the dual energy X-ray absorptiometry(DEXA, LUNAR DPZ. USA), and age and mandibular parameters, that is, the number of residual teeth, alveolar ridge resorption ratio, panoramic mandibular index (PMI), mandibular cortical width (MCW), angular cortical thickness (ACT), ramus cortical thickness (RCT), morphology of mandibular inferior cortical (MIC) were compared. And I divided the all tested women to the osteoporotic group and non-osteoporotic group by the use of T-score -2.0, which was derived from skeletal bone mineral density (BMD). To find the correlationship of the each group with mandibular parameters, t-test and discriminant analysis were done. The results of the t-test were that all parameters were highly related with 2 groups (p<0.05). Especially ACT, MIC, age have had even higher correlationship than others (p<0.001). The results of the discriminant analysis by the use of these ACT, MIC and age were that the discriminant function was Z = -2.973+(-1.447)$\times$(ACT)+1.131$\times$(MIC score)+(0.052)$\times$(age), the cutting score was 0.257 and the classification accuracy was 84.8%. Therefore I suggest that the consideration of the angular cortical thickness (ACT), the age of patient and the morphology of mandibular inferior cortical(MIC) may help find the osteoporosis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.4
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• pp.326-329
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• 2002

Adequate alveolar bone height and width are required for the successful placement of dental implants. Conventional therapeutic regimens for alveolar atrophy are bone grafts or augmentation using allografts and membrane (GBR). Conventional graft techniques have some limitations and complications such as infection, soft tissue problem and high resorption rate. Recently, distraction osteogenesis of alveolar bone is considered as a new alternative for ridge augmentation. Distraction osteogenesis was originally defined and popularized by Ilizarov for lengthening of long bone. Some clinicians have tried to apply distraction osteogenesis in treatment of maxillofacial discrepancies. It was also used to augment alveolar bone. Cologne study group successfully applied the technique for augmentation of alveolar bone and designed several miniplate-distractor systems fabricated by Martin Medizintechnik GmbH in Germany. Vertical distraction of alveolar bone was successfully completed in 104 patients with miniplate-distractor systems. The mean distance of distraction was 10.2mm (range: 6-15 mm) and the mean length of segment was 45 mm (range: 6-127 mm). 162 dental implants in 54 patients were placed immediately or 4 weeks later after removal of the distractor. The results of our study show that vertical distraction of alveolar bone is an effective and reliable technique to restore alveolar atrophy and alveolar vertical defect caused by trauma or tumor.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.250-255
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• 2015

In fully edentulous cases, which are accompanied by severe residual ridge resorption and impairment of supporting tissues of complete dentures, proper diagnosis and systemic treatment planning are required for the improvement in retention, stability, and support of prosthesis. Provisional restoration, while it is unfamiliar in complete denture restoration, can be used as a valuable tool, which makes possible to evaluate the stability of complete dentures and receive feedback from patients in complex clinical situations. In this case, a provisional denture was used to improve stability of impression, polished, and occlusal surfaces of complete denture, and to consider esthetic requirements before final denture construction. The result was clinically satisfactory in terms of functional and esthetical aspects.