• The Journal of Advanced Prosthodontics
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• 제8권2호
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• pp.85-93
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• 2016

PURPOSE. The purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-retained overdenture. MATERIALS AND METHODS. Maxillary implant-retained overdentures with 4 implants placed in the anterior region of edentulous maxilla were converted into a 3-D numerical model, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional finite element analysis. RESULTS. In all experimental models, the highest stress was concentrated on the most distal implant and implant supporting bone on loaded side. The stress at the most distal implant-supporting bone was concentrated on the cortical bone. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant and implant supporting bone on loaded side. CONCLUSION. It could be suggested that when making maxillary implant retained overdenture, using Hader bar instead of milled bar and full palatal coverage rather than partial palatal coverage are more beneficial in distributing the stress that is applied on implant supporting bone.

• Journal of Korean Dental Science
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• 제4권2호
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• pp.59-66
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• 2011

Purpose: This research sought to determine the resorption rate of bone grafted to the maxillary sinus according to the grafted material's type, patient's age, systemic disease, implant size, site of implant placement, and residual ridge height. Materials and Methods: This research targeted 24 patients who had immediate Osstem$^{(R)}$ implant (US Plus$^{(R)}$) placement after bone graft. The panorama was taken before the surgery, after the surgery, and 6 months after the surgery. Vertical height change and resorption rate of the grafted bone were measured with the same X-rays and compared. The influence of the following factors on the grafted bone material's resorption rate was evaluated: grafted material type, patient's age, systemic disease, implant size, site of implant placement, and residual ridge height. Results: Patients in their 40s had $34.0{\pm}21.1%$ resorption rate, which was significantly higher compared to the other age groups (P<0.05). There was no significant relationship between systemic disease and grafted bone resorption. There was no significant relationship between implant size (diameter, length) and grafted bone resorption. There was no significant relationship between the site of implant placement and grafted bone resorption. The ramal bone-grafted site was significantly more resorbed than the ramal bone/Bio-Oss$^{(R)}$-grafted site, maxillary tuberosity bone/Bio-Oss$^{(R)}$-grafted site, and ramal bone/maxillary tuberosity bone/Bio-Oss$^{(R)}$-grafted site (P<0.05). There was no significant difference in the grafted bone resorption rate in the sinus between more than 4 mm and less than 4 mm residual ridge heights. After an average of 6 months, a second surgery was done; given an average follow-up of 1.9 years, the success rate and survival rate of the implant were 96.9% and 98.4%, respectively. Conclusion: These results indicate that the bone resorption rate of grafted bone among patients in their 40s is higher compared to patients in their 50s and over, and that only autogenous bone (ramus) shows higher resorption rate than the mixed graft of autogenous bone and xenogenous graft (Bio-oss) after maxillary sinus graft.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권3호
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• pp.120-126
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• 2013

Objectives: This study sought to elucidate the effect of autogenous tooth bone material by experimenting on minipig's maxillary sinus and performing histological and histomorphometric analyses. Materials and Methods: Five 18-24 month-old male minipigs were selected, and right maxillary sinuses were grafted with bone graft material made of their respective autogenous teeth extracted eight weeks earlier. The left sides were grafted with synthetic hydroxyapatite as control groups. All minipigs were sacrificed at 12 weeks after bone graft, which was known to be 1 sigma (${\sigma}$) period for pigs. Specimens were evaluated histologically under a light microscope after haematoxylin-eosin staining followed by semi-quantitative study via histomorphometric analysis. The ratio of new bone to total area was evaluated using digital software for calculation of area. Results: All specimens were available, except one on the right side (experimental group), which was missing during specimen preparation. This study demonstrated new bone at the periphery of the existing bone in both groups, showing evidence of bone remodeling, however, encroachment of new bone on the central part of the graft at the 1 ${\sigma}$ period was observed only in the autogenous tooth bone group (experimental group). Histomorphometric analysis showed more new bone formation in the experimental group compared to the control group. Although the difference was not statistically significant (P>0.05), the mean percentage area for new bone for the experimental and control groups were $57.19%{\pm}11.16%$ and $34.07%{\pm}13.09%$, respectively. Conclusion: The novel bone graft material using autogenous tooth is a good alternative to autogenous bone, comparable to autogenous bone, and outperforming synthetic hydroxyapatite bone graft materials in terms of bone regeneration capacity. Augmentation with autogenous tooth bone materials will reduce donor site morbidity without hampering the safety of the autogenous bone graft.

• 대한치과의사협회지
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• 제58권9호
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• pp.573-582
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• 2020

Today, maxillary sinus graft is considered to be the most prognostic of bone augmentation surgery as a preprosthetic treatment. Implant survival rates of more than 95% can be expected if appropriate decisions are made on the basis of implants, implant surface morphology, and use of a shield over the maxillary sinus front-wall. In addition, maxillary sinus grafty has a low rate of complications, and even if complications occur during or after maxillary sinus graft, most are localized and easily recovered.

• 구강회복응용과학지
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• 제23권2호
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• pp.145-155
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• 2007

The advent of osseointegration and advances in biomaterials and techniques have contributed to increased application of dental implants in the restoration of maxillary partial edentulous patients. Often, in these patients, soft and hard tissue defects result from a variety of causes, such as infection, trauma, and tooth loss. These create an anatomically less favorable foundation for ideal implant placement. Reconstruction of the atrophic maxillary alveolar bone through a variety of regenerative surgical procedures has become predictable; it may be necessary prior to implant placement or simultaneously at the time of implant surgery to provide a restoration with a good long-term prognosis. Regenerative procedures are used for horizontal and vertical ridge augmentation. Many different techniques exist for effective bone augmentation. The approach is largely dependent on the extent of the defect and specific procedures to be performed for the implant reconstruction. It is most appropriate to use an evidenced-based approach when a treatment plan is being developed for bone augmentation cases. The cases presented in this article clinically demonstrate the efficacy of using a autogenous block graft, guided bone regeneration, ridge split, immediated implant placement technique on the atrophic maxillary area.

• Journal of Korean Dental Science
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• 제13권2호
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• pp.73-80
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• 2020

Purpose: The purpose of this case study series was to introduce successful implant cases that used the palatal bone in patients with severe maxillary alveolar bone atrophy or defects. Case Presentation: In this case series study, a total of four patients underwent implant placement in the palatal bone of the maxilla. A total of 6 implants were installed using the palatine bone. The patients' ages ranged from 40 to 73 years with an average age of 63.5 years. The patients had maxillary sinus-related diseases, such as maxillary sinusitis, oroantral fistula, and dentigerous cysts, prior to implantation. To achieve initial stability, the implants were placed on the palatal side, and buccally tilted. The average postoperative recovery period was 8 months. No postoperative complications occurred in any of the cases, and the approach was used without reported issues. Conclusion: Implant treatment by securing the initial fixation in the palatal bone is a good alternative when an implant must be installed in a patient who requires extensive and invasive bone graft.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권4호
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• pp.269-278
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• 2021

Objectives: The purpose of this animal research was to compare bone regeneration in augmented rabbit maxillary sinuses treated with demineralized particulate human-tooth graft and anorganic bovine bone by immunohistochemical analysis. Materials and Methods: Piezoelectric bilateral sinus augmentation was performed in eight adult rabbits. In the control group, anorganic bovine was grafted in the maxillary sinus following elevation of the sinus membrane. In the experimental group, demineralized human particulate tooth bone was grafted in the sinus. Bone regeneration in augmented sinuses was evaluated by immunohistochemical analysis using various markers of osteoprogenitor cells. Results: The number of bromodeoxyuridine-labeled cells was significantly higher in the experimental group than in the control group at eight weeks. The immunoreactivity of proliferating-cell nuclear antigen was increased slightly in the experimental group relative to the control group at eight weeks. Other bone markers were expressed equally in the two groups. Conclusion: In the rabbit maxillary sinus, higher osteoinduction was correlated with demineralized human particulate tooth bone grafting than with anorganic bovine grafting.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권5호
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• pp.482-487
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• 2006

As the uses of dental implants are prevailing, the need for sinus bone graft is increasing. Deproteinized bovine bone mineral (DBBM) was not mentioned in 1996 Sinus Bone Graft because of the deficit of the available data. Since then, many clinical and laboratory reports support the use of DBBM in the sinus bone graft procedure. In this report, the histological and clinical successes of sinus bone grafting with DBBM is discussed with available literatures. After sinus bone grafts with DBBM, the proportion of new bone formed was similar or superior to natural maxillary posterior alveolar bone after healing period of 6 months to 1 year. It seems that the grafted DBBM is not be either resorbed nor replaced with bone, but this may not disturb the osseointegration of dental implants installed into it. The clinical survival rates of dental implants installed on the sinus grafted with DBBM was similar to those installed on the ungrafted posterior maxillary alveolar ridge or grafted with autogenous bone. So, it can be concluded that DBBM can be used successfully in the sinus bone graft.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.575-579
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• 2006

Purpose : The purpose of this study was to evaluate peri-implant bone loss and implant success on anterior maxillary alveolar ridges and Compare Class III and Class IV ridges in the aspect of peri-implant bone loss. Material and Methods : 14 patients (aged 21 to 68, 6males and 8females), who lacked maxillary anterior teeth and were installed from January 2000 to April 2003 at Samsung Medical Center, were selected. The type of implant used included 30 $Br\ddot{a}nemark$ implant. They were taken with digital tomographic and conventional intraoral radiographic examinmation, and were treated with implant installaion without bone augmentation. The peri-implant bone resorption was measured at the mesial and distal aspect of implant on the conventional intraoral radiographs. Results : The study classified the anterior maxillary alveolar ridge and measured peri-implant bone resorption from the period of implant installation to the 2nd year after functional loading radiographically. The study revealed no statistically significant difference between two groups, which was classified by its morphology. The average bone resorption on healing period before loading was 0.18mm and 0.18mm, the 1st year of loading period, 0.77 mm and 0.84mm, and on the 2nd year of loading period, 0.07mm and 0.06mm, respectively on both Class III and class IV. Conclusion : In the knife edge form of anterior maxillary residual ridges(Class IV), implant placement without ridge augmentation does not have significant difference with that of Class III alveolar ridge in the concern of Implant success after 2 year functional loading period in the aspect of peri-implant bone resorption radiographically.

• Imaging Science in Dentistry
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• 제52권2호
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• pp.197-207
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• 2022

Purpose: This study evaluated the associations of the dental arch form, age-sex groups, and sagittal root position (SRP) with alveolar bone thickness of the maxillary central incisors using cone-beam computed tomography (CBCT) images. Materials and Methods: CBCT images of 280 patients were categorized based on the dental arch form and age-sex groups. From these patients, 560 sagittal CBCT images of the maxillary central incisors were examined to measure the labial and palatal bone thickness at the apex level and the palatal bone at the mid-root level, according to the SRP classification. The chi-square test, Kruskal-Wallis test, and multiple linear regression were used for statistical analyses. Results: Significant differences were found in alveolar bone thickness depending on the arch form and SRP at the apex level. The square dental arch form and class I SRP showed the highest bone thickness at both levels of the palatal aspect. The taper dental arch form and class II SRP presented the highest bone thickness at the apex level of the labial aspect. No association was found between the dental arch form and SRP. Elderly women showed a significant association with thinner alveolar bone. Age-sex group, the dental arch form, and SRP had significant associations with alveolar bone thickness at the apex level. Conclusion: The patient's age-sex group, dental arch form, and SRP were associated with alveolar bone thickness around the maxillary central incisors with varying magnitudes. Therefore, clinicians should take these factors into account when planning immediate implant placement.