• 대한치과의사협회지
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• 제56권3호
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.108-118
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• 2010

Introduction: Maxillary posterior region, compared to the mandible or maxillary anterior region, has a thin cortical bone layer and is largely composed of cancellous bone, and therefore, it is often difficult to achieve primary stability. In such cases, sinus elevation with bone graft is necessary. Materials and Methods: In this research, 121 patients who had implant placement after bone graft were subjected to a follow-up study of 5 years from the moment of the initial surgery. The total survival rate, 5-year cumulative survival rate and the influence of the following factors on implant survival were evaluated; the condition of the patient (sex, age, general body condition), the site of implant placement, diameter and length of the implant, sinus elevation technique, closure method for osseous window, type of prosthesis and opposing teeth. Results: 1. The 5-year cumulative survival rate of total implants was 90.5%, there was no significant difference between sex, age, the site of implant placement, diameter and length of the implant, sinus elevation technique, and the type of opposing teeth. 2. Patients with diabetes mellitus < osteoporosis and smooth-surfaced machined group < hydroxyapatite (HA)-treated group and homogenous demineralized freeze dried allogenic bone (DFDB) bone graft only group had significantly lower survival rate. 3. With less than 4 mm of residual alveolar ridge height, lateral approach without closing the osseous window resulted in a significantly lower survival rate. 4. Restoration of a single implant showed a significantly lower survival rate, compared to cases where the superstructure was joined with several implants in the area. Conclusion: Patients with diabetes or osteoporosis need longer period of time for osseointegration compared to the normal, and the dentists must be prudent when choosing a surface treatment type and the bone graft material. Also, as the vertical dimension of the residual alveolar ridge can influence the result, staged implant placement should be considered when it seems difficult for the implant to gain primary stability from the residual bone with less than 4 mm of vertical dimension. It is recommended to obdurate the bone window and that the superstructure be connected with several impants in the peripheral area.

• Journal of Yeungnam Medical Science
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• 제20권2호
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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 Periodontal and Implant Science
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• 제53권6호
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• pp.417-428
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• 2023

Purpose: To investigate the effect of xenogeneic collagen matrix (XCM) with polydeoxyribonucleotide (PDRN) for gingival phenotype modification compared to autogenous connective tissue graft. Methods: Five mongrel dogs were used in this study. Box-type gingival defects were surgically created bilaterally on the maxillary canines 8 weeks before gingival augmentation. A coronally positioned flap was performed with either a subepithelial connective tissue graft (SCTG) or XCM with PDRN (2.0 mg/mL). The animals were sacrificed after 12 weeks. Intraoral scanning was performed for soft tissue analysis, and histologic and histomorphometric analyses were performed. Results: One animal exhibited wound dehiscence, leaving 4 for analysis. Superimposition of STL files revealed no significant difference in the amount of gingival thickness increase (ranging from 0.69±0.25 mm to 0.80±0.31 mm in group SCTG and from 0.48±0.25 mm to 0.85±0.44 mm in group PDRN; P>0.05). Histomorphometric analysis showed no significant differences between the groups in supracrestal gingival tissue height, keratinized tissue height, tissue thickness, and rete peg density (P>0.05). Conclusions: XCM soaked with PDRN yielded comparable gingival augmentation to SCTG.

• 대한치과보철학회지
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• 제51권4호
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• pp.307-314
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• 2013

연구 목적: 본 연구는 골형성단백질의 서방출을 위해 헤파린과 골형성단백질 (rhBMP-2)을 화학적으로 고정시킨 양극산화 티타늄 임플란트가 골 결손부에서 임플란트 주변의 수직적 골증대에 미치는 효과를 방사선학적으로 평가하고자 시행되었다. 연구 재료 및 방법: Pure-Titanium을 사용하여 길이 7.0 mm, 직경 3.5 mm의 실험용 임플란트 18개를 제작하였다. 모든 임플란트를 양극산화처리 하였고, 플랫폼 하방 2.5 mm에 식립 기준선을 표시하였다. rhBMP-2가 코팅되지 않은 임플란트 집단을 대조군으로, dip and dry 방법으로 rhBMP-2를 물리적 흡착시킨 집단을 BMP군, 3,4-dihydroxyphenylalanine(DOPA)-heparin을 이식하고 rhBMP-2를 화학적으로 고정시킨 집단을 Hep-BMP군으로 설정하였다. 각군별6개씩의 임플란트를 3마리의 비글견 양측 하악에 한쪽에 3개씩 총 18개를 치조정 상방으로 2.5 mm 노출시켜 식립하였다. 식립 직후와 4주, 8주에 식립부위의 방사선학적 검사가 시행되었고, 각 시기별, 각 군별 임플란트의 근원심 변연골의 수직적 재생량에 대한 평균값과 표준편차를 얻었다. Kruskal-Wallis test와 Mann-Whitney U test를 이용하여 4주, 8주에서 대조군과 실험군들의 차이를 비교 분석하고, 유의 수준5%에서 통계적으로 검정하였다. 결과:방사선학적 관찰 결과 임플란트 근원심 변연골 재생량(평균값 ${\pm}$ 표준편차)은 4주에 대조군은 $0.09{\pm}0.22mm$, BMP군은 $1.02{\pm}0.72mm$, Hep-BMP군은 $1.29{\pm}0.51mm$ 였으며, 8주에서는 각각 $0.11{\pm}1.26mm$, $1.11{\pm}0.58mm$, $1.59{\pm}0.79mm$였다. 두 실험군 모두 4주와 8주에서 대조군과 비교 시 유의한 수직적 골증대를 나타냈으나(P<.05), Hep-BMP군과BMP군의 비교에서는 유의한 변연골 재생량 차이를 보이지 않았다(P>.05). 결론: 골형성단백질을 물리적으로 흡착시키거나 서방출 위해 헤파린을 이용하여 화학적으로 고정시킨 양극산화 임플란트 표면은 모두 골 결손부에서 임플란트 주변골의 수직적 증대에 효과적이었다. 그러나 방사선학적 관찰의 한계 내에서 골형성단백질의 이 두가지 적용방법간에는 수직적 골증대량에 유의한 차이가 없었다.

• Journal of Korean Dental Science
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• 제3권1호
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• pp.11-16
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• 2010

Objective : This prospective study sought to verify the stability of three types of short implants measuring 7mm or less. Materials and methods : Implants measuring 7mm or less were placed in patients at multicenter dental clinics in Korea, China, Taiwan, and Singapore. Initial stability, intraoperative and postoperative complications, crestal bone loss, and survival rate of the implant were prospectively evaluated. Results : The primary stability of a 6-mm implant was lower than that of a 7-mm implant. The marginal bone loss of short implants measuring less than 7mm was minimal. Complications such as wound dehiscence, implant mobility, and peri-implant mucositis developed, and these were associated with initial implant failure. The short-term survival rate of 6-mm implant was 93.7%, and that of 7-mm implant, 96.6%. Conclusion : Short implant for the mandible with insufficient height for the residual ridge can be selectively used. Poor primary stability and wound dehiscence can cause osseointegration failure and alveolar bone loss.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권1호
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• pp.85-92
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• 2005

Reconstruction of defect in the anterior part of the maxilla to enable implant placement or prothesis is a complicated treatment due to the anatomical position and lack of soft tissues. Two cases are presented in which autogenous iliac PMCB(particulate marrow and cancellous bone) with titanium mesh were used for premaxilla reconstruction and alveolar bone repair of the anterior maxillas prior to denture and implants fixation respectively. Cancellous bone from the anterior iliac crest was compressed and placed against a titanium mesh fixed to the bone of palate in a patient with severe defect of the anterior maxilla. There were no problem in the healing, and the anterior maxillas of two patients had increased height and width during the initial healing and remodeling. The clinical reports describe the use of titanium mesh for reconstruction of premaxilla. Autogenous bone grafts were harvested from the iliac crest and were loaded on a titanium mesh that were left in the patient's maxilla for 6 months before they were removed respectively. The radiographic analysis demonstrated that a 10mm vertical ridge augmentation had been achieved. In guided bone regeneration, the quantity of bone regenerated under the barrier has been demonstrated to be directly related to the amount of the space under the membrane. This space can diminish as a result of membrane collapse. To avoid this problem which involved the use of a titanium mesh barrier to protect the regenerating tissues and to achieve a rigid fixation of the bone segments, were used in association with autologous bone in 2 cases. The aim of this study was to evaluate the capability of a configured titanium mesh to serve as a mechanical and biologic device for restoring a vertically defected premaxilla.

• Journal of Periodontal and Implant Science
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• 제47권1호
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• pp.2-12
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• 2017

The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician.

• Journal of Korean Dental Science
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• 제16권2호
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• pp.172-181
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• 2023

Purpose: To investigate the effect of epidermal growth factor (EGF) with collagen matrix (CM) for increasing gingival thickness. Materials and Methods: In five mongrel dogs, bilateral gingival defects were surgically made on the maxillary canines. After two months, either a subepithelial connective tissue graft (group SCTG) or CM with EGF (0.1 ug/ml, group EGF) was grafted, and the flap was coronally positioned to cover the graft materials. The animals were sacrificed after three months. Intraoral scanning was performed for soft tissue analysis. Histologic and histomorphometric analyses were performed. Result: Two animals exhibited wound dehiscence during the healing phase, leaving three for analysis. No statistically significant difference was found in soft tissue changes (P>0.05). The level of gingival margin (GM) increased in both groups (1.02±0.74 mm in group SCTG vs. 1.24±0.83 mm in group EGF). Linear increases at the GM pre-augmentation in the soft tissue profile were 1.08±0.58 mm in group SCTG and 0.96±0.73 mm in group EGF. Histomorphometric parameters (keratinized tissue height, tissue thickness, and rete peg density) were not significantly different between the groups (P>0.05). Conclusion: EGF loaded onto CM led to comparable gingival phenotype enhancement to SCTG.

• Imaging Science in Dentistry
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• 제50권2호
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• pp.93-98
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• 2020

Purpose: Little is known regarding the accuracy of clinical magnetic resonance imaging (MRI) protocols with acceptable scan times in sinus graft assessment. The aim of this study was to evaluate the correlations between MRI and cone-beam computed tomographic (CBCT) measurements of maxillary sinus grafts using 2 different clinical MRI imaging protocols. Materials and Methods: A total of 15 patients who underwent unilateral sinus lift surgery with biphasic calcium phosphate were included in this study. CBCT, T1-weighted MRI, and T2-weighted MRI scans were taken 6 months after sinus lift surgery. Linear measurements of the maximum height and buccolingual width in coronal images, as well as the maximum anteroposterior depth in sagittal images, were performed by 2 trained observers using CBCT and MRI Digital Imaging and Communication in Medicine files. Micro-computed tomography (micro-CT) was also performed to confirm the presence of bone tissue in the grafted area. Correlations between MRI and CBCT measurements were assessed with the Pearson test. Results: Significant correlations between CBCT and MRI were found for sinus graft height (T1-weighted, r=0.711 and P<0.05; T2-weighted, r=0.713 and P<0.05), buccolingual width (T1-weighted, r=0.892 and P<0.05; T2-weighted, r=0.956 and P<0.05), and anteroposterior depth (T1-weighted, r=0.731 and P<0.05; T2-weighted, r=0.873 and P<0.05). The presence of bone tissue in the grafted areas was confirmed via micro-CT. Conclusion: Both MRI pulse sequences tested can be used for sinus graft measurements, as strong correlations with CBCT were found. However, correlations between T2-weighted MRI and CBCT were slightly higher than those between T1-weighted MRI and CBCT.