• Journal of Periodontal and Implant Science
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• 제53권5호
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• pp.388-401
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• 2023

Purpose: This study investigated the accuracy of free-hand implant surgery performed by an experienced operator compared to static guided implant surgery performed by an inexperienced operator on an anterior maxillary dental model arch. Methods: A maxillary dental model with missing teeth (No. 11, 22, and 23) was used for this in vitro study. An intraoral scan was performed on the model, with the resulting digital impression exported as a stereolithography file. Next, a cone-beam computed tomography (CBCT) scan was performed, with the resulting image exported as a Digital Imaging and Communications in Medicine file. Both files were imported into the RealGUIDE 5.0 dental implant planning software. Active Bio implants were selected to place into the model. A single stereolithographic 3-dimensional surgical guide was printed for all cases. Ten clinicians, divided into 2 groups, placed a total of 60 implants in 20 acrylic resin maxillary models. Due to the small sample size, the Mann-Whitney test was used to analyze mean values in the 2 groups. Statistical analyses were performed using SAS version 9.4. Results: The accuracy of implant placement using a surgical guide was significantly higher than that of free-hand implantation. The mean difference between the planned and actual implant positions at the apex was 0.68 mm for the experienced group using the free-hand technique and 0.14 mm for the non-experienced group using the surgical guide technique (P=0.019). At the top of the implant, the mean difference was 1.04 mm for the experienced group using the free-hand technique and 0.52 mm for the non-experienced group using the surgical guide technique (P=0.044). Conclusions: The data from this study will provide valuable insights for future studies, since in vitro studies should be conducted extensively in advance of retrospective or prospective studies to avoid burdening patients unnecessarily.

• 대한치과의사협회지
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• 제50권4호
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• pp.189-195
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• 2012

Various imaging modalities have been used for dental implant assessment in the different stages of implant treatment. Basic imaging, such as panoramic and periapical radiographs, are generally useful and cost-effective but do not provide the cross-sectional visualization or interactive image analysis that can be obtained with more sophisticated imaging techniques, such as Cone-Beam Computed Tomography(CBCT) imaging. This article includes the applications of CBCT imaging and their diagnostic contribution to presurgical evaluation, treatment planning, and postoperative assessment of dental implants.

• Imaging Science in Dentistry
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• 제31권3호
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• pp.165-173
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• 2001

Objectives : To evaluate the absorbed and effective doses of spiral and computed tomography for the dental implant planning. Materials and Methods: For radiographic projection, TLD chips were placed in 22 sites of humanoid phantom to record the exposure to skin and the mean absorbed dose to bone marrow, thyroid, pituitary, parotid and submandibular glands and nesophagus. Effective dose was calculated, using the method suggested by Frederiksen et al.. Patient situations of a single tooth gap in upper and lower midline region, edentulous maxilla and mandible were simulated for spiral tomography. 35 axial slices (maxilla) and 40 axial slices (mandible) with low and standard dose setting were used for computed tomography. All the radiographic procedures were repeated three times. Results: The mean effective dose in case of maxilla was 0.865 mSv, 0.452 mSv, 0.136 mSv and 0.025 mSv, in spiral tomography of complete edentulous maxilla, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p<0.05). That in case of mandible was 0.614 mSv, 0.448 mSv, 0.137 mSv and 0.036 mSv, in spiral tomography of complete edentulous mandible, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p<0.05). Conclusions: Based on these results, it can be concluded that low mAs computed tomography is recommended instead of spiral tomography for the complete edentulous maxilla and mandible dental implant treatment planning.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.281-290
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• 2020

Purpose: The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α=0.05). Results: The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors (P>0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r=0.232, P<0.05). Conclusion: There was a high prevalence of dental implant positioning errors, and positioning errors were not associated with the presence of anatomical variations. Professionals should be aware of the space available for implant placement during the preoperative planning stage.

• 대한치과보철학회지
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• 제61권1호
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• pp.55-62
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• 2023

완전 무치악 환자에게서 잔존 치조골의 흡수가 심할 경우 의치의 저작효율과 안정성 향상을 위해 임플란트로부터 지지를 얻는 피개의치를 고려해볼 수 있다. 임플란트 식립 위치를 선정할 때 디지털 진단 프로그램을 이용하면 환자의 해부학적 요소와 최종보철물의 형태를 고려한 수술용 가이드를 만들어 임플란트 수술의 정확도를 높일 수 있다. 임플란트 지지 피개의치에서 다양한 부착장치 중 milled bar 경우 임플란트간의 연결고정 효과뿐만 아니라 견고한 지지를 얻을 수 있는 이점이 있다. 이에 본 증례에서는 치조골 삭제 전, 후의 상황을 가정한 두 개의 수술용 가이드를 이용하여 임플란트를 식립한 후 milled bar를 이용한 임플란트 피개의치를 장착해주어 기능적이고 심미적인 결과를 얻었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권1호
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• pp.27-31
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• 2010

Purpose of study: The purpose of this study was to provide adequate diagnostic guideline for the maxillary sinuses prior to dental implant treatment for edentulous posterior maxillary areas. For this purpose, our procedure involves the estimation of the remaining alveolar bone height, the examination of the anatomical variation in the maxillary sinuses (e.g. sinus septum), and the evaluation of the incidence of preoperative pathological conditions in the maxillary sinuses. Materials and Methods: We selected 189 patients to undergo computerized tomography (CT) in order to account for the posterior maxillary anatomy found in patients of Korean ethnicity. We evaluated the following using Dentascan software: Remaining alveolar bone height, incidence of sinus septum, and rate of preoperative pathologic conditions in the maxillary sinus. The average amount of remaining alveolar bone height was analyzed using the student's t-test for differences according to anatomical site, and the ANOVA was used for the differences according to age group with the level of significance set at 0.05. Results: Alveolar bone heights of upper first premolar, second premolar, first molar, and second molar was 12.24 mm, 10.37 mm, 7.16 mm, and 7.15 mm, respectively with statistical significance (P < 0.05). Incidence of sinus septum as an anatomic variation was 17 out of 189 cases (9.0%). Incidence of mucosal thickening as a pathologic variation was 82 out of 189 cases (43.4%). Conclusion: In treatment planning of posterior maxillary edentulous area of Koreans, the consideration of augmentation surgery for maxillary sinus is required in maxillary molar area before dental implant installation, and preoperative screening of the asymptomatic maxillary sinuses can be regarded as a reasonable preoperative procedure in the planning of dental implant treatment on the posterior maxillary edentulous area.

• Imaging Science in Dentistry
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• 제48권4호
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• pp.269-275
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• 2018

Purpose: The aim of this study was to evaluate the correlations between measurements made using panoramic radiography and cone-beam computed tomography (CBCT) based on certain anatomical landmarks of the jaws, with the goal of preventing complications due to inaccurate measurements in the pre-surgical planning phase of dental implant placement. Materials and Methods: A total of 56 individuals who underwent panoramic radiography and a CBCT evaluation before dental implant surgery were enrolled in the study. Measurements were performed to identify the shortest vertical distance between the alveolar crest and neighboring anatomical structures, including the maxillary sinus, nasal floor, mandibular canal, and foramen mentale. The differences between the measurements on panoramic radiography and CBCT images were statistically analyzed. Results: Statistically significant differences were observed between the measurements on panoramic radiography and CBCT for all anatomical structures (P<.05). The correlation coefficients (r) between the paired samples obtained from panoramic radiography and CBCT were closely correlated (P<.05), with r values varying from 0.921 and 0.979 for different anatomical regions. Conclusion: The results of this study support the idea that panoramic radiography might provide sufficient information on bone height for preoperative implant planning in routine cases or when CBCT is unavailable. However, an additional CBCT evaluation might be helpful in cases where a safety margin cannot be respected due to insufficient bone height.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제50권2호
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• pp.70-79
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• 2024

Objectives: The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients' three-dimensional computed tomography scan of the desired implant site, a surgical guide can be created. During surgery, the surgical guide aids in achieving the designed implant placement position and direction. We examined and evaluated the long-term clinical outcomes of implant surgery using surgical guides. Materials and Methods: This study investigated a total of 15 patients with 32 implants that were placed using surgical guides from 2009 to 2011 with a mean follow-up period extended beyond 10 years. Patient demographics and implant survival rates were recorded. We analyzed marginal bone loss (MBL) by assessing the radiographs acquired at installation, three months after installation, and one month, one, two, and five years after prosthesis delivery. Results: The mean patient age was 57.33 years at implant placement. Of the 32 implants, five implants were placed in the anterior region and 27 implants were in the posterior region. Six implants failed and three of them were replaced, resulting in an 81.25% survival rate. The mean follow-up period was 10 years and nine months. Mean MBL compared to post-installation was significantly higher than at three months after installation, and one month, one, two, and five years after prosthesis delivery. Mean MBL at three months after installation, and one month, one year, and two years were significantly higher compared to the previous visit (P<0.05). However, MBL at five years after prosthesis delivery did not differ significantly compared to at two years. Conclusion: In this study, implant rehabilitation assisted by surgical guides exhibited favorable survival rates. With the limitation of the sample amount in this study, further research and more samples are required to evaluate the long-term clinical effectiveness of surgical guides.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권4호
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• pp.353-360
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• 2007

In a one-stage approach, where the implant installation is performed simultaneously with the iliac bone graft, various complications are observed. The observed complications are as follows; severe bone resorption at the maxillary anterior region and the area adjacent to the nasal cavity, shortage of soft tissue to cover the augmented alveolar bone, difficulties with oral hygiene care caused by the diminished vestibular space and non-esthetic prosthesis. These are good reasons for choosing the two-stage approach over the one-stage approach in spite of all the advantages it has, and should be taken into careful consideration when diagnosing and planning treatment using the one-stage approach.

• 대한소아치과학회지
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• 제42권3호
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• pp.270-274
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• 2015

성인에서의 임플란트 식립에 관해서는 치료 계획, 술식, 예후 등의 다양한 주제가 연구되어 왔으나 성장기 소아 청소년 환자에서의 임플란트 식립에 대해서는 연구가 제한적이다. 본 종설의 목적은 성장기 환자에서의 임플란트 식립에 대해 논하고 악골 및 치조골의 성장이 임플란트 장기적 예후에 갖는 영향을 살펴보고자 한다. 전반적인 골격성장의 유형에 대해 간략히 살펴보고 실제 임상적 치료법 선택에 대해 고찰하고자 한다.