• Imaging Science in Dentistry
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• v.51 no.3
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• pp.251-260
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• 2021

Purpose: Dental implants are widely used for the rehabilitation of edentulous sites. This study investigated the occurrence of dental implant malpositioning as shown on post-implantation cone-beam computed tomography (CBCT) and to identify related factors. Materials and Methods: Samples with at least 1 malpositioned dental implant were collected from a central radiology clinic in Tehran, Iran from January 2017 to January 2019. Variables such as demographic characteristics, length and diameter of implants, type of implant, sites of implant insertion, different types of implant malpositioning problems (cortical plate perforation, interference with anatomical structures), angulation of the implant, and the severity of malpositioning were assessed. In addition, the incidence of implant fracture and over-drilling was evaluated. Data were statistically analyzed using the chi-square test, 1-sample t-test, and Spearman correlation coefficients. Results: In total, 252 patients referred for implant postoperative CBCT evaluations were assessed. The cases of implant malpositioning included perforation of the buccal cortical plate (19.4%), perforation of the lingual cortical plate (14.3%), implant proximity to an adjacent implant (19.0%), implant proximity to an adjacent tooth (3.2%), interference with anatomical structures(maxillary sinus: 18.3%, mandibular canal: 11.1%, nasal cavity: 6.3%, mental foramen: 5.6%, and incisive canal: 0.4%). Implant fracture and over-drilling were found in 1.6% and 0.8% of cases, respectively. Severity was categorized as mild (9.5%), moderate (35.7%), severe (37.7%), and extreme (17.1%), and 52.4% of implants had inappropriate angulation. Conclusion: CBCT imaging is recommended for detecting dental implant malpositioning. The most common and severe type of malpositioning was buccal cortex perforation.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.227-235
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• 2018

PURPOSE. Implant site preparation may be adjusted to achieve the maximum possible primary stability. The aim of this investigation was to study the relation among bone-to-implant contact at insertion, bone density, and implant primary stability intra-operatively measured by a torque-measuring implant motor, when implant sites were undersized or tapped. MATERIALS AND METHODS. Undersized (n=14), standard (n=13), and tapped (n=13) implant sites were prepared on 9 segments of bovine ribs. After measuring bone density using the implant motor, 40 implants were placed, and their primary stability assessed by measuring the integral of the torque-depth insertion curve. Bovine ribs were then processed histologically, the bone-to-implant contact measured and statistically correlated to bone density and the integral. RESULTS. Bone-to-implant contact and the integral of the torque-depth curve were significantly greater for undersized sites than tapped sites. Moreover, a correlation between bone to implant contact, the integral and bone density was found under all preparation conditions. The slope of the bone-to-implant/density and integral/density lines was significantly greater for undersized sites, while those corresponding to standard prepared and tapped sites did not differ significantly. CONCLUSION. The integral of the torque-depth curve provided reliable information about bone-to-implant contact and primary implant stability even in tapped or undersized sites. The linear relations found among the parameters suggests a connection between extent and modality of undersizing and the corresponding increase of the integral and, consequently, of primary stability. These results might help the physician determine the extent of undersizing needed to achieve the proper implant primary stability, according to the planned loading protocol.

• The Journal of the Korean dental association
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• v.19 no.11 s.150
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• pp.975-979
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• 1981

In May 1981, the author placed Free Design Blade Implant into a 24-year old female patient with missing teeth of lower left molars, who did not want a removable partial denture. The bone available was good enough and in apparent general good health. The implant bridge was mad by four units, from 1st premolar to implant head, which is now in good esthetics and function.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.1
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• pp.29-33
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• 2019

Objectives: Bone density seems to be an important factor affecting implant stability. The relationship between bone density and primary and secondary stability remains under debate. The aim of this study was to compare primary and secondary stability measured by resonance frequency analysis (RFA) between different bone types and to compare implant stability at different time points during 3 months of follow-up. Materials and Methods: Our study included 65 implants (BioHorizons Implant Systems) with 3.8 or 4.6 mm diameter and 9 or 10.5 mm length in 59 patients. Bone quality was assessed by Lekholm-Zarb classification. After implant insertion, stability was measured by an Osstell device using RFA at three follow-up visits (immediately, 1 month, and 3 months after implant insertion). ANOVA test was used to compare primary and secondary stability between different bone types and between the three time points for each density type. Results: There were 9 patients in type I, 18 patients in type II, 20 patients in type III, and 12 patients in type IV. Three implants failed, 1 in type I and 2 in type IV. Stability values decreased in the first month but increased during the following two months in all bone types. Statistical analysis showed no significant difference between RFA values of different bone types at each follow-up or between stability values of each bone type at different time points. Conclusion: According to our results, implant stability was not affected by bone density. It is difficult to reach a certain conclusion about the effect of bone density on implant stability as stability is affected by numerous factors.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.35-48
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• 2004

Since the occlusal loading is transmitted to the surrounding bone, the success of an implant treatment is closely related to the distribution of the stress on the implant. The finite element analysis method is often used in order to produce a model for dispersion of stress. Assessment of the success of the implant is usually based on the degree of osseointegration which is a bone and implant surface interface. Implant used in this research was designed through the method of shape optimization after the stress on implant was anaylzed by the finite element analysis method. This study was pertinently assessed by a clinical, histologic, histomorphometric analysis after the shape optimized implant was installed on beagle dog tibia. The results are as follows 1. It clinically showed a good result without mobility and imflammatory reaction. 2. Implant was supported by dense bone and bone remodeling showed on the surrounding area of the implant 3. The average percentage of bone-implant contact was 58.1%.The percentage of bone density was 57.6%. Having above results, shape optimized implant showed the pertinence through clinical and histologic aspects. However, to use the shape optimized implant, the further experiment is required for finding problems, improvement.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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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.

• Journal of Korean Academy of Dental Administration
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• v.10 no.1
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• pp.1-8
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• 2022

This study introduces research on the quality of medical services, optimization of medical services, dental medical services, implant medical services, and time schedules, as well as the effective process of dental implant medical services, which is expensive and requires a long treatment period. For improvement, it is suggested to evaluate using a time schedule. In this method, a time schedule is prepared in which each step, starting from the patients appointment until the completion of the treatment process, is allotted a certain time. This schedule was finalized in consultation with the employees. When performing all implant operations, the starting time of each item was checked to evaluate the degree of compliance and to understand any reasons for delay in each step. After identifying the causes for delay at each step, suitable steps to rectify the drawbacks were developed, and an optimal plan for patient management was determined. Changes in waiting time and human resource utilization were shown as concrete data, suggesting that such a schedule is meaningful as a decision-making support tool.

• Investigative Magnetic Resonance Imaging
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• v.19 no.3
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• pp.191-195
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• 2015

We present a 53-year-old woman with a large chest wall mass in the interpectoral space, which was eventually confirmed as a lipogranuloma resulting from hydrogel implant rupture. Ultrasonography (US) showed reduced implant volume with surrounding peri-implant fluid collection, suggesting the possibility of implant rupture. A heterogeneously hypoechoic mass was found between the pectoralis major and minor muscles adjacent to the ruptured implant. On magnetic resonance imaging (MRI), there was a large mass in the left interpectoral space of the upper inner chest wall. The mass showed slightly high signal intensity (SI) on pre-contrast T1-weighted image (WI) with mixed iso and high SI on T2-WI. The signal of the mass was suppressed using the water suppression technique but not with the fat suppression technique on T2-WI. The mass showed diffuse enhancement upon contrast enhancement. The enhancing kinetics showed persistent enhancement pattern. US-guided core needle biopsy revealed a lipogranuloma and removal confirmed a ruptured PIP hydrogel implant.

• Archives of Plastic Surgery
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• v.34 no.5
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• pp.622-627
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• 2007

Purpose: Although the autogenous tissue transfer has been the mainstay of the breast reconstruction, concern for the donor site morbidity can lead to the superseded method using tissue expander with implant or permanent expander-implant. However, the additional procedure of tissue expansion possibly cause discomfort and raise the cost. We tried to verify the efficacy of using the saline-filled breast implant by itself for the safe and convenient immediate breast reconstruction modality if the patients have small, round and non-ptotic breasts and the sufficient breast skin can be saved with mastectomy. Methods: From July 2002 to July 2005, 29 breasts of 26 patients were restored only with the saline-filled breast implant immediately after the skin sparing or nipple-areolar skin sparing mastectomy in Asan Medical Center. A pocket with pectoralis major and serratus anterior muscle was created and the implant was covered with this muscle pocket. Simultaneous contralateral augmentation was performed in patients whose mastectomy specimen weighed less than 100g. Results: Using only the saline-filled breast implant resulted in the successful reconstruction with few complications including partial necrosis of nipple areolar skin (five cases, 17.2%), capsular contracture (three cases, 10.3%), hematoma (one case, 3.4%), depigmentation of areolar skin (one case, 3.4%), hypertrophic scar (one case, 3.4%), which were all healed by conservative management. There were no significant complications such as implant exposure and subsequent removal. Conclusion: Immediate breast reconstruction only with the saline-filled breast implant can be a satisfactory alternative option for the patients whose breast is small, round and non-ptotic, especially when the nipple-areolar skin of the breast is preserved in the mastectomy.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.519-522
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• 2011

Purpose: Breast implant surgery is increasing in Korea. NTM (non tuberculous mycobacteria) infection after breast implant surgery is rare, but it has been there reported in several foreign countries. However, no report has been issued on NTM infection after breast reconstruction surgery with an implant in Korea. The purpose of this article is to report a case of NTM infection after breast reconstruction surgery with an implant. Methods: A female patient who underwent total mastectomy and immediate breast reconstruction with a latissimus dorsi myocutaneous flap and an implant exhibited signs of inflammation after the surgery. Fluid cultures taken at the time of wound exploration were initially negative, but NTM was isolated by culture 10 days later. Results: The implant was removed. M. fortuitum was identified by acid-fast culture and NTM-PCR. The patient was treated with combined antibiotic therapy. Conclusion: Although it is difficult to diagnose NTM infection after breast surgery, it is important that surgeons include NTM infection in the differential diagnosis of a post mammoplasty infection after breast implant surgery.