• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.37.1-37.5
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• 2016

Background: The dimensions and shape of the forehead determine the esthetics of the upper third of the face. Korean young people consider a broad and smooth, rounded forehead more attractive. As a result, frontal augmentation becomes more popular in patients with dentofacial deformities. Various surgical procedures and materials have been used in frontal augmentation surgery, with associated advantages and disadvantages. Silicone is a good candidate for frontal augmentation. The author presents two cases of esthetic frontal augmentation with a prefabricated silicone implant in female patients with dentofacial deformities. Case presentation: In case 1, a 24-year-old female patient underwent frontal augmentation surgery with simultaneous maxillomandibular and zygomatic osteotomies to correct facial asymmetry. A silicone implant was fabricated preoperatively using a positive template stone mold of her forehead. In case 2, a 23-year-old female patient underwent total facial contouring surgery including frontal augmentation for improved facial esthetics. A computed tomography (CT)-guided rapid prototype (RP) model was used to make the silicone implants. The operative procedure was safe and simple, and the silicone implants were reliable for a larger degree of frontal augmentation. Six months later, both patients had recovered from the surgery and were satisfied with their frontal shape and projection. Conclusions: Frontal augmentation with silicone implants can be an effective adjuvant strategy to improve facial esthetics in patients with a flat and narrow forehead who undergo orthognathic reconstruction or total facial contouring surgery.

• Archives of Plastic Surgery
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• 제48권2호
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• pp.165-174
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• 2021

Background In recent years, implant-based breast reconstruction has been performed because of its simplicity, short operation time, and rapid recovery of patients. Several studies have reported treatment methods for implant surgery-related infection, which is a serious complication. The aim of this study was to introduce our strategy for salvaging infected implants and to evaluate its effectiveness. Methods The authors performed a retrospective study of 145 cases from 132 patients who underwent implant-based breast reconstruction from January 2012 to December 2018. Empirical antibiotics were immediately administered to patients with suspected infections. The patients then underwent salvage treatment including appropriate antibiotics, ultrasonography-guided aspiration, debridement, antibiotic lavage, and implant exchange through a multidisciplinary approach. Patient demographics, operative data, duration until drain removal, adjuvant treatment, and complications were analyzed. Results The total infection rate was 5.5% (8/145). A longer indwelling catheter period and adjuvant treatment were significantly associated with infection. The salvage treatment showed a success rate of 87.5% (7/8). Seven patients who received early aggressive salvage treatment recovered from infection. One patient with methicillin-resistant Staphylococcus aureus, who received salvage treatment 11 days after symptom onset, did not respond to drainage and antibiotic treatment. That patient subsequently underwent explantation. Conclusions In implant-based breast reconstruction, prevention of infection is of the utmost importance. However, if an infection is suspected, proactive empirical antibiotic therapy and collaboration with the necessary departments are required. Through a multidisciplinary approach and proactive early management, swift and appropriate salvage should be performed.

• 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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• 제55권12호
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• pp.842-849
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• 2017

The term, 'crossed occlusion' implies clinical situation in which the residual teeth in one arch have no contact with those in the antagonistic arch, resulting in the collapse of occlusal vertical dimension. The treatment goal of this pathologic condition is restoration of the collapsed vertical dimension and stabilization of abnormal mandibular position. Previously, konus removable prostheses or tooth supported overdentures were suggested to solve crossed occlusion. Nowadays, dental implants have been used for definitive support to solve this problem. In this case report, a 65 years old female patient had a crossed occlusion, in which the maxillary posterior residual teeth and mandibular anterior residual teeth cross. Interim removable and fixed dental prostheses were used to confirm the proper vertical and horizontal jaw relation. After that, the mandibular posterior edentulous region was restored with implant-supported fixed dental prostheses. Computer tomography guided implant surgery was performed according to the concept of the restoration-driven implant placement. The maxillary anterior edentulous region was restored with Kennedy class IV removable prosthesis, considering the patient's economic status. The patient's jaw position and prostheses have been well maintained at the follow-up after 6 months of definitive restoration. The antero-posterior crossed occlusion problems appeared to be effectively solved with the combination of removable in one arch and implant-supported fixed prostheses in the other.

• Journal of Periodontal and Implant Science
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• 제44권4호
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• pp.184-193
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• 2014

Purpose: The aim of the present study was to evaluate the in vivo accuracy of flapless, computer-aided implant placement by comparing the three-dimensional (3D) position of planned and placed implants through an analysis of linear and angular deviations. Methods: Implant position was virtually planned using 3D planning software based on the functional and aesthetic requirements of the final restorations. Computer-aided design/computer-assisted manufacture technology was used to transfer the virtual plan to the surgical environment. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by overlapping the pre- and postoperative computed tomography scans using dedicated software. Results: The comparison of 14 implants showed a mean linear deviation of the implant head of 0.56 mm (standard deviation [SD], 0.23), a mean linear deviation of the implant apex of 0.64 mm (SD, 0.29), and a mean angular deviation of the long axis of $2.42^{\circ}$ (SD, 1.02). Conclusions: In the present study, computer-aided flapless implant surgery seemed to provide several advantages to the clinicians as compared to the standard procedure; however, linear and angular deviations are to be expected. Therefore, accurate presurgical planning taking into account anatomical limitations and prosthetic demands is mandatory to ensure a predictable treatment, without incurring possible intra- and postoperative complications.

• Journal of Periodontal and Implant Science
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• 제53권1호
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• pp.85-95
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• 2023

Purpose: In recent years, guided implant surgery has been widely used for the convenience of patients and surgeons. Further streamlining the surgical procedure would make implant surgery more convenient. Low-speed water-free conditions are often used in guided implant surgery. Therefore, in this study, we attempted to confirm once again whether drilling was safe at a low speed without water. The main purpose of this study was to evaluate whether a simplified drilling protocol that omits some intermediate steps in the drilling process was safe from the viewpoint of heat generation. Methods: D1 density artificial bone blocks were drilled under 50 rpm, 10 N·cm water-free conditions, and the surface temperature was measured using a digital infrared camera. First, drilling was performed with the sequential drilling method, which is the most widely used technique. Second, for each drill diameter, the temperature change was measured while performing simplified drilling with omission of the previous 1, 2, or 3 steps. Results: In sequential drilling, the heat generated during drilling at all diameters was less than the critical temperature of osteonecrosis (47℃) except for the ⌀2 drill. Statistical significance was observed in all groups when comparing sequential and simplified drilling in the ⌀3.2, ⌀3.8, and ⌀4.3 drills (P<0.001). However, in the simplified drilling procedures, the temperature was below the osteonecrosis threshold temperature (47℃) except for the ⌀4.3 drill with the omission of the previous 3 steps (⌀3.0, ⌀3.2, and ⌀3.8). Conclusions: In general, drilling under low-speed, water-free conditions has shown stable results in terms of heat generation. Simplified drilling showed statistically significantly greater heat generation than sequential drilling. However, most of the diameters and omitted steps seem to be clinically acceptable, so it will be useful if an appropriate selection is made according to the patient's clinical condition.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권4호
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• pp.333-339
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• 2007

Adequate bone quantity is one of the important factor to obtain osseointegration after implantation. Guided bone regeneration (GBR) has widely used in implantation for reconstruction of bony defects. Since introducing this procedure, there are many studies about survival rate of implants, changing in surrounding bone volume after function. The purpose of this study was to evaluate the amount of resorption according to placement timing and survival rate after function. The subjects were patients who had been operated with GBR from Jun 2003 to Jun 2004 in Seoul National University Bundang Hospital. They were divided into simultaneous and delayed placement group. The follow up had been performed at the time of just after GBR, 1, 3, 6, 12, 24-month later and standard periapical radiographs were taken to estimate the bone level at the time. The total average of bone level change in radiographs was 1.94mm(${\pm}0.25$), and 1.92mm(${\pm}0.72$) in simultaneous installation, 2.03mm(${\pm}0.25$) in delayed installation. In this report, the survival rates were 92.2% in simulataneous group and 92.3% in delayed group. Insufficient primary stability, early contamination of wound, overloading, poor oral hygiene, and infection were thought to be associated factors in the failed cases.

• 대한치과보철학회지
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• 제57권3호
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• pp.219-224
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• 2019

목적:컴퓨터 가이드 임플란트 수술에서 방사선 영상과 디지털 영상과의 정합은 필수적인 과정이다. 본 연구의 목적은 마이크로스크류의 사용이 가이드 수술을 위한 영상정합 과정에서 작업시간과 술자편의성에 미치는 영향을 조사하는 것이다. 재료 및 방법: 연구모형의 제작을 위해 Kennedy class I 하악 덴티폼에 마이크로스크류 2개를 후구치 삼각 부위에 식립 후 컴퓨터 단층촬영과 디지털 스캔을 통해 방사선 영상과 스캔 영상을 획득하였다. 영상들은 잔존 치아 부위만을 이용하는 방법과 치아와 마이크로스크류를 이용하는 방법을 이용하여 12명의 술자에 의해 중첩되었다. 이 중첩된 영상에 대하여 작업시간, 술자편의성, 만족도의 자료가 수집되고, Mann-Whitney U test을 통해 분석되었다. 결과: 작업시간은 영상정합 조건 사이에 통계학적인 차이가 없었다 (P > .05). 술자편의성과 만족도는 치아와 마이크로스크류를 이용하는 방법에서 잔존 치아 부위만을 이용하는 방법보다 높았다 (P < .001). 결론: 영상정합에서 마이크로스크류의 이용은 작업시간의 단축에는 영향을 미치지 않지만 술자편의성과 만족도는 향상시킨다.

• 대한치과보철학회지
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• 제60권1호
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• pp.44-54
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• 2022

다수 치아의 상실 상태로 장시간 지속시 구치부 지지의 부족 및 치아들의 과정출이 발생되어 교합 부조화, 수직고경 상실 및 기능 장애 등의 심각한 문제가 초래된다. 본 증례는 장기간 다수치아 결손으로 인하여 대합치가 정출하면서 교합평면의 붕괴가 일어난 환자의 완전 구강 회복에 관한 증례이다. 상기 환자는 서울대학교 치과병원 치과보철과로 내원한 68세 남환으로 오래된 상악 의치를 빼다가 치아가 함께 발거되었으며, 하악 전치부가 상악 전치부와 강하게 닿아서 불편함을 호소하며 내원하였다. 여러가지 평가를 통해 수직고경을 4 mm 거상하였으며, 무치악부는 진단 및 치료계획시 설계한 최종 보철 수복물 제작을 고려하여 정확한 임플란트 식립을 위해 CAD-CAM (Computer-aided design-computer-aided manufacturing) 기술을 이용한 Computer guided implant surgery를 시행하고, 임플란트 고정성 보철 수복으로 진행하였고, 환자는 저작, 기능 및 심미 모두 큰 개선에 만족하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권1호
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• pp.66-72
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• 2011

A severely vertical resorbed ridge is a significant challenge in implant dentistry. To solve this problem, several augmentation techniques, such as guided bone regeneration (GBR), onlay bone grafts, distraction osteogenesis, and ridge splitting techniques, have been proposed and used for several years. Among these methods, vertical ridge augmentation using guided bone regeneration aims to build space and guide osteoblasts to this space to promote osteogenesis. The aim of guided bone regeneration is to maintain and stabilize the space and block the proliferation of adjacent soft tissue. In our hospital, we encountered a case of a woman in her forties with an atrophied mandible, who underwent implant surgery in the right mandible. Titanium reinforced Gore-Tex (TRG) was used to augment the mandible and titanium mesh was used in the left mandible. Favorable results were obtained. This report compares the two methods and reviews the relevant literature.