• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.32-38
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• 2019

Purpose: The objective of this study is to evaluate the geometrical accuracy of a patient-specific bolus based on a three-dimensional (3D) printed mold and casting method. Materials and Methods: Three breast cancer patients undergoing treatment for a superficial region were scanned using computed tomography (CT) and a designed bolus structure through a treatment planning system (TPS). For the fabrication of patient-specific bolus, we cast harmless certified silicone into 3D printed molds. The produced bolus was also imaged using CT under the same conditions as the patient CT to acquire its geometrical shape. We compared the shapes of the produced bolus with the planned bolus structure from the TPS by measuring the average distance between two structures after a surface registration. Results and Conclusions: The result of the average difference in distance was within 1 mm and, as the worst case, the absolute difference did not exceed ${\pm}2mm$. The result of the geometric difference in the cross-section profile of each bolus was approximately 1 mm, which is a similar property of the average difference in distance. This discrepancy was negligible in affecting the dose reduction. The proposed fabrication of patient-specific bolus is useful for radiation therapy in the treatment of superficial regions, particularly those with an irregular shape.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권1호
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• pp.11-16
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• 2014

Objectives: The aim of this study was to evaluate the pattern of lingual split line when performing a bilateral sagittal split osteotomy (BSSO) for asymmetric prognathism. This was accomplished with the use of cone-beam computed tomography (CBCT) and three-dimensional (3D) software program. Materials and Methods: The study group was comprised of 40 patients (20 males and 20 females) with asymmetric prognathism, who underwent BSSO (80 splits; n=80) from January 2012 through June 2013. We observed the pattern of lingual split line using CBCT data and image analysis program. The deviated side was compared to the contralateral side in each patient. To analyze the contributing factors to the split pattern, we observed the position of the lateral cortical bone cut end and measured the thickness of the ramus that surrounds the mandibular lingula. Results: The lingual split patterns were classified into five types. The true "Hunsuck" line was 60.00% (n=48), and the bad split was 7.50% (n=6). Ramal thickness surrounding the lingual was $5.55{\pm}1.07$ mm (deviated) and $5.66{\pm}1.34$ mm (contralateral) (P =0.409). The position of the lateral cortical bone cut end was classified into three types: A, lingual; B, inferior; C, buccal. Type A comprised 66.25% (n=53), Type B comprised 22.50% (n=18), and Type C comprised 11.25% (n=9). Conclusion: In asymmetric prognathism patients, there were no differences in the ramal thickness between the deviated side and the contralateral side. Furthermore, no differences were found in the lingual split pattern. The lingual split pattern correlated with the position of the lateral cortical bone cut end. In addition, the 3D-CT reformation was a useful tool for evaluating the surgical results of BSSO of the mandible.

• 한국임상수의학회지
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• 제33권6호
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• pp.385-388
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• 2016

A 2-year-old, castrated male Chihuahua dog was referred for revision surgery for reluxation of the patella following surgery for medial patellar luxation (MPL) of the left stifle joint. On general inspection, the patient showed bilateral hindlimb weight-bearing lameness. On physical examination, bilateral non-reducible MPL was detected through palpation. Radiographs revealed bone deformities of both hindlimbs. Computed tomography (CT) was applied for a three-dimensional (3D) printing bone model to establish an accurate surgical plan. The bone plate was pre-contoured over the 3D-printing bone model after execution of corrective osteotomy and sterilized prior to use in surgery. Corrective osteotomy was performed through a staged, bilateral procedure. The patient showed improvement of limb function following surgery without reluxation of the patella. The use of 3D-printing bone model for accurate surgical planning of corrective osteotomy appears to be effective in increasing the accuracy of surgery. That may lead to successful surgical outcomes.

• 구강회복응용과학지
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• 제32권1호
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• pp.60-69
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• 2016

목적: 본 연구에서는 실제 환자의 석고모형의 콘빔CT (Cone Beam Computed Tomography)이미지로 디지털 모델을 제작하고 이 디지털 모델을 동일한 석고모형을 3차원 광학 스캐너로 스캔 하여 얻은 디지털 모델과 비교하였다. 연구 재료 및 방법: 총 11쌍의 석고모형에 대하여 실험을 진행 하였다. 콘빔CT를 이용하여 CT 영상을 촬영하여 디지털 모델을 제작 하였고 3차원 광학 스캐너를 사용해 대조군이 되는 디지털 모델을 제작하였다. 이를 이용해 각 석고모형에 대하여 콘빔CT와 3차원 광학 스캐너를 이용하여 만든 디지털 모델을 한 쌍으로 묶어 상, 하악 11개의 비교 쌍을 구성하고 각 쌍에 대하여 차이점을 분석하였다. 결과: 대조군과 비교 시 콘빔CT 영상으로부터 구성된 디지털 모델이 대조군 보다 과다 추정된 부분인 양의 오차의 평균은 0.059 - 0.117 mm, 과소 추정된 부분인 음의 오차의 평균은 0.066 - 0.146 mm의 범위 내에 존재했다. 또한 유의수준 0.05에서 양의 오차의 평균은 $70-100{\mu}m$, 음의 오차의 평균은 $100-120{\mu}m$ 내에 존재 함을 확인하였다. 결론: 석고모형의 콘빔CT 영상으로부터 구성된 디지털 모델은 최종 수복물 제작에는 부적합하나 임시수복물 제작 및 교정 진단 과정에 활용될 수 있는 가능성이 있다.

• Journal of Korean Neurosurgical Society
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• 제44권3호
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• pp.124-130
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• 2008

Objective : Our purpose of this study is to compare insertion angles and screw lengths from Roy-Camille, Magerl, and our designed method for cervical lateral mass screw fixation in the Korean population by quantitative measurement of reformatted two dimensional (2D) computed tomography (CT) images. Methods : We selected thirty Korean patients who were evaluated with thin section CT scans and reconstruction program to obtain reformatted 2D-CT images of the transversal plane passing the cranio-caudal angle using three different techniques. We measured the minimum angle to avoid vertebral artery (VA) injury, the ideal angle and depth for bicortical screwing of cervical lateral mass. Morphometric measurements of the lateral masses from C3-C7 were also taken. Results : In all three techniques, the mean safety angles from the VA were less than 8 degrees and the necessary depth of the screw was about 14 mm for safety to the VA and for the bicortical purchase. In our designed technique, the mean $\beta$ angles of each level from C3 to C7 were 29.0. 29.8. 29.5. 26.3. and 23.9 degrees, respectively. Conclusion : Results of this study and data from the literature indicate that differences may exist between the Korean and Western people in the length and angle for ideal lateral mass screw fixation. In addition, our technique needs further cadaveric and clinical study for safety and efficacy for being performed as alternative method for cervical lateral mass fixation.

• 대한두개안면성형외과학회지
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• 제17권1호
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• pp.9-13
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• 2016

Background: Position of the facial foramina is important for regional block and for various maxillofacial surgical procedures. In this study, we report on anthropometry and morphology of these foramina using three-dimensional computed tomography (3D-CT) data. Methods: A retrospective review was performed for all patients who have undergone 3D-CT scan of the facial skeleton for reasons other than fracture or deformity of the facial skeleton. Anthropometry of the supraorbital, infraorbital, and mental foramina (SOF, IOF, MF) were described in relation to facial midline, inferior orbital margin, and inferior mandibular margin (FM, IOM, IMM). This data was analyzed according to sex and age. Additionally, infraorbital and mental foramen were classified into 5 positions based on the anatomic relationships to the nearest perpendicular dentition. Results: The review identified 137 patients meeting study criteria. Supraorbital foramina was more often in the shape of a foramen (62%) than that of a notch (38%). The supraorbital, infraorbital, and mental foramina were located 33.7 mm, 37.1 mm, and 33.7 mm away from the midline. The mean vertical distance between IOF and IOM was 13.4 mm. The mean distance between MF and IMM was 21.0 mm. The IOF and MF most commonly coincided with upper and lower second premolar dentition, respectively. Between the sex, the distance between MF and IMM was significantly higher for males than for female. In a correlation analysis, SOF-FM, IOF-FM and MF-FM values were significantly increased with age, but IOF-IOM values were significantly decreased with age. Conclusion: In the current study, we have reported anthropometric data concerning facial foramina in the Korean population, using a large-scale data analysis of three-dimensional computed tomography of facial skeletons. The correlations made respect to patient sex and age will provide help to operating surgeons when considering nerve blocks and periosteal dissections around the facial foramina.

• Clinics in Shoulder and Elbow
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• 제25권4호
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• pp.265-273
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• 2022

Background: Massive rotator cuff tears (MRCTs) with subscapularis (SSC) tears cause severe shoulder dysfunction. In the present study, the influence of SSC tears on three-dimensional (3D) shoulder kinematics during scapular plane abduction in patients with MRCTs was examined. Methods: This study included 15 patients who were divided into two groups: supraspinatus (SSP) and infraspinatus (ISP) tears with SSC tear (torn SSC group: 10 shoulders) or without SSC tear (intact SSC group: 5 shoulders). Single-plane fluoroscopic images during scapular plane elevation and computed tomography (CT)-derived 3D bone models were matched to the fluoroscopic images using two-dimensional (2D)/3D registration techniques. Changes in 3D kinematic results were compared. Results: The humeral head center at the beginning of arm elevation was significantly higher in the torn SSC group than in the intact SSC group (1.8±3.4 mm vs. -1.1±1.6 mm, p<0.05). In the torn SSC group, the center of the humeral head migrated superiorly, then significantly downward at 60° arm elevation (p<0.05). In the intact SSC group, significant difference was not observed in the superior-inferior translation of the humeral head between the elevation angles. Conclusions: In cases of MRCTs with a torn SSC, the center of the humeral head showed a superior translation at the initial phase of scapular plane abduction followed by inferior translation. These findings indicate the SSC muscle plays an important role in determining the dynamic stability of the glenohumeral joint in a superior-inferior direction in patients with MRCTs.

• 디지털융복합연구
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• 제18권6호
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• pp.373-378
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• 2020

의료 정보의 상호운용성 향상을 위해서 Health level 7은 의료 정보 교환을 위한 차세대 체계인 Fast health interoperability resource (FHIR)를 개발하였다. 그러나, 이를 이용하여 임상 정보를 포함한 3차원 의료 영상을 교환하려는 시도는 없어 새로운 방법을 제시하고자 한다. CT 영상에서 만들어진 3차원 의료 영상을 javascript object notation (JSON) 형식으로 전환하고, 임상 정보를 추가하였다. 우리는 시험용 FHIR 서버를 만들고, 클라이언트는 postman을 사용하였다. 생성된 JSON 파일은 body에 첨부하여 전송되었다. JSON 형식으로 전송된 3차원 의료 영상은 웹 브라우저를 통해서 볼 수 있었고, 원시 코드를 확인하여 동봉된 임상 정보를 볼 수 있었다. 우리는 3차원 의료 영상 교환을 최초로 시행하였다. 이 방법을 적용한 앱이나 FHIR 리소스 개발을 위해 추가적인 연구가 필요할 것이다.

• 대한치과교정학회지
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• 제41권4호
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• pp.224-236
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• 2011

본 연구는 정상교합자의 치열궁과 기저골 형태를 파악하기 위해 시행하였다. 정상교합자 27명(남-15명: 25Y $10M{\pm}4Y$ 4M/여-12명: 26Y $1M{\pm}7Y$ 4M)을 대상으로 두개골의 전산화 단층촬영을 시행하고 입체영상을 제작한 뒤, 상악 중절치의 FA point의 중점을 원점으로 하는 3차원 좌표계를 형성하였다. 또한 상악 교합평면과 평행한 면으로 절단하여 상하악의 치열궁과 기저골의 형태에 대해 분석하였다. 상하악기저골은 A point, B point 부위와 양측 제1대구치 부위의 좌표에서 통계적으로 유의한 차이가 나타나지 않았다. 또한 상하악의 치열궁은 기저골악궁에 비해 전치부에서 순측으로 위치하였다. 또한 치열궁과 기저골악궁의 협설측 교차는 상악은 대구치 부위에서, 하악은 소구치 부위에서 이루어졌다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.13.1-13.12
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• 2016

Background: Mandibular motion tracking system (ManMoS) has been developed for orthognathic surgery. This article aimed to introduce the ManMoS and to examine the accuracy of this system. Methods: Skeletal and dental models are reconstructed in a virtual space from the DICOM data of three-dimensional computed tomography (3D-CT) recording and the STL data of 3D scanning, respectively. The ManMoS uniquely integrates the virtual dento-skeletal model with the real motion of the dental cast mounted on the simulator, using the reference splint. Positional change of the dental cast is tracked by using the 3D motion tracking equipment and reflects on the jaw position of the virtual model in real time, generating the mixed-reality surgical simulation. ManMoS was applied for two clinical cases having a facial asymmetry. In order to assess the accuracy of the ManMoS, the positional change of the lower dental arch was compared between the virtual and real models. Results: With the measurement data of the real lower dental cast as a reference, measurement error for the whole simulation system was less than 0.32 mm. In ManMoS, the skeletal and dental asymmetries were adequately diagnosed in three dimensions. Jaw repositioning was simulated with priority given to the skeletal correction rather than the occlusal correction. In two cases, facial asymmetry was successfully improved while a normal occlusal relationship was reconstructed. Positional change measured in the virtual model did not differ significantly from that in the real model. Conclusions: It was suggested that the accuracy of the ManMoS was good enough for a clinical use. This surgical simulation system appears to meet clinical demands well and is an important facilitator of communication between orthodontists and surgeons.