• Imaging Science in Dentistry
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• 제44권3호
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• pp.207-212
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• 2014

Purpose: This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Materials and Methods: Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. Results: The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. Conclusion: In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

• 대한치과교정학회지
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• 제19권1호
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• pp.169-185
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• 1989

정상교합 및 안모가 단정한 성인(남자 60명, 여자 62명)을 대상으로 악교정수술을 위한 한국인 기준치를 얻고자 측모 두부방사선 규격사진을 이용하여 계측 분석과 결과 다음과 같은 결론을 얻었다. 카 계측항목의 평균치, 표준편차를 구하였다. 골격계측 항목중 각도계측치에서는 FH-SN과 SN-MP가 여자에서 더 크며, 거리계측치에서는 전 항목에서 남자가 더 큰 것으로 나타났다. 치아계측 항목에서는 수직적 관계를 나타내는 항목에서만 남녀간에 유의한 차를(P<0.05) 보였는데 ADH, PDH, overbite에서는 여자가 더 크고 Incisor exposure에서는 여자가 더 크게 나타났다. 연조직계측 항목에서는 NLA를 제외한 전 항목 즉 FCA, UFH, ULL, LLL에서 남자가 여자보다 더 크게 나타났다.

• 대한치과교정학회지
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• 제47권5호
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• pp.298-305
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• 2017

Objective: This paper describes changes in the characteristics of patients seeking orthodontic treatment over the past decade and the treatment they received, to identify any seasonal variations or trends. Methods: This single-center retrospective cohort study included all patients who presented to Seoul National University Dental Hospital for orthodontic diagnosis and treatment between January 1, 2005 and December 31, 2015. The study analyzed a set of heterogeneous variables grouped into the following categories: demographic (age, gender, and address), clinical (Angle Classification, anomaly, mode of orthodontic treatment, removable appliances for Phase 1 treatment, fixed appliances for Phase 2 treatment, orthognathic surgery, extraction, mini-plate, mini-implant, and patient transfer) and time-related variables (date of first visit and orthodontic treatment time). Time series analysis was applied to each variable. Results: The sample included 14,510 patients with a median age of 19.5 years. The number of patients and their ages demonstrated a clear seasonal variation, which peaked in the summer and winter. Increasing trends were observed for the proportion of male patients, use of non-extraction treatment modality, use of ceramic brackets, patients from provinces outside the Seoul region at large, patients transferred from private practitioners, and patients who underwent orthognathic surgery performed by university surgeons. Decreasing trends included the use of metal brackets and orthodontic treatment time. Conclusions: Time series analysis revealed a seasonal variation in some characteristics, and several variables showed changing trends over the past decade.

• Journal of Oral Medicine and Pain
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• 제38권3호
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• pp.255-260
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• 2013

양측 하악지 시상 골절단술은 악안면 기형 및 부정교합을 치료하기 위해 흔히 사용되는 필수불가결한 술식이라고 할 수 있다. 하악지 시상 골절단술 후 발생할 수 있는 합병증으로는 하치조 신경 손상, 출혈, 측두하악장애, 부적절한 골면의 유합 및 골절, 재발 등이 있다. 악교정 수술 후 안면신경 마비의 발생 유병율은 최근 0.1 퍼센트로 보고되고 있다. 증상 발생의 원인으로는 안면신경의 압박, 신경의 불완전 또는 완전 손상, 신경의 견인, 마취제에 의한 신경의 허혈 등이 있다. 술 후 발생된 안면 신경의 마비는 환자의 삶의 질을 저해하고 사회활동을 기피하게 함으로써 가장 심각한 합병증 중 하나라고 볼 수 있다. 본 증례에서는 양측 하악지 시상 골전달술을 시행 후 발생한 안면신경 마비에 대하여 보고하고 있다.

• 대한치과교정학회지
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• 제50권2호
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• pp.136-144
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• 2020

Hemifacial microsomia (HFM) patients may experience emotional withdrawal during their growth period due to their abnormal facial appearance. Distraction osteogenesis at an early age to improve their appearance can encourage these patients. Some abnormalities of the affected side can be overcome by distraction osteogenesis at an early age. However, differences in the growth rate between the affected and unaffected sides during the rest of the growth period are inevitable due to the characteristics of HFM. Therefore, re-evaluation should be performed after completion of growth in order to achieve stable occlusion through either orthognathic surgery or camouflage orthodontic treatment. An eight-year-old patient visited the clinic exhibiting features of HFM with slight mandibular involvement. He received phase I treatment with distraction osteogenesis and a functional appliance. Distraction osteogenesis was performed at the right ramus, which resulted in an open bite at the right posterior dentition. After distraction osteogenesis, a functional appliance and partial fixed appliance were used to achieve extrusion of the affected posterior dentition and settlement of the occlusion adjustment on the unaffected posterior dentition. The patient visited the clinic regularly for follow-up assessments, and at the age of 20 years, he showed facial asymmetry of the mandible, which had deviated to the right side. He received orthodontic treatment to improve the occlusion of his posterior dentition after the growth period. Without orthognathic surgery, stable occlusion and a satisfactory facial appearance were obtained through camouflage orthodontic treatment.

• Journal of Periodontal and Implant Science
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• 제50권3호
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• pp.146-158
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• 2020

Purpose: The aim of this study was to investigate and identify the main causes of periodontal tissue change associated with labial gingival recession by examining the anterior region of patients who underwent orthodontic treatment. Methods: In total, 45 patients who had undergone orthodontic treatment from January 2010 to December 2015 were included. Before and after the orthodontic treatment, sectioned images from 3-dimensional digital model scanning and cone-beam computed tomography images in the same region were superimposed to measure periodontal parameters. The initial labial gingival thickness (IGT) and the initial labial alveolar bone thickness (IBT) were measured at 4 mm below the cementoenamel junction (CEJ), and the change of the labial gingival margin was defined as the change of the distance from the CEJ to the gingival margin. Additionally, the jaw, tooth position, tooth inclination, tooth rotation, and history of orthognathic surgery were investigated to determine the various factors that could have affected anterior periodontal tissue changes. Results: The mean IGT and IBT were 0.77±0.29 mm and 0.77±0.32 mm, respectively. The mean gingival recession was 0.14±0.57 mm. Tooth inclination had a significant association with gingival recession, and as tooth inclination increased labially, gingival recession increased by approximately 0.2 mm per 1°. Conclusions: In conclusion, the IGT, IBT, tooth position, tooth rotation, and history of orthognathic surgery did not affect labial gingival recession. However, tooth inclination showed a significant association with labial gingival recession of the anterior teeth after orthodontic treatment.

• 대한치과교정학회지
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• 제46권3호
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• pp.137-145
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• 2016

Objective: The purpose of this study was to investigate the characteristics of orthodontic patients at Yonsei Dental Hospital from 2008 to 2012. Methods: We evaluated Angle's classification from molar relationships, classification of skeletal malocclusion from the A point-nasion-B point angle, facial asymmetry, and temporomandibular joint disorders (TMDs) from the records of 7,476 patients who received an orthodontic diagnosis. The orthognathic surgery rate, extraction rate, and extraction sites were determined from the records of 4,861 treated patients. Results: The patient number increased until 2010 and gradually decreased thereafter. Most patients were aged 19-39 years, with a gradual increase in patients aged ${\geq}40years$. Angle's Class I, Class II divisions 1 and 2, and Class III malocclusions were observed in 27.7%, 25.6%, 10.6%, and 36.1% patients, respectively, with a gradual decrease in the frequency of Class I malocclusion. The proportion of patients with skeletal Class I, Class II, and Class III malocclusions was 34.3%, 34.3%, and 31.4%, respectively, while the prevalence of facial asymmetry and TMDs was 11.0% and 24.9%, respectively. The orthognathic surgery rate was 18.5%, with 70% surgical patients exhibiting skeletal Class III malocclusion. The overall extraction rate among nonsurgical patients was 35.4%, and the maxillary and mandibular first premolars were the most commonly extracted teeth. Conclusions: The most noticeable changes over time included a decrease in the patient number after 2010, an increase in the average patient age, and a decrease in the frequency of Angle's Class I malocclusion. Our results suggest that periodic characterization is necessary to meet the changing demands of orthodontic patients.

• Journal of Yeungnam Medical Science
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• 제18권2호
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• pp.208-214
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• 2001

성장기 3급 부정 교합인 남아 20명의 두부계측방사선 사진을 Harvold 분석법을 중심으로 하여 정상 대조군과 비교하여 다음과 같은 결론을 얻었다. 상하악간 상대적인 길이 차를 나타내는 악간 길이 차는 3급 부정교합자군에서 유의하게 더 크게 나타났다(p<0.05). 전하안면 고경은 3급 부정교합군에서 정상교합군보다 더 크게 나타났으나, 통계적으로 유의한 차는 없었다.

• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1101-1110
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• 2023

Streptococcus mutans is the primary causative agent of caries, which is one of the most common human diseases. Thus, rapid and early detection of cariogenic bacteria is critical for its prevention. This study investigated the combination of loop-mediated isothermal amplification (LAMP) and microfluid technology to quantitatively detect S. mutans. A low-cost, rapid microfluidic chip using LAMP technology was developed to amplify and detect bacteria at 2.2-2.2 × 10⁶ colony-forming units (CFU)/ml and its detection limits were compared to those of standard polymerase chain reaction. A visualization system was established to quantitatively determine the experimental results, and a functional relationship between the bacterial concentration and quantitative results was established. The detection limit of S. mutans using this microfluidic chip was 2.2 CFU/ml, which was lower than that of the standard approach. After quantification, the experimental results showed a good linear relationship with the concentration of S. mutans, thereby confirming the effectiveness and accuracy of the custom-made integrated LAMP microfluidic system for the detection of S. mutans. The microfluidic system described herein may represent a promising simple detection method for the specific and rapid testing of individuals at risk of caries.

• 대한구순구개열학회지
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• 제6권2호
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• pp.91-105
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• 2003

There are significant limitations in the precision of mandibular distraction in setting a desired occlusal and facial esthetic outcome. The purpose of this study is to present the simulation method for the distraction osteogenesis treatment planning. 3-D surgery simulation software programs V-works and V-Surgery(Cybermed, Seoul, Korea) were used from the 3D CT data in addition to the conventional data facial photography, panorama and cephalogram, dental cast model. We have utilized already for the various surgical procedures to get information preoperatively for the maxillofacial surgery like cancer localization and reconstructive surgery, orthognathic surgery and implant surgery in the department of Oral and Maxillofacial surgery, Seoul National University Hospital. On the software, bone cutting can be done at any place and any direction. Separated bone segment can be mobilized in all 3 dimensional direction. After the 3D simulation on the software program, mock surgery on the RP model can be performed. This planning method was applied to two hemifacial microsomia patients. With this protocol, we could simulate the movement of bony segment after maxillofacial distraction osteogenesis