• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권1호
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• pp.51-55
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• 2000

Purpose : The purpose of this study is to setup a standard treatment protocol in surgical correction of skeletal malocclusion with Angle Class III patients. We asessed the soft tissue changes according to skeletal changes of patients who have undergone orthognathic surgery with bilateral split sagittal ramus osteotomy (BSSRO) and advancing genioplasty. Materials & Methods : The soft tissue change of 9 skeletal Class III patients was assessed after BSSRO and advancing genioplasty. The patient group was skeletal Class III who was surgically treated by BSSRO & advancing genioplasty. The average follow up period is 13 months with the range of 6 and 30 months. All patients have undergone preoperative and postoperative orthodontic treatment. The assessment was devided into two groups. One was antero-posterior relationship and the other was vertical relationship of dimensional changes of soft tissue after orthognathic surgery. Results : In antero-posterior dimensional changes after surgery, the percentage of soft tissue change in comparison to hard tissue was 89%. Vertical ratio after surgery, 86% soft tissue changes were assessed.

• 대한치과교정학회지
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• 제37권3호
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• pp.192-203
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• 2007

본 연구는 비폐쇄를 보이는 III급 부정교합아동에서, 기도 공간의 형태와 안모 골격 형태 사이의 상관관계를 평가하였다. III급 부정교합을 보이며, 비폐쇄 소견을 보여 이비인후과로 의뢰된 환아 100명의 초진 측모 두부 규격 방사선 사진에서 상 인두기도 공간(upper PAS), 하 인두기도 공간(lower PAS), 편도의 크기, 구개-혀 공간을 측정하여 기도 공간 형태를 분석하였으며, 통상적인 계측점을 사용하여 안면 골격 분석을 시행하여 기도 공간 형태 계측항목과 안면 골격분성 항목간의 상관관계를 연구하여 다음과 같은 결과를 얻었다. Upper PAS는 ramal height, SNA, SNB, PFH, FHR, facial plane angle 항목과 양의 상관관계를 보였으며, saddle angle, articular angle, gonial angle의 sum, SN-GoGn, Y-axis to SN, FMA 항목과 음의 상관관계를 보였다. Lower PAS는 genial angle, FMA와 양의 상관관계를 보였으며, articular angle, facial depth, PFH, FHR와 음의 상관관계를 보였다. 편도의 크기는 PCBL, ramal height, Mn. body length, Mn. body length to ACBL, facial depth, facial length, PFH, AFH와 양의 상관관계를 보였다. 구개-혀 공간은 saddle angle, articular angle, genial angle의 합, facial length, AFH, FMA, LFH와 양의 상관관계를 보였으며, IMPA, overbite와 음의 상관관계를 보였다.

• 대한치과교정학회지
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• 제47권6호
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• pp.401-413
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• 2017

Objective: The aim of this systematic review was to assess the occlusal outcome and duration of fixed orthodontic therapy from clinical trials in humans with the Objective Grading System (OGS) proposed by the American Board of Orthodontics. Methods: Nine databases were searched up to October 2016 for prospective/retrospective clinical trials assessing the outcomes of orthodontic therapy with fixed appliances. After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of the mean OGS score and treatment duration were performed and 95% confidence intervals (CIs) were calculated. Results: A total of 34 relevant clinical trials including 6,207 patients (40% male, 60% female; average age, 18.4 years) were identified. The average OGS score after treatment was 27.9 points (95% CI, 25.3-30.6 points), while the average treatment duration was 24.9 months (95% CI, 24.6-25.1 months). There was no significant association between occlusal outcome and treatment duration, while considerable heterogeneity was identified. In addition, orthodontic treatment involving extraction of four premolars appeared to have an important effect on both outcomes and duration of treatment. Finally, only 10 (39%) of the identified studies matched compared groups by initial malocclusion severity, although meta-epidemiological evidence suggested that matching may have significantly influenced their results. Conclusions: The findings from this systematic review suggest that the occlusal outcomes of fixed appliance treatment vary considerably, with no significant association between treatment outcomes and duration. Prospective matched clinical studies that use the OGS tool are needed to compare the effectiveness of orthodontic appliances.

• 대한치과교정학회지
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• 제47권1호
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• pp.39-49
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• 2017

Objective: This retrospective, cross-sectional study aimed to establish reference data for normal crown and root lengths and the root-crown ratios (R/C ratios) for the mature maxillary and mandibular incisors in a Korean population by using cone-beam computed tomography (CBCT). Methods: We included 672 Korean patients (141 men and 531 women; mean age, $27.2{\pm}7.7years$) who underwent CBCT examinations during various dental treatments. Crown and root lengths and the R/C ratios of the maxillary and mandibular incisors were measured using CBCT data, which were analyzed to detect significant differences between demographic factors as well as sagittal and vertical skeletal or occlusal relationships. Results: Teeth of the same type in each half-arch were symmetrical. The mean R/C ratios varied from 1.1 to 1.2 for the maxillary incisors and from 1.3 to 1.4 for the mandibular incisors. Crown and root lengths were greater in men than in women, regardless of tooth type. Root lengths and R/C ratios for the mandibular incisors were significantly greater in patients with skeletal Class II malocclusion or an excessive overjet than in the other patients. The R/C ratios for the mandibular incisors were lower in patients with an open bite than in those with a normal or deep bite. Moreover, the R/C ratios for the mandibular incisors increased with age. Conclusions: The data obtained in our study can serve as reference values for crown and root lengths and the R/C ratios for the maxillary and mandibular incisors in the Korean population.

• 대한두개안면성형외과학회지
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• 제9권2호
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• pp.45-50
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• 2008

Purpose: Traditionally, titanium miniplate has been used for rigid fixation of mandible fractures. However, the limitations of metal plate have been reported such as hypersensitivity, interference with the cranio-facial growth of growing child, secondary bone resorption around the plate, foreign body reaction, declination of primary callus formation, and bone atrophy, and so forth. Recently, biodegradable miniplate has been introduced and used as an alternative to the metal plate despite of its lower strength. This study evaluated the usefulness and stability of biodegradable plate and screw for treatment of mandible fractures. Methods: In this study, 61 patients(92 areas) diagnosed as mandible fracture in the last 2 years have been reviewed. We used titanium plate and screw in 32 patients, and biodegradable plate and screw($INION^{(R)}$) in 29 patients. Stability of plates and screws, bony healing process and its side effects were observed by clinical and radiographic assessment. Results: In the titanium material group, one of malocclusion, two of mouth opening limitation, three of pain, three of palpation were shown. The plate of six patients involved in these complications were removed. In the biodegradable group, two of mouth opening limitation, two of pain, one of localized wound infection were shown and one plate was removed secondarily. Conclusion: There was no statistical difference between two groups in bony healing and complication rates. Biodegradable implants show efficient stability during initial bone healing and low side effects in long-term follow up periods.

• 대한치과교정학회지
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• 제52권5호
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• pp.313-323
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• 2022

Objective: This study aimed to estimate the clinical effects of different types of bone-anchored maxillary protraction devices by using a network meta-analysis. Methods: We searched seven databases for randomized and controlled clinical trials that compared bone-anchored maxillary protraction with tooth-anchored maxillary protraction interventions or untreated groups up to May 2021. After literature selection, data extraction, and quality assessment, we calculated the mean differences, 95% confidence intervals, and surface under the cumulative ranking scores of eleven indicators. Statistical analysis was performed using R statistical software with the GeMTC package based on the Bayesian framework. Results: Six interventions and 667 patients were involved in 18 studies. In comparison with the tooth-anchored groups, the bone-anchored groups showed significantly more increases in Sella-Nasion-Subspinale (°), Subspinale-Nasion-Supramentale(°) and significantly fewer increases in mandibular plane angle and the labial proclination angle of upper incisors. In comparison with the control group, Sella-Nasion-Supramentale(°) decreased without any statistical significance in all treated groups. IMPA (angle of lower incisors and mandibular plane) decreased in groups with facemasks and increased in other groups. Conclusions: Bone-anchored maxillary protraction can promote greater maxillary forward movement and correct the Class III intermaxillary relationship better, in addition to showing less clockwise rotation of mandible and labial proclination of upper incisors. However, strengthening anchorage could not inhibit mandibular growth better and the lingual inclination of lower incisors caused by the treatment is related to the use of a facemask.

• 대한치과교정학회지
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• 제31권4호
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• pp.393-401
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• 2001

교정치료의 결과를 평가하는 방법에는 두부방사선계측이나 석고모형을 이용하는 방법등이 있다. 교합지수는 석고 모형을 이용한 평가방법 중 하나로, 교합 상태를 하나의 수치로 표현하기 때문에 정량적으로 평가할 수 있고 계측이 객관적이며 교정치료의 결과를 평가하는데 있어서 표준화가 가능하다는 장점이 있다. 이 연구는 PAR지수를 이용하여 경희대학교 치과대학 교정과에서 시행되는 교정치료의 결과를 평가하고, 교정치료 증례들의 교정치료 전과 추적 관찰기의 교합 변화를 평가하며, 교정치료 전후의 결과가 치료 전 증례의 Angle 분류와 상관성이 있는지를 평가하기 위해 시행되었다. 영구치열기에 교정치료를 시작하여 고정식 교정장치로 치료하였고, 교정장치를 제거한 후 최소 24개월이 경과한 I급 부정교합 9 증례, II급 1류 부정교합 8 증례, III급 부정교합 8 증례 등 총 25 증례의 교정치료 전, 교정치료 종료 시, 추적 관찰기의 석고모형을 대상으로 PAR (Peer Assessment Rating) 지수를 이용한 교정치료의 결과 및 재발에 관한 연구를 시행하여 다음의 결론을 얻었다. 1. 교정치료 종료 시 평균 85.05%의 가중된 PAR 점수의 개선을 보였으며, 이는 'high standard of treatment'에 해당된다. 2. 추적 관찰기에는 교정치료 전과 비교하여 평균 75.40%의 가중된 PAR점수 개선을 보였으며 교정치료 종료 시와 비교하여 추적 관찰 기간동안 9.65%의 가중된 PAR 점수의 증가가 있었다. 3. 교정치료 전 Angle 분류와 치료 전후의 PAR 지수 변화량 간에는 상관관계가 없었다.

• 대한치과교정학회지
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• 제53권2호
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• pp.77-88
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• 2023

Objective: To develop a method for generating three-dimensional (3D) digital models of the periodontal ligament (PDL) using 3D cone-beam computed tomography (CBCT) reconstruction and to evaluate the accuracy and agreement of the 3D PDL models in the measurement of periodontal bone loss. Methods: CBCT data collected from four patients with skeletal Class III malocclusion prior to periodontal surgery were reconstructed at three voxel sizes (0.2 mm, 0.25 mm, and 0.3 mm), and 3D tooth and alveolar bone models were generated to obtain digital PDL models for the maxillary and mandibular anterior teeth. Linear measurements of the alveolar bone crest obtained during periodontal surgery were compared with the digital measurements for assessment of the accuracy of the digital models. The agreement and reliability of the digital PDL models were analyzed using intra- and interexaminer correlation coefficients and Bland-Altman plots. Results: Digital models of the maxillary and mandibular anterior teeth, PDL, and alveolar bone of the four patients were successfully established. Relative to the intraoperative measurements, linear measurements obtained from the 3D digital models were accurate, and there were no significant differences among different voxel sizes at different sites. High diagnostic coincidence rates were found for the maxillary anterior teeth. The digital models showed high intra- and interexaminer agreement. Conclusions: Digital PDL models generated by 3D CBCT reconstruction can provide accurate and useful information regarding the alveolar crest morphology and facilitate reproducible measurements. This could assist clinicians in the evaluation of periodontal prognosis and establishment of an appropriate orthodontic treatment plan.

• 대한치과교정학회지
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• 제30권1호
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• pp.1-7
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• 2000

교정 치료계획을 세우기 전에 부정교합에 기여하는 안면 비대칭의 정도를 정확히 평가하는 것은 무엇보다도 중요하다. 안면 비대칭의 진단은 주로 정모, 이하 두정, 두정 이하 방사선 사진이 이용되고 있다. 이중 이하 두정 방사선 사진은 반복재현성이 벌어지고 연구자료와 적절한 분석방법이 없다는 이유로 많이 사용되지 않고 있다. 이에 이 연구의 목적은 교정환자나 악교정 수술을 요하는 환자의 치료를 위하여 임상적으로 이용할 수 있는 이하 두정 방사선 계측사진의 분석방법을 개발하고 한국 성인에서의 정상치를 얻는데 있다. 연구 대상은 조화를 이루고 균형 잡힌 안모를 가진 교정치료 경험이 없는 40명의 성인을 대상으로 하였으며, 이하 두정 방사선 사진을 촬영하여 2개의 각도계측 항목과 9개의 선 계측항목을 측정하였다. 이하 두정 방사선 사진 분석에서 정상인에서 하악체의 길이는 좌, 우측 차이를 발견할 수 없었으나 정모, 측모 방사선사진의 계측 값과는 큰 차이를 보여, 비대칭의 절대적 양의 측정에는 어느 정도 한계가 있다. 기준선에 대한 좌, 우측 비교는 기준선을 설정하는 방법에 따라 큰 차이를 보였다. 과두의 위치 평가는 f. spinosum을 연결한 선의 수직이등분선을 정중선으로 사용하는 것이 가장 작은 편차를 보였으며, 상, 하악의 skeletal midline과 dental midline의 일치 여부 등을 판단할 때는 crista gli와 anterior process of atlas와 같이 midsagittal line 상에 위치하는 구조물을 이용하여 정중선을 설정하는 것이 가장 작은 편차를 보였다. 그리고 하악 과두 및 하악체의 형태이상을 관찰하는데는 매우 높은 진단적 가치를 가지고 있다. 그러므로 이하 두정방사선사진의 한계를 정확히 이해하고 정모, 측모 두부방사선사진과 함께 비대칭 분석에 이용한다면 보다 정확하게 비대칭 부위와 정도를 측정하는데 도움이 될 것이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.6.1-6.6
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• 2020

Background: Various types of miniplates have been developed and used for the reduction of facial bone fractures. We introduced Yang's Keyhole (YK) plate, and reported on its short-term stability. The purpose of this study was to evaluate the long-term stability of the YK plate, as a follow-up study, by examining the patients who had used the YK plate among the patients with the reduction of mandible fractures and who visited for plate removal. Methods: We reviewed the medical records of 16 patients who underwent mandibular fracture fixation using a YK plate (group I) and 17 patients who underwent mandibular fracture fixation using a conventional plate (group II). Assessment was then made on malunion, occlusal stability, discomfort during the application, and clinical symptoms. Results: From January 2015 to December 2017, a total of 36 patients underwent mandibular fracture surgery using a YK plate. A total of 16 patients received plate removal. Among them, 15 were male and 1 female. The average age was 26 years. The applied surgical sites were the 12 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of YK plate was an average of 335 days. During the same period, 45 people underwent surgery on the conventional plate. A total of 17 patients received plate removal. Among them, 15 were male and 2 females. The average age was 36 years. The applied surgical sites were the 8 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of the conventional plate was an average of 349 days. No malocclusion occurred at the time of removal, and occlusion was stable. No patient complained of joint disease or discomfort. Conclusion: The YK plate system, in which the screw was first inserted and the plate was applied, for clinical convenience did not cause any particular problem and no significant difference from the conventional plate.