• Imaging Science in Dentistry
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• 제53권3호
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• pp.209-216
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• 2023

Purpose: This study was conducted to compare dental plaque scores obtained through clinical examinations and various imaging techniques, as well as to assess the effectiveness of herbal and conventional toothpastes for plaque removal. Materials and Methods: Thirty volunteers were divided into 3 groups. Each group was given a different toothpaste (from 2 herbal toothpastes and a conventional toothpaste) with which to brush their teeth for 21 days. Both initially and after brushing, dental plaque samples were collected, and plaque on the buccal surfaces of anterior teeth was scored using several imaging systems after staining with a disclosing agent. Specifically, digital dental photography, intraoral digital scanning, and FluoreCam imaging were employed to capture intraoral images. The Turesky Modified Quigley-Hein Plaque Index was used for clinical examination and image analysis. Quantitative polymerase chain reaction analyses and correlational assessments between clinical examination and imaging scores were conducted before and after toothpaste use. The Shapiro-Wilk test and Pearson correlations were utilized. Results: The lowest mean value was observed in the clinical examination without staining, while the highest was obtained using the FluoreCam method. No significant change was found in the level of any microorganism assessed following toothpaste use (P<0.05), with the exception of a decrease in S. mutans levels after using conventional toothpaste (P<0.05). Conclusion: Herbal toothpaste demonstrated plaque-removal effectiveness comparable to that of conventional toothpaste. The use of imaging methods for measuring plaque index has been suggested as a means to educate patients about plaque control and promote ongoing oral care.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.11.1-11.5
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• 2015

Rapid palatal expansion(RPE) with the tooth-born appliance is not sufficient to apply to the patients with periodontal problem or insufficient tooth anchorage, and it leads to tipping of the anchorage teeth and increasing teeth mobility and root resorption. To avoid these disadvantages, we present the case using palatal screws and custommade palatal expander. A 23-year-old patient underwent surgically assisted rapid maxillary expansion with the Hyrax expansion using 4 tent screws. The study models were used to measure the pre-/-post surgical width of the anterior and posterior dental arches with a digital sliding caliper. In the result, the custom-made palatal expander with 4 tent screws is suitable for delivering a force to the mid-palatal suture expansion. And it is low cost, small sized and simply applied. The results indicated that maxillary expansion with the custom-made palatal anchorage device is predictable and stable technique without significant complications in patients.

• 대한치과교정학회지
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• 제54권2호
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• pp.117-127
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• 2024

Objective: To evaluate the effect of clear aligner treatment and differential sequence distalization of maxillary posterior teeth on anchorage loss in the upper incisors (U1s). Methods: This study used lateral cephalometries and digital models of 12 patients treated with 33% sequential distalization (group 1, mean age: 22.9 ± 0.7 years, five males, seven females) and 12 treated with 50% sequential distalization (group 2, mean age: 25.83 ± 0.5 years, three males, nine females) acquired before and after distalization of upper second premolars (U5) and upper first molars (U6) and upper second molars (U7). The amount of distalization was determined as 2.5 mm in both the groups. Independent Samples t test was used to compare normally distributed parameters. Mann-Whitney U and Wilcoxon tests were used to compare parameters that were not normally distributed. Results: In both groups, the posterior teeth significantly moved by tipping distally and the U1s were displaced anteriorly. Increase in maxillary posterior transverse width (P < 0.001) and distopalatal rotation were observed in U5, U6, and U7 after distalization. It was also observed that U1 was significantly more proclined (1.82°; P < 0.001) and protruded (0.62 mm; P < 0.001), and the overjet (0.45 mm; P < 0.001) increased more in group 1 than in group 2. Conclusions: After sequential distalization of maxillary posterior teeth, more anchorage loss was observed in the anterior region in group 1 than in group 2.

• 대한소아치과학회지
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• 제51권3호
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• pp.265-278
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• 2024

This study investigates the potential of cone-beam computed tomography (CBCT)-generated cephalograms as a replacement for conventional lateral cephalograms (LCs) in children and adolescents. This retrospective study included 60 individuals, equally divided into permanent and mixed dentition groups. Both groups underwent conventional LCs and CBCT scans on the same day. LCs were then derived from CBCT scans. The same examiner performed digital measurements twice, with a week's interval, identifying landmarks and obtaining 7 angular and 5 linear measurements. In the permanent dentition group, significant differences were observed between the two imaging modalities for 6 angular and 2 linear measurements. In the mixed dentition group, significant differences were observed for 3 angular and 2 linear measurements. However, none of these differences exceeded the clinically acceptable limit of 2.0° or 2.0 mm. No significant differences in any measurement were found between the two groups (p < 0.05). CBCT-generated LCs demonstrated comparable results with good reliability in both dentition groups, suggesting their potential as suitable alternatives for children and adolescents who require CBCT for clinical purposes.

• 대한심미치과학회지
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• 제27권2호
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• pp.82-96
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• 2018

3D 프린팅은 삼차원 이미지 정보를 이용하여 레이어로 분할한 후 선택한 소재를 적층하여 가공하는 방법을 말한다. 소재를 적층하는 방법에 따라 다양한 종류의 3D 프린팅이 존재하는데 최근 치과분야에서는 SLA방식과 DLP방식으로 광원을 이용한 경화를 통해 적층 가공하는 3D 프린팅이 널리 보급되어 사용되고 있다. 전악 범위의 3D프린팅 치과용 모델은 전통적인 인상 채득으로 제작된 스톤모델보다는 다소 정확성이 부족한 것으로 보고되었으나, 같은 STL파일을 이용하여 4분악 범위를 3D 프린팅한 모델은 밀링 방법으로 가공한 모델보다 정확하였다. 디자인 소프트웨어의 활용도에 따라 보철치료의 진단, 임시 보철물의 제작, 의치의 제작이 가능하였다. 교정에서는 투명 교정 모델과 브라켓 간접 부착을 위한 트레이 제작이 가능하였다. 임플란트 수술에 있어서 CT를 기반으로 한 정확한 위치에 임플란트를 식립하는 가이드 제작에 활용하고 있다. 출력 방식의 발전으로 인하여 3D 프린터의 출력시간이 계속적으로 단축되고 있으며, 이로 인해 치과 진료실 내에서 3D 프린터가 기존의 전통적인 가공 방법을 대체할 수 있을 것으로 기대한다.

• Imaging Science in Dentistry
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• 제45권1호
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• pp.15-22
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• 2015

Purpose: This study was performed to assess the reproducibility of identifying the sella turcica landmark in a three-dimensional (3D) model by using a new sella-specific landmark reference system. Materials and Methods: Thirty-two cone-beam computed tomographic scans (3D Accuitomo$^{(R)}$ 170, J. Morita, Kyoto, Japan) were retrospectively collected. The 3D data were exported into the Digital Imaging and Communications in Medicine standard and then imported into the Maxilim$^{(R)}$ software (Medicim NV, Sint-Niklaas, Belgium) to create 3D surface models. Five observers identified four osseous landmarks in order to create the reference frame and then identified two sella landmarks. The x, y, and z coordinates of each landmark were exported. The observations were repeated after four weeks. Statistical analysis was performed using the multiple paired t-test with Bonferroni correction (intraobserver precision: p<0.005, interobserver precision: p<0.0011). Results: The intraobserver mean precision of all landmarks was <1 mm. Significant differences were found when comparing the intraobserver precision of each observer (p<0.005). For the sella landmarks, the intraobserver mean precision ranged from $0.43{\pm}0.34mm$ to $0.51{\pm}0.46mm$. The intraobserver reproducibility was generally good. The overall interobserver mean precision was <1 mm. Significant differences between each pair of observers for all anatomical landmarks were found (p<0.0011). The interobserver reproducibility of sella landmarks was good, with >50% precision in locating the landmark within 1 mm. Conclusion: A newly developed reference system offers high precision and reproducibility for sella turcica identification in a 3D model without being based on two-dimensional images derived from 3D data.

• 대한치과교정학회지
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• 제32권5호
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• pp.313-325
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• 2002

3차원 CT에서는 환자의 움직임에 의한 오차와 상의 확대나 왜곡을 감소시킨 실측치를 얻을 수 있으며 두개안면부의 입체적인 영상을 구성할 수 있고 원하는 조직이나 구조물의 관찰이 용이하다 디지털 영상 기술이 빠르게 발전하고 있고 치료의 범위가 더욱 넓어지면서 두개악안면 구조의 3차원적인 분석법의 개발은 시급한 과제가 되었다. 이에 본 연구에서는 Vworks 프로그램$^{TM}$ (Cybermed Inc., Seoul, Korea)과 건조두개골을 이용하여 3차원 CT 영상의 오차와 확대율을 평가하고Vmorph-proto프로그램 $^{TM}$ (Cybermed Inc., Seoul, Korea)을 이용하여 정상인과 비대칭 환자의 3차원 CT영상에서 지정이 용이하고 반복재현성이 높은 계측점을 설정하고자 하여 다음과 같은 결론을 얻었다 ; 1. 건조두개골의 실측치와 Vworks 프로그램을 이용하여 구성한 3차원 CT영상에서 의 계측치를 비교한 결과 평균오차가 0.99mm, 확대율이 1.04%로 나타났다. 2. 3차원 CT영상에서 경조직 계측점으로 Supraorbitale, Lateral orbital margin, Infraorbitale, Natron, ANS, A point, Zygomaticomaxilla, Upper incisor, Lower incisor, B point, Pogonion, Menton, PNS, Condylar inner margin, Condylar outer margin, Porion, Condylion, Gonionl, Gonion2, Gonion3, Sigmoid notch, Basion 등이 임상적으로 유용하다고 판단되었다. 3. 3차원 CT영상에서 연조직 계측점으로 Endocanthion, Exocanthion, Soft tissue Nasion, Pronasale, Alare lateralis, Upper nostril point, Lower nostril point, Subnasale, Upper lip point, Cheilion, Stomion, Lower lip center, Soft tissue B, Pogonion, Menton, Preaurale 등이 임상적으로 유용하다고 판단되었다. Vworks 프로그램으로 3차원 CT영상을 구성하고 계측하는 것이 임상적으로 유용하다고 판단되었다. 또한 위에서 제안된 연조직 및 경조직 계측점들은 3차원 CT영상에서 반복 재현성이 높고 지정이 용이하며 해부학적 특징을 나타내주는 점들로 두개악안면 구조의 3차원적인 진단과 술전, 술후의 예측과 비교에 유용하게 사용될 것으로 사료되는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.41.1-41.6
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• 2019

Backgrounds: The purpose of this study is to discuss the total joint reconstruction surgery for a patient with recurrent ankylosis in bilateral temporomandibular joints (TMJs) using three-dimensional (3D) virtual surgical planning, computer-aided manufacturing (CAD/CAM)-fabricated surgical guides, and stock TMJ prostheses. Case presentation: A 66-year-old female patient, who had a history of multiple TMJ surgeries, complained of severe difficulty in eating and trismus. The 3D virtual surgery was performed with a virtual surgery software (FACEGIDE, MegaGen implant, Daegu, South Korea). After confirmation of the location of the upper margin for resection of the root of the zygoma and the lower margin for resection of the ankylosed condyle, and the position of the fossa and condyle components of stock TMJ prosthesis (Biomet, Jacksonville, FL, USA), the surgical guides were fabricated with CAD/CAM technology. Under general anesthesia, osteotomy and placement of the stock TMJ prosthesis (Biomet) were carried out according to the surgical planning. At 2 months after the operation, the patient was able to open her mouth up to 30 mm without complication. Conclusion: For a patient who has recurrent ankylosis in bilateral TMJs, total joint reconstruction surgery using 3D virtual surgical planning, CAD/CAM-fabricated surgical guides, and stock TMJ prostheses may be an effective surgical treatment option.

• Imaging Science in Dentistry
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• 제42권1호
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• pp.25-33
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• 2012

Purpose : This study was performed to determine the accuracy of linear measurements on three-dimensional (3D) images using multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). Materials and Methods : MDCT and CBCT were performed using 24 dry skulls. Twenty-one measurements were taken on the dry skulls using digital caliper. Both types of CT data were imported into OnDemand software and identification of landmarks on the 3D surface rendering images and calculation of linear measurements were performed. Reproducibility of the measurements was assessed using repeated measures ANOVA and ICC, and the measurements were statistically compared using a Student t-test. Results : All assessments under the direct measurement and image-based measurements on the 3D CT surface rendering images using MDCT and CBCT showed no statistically difference under the ICC examination. The measurements showed no differences between the direct measurements of dry skull and the image-based measurements on the 3D CT surface rendering images (P>.05). Conclusion : Three-dimensional reconstructed surface rendering images using MDCT and CBCT would be appropriate for 3D measurements.

• 대한치과교정학회지
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• 제50권4호
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• pp.258-267
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• 2020

Objective: This study aimed to analyze the correlation of horizontal and sagittal planes used in two-dimensional diagnosis with lip canting by using three-dimensional (3D) analysis. Methods: Fifty-two patients (25 men, 27 women; average age: 24 years) undergoing treatment for dentofacial deformity were enrolled. Computed tomography images were acquired, and digital imaging and communication in medicine files were reconstructed into a 3D virtual model wherein horizontal and sagittal craniofacial planes were measured. Subsequently, the correlations of lip canting with these horizontal and sagittal planes were investigated. Results: The mandibular symmetry plane, the occlusal plane, Camper's plane, the mandibular plane, Broadbent's plane, and the nasal axis plane were correlated with the amount of lip canting (Pearson's correlation coefficients: 0.761, 0.648, 0.556, 0.526, 0.438, and 0.406, respectively). Planes associated with the lower part of the face showed the strongest correlations; the strength of the correlations decreased in the midfacial and cranial regions. None of the planes showed statistically significant differences between patients with clinical lip canting (> 3°) and those without prominent lip canting. Conclusions: The findings of this study suggest that lip canting is strongly correlated with the mandibular symmetry plane, which includes menton deviation. This finding may have clinical implications with regard to the treatment of patients requiring correction of lip canting. Further studies are necessary for evaluating changes in lip canting after orthognathic surgery.