• 대한치과교정학회지
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• 제52권1호
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• pp.3-19
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• 2022

Objective: The purpose of this study was to investigate the accuracy of one-step automated orthodontic diagnosis of skeletodental discrepancies using a convolutional neural network (CNN) and lateral cephalogram images with different qualities from nationwide multi-hospitals. Methods: Among 2,174 lateral cephalograms, 1,993 cephalograms from two hospitals were used for training and internal test sets and 181 cephalograms from eight other hospitals were used for an external test set. They were divided into three classification groups according to anteroposterior skeletal discrepancies (Class I, II, and III), vertical skeletal discrepancies (normodivergent, hypodivergent, and hyperdivergent patterns), and vertical dental discrepancies (normal overbite, deep bite, and open bite) as a gold standard. Pre-trained DenseNet-169 was used as a CNN classifier model. Diagnostic performance was evaluated by receiver operating characteristic (ROC) analysis, t-stochastic neighbor embedding (t-SNE), and gradient-weighted class activation mapping (Grad-CAM). Results: In the ROC analysis, the mean area under the curve and the mean accuracy of all classifications were high with both internal and external test sets (all, > 0.89 and > 0.80). In the t-SNE analysis, our model succeeded in creating good separation between three classification groups. Grad-CAM figures showed differences in the location and size of the focus areas between three classification groups in each diagnosis. Conclusions: Since the accuracy of our model was validated with both internal and external test sets, it shows the possible usefulness of a one-step automated orthodontic diagnosis tool using a CNN model. However, it still needs technical improvement in terms of classifying vertical dental discrepancies.

• Journal of Periodontal and Implant Science
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• 제46권6호
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• pp.405-414
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• 2016

Purpose: This study aimed to evaluate the effects of a policy change to expand Korean National Health Insurance (KNHI) benefit coverage to include scaling on access to dental care at the national level. Methods: A nationally representative sample of 12,794 adults aged 20 to 64 years from Korea National Health and Nutritional Examination Survey (2010-2014) was analyzed. To examine the effect of the policy on the outcomes of interest (unmet dental care needs and preventive dental care utilization in the past year), an estimates-based probit model was used, incorporating marginal effects with a complex sampling structure. The effect of the policy on individuals depending on their income and education level was also assessed. Results: Adjusting for potential covariates, the probability of having unmet needs for dental care decreased by 6.1% and preventative dental care utilization increased by 14% in the post-policy period compared to those in the pre-policy period (2010, 2012). High income and higher education levels were associated with fewer unmet dental care needs and more preventive dental visits. Conclusions: The expansion of coverage to include scaling demonstrated to have a significant association with decreasing unmet dental care needs and increasing preventive dental care utilization. However, the policy disproportionately benefited certain groups, in contrast with the objective of the policy to benefit all participants in the KNHI system.

• 대한치과보철학회지
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• 제55권2호
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• pp.218-224
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• 2017

방사선치료를 받은 상악에 임플란트 지지 고정성 보철물을 이용하여 수복하는 것은 골치유능력이 낮기 때문에 상세한 치료계획이 필요하다. All-on-4 개념에 의한 임플란트 식립은 골이식을 피하면서 임플란트를 매식할 수 있어 유리하다. 일반적으로 경사된 임플란트에는 기성 경사형 지대주를 사용해왔다. 본 임상증례에서는 computer-aided design and computer-aided manufacturing (CAD/CAM)으로 제작된 지대주를 사용하였다. 본 증례는 all-on-4 개념에 의해 임플란트를 매식하고 CAD/CAM titanium 지대주를 제작한 다음 CAD/CAM zirconia 고정성 보철물로 수복하여 좋은 결과를 얻었기에 보고하고자 한다.

• 대한치과의사협회지
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• 제52권3호
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• pp.132-138
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• 2014

The emergence of Cone Beam Computed Tomography(CBCT) in the late 1990s represented an innovative advancement in the field of dental and maxillofacial radiology because it greatly reduced the radiation exposure to patients and offered 3D images easily. The 3D information generated by this technique brings the potential of improved diagnosis and treatment planning for a wide range of clinical applications in dentistry. The use of CBCT includes diagnosis and surgical assessment of the orofacial hard tissue lesions, dental implant treatment planning and postoperative evaluation, TMJ assessment, diagnosis of craniofacial fracture, orthodontics, endodontics, and so on. All CBCT examinations should be justified on an individualized needs. The clinical benefits to the patient for each CBCT scan must outweigh the potential risks associated with exposure to ionizing radiation. CBCT scans should be taken with initially obtained medical and dental histories of patients and a close clinical examination. CBCT should be considered as an imaging alternative of other conventional radiography in cases where the anatomical structures of interest may not be seen. The smallest possible field of view(FOV) and the lowest setting of tube current and scan time should be chosen, and the entire images scanned should be interpreted by a qualified expert.

• 대한소아치과학회지
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• 제2권1호
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• pp.57-66
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• 1975

The study was performed to evaluate the Parent's knowledge and attitudes concerning the dental health of their children. A questionnaire consisting of 17 questions was given to each of the 664 parents by their children who are attending in primary school and was completed by them. The collected information from the questionnaire was analyzed by the visits to dental clinic, age and education. The results obtained from this study are as follows: 1) The more educated parents were more interested to the dental health of children. 2) In the know ledge concerning the dental health of their children, the parents who were more educated and had visited the dental clinic gave the better. responses. 3) There were no clear differences in age groups in the knowledge and attitudes on their children's dental health. 4) The reason for first visiting the dental clinic was dental treatment 43.2%, toothache 35.4%, for the purpose of oral examination 21.2%, and others were 9.2%. 5) 13.1% of the parents who had visited the dental clinic couldn't or didn't follow the recommended treatment because of economic difficulty 53.3%, lack of time 25%, lack of understanding of child's dental needs 18.3%, and other reasons were 3.3%.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권1호
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• pp.9-15
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• 2016

Programs provided by the Korea Association of Cardiopulmonary Resuscitation include Basic Life Support (BLS), Advanced Cardiac Life Support (ACLS), Pediatric Advanced Life Support (PALS), and Korean Advanced Life Support (KALS). However, programs pertinent to dental care are lacking. Since 2015, related organizations have been attempting to develop a Dental Advanced Life Support (DALS) program, which can meet the needs of the dental environment. Generally, for initial management of emergency situations, basic life support is most important. However, emergencies in young children mostly involve breathing. Therefore, physicians who treat pediatric dental patients should learn PALS. It is necessary for the physician to regularly renew training every two years to be able to immediately implement professional skills in emergency situations. In order to manage emergency situations in the pediatric dental clinic, respiratory support is most important. Therefore, mastering professional PALS, which includes respiratory care and core cases, particularly upper airway obstruction and respiratory depression caused by a respiratory control problem, would be highly desirable for a physician who treats pediatric dental patients. Regular training and renewal training every two years is absolutely necessary to be able to immediately implement professional skills in emergency situations.

• 구강회복응용과학지
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• 제24권4호
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• pp.351-359
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• 2008

임플란트의 도입으로 악골이 흡수된 무치악 환자의 보철 치료에 획기적인 변화가 가능해졌다. 특히 하악 무치악 환자의 경우 2개의 임플란트에 의해 유지를 얻는 피개의치가 일반적인 총의치의 대안으로 자리잡았으며 첫 번째로 고려되어야 할 치료 방법으로 받아들여지고 있다. 본 증례는 상하악 완전 무치악 환자로서 상악에는 일반적인 총의치, 하악에는 2개의 임플란트를 식립하고 $Locator^{(R)}$ Attachment를 사용하여 수복한 임상과정 및 결과에 관하여 보고하고자 한다.

• 대한치과마취과학회지
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• 제14권2호
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• pp.89-94
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• 2014

Local anesthesia known as the safe and essential procedure to control pain in dentistry may cause sensory changes such as paresthesia or altered taste at the affected sites after even successful local anesthesia. Although the prognosis of the nerve injuries after local anesthesia is favorable, it might cause prolonged problems such as dysesthesia. The lingual nerve is a single fascicle at the level of the lingual among 1/3 of patients and more movable during regeneration compared to the inferior alveolar nerve after the injury. As a result, the lingual nerve is more vulnerable and has poorer outcomes. More vigilant clinical considerations are required to the lingual nerve injury after local anesthesia. Generally, more than 80% of cases are spontaneously resolved within 2 weeks after the local anesthesia even without any specific treatment. However, the patient having long lasting abnormal sensations more than 2 weeks needs specialists' care for further assessment. In case of dysesthesia which is a symptom of neuropathic pain, immediate referral to specialists is mandatory. The exact mechanism, how to prevent its occurrence, or specific treatments of the nerve injury related to the local anesthesia have not been elucidated. To prepare clinical or medicolegal problems, many cautious considerations are given to the patients who complain sensory changes after local anesthesia.

• Journal of Oral Medicine and Pain
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• 제25권2호
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• pp.229-234
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• 2000

The patient, 62-years-old woman, had a constant dull pain in the right mandible and an intermittent spontaneous burning sensation of the mouth. The pain began 6 months ago. About 5 years ago, a trauma in her right mandible which was so severe that kept her in the hospital for 2 days. This was followed by mouth opening disturbance with pain for about 2 years. However, she did not have a treatment for the temporomandibular disorder symptoms. After then, she experienced the trigeminal neuralgia characterized by an electrical pain which lasted about 30 minutes in her right face and head when touching the skin or hair. After taking a year course treatment of trigeminal neuralgia, the symptom disappeared. The pain was a constant dull pain and a intermittent burning pain which are contradictory. And the pain responded to various modalities such as physical therapy, anti-inflammatory drug, carbamazepine, and amitriptyline, among which carbamazepine was most effective. The diagnosis was clinically made as an atypical trigeminal neuralgia. The term 'atypical' is used when there is something unknown and the problem is not identified. It is thought that an atypical pain may be approached in the perspective of chronic pain, neuropathic pain, and myofascial pain, the mchanisms of which are poorly understood. As the knowledge of pain physiology improves, there needs to be modification and re-evaluation. Pain disorders must be classified on the basis of an understanding of the underlying mechanism and etiology.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.52.1-52.11
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• 2020

Objectives: Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated. Materials and Methods: Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis. Results: The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions. Conclusions: The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.