Dental Age Estimation Using the Demirjian Method: Statistical Analysis Using Neural Networks

노병윤,안종모,이종석,임상범,류혜원,전수정,이주헌,서요섭,류지원 대한법의학회 2023 대한법의학회지 Vol.47 No.1

In children and adolescents, dental age estimation is performed with the development of the teeth. Various statistical analysis methods have been used to determine the relationship between age and dental maturity and develop an accurate method of age calculation. This study attempted to apply a neural network model for the statistical analysis of dental age estimation in children and evaluated its applicability. This study used 1196 panoramic radiographs of patients aged 3–16 years, and 996 and 200 were randomly classified into training and test sets, respectively. The dental maturity of the mandibular left teeth was evaluated using Demirjian's method, the neural network model using the backpropagation algorithm was derived using training sets, and the errors were evaluated using 100 radiographs of each male and female as test sets. In addition, multiple linear regression analysis was conducted on the same training set, and the error was calculated by applying it to the test set and comparing it with the error of the neural network model. In the neural network model, the mean absolute error (MAE) and root mean squared error (RMSE) were 0.589 and 0.783 in male subjects and 0.529 and 0.760 in female subjects, respectively. In the multiple linear regression model, the MAE and RMSE were 0.600 and 0.748 in male subjects and 0.566 and 0.789 in female subjects, respectively. When applying the neural network model to the statistical analysis of the dental developmental stage, the results were as accurate as those of conventional statistical analysis methods. This study’s approach is expected to be useful for estimating the ages of children.

사업비차배당제도(事業費差配當制度)의 도입(導入) 및 대응방안(對應方案)

노병윤,장강봉 보험연구원 1999 연구보고서 Vol.1999 No.7

구강내 다형홍반의 증례보고

노병윤,안종모,윤창륙,유지원,Roh, Byung-Yoon,Ahn, Jong-Mo,Yoon, Chang-lyuk,Ryu, Ji-Won 대한안면통증구강내과학회 2013 Journal of Oral Medicine and Pain Vol.38 No.1

다형 홍반은 피부 혹은 점막에 영향을 미치는 수포성, 궤양성의 염증성 질환이다. 이는 단순포진 바이러스와 같은 감염이나, 항생제나 진통제와 같은 약물에 의해 유발하는 것으로 알려져 있다. 증상으로는 피부에 과녁모양의 전형적인 병소가 나타나는 것으로 알려져 있으며, 구강 내에 증상이 발현 될 경우, 입술, 볼, 혀에 미란성의 병소가 발현되는 것으로 알려져 있고, 이는 다른 구강내 병소와의 감별을 필요로 한다. 본 증례에서 트리코모나스 감염 또는 메트로니다졸 투여로 인해 유발되었을 것으로 추정되는, 구강에 발생한 다형홍반의 사례를 소개하고, 다형홍반의 진단 및 치료에 대해서 고찰해 보고자 한다. Erythema multiforme(EM), a blistering and ulcerative inflammatory disorder, affect skins or mucosa, and is thought to be triggered mainly by preceding infection, such as Herpes simplex virus, or exposure to drugs and medication, particular antibiotics or analgesics. Symptoms include typical cutaneous target lesions on skins and in case of oral manifestation, erosive and ulcerative lesions on lips, buccal mucosa, and tongue are known to occur, which needs differential diagnosis with other intraoral lesions. In this case, EM assumed that it is occurred by giving Trichomonas infection or Metronidazole in oral region is introduced with a review of diagnosis and treatment of EM.

가철성 유해자극차단장치를 이용한 구강작열감증후군의 치료 증례

노병윤,안종모,윤창륙,유지원,Roh, Byung-Yoon,Ahn, Jong-Mo,Yoon, Chang-Lyuk,Ryu, Ji-Won 대한안면통증구강내과학회 2012 Journal of Oral Medicine and Pain Vol.37 No.1

구강작열감증후군(Burning Mouth Syndrome: BMS)은 특기할 임상적인 증상 없이, 구강 내에 나타나는 병적인 작열감 또는 통증을 지칭한다. 구강작열감증후군은 주로 혀 전방 그리고 측방에 증상이 나타나며, 경구개 전방, 입술 등의 다른 구강점막에도 나타나는 것으로 보고되고 있다. 구강작열감증후군의 원인은 분명하게 밝혀져 있지 않으며, 여러 가지 요인들이 작용하는 것으로 알려져 있다. 감염과 외상 같은 국소적 요인, 내분비 변화, 당뇨, 영양결핍(비타민, 아연 등), 철분 또는 엽산 결핍과 관련된 빈혈과 같은 전신적인 요인 등이 영향을 미치는 것으로 알려져 있고, 불안, 우울, 암공포증과 같은 심리적 요인 또한 영향을 미치는 것으로 알려져 있다. 최근의 연구는 구강작열감증후군이 신경학적 병변에 의한 신경병변성 통증의 특성을 나타냄을 보고하고 있다. 구강작열감증후군의 치료는 알려진 원인이 분명하지 않기 때문에 치료 또한 여러 각도로 시행되고 있다. 그 중, clonazepam의 국소적 적용, capsaicin, alpha lipoic acid 투여 등의 약물요법이 주로 이루어지며, 저주파 에너지 레이저 조사, 침술요법과 같은 치료법도 보고되고 있다. 최근의 몇몇 연구들은 혀를 국소적 자극요인으로부터 보호하여 구강작열감증후군의 증상을 완화시킨 사례들을 보고하고 있다. 본 연구는 구강작열감증후군 증상을 보이는 환자에게 하악 치아에 가철성 유해자극차단장치를 장착하여 증상이 개선된 증례를 소개하고, 구강 이상악습관과 구강작열감증후군의 연관성 및 이에 대한 치료법을 소개하고자 한다. Burning mouth syndrome(BMS) refers to a chronic orofacial pain disorder usually unaccompanied by mucosal lesions or other clinical signs. Tongue(anterior and lateral border) is found to be the most common site for the burning sensations in the oral cavity, and various oral sites may be affected including hard palate and lips. The etiology of this disorder remains poorly understood, but the various factors might be related with the pathogenesis of the BMS. These factors have been devided into local, systemic and psychological. Recently, there have been increasing reports that the pain of BMS may be neuropathic in origin. The complex and multifactorial etiology of BMS necessitates multidisciplinary approach for the management of these patients. Recently, several studies have reported that oral parafunctional habits could be related the pathogenesis of BMS, and tried to control the symptom of BMS with various methods. We reported the cases who had the symptom of burning mouth syndrome with removable anti-nociceptive appliance in the lower dentition.

클러스터링과 분산탐색을 이용한 PSO

노병윤,임동현,김현태,안창욱 한국지능정보시스템학회 2009 한국지능정보시스템학회 학술대회논문집 Vol.2009 No.11

Particle Swarm Optimization(PSO)는 개체 집단의 이동에서, 집단을 대표하는 개체가 그 집단을 이끌어 나가는 모습을 기반으로 해서 설계되었다. 이러한 일반적인 PSO기법에 입자들을 균일하게 분획하여 각각의 새로운 Search space를 만들어주는 Clustering 기법과 입자 위치의 재설정 과정에서 분산된 입자들 사이의 최적값을 이용함으로써 더 나은 성능을 가진 PSO를 설계해 본다.

Age Estimation Based on Mandibular Premolar and Molar Development: A Pilot Study

노병윤,김의주,서인수,김형건,류혜원,이주헌,서요섭,유지원,안종모 대한안면통증∙구강내과학회 2021 Journal of Oral Medicine and Pain Vol.46 No.4

Purpose: The dental age estimation of children is performed using dental maturity. Postmortem missing of the anterior teeth or the distortion of image of the anterior teeth in panoramic radiographs can make it difficult to analyze the development of the anterior teeth. This pilot study was conducted to derive a new age estimation method based only on the developmental stage of mandibular posterior teeth. Methods: This study was conducted using panoramic radiographs of 650 subjects aged 3 to 15 years old. The dental developmental stages of the lower left first premolar, second premolar, first molar and second molar were evaluated according to the Demirjian’s criteria. The intra-/inter-observer reliability was evaluated, and multiple linear regression analyses were performed including the developmental stage of each tooth as an independent variable. Results: The intra-/inter-observer reliability was 0.9626 and 0.8877, respectively, and showed very high reproducibility. Multiple linear regression analyses were performed for males and females, and the age calculation table was derived by obtaining the intercept and the coefficient according to the development stage of each tooth. The coefficient of determination (r 2 ) of the age calculation method was 0.9634 for male and 0.9570 for female subjects, and the mean difference between chronological age and estimated dental age was –0.42 and –0.21, respectively. Conclusions: This pilot study evaluated the developmental stages of four lower posterior teeth in the Korean group according to Demirjian’s criteria, and derived age estimation method. The accuracy was lower than when more teeth were used, but it will be useful to estimate age of children when the anterior teeth are difficult to accurately analyze

생명보험상품(生命保險商品)의 손익기여도분석(損益寄與度分析)

노병윤,장강봉 보험연구원 2000 연구보고서 Vol.2000 No.4

해방후 文解敎育의 역사적 조명

노병윤 한국사상문화학회 2015 韓國思想과 文化 Vol.76 No.-

This study examines the transition process of Korean literacy education and how its history has developed in each government. Korean literacy education after liberation can be examined according to historical trends as follow:First, it can be the period of state-dominated activity. The anti-illiteracy crusade to prepare the ground to build up a early democratic state until the end of 1950 after liberation established the foundation of the state. It’s the period that people realized that literacy ability is the important means and tool to establish the foundation of the state. Second, it can be the period of privately led literacy education activity. Literacy education was arranged without national support underwater from the end of 1960 to the end of 1990. Since then, it was the period that the non-governmental activity to be established as adult basic education based on development of social education. Third, it’s the period that the private activity was changed to the state-dominated activity. It placed the real condition of illiterate persons before the world from 1990 to the middle of 2000 and found literacy education institutions and literacy fields. It was the period to make a rough sketch of preparing the support systems and legislation. Fourth, it can be the period that private organizations and the state cooperated with each other. After the legal system was carried out through the systematic operation of literacy education at national and private level based on institutionalization of the lifelong education act in 2007, alternatives to meet changed situations and long-term vision are required. Literacy education which has recently been arranged is similar with the process of ‘anti-illiteracy crusade’ which was done at national level in 1950s. It has been 30 years until literacy education saw the light of day again since it had gone to hibernation after 1960s. Therefore, this study can be significantly meaningful in development of literacy education in that it sheds new light on Korean literacy education’s history when public interest in it has been higher. 본 연구는 한국의 문해교육(文解敎育) 변천과정을 살펴보고 문해교육의 역사가 정부 별로 어떻게 전개되어 왔는지 살펴보는 것이다. 해방후 한국의 문해교육을 역사적 흐름에 따라 살펴보면 다음과 같다. 첫째, 국가주도의 활동시기로 볼 수 있다. 해방 후 1950년대 말까지 초기 민주국가 건설의 기반 조성을 위한 문맹퇴치 활동은 국가의 기반을 다지는데 문해의 능력은 중요한 수단이며 도구임을 자각하는 시기였다. 둘째, 민간주도의 문해교육 활동 시기로 볼 수 있다. 1960년대 말부터 1990년도 말까지 문해교육은 국가 지원없이 수면아래에서 진행되었다. 이후 사회교육발전에 기초한 성인기초교육으로서의 정착을 위한 민간차원의 활동이 활발하였던 시기였다. 셋째, 민간에서 국가주도로 전환되는 시기다. 1990년∼2000년대 중반까지 비문해자의 실태를 세상에 알리고 문해교육기관과 문해현장을 발굴하는 시기로 지원제도 마련과 법제화를 위한 밑그림을 그리는 시기였다. 넷째, 민간과 국가의 협력시기로 볼 수 있다. 2007년 평생교육법의 제도화를 기반으로 문해교육에 대한 국가차원의 지원과 민간차원의 체계적인 운영을 통한 법제도화 시행 후 변화된 상황에 맞춘 대안과 장기적인 비전이 요구되는 시기로 볼 수 있다. 최근 진행되고 있는 ‘문해교육’은 1950년대 국가차원에서 진행된 ‘문맹퇴치운동’과 진행과정의 유사성을 갖고 있다. 1960년대 이후 긴 동면기로 들어간 문해교육이 다시 세상 빛을 보기까지 약 30년의 세월이 흘렀다. 따라서 본 연구는 문해교육이 고조된 시점에서 한국문해교육의 역사를 재조명해 보는 것은 문해교육 발전에 소중한 의의를 갖는다고 볼 수 있다.

치근단 방사선 사진에서 Paewinsky 연령추정법 적용에 대한 연구

노병윤,서정욱,김창겸,최창운,이원준,이상섭 대한법의학회 2018 대한법의학회지 Vol.42 No.4

There have been many radiographic studies on age estimation that evaluate reduction in size of dental pulp cavity with secondary dentin formation. The Paewinsky method reported high accuracy in estimating ages by measuring the width of the pulp cavity in panoramic radiographs. The aim of this study was to evaluate the application of the Paewinsky method to digital periapical radiographs. This study was conducted on 103 cases that reported to the Section of Human Identification of the National Forensic Service. The age was calculated by applying the Paewinsky method that measures the root and pulp canal width at three points in a tooth. The estimation results were compared with those calculated by the Johanson method. When the Paewinsky models were applied to digital periapical radiographs, the errors were significantly greater as compared to the original study. The errors of the maxillary second premolar and mandibular lateral incisor were greater than those of the maxillary central incisor, lateral incisor, mandibular canine, and first premolar. Furthermore, errors of the age estimation models in level C were greater than those in levels A and B. This study could be a reference for the application of the Paewinsky method to digital periapical radiographs.

한국(韓國)의 문화(文化) : 해방후 문해교육(文解敎育)의 역사적 조명

노병윤 ( Byeong Yun Noh ) 한국사상문화학회 2015 韓國思想과 文化 Vol.76 No.-

본 연구는 한국의 문해교육(文解敎育) 변천과정을 살펴보고 문해교육의 역사가 정부 별로 어떻게 전개되어 왔는지 살펴보는 것이다. 해방후 한국의 문해교육을 역사적 흐름에 따라 살펴보면 다음과 같다. 첫째, 국가주도의 활동시기로 볼 수 있다. 해방 후 1950년대 말까지 초기 민주국가 건설의 기반 조성을 위한 문맹퇴치 활동은 국가의 기반을 다지는데 문해의 능력은 중요한 수단이며 도구임을 자각하는 시기였다. 둘째, 민간주도의 문해교육 활동 시기로 볼 수 있다. 1960년대 말부터 1990년도 말까지 문해교육은 국가 지원없이 수면아래에서 진행되었다. 이후 사회교육발전에 기초한 성인기초교육으로서의 정착을 위한 민간차원의 활동이 활발하였던 시기였다. 셋째, 민간에서 국가주도로 전환되는 시기다. 1990년∼2000년대 중반까지 비문해자의 실태를 세상에 알리고 문해교육기관과 문해현장을 발굴하는 시기로 지원제도 마련과 법제화를 위한 밑그림을 그리는 시기였다. 넷째, 민간과 국가의 협력시기로 볼 수 있다. 2007년 평생교육법의 제도화를 기반으로 문해교육에 대한 국가차원의 지원과 민간차원의 체계적인 운영을 통한 법제도화 시행 후 변화된 상황에 맞춘 대안과 장기적인 비전이 요구되는 시기로 볼 수 있다. 최근 진행되고 있는 ‘문해교육’은 1950년대 국가차원에서 진행된 ‘문맹퇴치운동’과 진행과정의 유사성을 갖고 있다. 1960년대 이후 긴 동면 기로 들어간 문해교육이 다시 세상 빛을 보기까지 약 30년의 세월이 흘렀다. 따라서 본 연구는 문해교육이 고조된 시점에서 한국문해교육의 역사를 재조명해 보는 것은 문해교육 발전에 소중한 의의를 갖는다고 볼 수 있다. This study examines the transition process of Korean literacy education and how its history has developed in each government. Korean literacy education after liberation can be examined according to historical trends as follow: First, it can be the period of state-dominated activity. The anti-illiteracy crusade to prepare the ground to build up a early democratic state until the end of 1950 after liberation established the foundation of the state. It`s the period that people realized that literacy ability is the important means and tool to establish the foundation of the state. Second, it can be the period of privately led literacy education activity. Literacy education was arranged without national support underwater from the end of 1960 to the end of 1990. Since then, it was the period that the non-governmental activity to be established as adult basic education based on development of social education. Third, it`s the period that the private activity was changed to the state-dominated activity. It placed the real condition of illiterate persons before the world from 1990 to the middle of 2000 and found literacy education institutions and literacy fields. It was the period to make a rough sketch of preparing the support systems and legislation. Fourth, it can be the period that private organizations and the state cooperated with each other. After the legal system was carried out through the systematic operation of literacy education at national and private level based on institutionalization of the lifelong education act in 2007, alternatives to meet changed situations and long-term vision are required. Literacy education which has recently been arranged is similar with the process of ‘anti-illiteracy crusade’ which was done at national level in 1950s. It has been 30 years until literacy education saw the light of day again since it had gone to hibernation after 1960s. Therefore, this study can be significantly meaningful in development of literacy education in that it sheds new light on Korean literacy education`s history when public interest in it has been higher.