1.Dental Age Estimation in Children Using Convolution Neural Network Algorithm: A Pilot Study
Byung-Yoon ROH ; Hyun-Jeong PARK ; Kyung-Ryoul KIM ; In-Soo SEO ; Yeon-Ho OH ; Ju-Heon LEE ; Chang-Un CHOI ; Yo-Seob SEO ; Ji-Won RYU ; Jong-Mo AHN
Journal of Oral Medicine and Pain 2024;49(4):118-123
Purpose:
Recently, deep learning techniques have been introduced for age estimation, with automated methods based on radiographic analysis demonstrating high accuracy. In this study, we applied convolutional neural network (CNN) techniques to the lower dentition area on orthopantomograms (OPGs) of children to develop an automated age estimation model and evaluate its accuracy for use in forensic dentistry.
Methods:
In this study, OPGs of 2,856 subjects aged 3-14 years were analyzed. The You Only Look Once (YOLO) V8 object detection technique was applied to extract the mandibular dentition area on OPGs, designating it as the region of interest (ROI). First, 200 radiographs were randomly selected, and were used to train a model for extracting the ROI. The trained model was then applied to the entire dataset. For the CNN image classification task, 80% of OPGs were allocated to the training set, while the remaining 20% were used as the test set. A transfer learning approach was employed using the ResNet50 and VGG19 backbone models, with an ensemble technique combining these models to improve performance. The mean absolute error (MAE) on the test set was used as the validation metric, and the model with the lowest MAE was selected.
Results:
In this study, the age estimation model developed using mandibular dentition region from OPGs achieved MAE and root mean squared error (RMSE) values of 0.501 and 0.742, respectively, on the test set, and MAE and RMSE values of 0.273 and 0.354, respectively, on the training set.
Conclusions
The automated age estimation model developed in this study demonstrated accuracy comparable to that of previous research and shows potential for applications in forensic investigations. Increasing the sample size and incorporating diverse deep learning techniques are expected to further enhance the accuracy of future age estimation models.
2.Secondary publication Sudden Aortic Rupture in Ehlers-Danlos Syndrome Type IV.
Taehwa BAEK ; Minjung KIM ; Chang Seok KI ; Seong Hwan PARK ; Heon LEE ; Kyung Ryoul KIM ; Byung Ha CHOI
Korean Journal of Legal Medicine 2016;40(2):61-64
Ehlers-Danlos syndrome type IV (EDS IV) is a hereditary disorder of the connective tissue, characterized by easy bruising, thin skin with visible veins, and spontaneous rupture of the large arteries, uterus, or bowel. EDS IV is caused by mutations of the gene for type III procollagen (COL3A1), resulting in insufficient collagen production or a defect in the structure of collagen. EDS IV can have fatal complications such as the rupture of great vessels or organs, which can cause hemorrhaging and sudden unexpected death. Here, we report a case of a 43-year-old female who collapsed after a struggle with a neighbor. In this patient, the bifurcation of the bilateral common iliac artery ruptured, with no evidence of trauma, inflammation, or atherosclerosis. Genetic analysis of COL3A1 showed the presence of a c.2771G>A (p.Gly924Arg) mutation, which may be associated with EDS IV. The forensic pathologist should consider the possibility that the spontaneous visceral or arterial rupture was caused by EDS IV. Genetic analysis is not currently a routine procedure during autopsy. However, in this case, we suggest that the patient possibly had an underlying EDS IV condition, and we recommended family members of the deceased to seek genetic analysis and counseling.
Adult
;
Aortic Rupture*
;
Arteries
;
Atherosclerosis
;
Autopsy
;
Collagen
;
Collagen Type III
;
Connective Tissue
;
Counseling
;
Ehlers-Danlos Syndrome*
;
Female
;
Humans
;
Iliac Artery
;
Inflammation
;
Rupture
;
Rupture, Spontaneous
;
Skin
;
Uterus
;
Veins
3.Job Stress and Self-perceived Fatigue in Korean Farmers.
Ki Hyun LEE ; Sang Baek KOH ; Dongmug KANG ; Jin Joo CHUNG ; Hyoung Ryoul KIM ; In Ah KIM ; Kyung Suk LEE ; Sook Jung HYUN ; Kang Myoung LEE ; Jin Ha YOON ; Sung Kyung KIM ; In Jung CHO ; Jung Kyu CHOI ; Sung Soo OH ; Bong Suk CHA ; Sei Jin CHANG
Korean Journal of Occupational and Environmental Medicine 2011;23(2):213-224
OBJECTIVES: A growing body of research has documented that job stress has a pivotal role in developing adverse health outcomes. However, little is known about the relationship between farmers' job stress and health outcomes. This study was undertaken to identify the relationship between job stress and self-perceived fatigue in Korean farmers. METHODS: A total of 526 Korean farmers were asked to participate in this study. A self-administered questionnaire was used to assess the participants' general characteristics, job stress and self-perceived fatigue. Job stress was measured using a forty-eight item Farm Stressor Inventory (FSI), and the self-perceived fatigue was estimated by Multidimensional Fatigue Scale (MFS). Binary logistic regression analysis was conducted to examine the relationship between job stress and self-perceived fatigue. RESULTS: The result showed that job stress was associated with self-perceived fatigue. For the farmers with high job stress, the risk of self-perceived fatigue was more likely to increase compared to those with low job stress. For males, labor intensity (OR, 3.88; 95% CI, 1.91~7.89), job environment (OR, 2.45; 95% CI, 1.22~4.93), social support (OR, 2.10; 95% CI, 1.07~4.13), social isolation (OR, 2.45; 95% CI, 1.15~5.60), financial problems (OR, 3.25; 95% CI, 1.53~6.91), uncertainty (OR, 2.48; 95% CI, 1.30~4.75) and health problems (OR, 5.77; 95% CI, 2.46~13.53) were associated with self-perceived fatigue. For females, job environment (OR, 2.23; 95% CI, 1.22~4.08), social isolation (OR, 2.08; 95% CI, 1.05-4.15), physical environment & weather condition (OR, 2.61; 95% CI, 1.33~5.12), financial problems (OR, 2.87; 95% CI, 1.55~5.32), uncertainty (OR, 3.65; 95% CI, 1.95~6.83) and health problems (OR, 3.38; 95% CI, 1.57~7.27) were associated with self-perceived fatigue. CONCLUSIONS: This result suggests that farmers' job stress plays a role in the development of fatigue, and job stressors related to fatigue are slightly different according to gender.
Agriculture
;
Fatigue
;
Female
;
Humans
;
Logistic Models
;
Male
;
Questionnaires
;
Social Isolation
;
Uncertainty
;
Weather
4.Association of Subway Driver's Depressive Symptoms and Experience of Work-Related Problems.
Sun Jin JO ; Hyeon Woo YIM ; Hyoung Ryoul KIM ; Kang Sook LEE ; Jong Ik PARK ; Sung Man CHANG
Epidemiology and Health 2010;32(1):e2010010-
OBJECTIVES: Subway drivers experience various types of work-related problems during their driving, and those experiences can act as risk factors for depressive symptoms. This study was conducted to investigate the association between work-related problems and subway driver's depressive symptoms. METHODS: We recruited all of the 961 current subway drivers of a subway company located in Seoul, South Korea and conducted a survey of their socio-demographic and vocational characteristics, hospital visits as an outpatient or inpatient, and work-related problem experiences during the last year. Work-related problems included an accident resulting in death or injury, a conflict with a customer, a sudden stop from an emergency bell, or a near accident. Depressive symptoms were measured with the Center for Epidemiologic Studies-Depression (CES-D) instrument. The survey was performed using a self-report questionnaire from April 16 to July 13, 2007. The data of 827 drivers (86.2%) were analyzed. RESULTS: Experience of a conflict with a passenger (p=0.011), a sudden stop from an emergency bell (p=0.001), or a near accident (p=0.001) increased the prevalence of depressive symptoms among subway drivers. A multiple logistic regression analysis revealed that a sudden stop from an emergency bell increased the risk of depressive symptoms significantly (OR=2.59, p=0.026). Near accidents were marginally associated with a higher risk for depressive symptoms (OR=1.62, p=0.062). CONCLUSION: The experience of a sudden stop from an emergency bell increased subway driver's depressive symptoms, and near accidents may increase the risk of depressive symptoms. Therefore, interventions for the drivers who had experienced these work-related problems are needed.
Depression
;
Emergencies
;
Humans
;
Inpatients
;
Logistic Models
;
Outpatients
;
Prevalence
;
Railroads
;
Republic of Korea
;
Risk Factors
;
Surveys and Questionnaires
5.Effect of dexamethasone concentrations on osteogenic activity of cultured human periosteal-derived cells
Jong Ryoul KIM ; Bong Wook PARK ; Chang Il LEE ; Young Sool HAH ; Deok Ryong KIM ; Yeong Cheol CHO ; Iel Yong SUNG ; June Ho BYUN
Journal of the Korean Association of Maxillofacial Plastic and Reconstructive Surgeons 2009;31(4):287-293
6.Case Series for Occupational Skin Disorders in Carbon Fiber Exposed Packing Workers.
Hye Eun LEE ; Chang Bum BYUN ; Sinye LIM ; Seung Ho JEON ; Sang Yong OH ; Hyoung Ryoul KIM ; Soon CHOI ; Domyung PAEK ; Mijin PARK
Korean Journal of Occupational and Environmental Medicine 2006;18(3):199-208
OBJECTIVES: We report an outbreak of skin disorder in semiconductor packing workers. Through an evaluation of the degree of work-relatedness in this case, we aim to develop a method to overcome such health problems in the workplace. METHODS: A questionnaire investigating the job characteristics and skin symptoms was administered to 51 packing workers working in a semiconductor production factory and 49 questionnaires returned. The 16 subjects in the exposure group and 12 in the non-exposure group underwent doctor's examination and patch test. Two of 28 subjects were excluded in patch test. We investigated the work environment and carbon fiber level which was the potential causative agent. RESULTS: Forty-five (91.8%) of 49 packing workers complained of itching and stinging. Three of 14(21.4%) in the exposure group and 3 of 11 (27.3%) in the non-exposure group were positive at 48hr reading of patch test for carbon fiber and carbon fiber paper. None was positive at 96hr reading of patch test. Prominent carbon fibers were microscopically observed on the surface of the packing box and the fiber diameter, measured up to 6.0~7.5 micrometer, was likely to induce skin irritation to skin. To avoid worker's direct contact with to carbon fiber, carbon fiber paper box was substituted by a wax coated carbon fiber paper box was substituted for the original carbon fiber paper box, which caused and the workers' symptoms to of workers disappeared. CONCLUSION: The probably cause of this outbreak of skin disorder was mild irritant contact dermatitis for carbon fiber. To prevent outbreaks of such occupational skin disorder like this, workers should avoid direct contact with carbon fiber.
Bites and Stings
;
Carbon*
;
Dermatitis, Contact
;
Disease Outbreaks
;
Patch Tests
;
Pruritus
;
Questionnaires
;
Semiconductors
;
Skin*
7.Developing an Occupational Stress Scale for Korean Employees.
Sei Jin CHANG ; Sang Baek KOH ; Dongmug KANG ; Seong Ah KIM ; Myung Geun KANG ; Chul Gab LEE ; Jin Joo CHUNG ; Jung Jin CHO ; Mia SON ; Chang Ho CHAE ; Jung Won KIM ; Jung Il KIM ; Hyeong Su KIM ; Sang Chul ROH ; Jae Beom PARK ; Jong Min WOO ; Soo Young KIM ; Jeong Youn KIM ; Mina HA ; Jungsun PARK ; Kyung Yong RHEE ; Hyoung Ryoul KIM ; Jeong Ok KONG ; In Ah KIM ; Jeong Soo KIM ; Jun Ho PARK ; Sook Jung HUYUN ; Dong Kook SON
Korean Journal of Occupational and Environmental Medicine 2005;17(4):297-317
BACKGROUND AND PURPOSES: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and METHODS: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002- 2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Fortythree items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. RESULTS: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. CONCLUSION: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.
Chronic Disease
;
Classification
;
Climate
;
Korea
;
National Institute for Occupational Safety and Health (U.S.)
;
Reward
;
Risk Factors
8.A Case of Antral and Duodenal Nonpolypoid Adenomas in a Patient with Familial Adenomatous Polyposis.
Young Suk LEE ; So Jean CHOI ; Chang Ryoul LEE ; Jun Ho LEE ; Dong Suk LEE ; Woo Seung KIM ; Hee Seung PARK ; Seong Ho CHOI
Korean Journal of Gastrointestinal Endoscopy 2000;20(1):68-72
Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited colon cancer-predisposing disorder, characterized by the development of innumerable adenomas in the large intestine. Polyps are present in the upper gastrointestinal tract in almost all FAP patients and there is a peculiar predilection for adenomatous change in the duodenum. Colonic adenomas in FAP are commonly observed as polyps but nonpolypoid adenomas can also be seen in the upper gastrointestinal tract. Careful endoscopic examination is needed for detecting such nonpolypoid lesions. At present, the adenoma-carcinoma sequence is thought to exist also in the duodenum, and malignancy of the duodenum represents one of the most common causes of mortality among patients with FAP. Therefore, careful periodic follow-up of upper intestinal endoscopies are recommended in patients with this disease, in consideration to the possible development of duodenal nonpolypoid adenomatous lesions. A case involving an experience of antral and duodenal nonpolypoid adenomas in a patient with FAP is herein reported.
Adenoma*
;
Adenomatous Polyposis Coli*
;
Colon
;
Duodenum
;
Follow-Up Studies
;
Humans
;
Intestine, Large
;
Mortality
;
Polyps
;
Pyloric Antrum
;
Upper Gastrointestinal Tract
9.A Case of Acute Phlegmonous Esophagitis.
Chang Ryoul LEE ; Joon Ho LEE ; So Jin CHOI ; Dong Seok LEE ; Woo Seong KIM ; Seo Ryoung HAN ; No Won CHUNG ; Hee Seung PARK ; Seong Ho CHOI
Korean Journal of Gastrointestinal Endoscopy 2000;20(2):119-123
Phlegmonous esophagitis is an uncommon disease characterized by purulent infection of the esophageal wall, sparing the mucosa. Bacterial infection of the eosphagus is usually presented as a superimposed infection upon a preexisting viral or fungal esophagitis and most victims are immunocompromised hosts. A case was experienced involving an acute phlegmonous esophagitis in an 21-year-old man who was immunologically normal and whose main symptoms were epigastric pain and fever for one day. Esophagographic examination revealed a large ulceration of the eosphagus with exudation, and submucosal lesions. Due to its rarity, this case is herein reported with a review of the corresponding literature.
Bacterial Infections
;
Cellulitis*
;
Esophagitis*
;
Fever
;
Humans
;
Immunocompromised Host
;
Mucous Membrane
;
Ulcer
;
Young Adult
10.A case of cerebellar embolic infarction in thyrotoxic atrial fibrillation.
So Jean CHOI ; Chang Ryoul LEE ; Jun Ho LEE ; Dong Suk LEE ; Seo Ryong HAN ; Woo Seung KIM ; Seong Pyo SON
Korean Journal of Medicine 2000;59(2):192-197
Atrial fibrillation occurs in 10 to 25% of patients with thyrotoxicosis. Several recent studies have found a high frequency of cerebral thromboembolism in such patients. Thus anticoagulation has been recommended for patients with thyrotoxic atrial fibrillation to prevent embolic complications especially when associated with predictors of an increased risk of arterial thromboembolism in nonrheumatic atrial fibrillation such as recent congestive heart failure, history of hypertension, previous thromboembolism, left atrial enlargement, and global left ventricular dysfunction. Most reported cases of embolic events involving central nervous system in thyrotoxic atrial fibrillation affected cerebrum, and cerebellar embolic infarction from the heart was rarely seen. We herein report our experience of a case of cerebellar embolism in thyrotoxic atrial fibrillation.
Atrial Fibrillation*
;
Central Nervous System
;
Cerebrum
;
Embolism
;
Heart
;
Heart Failure
;
Hepatitis
;
Humans
;
Hypersensitivity
;
Hypertension
;
Infarction*
;
Thromboembolism
;
Thyrotoxicosis
;
Ventricular Dysfunction, Left

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