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.

The aim of this study was to elucidate the diatomological investigation and the forensic role of spleen tissue in cases of drowning or non-drowning. Specimens of spleen tissue and other organ tissue from 136 drowning cases, as well as 21 cases where death resulted from causes other than drowning (acting as controls), were examined for the presence of diatoms. The diatom test was performed on all cases using the acid digestion method, involving fumed nitric acid on a hot sand bath. The presence of diatoms in spleen tissue was observed in drowning cases but not in non-drowning cases. Diatoms in spleen tissue showed a positive association with drowning (P=0.011). Among the 136 drowning cases, diatoms were most frequently found in lung tissue (n=134, 99%), followed by spleen (n=33, 24%), kidney (n=28, 21%), liver (n=27, 20%), and heart (n=22, 16%) tissues. Moreover, in 95 cases where putrefaction did not progress, diatoms were detected in spleen tissues in 14 cases, indicating that the highest detection rate among other enclosed organ tissues, excluding lung tissues. Furthermore, a significant correlation was observed between the presence of diatoms in spleen tissue and those in enclosed organs, including the liver, kidney, and heart, but not in lung tissues. Our results revealed a significant correlation between the presence of diatoms in spleen tissue and drowning. Thus, the present study provides evidence that the presence of diatoms in spleen tissue may be a reliable indicator of death by drowning.

BACKGROUND: Despite the necessity of job retention in achieving return-to-work (RTW) goals, many workers leave their jobs after returning to work. The objective of this study was to examine the impacts of RTW type and period on job retention in Korean workers with occupational injuries and diseases. METHODS: Data were derived from the Panel Study of Worker's Compensation Insurance, including data from 2,000 systemically sampled workers who had finished recuperation in 2012; three waves of survey data were included in the analyses. Workers who returned to work (n = 1,610) were included in the analysis of the relationship between RTW type and job retention, and 664 workers who returned to their original workplaces were included in the analysis of the relationship between RTW period and job retention. The participants completed a questionnaire, and administrative data were provided by workers' compensation insurance. RESULTS: A Cox proportional-hazards regression analysis showed an increased hazard ratio (HR) for non-retention of 2.66 (95% confidence interval, 2.11–3.35) in reemployed workers compared to that in workers returning to their original workplaces. Among workers returning to their original workplaces, HRs for non-retention were increased in workers with a RTW period of 13–24 months (3.03 [1.52–6.04]) and > 24 months (5.33 [2.14–13.25]) compared to workers with a RTW period of ≤ 3 months. CONCLUSION: RTW type and period were significantly related to job retention, suggesting that policies for promoting job retention rate should be implemented.
Insurance ; Occupational Diseases ; Occupational Health ; Occupational Injuries ; Return to Work ; Workers' Compensation

Hepatocellular carcinoma (HCC) is one of the major cancers with a high incidence and mortality in Korea. A Korean multidisciplinary collaborative committee consisting of hepatologists, radiologists, epidemiologists and family medicine doctors systematically reviewed clinical practice guidelines in the world and literatures. The level of evidence for each recommendation was assessed and discussed to reach a consensus. Meta-analysis was also conducted to evaluate the grade of recommendation for the five key questions. Several randomized controlled studies and cohort studies showed a survival gain associated with surveillance for those at risk of developing HCC. The target populations for HCC surveillance were identified as hepatitis B virus or hepatitis C virus carriers and cirrhotic patients, since numerous studies revealed that these patients have significantly higher risk of HCC compared with non-infected or non-cirrhotic controls. Individual surveillance strategy according to treatment history or degree of fibrosis in patients with viral hepatitis remains to be settled. Based on several cohort and randomized studies, a surveillance interval of six months was recommend. The starting age of surveillance was determined as 40 years from the epidemiologic data. Although ultrasonography (US) is the mainstay for detection of HCC, its sensitivity is not fully accepted. Measurement of serum alpha-fetoprotein can complement US examination, increasing the sensitivity of HCC detection. The recommendation for HCC surveillance is that those with hepatitis B virus (or hepatitis C virus) infection or cirrhosis should have liver US and serum alpha-fetoprotein measurement every six months from 40 years of age or at the time of diagnosis of cirrhosis.
alpha-Fetoproteins ; Carcinoma, Hepatocellular* ; Cohort Studies ; Complement System Proteins ; Consensus ; Diagnosis ; Fibrosis ; Health Services Needs and Demand ; Hepacivirus ; Hepatitis ; Hepatitis B virus ; Hepatitis C ; Humans ; Incidence ; Korea ; Liver ; Mortality ; Ultrasonography

PURPOSE: To compare the result of endoscopic versus open bursectomy in lateral malleolar bursitis, which was not treated conservatively. MATERIALS AND METHODS: Between January 2008 and October 2009, We divided to two groups, endoscopy (group A) 11 cases, open bursectomy (group B) 11 cases. The average follow up period was 15 months (range, 12 to 18), the mean age was 66 (range, 38 to 79). We compared patients satisfaction, complete healing time, operation time, complications and recurrence. RESULTS: Group A had significant difference in terms of the clinical satisfactions, complete healing time. operation time, complications. Group A showed satisfaction (excellent 9, good 2), mean complete healing time 11.9 (8~14) days, operation time 37 (25~45) minutes, 1 case recur. Group B showed satisfaction (excellent 4, good 3, fair 1, poor 3), complete healing time 32.7 (14~98) days, operation time 22 (18~26) minutes. complication were one case of skin necrosis, one case of wound dehiscence, two cases of superficial peroneal nerve injury, no recurrence. Significant advantages of endoscopic method include lower morbidity and rapid wound healing period (p<0.05). CONCLUSION: Endoscopic resection of the lateral malleolar bursitis is a promising technique and shows favourable results compared to the open resection. Significant advantages of this method include lower morbidiy and rapid wound healing.
Animals ; Ankle ; Bursitis ; Endoscopy ; Follow-Up Studies ; Humans ; Necrosis ; Peroneal Nerve ; Recurrence ; Skin ; Wound Healing

PURPOSE: We report the clinical and radiographic result of ligament reconstruction using plantaris and total ankle replacement in end-stage ankle arthritis with ankle instability. MATERIALS AND METHODS: The study is based on the 9 cases among total 48 patients of end-stage ankle arthritis that were treated with total ankle prosthesis and ligament reconstruction from 2007 to 2009 at least 12 months follow-up. We evaluated the VAS (Visual analogue scale) pain score, AOFAS (American orthopedic foot and ankle society) score and radiographic measurements. RESULTS: Average age was 59.4 years (53~67 years) old. VAS pain score improved from preoperative average 8.2+/-0.9 (range, 7~10) to 2.7+/-1.7 (range, 0~6) and the AOFAS score improved from 46.4+/-14.6 points (range, 23~69) to 80.1+/-9.3 points (range, 65~95) at final follow-up. Anterior draw test improved 15.2+/-3.4 mm (range, 12~23 mm) to 8.8+/-2.6 mm (range, 6~13mm),varus stress test improved from 13.9+/-4.6degrees (range,10-18degrees) to 6.2+/-4.7degrees (range,2-18degrees) at final follow up. CONCLUSION: Plantaris ligament reconstruction is good option as part of the management of ankle instability with end-stage ankle arthritis. We achieved good clinical and radiographic results.
Animals ; Ankle ; Arthritis ; Arthroplasty ; Arthroplasty, Replacement, Ankle ; Exercise Test ; Follow-Up Studies ; Foot ; Humans ; Ligaments ; Orthopedics ; Prostheses and Implants

OBJECTIVES: The lung cancer mortality in Korea has increased remarkably during the last 20 years, and has been the first leading cause of cancer-related deaths since 2000. The aim of the current study was to examine the time trends of occupational lung cancer and carcinogens exposure during the period 2006-2009 in South Korea, by assessing the proportion of occupational burden. METHODS: We defined occupational lung cancer for surveillance, and developed a reporting protocol and reporting website for the surveillance of occupational lung cancer. The study patients were chosen from 9 participating university hospitals in the following 7 areas: Seoul, Incheon, Wonju, Daejeon, Daegu, Busan, and Gwangju. RESULTS: The combined proportion of definite and probable occupational lung cancer among all lung cancers investigated in this study was 10.0%, 8.6%, 10.7%, and 15.8% in the years 2006 to 2009, respectively, with an average of 11.7% over the four-year study period. The main carcinogens were asbestos, crystalline silica, radon, polyaromatic hydrocarbons (PAHs), diesel exhaust particles, chromium, and nickel. CONCLUSION: We estimated that about 11.7% of the incident lung cancer was preventable. This reveals the potential to considerably reduce lung cancer by intervention in occupational fields.
Asbestos ; Carcinogens ; Chromium ; Crystallins ; Hospitals, University ; Humans ; Hydrocarbons ; Korea ; Lung ; Lung Neoplasms ; Radon ; Republic of Korea ; Silicon Dioxide ; Vehicle Emissions

Adult ; Animals ; Bone Regeneration ; Bone Transplantation ; Durapatite ; Ear ; Fibrin ; Fibrin Tissue Adhesive ; Humans ; Minerals ; Osteocalcin ; Osteogenesis ; Skin ; Swine ; Transplants

Mesenchymal chondrosarcoma is a rare malignant tumor of bone and soft tissue. This aggressive form of chondrosarcoma represents only 3% to 9% of all chondrosarcomas. This neoplasm is characterized by sheets or clusters of undifferentiated spindle or round cells surrounding discrete nodules of well-differentiated cartilage. We experienced a case of mesenchymal chondrosarcoma on mandibular body. Two years ago, the patient had been treated the intrabony cystic lesion on mandiblular left body. At that time, cartilage portion was not detected in the cystic specimen. Two years after cyst enucleation, the recurred large neoplasm in the mandibular left body was noted, and it was diagnosed as 4.5 cm sized mesenchymal chondrosarcoma. The mandibular tumor was widely resected and rigid-plate and cervical musculocutaneous flap were used for reconstruction of resected bone and soft tissues. No complications and recurrence were noted for 6 months postoperatively.
Cartilage ; Chondrosarcoma ; Chondrosarcoma, Mesenchymal ; Humans ; Recurrence

There are increasing reports regarding regeneration of the defected tissues using tissue engineering technique. In this technique, multipotential stem cells are essential. There are many potential sources of adult stem cells, such as bone marrow, umbilical cord blood, fat, muscle, dental tissues and skin. Among them, skin is highly accessible and easily obtained with a minimum of donor site complications. Moreover, skin is an abundant adult stem cell sources and has the potential for self-replication and immune privilege. In this study, we isolated skin-derived precursor cells (SKPs) from the ear of adult miniature pigs. In these SKPs, the expression of transcriptional factors, Oct-4, Sox-2, and Nanog were detected by RT-PCR. In vitro osteogenesis and adipogenesis were observed at 3 weeks after transdifferentiations as assayed by positive von Kossa and Oil-red O staining, respectively. In addition, expression of osteocalcin and osteonectin in the osteogenic differentiation medium and PPAR GAMMA2 and aP2 in the adipogenic differentiation medium were detected by RT-PCR. In vitro neurogenesis of porcine SKPs was observed during 24 and 72 hours after treatment of neurogenic differentiation medium. The results of this study suggest that SKPs demonstrate the properties of pluripotence or multipotence and multi-lineage differentiation. This indicates that autogenous SKPs are a reliable and useful source of adult stem cells for regenerative medicine.
Adipogenesis ; Adult ; Adult Stem Cells ; Bone Marrow ; Durapatite ; Ear ; Fetal Blood ; Humans ; Muscles ; Neurogenesis ; Osteocalcin ; Osteogenesis ; Osteonectin ; Peroxisome Proliferator-Activated Receptors ; Regeneration ; Regenerative Medicine ; Skin ; Stem Cells ; Swine ; Tissue Donors ; Tissue Engineering