OBJECTIVES: The purpose of this study was to evaluate the polymerization shrinkage stress among conventional methacrylate-based composite resins and a silorane-based composite resin. MATERIALS AND METHODS: The strain gauge method was used for the determination of polymerization shrinkage strain. Specimens were divided by 3 groups according to various composite materials. Filtek Z-250 (3M ESPE) and Filtek P-60 (3M ESPE) were used as a conventional methacrylate-based composites and Filtek P-90 (3M ESPE) was used as a silorane-based composites. Measurements were recorded at each 1 second for the total of 800 seconds including the periods of light application. The results of polymerization shrinkage stress were statistically analyzed using One way ANOVA and Tukey test (p = 0.05). RESULTS: The polymerization shrinkage stress of a silorane-based composite resin was lower than those of conventional methacrylate-based composite resins (p < 0.05). The shrinkage stress between methacrylate-based composite resin groups did not show significant difference (p > 0.05). CONCLUSIONS: Within the limitation of this study, silorane-based composites showed lower polymerization shrinkage stress than methacrylate-based composites. We need to investigate more into polymerization shrinkage stress with regard to elastic modulus of silorane-based composites for the precise result.
Composite Resins ; Elastic Modulus ; Light ; Polymerization ; Polymers ; Sprains and Strains

PURPOSE: . This study aimed to fabricate provisional crowns at varying build directions using the digital light processing (DLP)-based 3D printing and evaluate the marginal and internal fit of the provisional crowns using the silicone replica technique (SRT). MATERIALS AND METHODS. The prepared resin tooth was scanned and a single crown was designed using computer-aided design (CAD) software. Provisional crowns were printed usinga DLP-based 3D printer at 6 directions (120°, 135°, 150°, 180°, 210°, 225°) with 10 crowns in each direction. In total, sixty crowns were printed. To measure the marginal and internal fit, a silicone replica was fabricated and the thickness of the silicone impression material was measured using a digital microscope. Sixteen reference points were set and divided into the following 4 groups: marginal gap (MG), cervical gap (CG), axial gap (AG),and occlusal gap (OG). The measurements were statistically analyzed using one-way ANOVA and Dunnett T3. RESULTS: MG, CG, and OG were significantly different by build angle groups (P<.05). The MG and CG were significantly larger in the 120° group than in other groups. OG was the smallest in the 150° and 180° and the largest in the 120° and 135° groups. CONCLUSION The marginal and internal fit of the 3D-printed provisional crowns can vary depending on the build angle and the best fit was achieved with build angles of 150°and 180°

BACKGROUND: Methyl alcohol poisoning has been mainly reported in community. Two cases of methyl alcohol poisoning occurred in a small-sized subcontracted factory which manufactured smartphone parts in Korea. CASE PRESENTATION: One young female patient presented with dyspnea and visual disturbance. Another young male patient presented with visual disturbance and myalgia. They treated with sodium bicarbonate infusion and hemodialysis for metabolic acidosis. In addition, he received ethyl alcohol per oral treatment. Her and his urinary methyl alcohol concentration was detected as 7.632 mg/L, 46.8 mg/L, respectively, although they were treated hemodialysis. Results of the working environment measurement showed that the concentration of methyl alcohol (1030.1–2220.5 ppm) in the air exceeded the time weighted average (200 ppm). They were diagnosed with optic neuropathy due to methyl alcohol poisoning and still have visual impairment. CONCLUSIONS: Workers who hired as dispatched employees in a small-sized subcontracted factory were exposed to high concentrations of methyl alcohol. The workplace had poor ventilation system. In addition, workers did not wear proper personal protect equipment. Working environment measurement and annual chekups for workers were not performed. They were in a blind spot to occupational safety and health. More attention is needed to protect vulnerable workers’ health.
Acidosis ; Aluminum* ; Dyspnea ; Ethanol ; Female ; Humans ; Inhalation* ; Korea ; Male ; Methanol* ; Myalgia ; Occupational Health ; Optic Disk ; Optic Nerve Diseases ; Poisoning ; Renal Dialysis ; Smartphone ; Sodium Bicarbonate ; Ventilation ; Vision Disorders

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare and fatal cancer-related pulmonary complication leading to severe pulmonary hypertension, right heart failure, and death. Few cases of PTTM have been diagnosed antemortem. A 62-year-old male showing complete remission of gastric cancer presented with exertional dyspnea. Transthoracic echocardiography showed marked dilation of the right atrium, right ventricle, and the small left ventricle with normal left ventricular function. Right heart catheterization also showed mild to moderate pulmonary hypertension. A chest computed tomography scan revealed no evidence of acute pulmonary thromboembolism, but it showed consolidations with subpleural nodules in both lower lobes, and a lung perfusion scan showed multifocal, non-segmental perfusion defects. Finally, a diagnostic lung biopsy with video-assisted thoracoscopic surgery was performed, and the pathologic findings were compatible with PTTM. Here, we report a case of gastric cancer-related PTTM that was diagnosed antemortem.
Biopsy ; Cardiac Catheterization ; Cardiac Catheters ; Dyspnea ; Echocardiography ; Heart Atria ; Heart Failure ; Heart Ventricles ; Humans ; Hypertension, Pulmonary ; Lung ; Male ; Middle Aged ; Perfusion ; Pulmonary Embolism ; Stomach Neoplasms* ; Thoracic Surgery, Video-Assisted ; Thorax ; Thrombotic Microangiopathies* ; Ventricular Function, Left

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare and fatal cancer-related pulmonary complication leading to severe pulmonary hypertension, right heart failure, and death. Few cases of PTTM have been diagnosed antemortem. A 62-year-old male showing complete remission of gastric cancer presented with exertional dyspnea. Transthoracic echocardiography showed marked dilation of the right atrium, right ventricle, and the small left ventricle with normal left ventricular function. Right heart catheterization also showed mild to moderate pulmonary hypertension. A chest computed tomography scan revealed no evidence of acute pulmonary thromboembolism, but it showed consolidations with subpleural nodules in both lower lobes, and a lung perfusion scan showed multifocal, non-segmental perfusion defects. Finally, a diagnostic lung biopsy with video-assisted thoracoscopic surgery was performed, and the pathologic findings were compatible with PTTM. Here, we report a case of gastric cancer-related PTTM that was diagnosed antemortem.
Biopsy ; Cardiac Catheterization ; Cardiac Catheters ; Dyspnea ; Echocardiography ; Heart Atria ; Heart Failure ; Heart Ventricles ; Humans ; Hypertension, Pulmonary ; Lung ; Male ; Middle Aged ; Perfusion ; Pulmonary Embolism ; Stomach Neoplasms* ; Thoracic Surgery, Video-Assisted ; Thorax ; Thrombotic Microangiopathies* ; Ventricular Function, Left

The nationwide prevalence of major depressive disorder in Korea is lower than most countries, despite the high suicide rate. To explain this unexpectedly low prevalence, we examined the functional disability and quality of life in community-dwelling subjects with significant depressive symptoms not diagnosable as depressive disorder. A total of 1,029 subjects, randomly chosen from catchment areas, were interviewed with the Center for Epidemiologic Studies Depression scale, Mini International Neuropsychiatric Interview, WHO Quality of Life scale, and the WHO Disability Assessment Schedule. Those with scores over 21 on the depression scale were interviewed by a psychiatrist for diagnostic confirmation. Among community-dwelling subjects, the 1-month prevalence of major depressive disorder was 2.2%, but the 1-month prevalence of depressive symptoms not diagnosable as depressive disorder was 14.1%. Depressive disorders were the cause of 24.7% of work loss days, while depressive symptoms not diagnosable as depressive disorder were the cause of 17.2% of work loss days. These findings support the dimensional or spectrum approach to depressive disorder in the community and might be the missing link between the apparent low prevalence of depressive disorder and high suicide rate in Korea.
Adolescent ; Adult ; Analysis of Variance ; Depression/*diagnosis/epidemiology ; Female ; Humans ; Interviews as Topic ; Male ; Mental Health ; Middle Aged ; Prevalence ; *Quality of Life ; Young Adult

Neonatal gastric perforation is a rare but fatal disease, occurred mainly in preterm infants. In general, primary surgical repair is the main treatment. To the best of our knowledge, there has been only one report of improvement of gastric perforation in neonates after percutaneous peritoneal drainage alone. We describe a case of gastric perforation in a premature extremely low-birth-weight infant girl of 25(+4) weeks gestational age. We present this case to emphasize that gastric perforation may improve with percutaneous peritoneal drainage.
Drainage* ; Female ; Gestational Age ; Humans ; Infant, Extremely Low Birth Weight ; Infant, Low Birth Weight ; Infant, Newborn* ; Infant, Premature

OBJECTIVES: Obesity is considered to be one of the most important risk factors for obstructive sleep apnea (OSA) but less is known about the role of ethnicity in OSA. The purpose of this study was to investigate the interethnic difference of obesity-related phenotypes in OSA and to reveal the role of ethnicity in OSA. METHODS: We searched MEDLINE, LILACS, Scopus, and the Cochrane Library using the key words "sleep apnea," "body mass index," "neck circumference," "waist circumference," "waist to hip ratio," etc. Inclusion criteria were adults over 18 years of age, and studies that included polysomnography, obesity-related parameters, and a clear demarcation of ethnicity in the patient population. Included studies were reviewed by 2 independent reviewers. The following information was collected for controls and OSA: number, age, gender, country, ethnicity (Asian or Caucasian), study design, apnea-hypopnea index/respiratory disturbance index, body mass index (BMI), neck circumference (NC), waist circumference (WC), and/or waist to hip ratio (WHR). RESULTS: A total of 8,312 publications were retrieved with a subsequent 19 manuscripts that met the selection criteria. A total of 2,966 patients were included for analysis. The main findings were as follows: There was no difference in BMI, WC, and WHR between patients with OSA and controls after accounting for publication bias; Patients with OSA have greater NC than controls (standard mean difference, 0.89; 95% confidence interval, 0.63 to 1.14); and There was no difference in NC between Asian and Caucasians patients (P=0.178). CONCLUSION: OSA might not be related with BMI, WC, and WHR. Only NC demonstrated a strong association with OSA, and this finding was not different between Asians and Caucasians.
Adult ; Asian Continental Ancestry Group* ; Body Mass Index ; Hip ; Humans ; Neck ; Obesity ; Patient Selection ; Phenotype ; Polysomnography ; Publication Bias ; Risk Factors ; Sleep Apnea, Obstructive* ; Waist Circumference ; Waist-Hip Ratio

Although intracranial hemorrhage from arteriovenous malformation (AVM) during pregnancy is rare, it can have fatal consequences. Anesthetic techniques for these patients should ensure precise hemodynamic control, and the goals of anesthesia should include both fetal and maternal well-being. We report a case of anesthetic management for cesarean section in a 31-year-old woman who presented at 32 weeks gestation with an acute intracranial hemorrhage secondary to rupture of a previously diagnosed AVM. Our medical team decided to perform emergent cesarean section under regional anesthesia before transferring the patient to the neurosurgical intensive care unit for further monitoring and appropriate postoperative pain control. The patient was alert and cooperative during neuraxial anesthesia. The operation was successful, and the patient showed gradual improvement in neurosurgical status after several days. We concluded that in case of emergency, regional anesthesia can be a safe strategy for cesarean section in a pregnant woman with symptomatic AVM.
Adult ; Anesthesia ; Anesthesia, Conduction ; Arteriovenous Malformations ; Cesarean Section ; Emergencies ; Female ; Hemodynamics ; Humans ; Intensive Care Units ; Intracranial Arteriovenous Malformations* ; Intracranial Hemorrhages ; Pain, Postoperative ; Pregnancy ; Pregnant Women* ; Rupture

PURPOSE: We evaluated brain perfusion SPECT findings of MELAS syndrome and mitochondrial myopathy in correlation with MR imaging in search of specific imaging features. MATERIALS AND METHODS: Subjects were five patients (four females and one male; age range, 1 to 25 year) who presented with repeated stroke-like episodes, seizures or developmental delay or asymptomatic but had elevated lactic acid in CSF and serum. Conventional non-contrast MR imaging and Tc-99m-ethyl cysteinate dimer (ECD) brain perfusion SPECT were performed and imaging features were analyzed. RESULTS: MRI demonstrated increased T2 signal intensities in the affected areas of gray and white matters mainly in the parietal (4/5) and occipital lobes (4/5) and in the basal ganglia (1/5), which were not restricted to a specific vascular territory. SPECT demonstrated decreased perfusion in the corresponding regions of MRI lesions. In addition, there were perfusion defects in parietal (1 patient), temporal (2), and frontal (1) lobes and basal ganglia (1) and thalami (2). In a patient with mitochondrial myopathy who had normal MRI, decreased perfusion was noted in left parietal area and bilateral thalami. CONCLUSION: Tc-99m ECD SPECT imaging in patients with MELAS syndrome and mitochondrial myopathy showed hypoperfusion of parieto-occipital cortex, basal ganglia, thalamus and temporal cortex, which were not restricted to a specific vascular territory. There were no specific imaging features on SPECT. The significance of abnormal perfusion on SPECT without corresponding MR abnormalities needs to be evaluated further in larger number of patients.
Basal Ganglia ; Brain* ; Female ; Humans ; Lactic Acid ; Magnetic Resonance Imaging ; Male ; MELAS Syndrome* ; Mitochondrial Encephalomyopathies ; Mitochondrial Myopathies* ; Occipital Lobe ; Perfusion ; Rabeprazole ; Seizures ; Thalamus ; Tomography, Emission-Computed, Single-Photon*