The Dentists’ View of Dental Hygienist Duties in Korea / 치위생과학회지

Background@#The number and curriculum of dental hygienists in Korea have dramatically increased. Controversies have since resulted from insufficient job descriptions of the work performed by a dental hygienist. A dentist's perception was examined to legally reflect the actual work of dental hygienists. @*Methods@#Four hundred and nineteen dentists were surveyed about the duties of a dental hygienist. Their views on the career and availability of each job were examined. The duties of the dental hygienist include 13 items in dental treatment preparation, 14 items of radiography, 21 items of preventive dentistry, 6 items of periodontal treatment, 12 items of oral medicine, 12 items of conservative dentistry, 8 items of prosthetics, 10 items of orthodontics, 7 items of oral and maxillofacial surgery, 6 items of implantation, 6 items of impression taking and model fabrication, 5 items of anesthesia and injection, 11 items of management and administrative, and 3 items of self-development. @*Results@#Most of the duties were doable by a dental hygienist. Many dentists reported that managing implants, oral hygiene of special patients, some duties in oral medicine, teeth brightening, making temporary crowns, making individual trays, selecting shades, ligaturing, and precision impressions need ≥3 years of experience. Duties perceived by dentists not to be performed by dental hygienists were reading radiographs (55.4%), suture and stitch out (48.0%), intramuscular injection (36.0%), root planning (27.2%), cementation and removal of prostheses (23.2%), and examining pulp vitality (22.0%). @*Conclusion@#Current laws are to be revised to include, the care provided by dental hygienists and under a physician’s supervision. Flexibility is also needed to cope with rapidly changing dental technology.

Factors Affecting Scaling Experiences of Adolescent Children from Multicultural and Native Families / 치위생과학회지

Background@#Multicultural families are constantly on the rise as marriage migrants and foreign workers increase. Multicultural families appear to record poor health levels compared to native families. As health is a social issue, children of surviving generations of multicultural families are also a growing interest. This study was conducted to confirm the effect of multicultural families and parents’ educational level on the scaling experience of children. @*Methods@#For this study, the 2016∼2018 Korea Youth Risk Behavior Web-based Survey data were used. In order to make the two groups of adolescents belonging to multicultural and native families similar, a total of 5,362 people were included in the survey, consisting of 2,681 individuals each from multicultural and native families using the propensity score matching method. Logistic analysis was performed to identify factors influencing the scaling experience of adolescent children. @*Results@#The results confirm that, even after controlling for factors such as parents’ educational level, household income, and children’s oral health behavior, parents’ nationality appeared to have a statistically significant effect on their children’s scaling experience. In addition, it was confirmed that the experience of oral health education had a significant effect. @*Conclusion@#Cultural heterogeneity and the lack of adequate language ability of immigrants affects health behavior and medical accessibility. Therefore, children from multicultural families are more likely to be exposed to unhealthy environments compared to the children of native Korean families. Based on an understanding of the socioeconomic multicultural background of individuals, education and public policy should be prepared to improve the awareness for the need for preventive oral health and provide unhindered accessibility to dental services.

Study of Clinical Practice Standardization in Dental Hygiene / 치위생과학회지

There are 82 dental hygiene departments and clinical training institutes across the country with a very wide range of clinical practice content and evaluation methods, making standardization difficult. Therefore, there is a need to establish a standard protocol outlining clinical practice content and evaluation methods for systematic and efficient operation of clinical practice. Thus, this study attempted to propose such a protocol for standardization of dental hygiene clinical practice in dental clinics and hospitals to examine the contents of clinical practice by reviewing relevant literature, and relating it to professional practice within the dental hygienic curriculum to facilitate enhancement of expertise. Clinical practice content was extracted from 74 cases, and was consisted of classifying mandatory and optional clinical practice, training time, and activity methods for each component. To standardize effective clinical practice, it is necessary to organize the components acquired in the course of clinical dentistry training in line with their arrangement on each university's curriculum, in order to learn all components step by step. To do this, it is necessary to present a standardized clinical practice protocol and a organic cooperation between educational institutions and clinical training institutions.

Effects of Empathic Ability and Campus Life Stress on Stress Coping Behaviors in Dental Hygiene Students / 치위생과학회지

The purpose of this study was to investigate the effect of empathic ability and campus life stress on the stress coping behaviors among 395 dental hygiene students. The analysis was performed using PASW Statistics ver. 18.0, and the following conclusions were obtained. The empathic concern factor was the highest in the subscale of empathic ability (3.60). The interpersonal relationship stress was 1.65 and the task-related stress was 2.72. The stress coping behaviors were the highest among the sub-domains, with 3.69 for wishful thinking. The differences of stress coping behaviors according to general characteristics were as follows. The lower the age and grade, the higher the problem-focused coping; when they were religious there was a high pursuit of seeking social support. When they were satisfied with their economic level, wishful thinking was high. There was a low negative correlation between empathic concern and interpersonal relationship stress in campus life (p<0.01). There was a positive correlation between personal distress and task-related stress (p<0.001). The relationship between empathic ability and stress coping behaviors was most associated with personal distress and wishful thinking. Among the sub-domains of stress coping behaviors, factors that have a common impact on personal distress and seeking social support are viewpoint acceptance. Factors supporting emotional focus and wishful thinking were task-related stress. Dental hygiene students are not able to completely eliminate the stress that they are actually under. However, as the research results show, it is necessary to use stress coping techniques to cope effectively with individual tendencies and situations, and to improve the ability to sympathize with another individual.

Understanding of Cementum Formation by the Wnt/β-Catenin Signaling / 치위생과학회지

Periodontal disease is one of the major dental diseases. Currently, various methods are used for healing and successful regeneration of periodontal tissue damaged by periodontal disease. The periodontal ligament and alveolar bone have received considerable interest for use in periodontal tissue regeneration and induction. However, as the functions of the factors required for tooth attachment and key regulatory factors for periodontal tissue regeneration in the cementum have recently been identified, interest in cementum formation and regeneration has increased. Dental cementum forms in the late phase of tooth development because of the reciprocal regulatory interaction between cervical loop epithelial cells and surrounding mesenchymal cells, which is regulated by various gene signaling networks. Many attempts have been made to understand the regulatory factors and cellular and molecular mechanisms associated with new cementum formation. In this paper, we reviewed the study outcomes to date on the regulatory factors that induce cementum formation and regeneration, focusing on understanding the roles and functions of Wnt signaling in the regulation of cementum formation. In addition, we aimed to obtain information on the useful reciprocal regulatory factors that mediate cementum formation and regeneration through a series of molecular mechanisms.

Requirement of Smad4-mediated signaling in odontoblast differentiation and dentin matrix formation / 대한해부학회지

Dentin is the major part of tooth and formed by odontoblasts. Under the influence of the inner enamel epithelium, odontoblasts differentiate from ectomesenchymal cells of the dental papilla and secrete pre-dentin which then undergo mineralization into dentin. Transforming growth factor-beta (TGF-β)/bone morphogenetic protein (BMP) signaling is essential for dentinogenesis; however, the precise molecular mechanisms remain unclear. To understand the role of TGF-β/BMP signaling in odontoblast differentiation and dentin formation, we generated mice with conditional ablation of Smad4, a key intracellular mediator of TGF-β/BMP signaling, using Osr2 or OC-Cre mice. Here we found the molars of Osr2(Cre)Smad4 mutant mice exhibited impaired odontoblast differentiation, and normal dentin was replaced by ectopic bone-like structure. In Osr2(Cre)Smad4 mutant mice, cell polarity of odontoblast was lost, and the thickness of crown dentin was decreased in later stage compared to wild type. Moreover, the root dentin was also impaired and showed ectopic bone-like structure similar to Osr2(Cre)Smad4 mutant mice. Taken together, our results suggest that Smad4-dependent TGF-β/BMP signaling plays a critical role in odontoblast differentiation and dentin formation during tooth development.

Recent Advances in Skeletal Muscle Stem Cells for Duchenne Muscular Dystrophy Treatment / 한양의대학술지

Muscle stem cells, which are known as satellite cells have heterogeneous components of committed myogenic progenitors, non-committed satellite cells, and mesenchymal stem cells. This distinguishing organization of self-renewal and differentiation capacities encourages the remarkable regenerative ability of skeletal muscles. Lately it has been proved that the satellite cell is the derivation of muscle regeneration and with the self-renew function, it roles as a true muscle stem cell. Therefore, stem cell therapy using satellite cells is considered to be ideal therapy for muscular dystrophies, which is deficient in specific muscle protein and causes muscle degeneration. Especially, Duchenne Muscular Dystrophy (DMD), which is caused by mutations at the dystrophin gene, has been targeted by much research. In this article the satellite cell characteristics, regulation of cell function, and stem cell therapy for DMD and the present progressive clinical trials will be reviewed.

Effects of Sodium Citrate on Salt Sensitivity and Kidney Injury in Chronic Renal Failure

Metabolic acidosis, which is observed in salt-sensitive hypertension, is also associated with kidney injury. Alkali therapy in chronic renal failure (CRF) may ameliorate the progression of kidney disease; however, few studies have examined the effects of alkali therapy on salt sensitivity and kidney injury in CRF. We randomly administered standard diet (SD), sodium chloride with 20% casein diet (NACL), or sodium citrate with 20% casein diet (NACT) to Sprague-Dawley rats after a CRF or a sham operation. Four weeks after 5/6 nephrectomy, serum bicarbonate levels were higher in the NACT-treated group. On the pressure-natriuresis curve, NACT-treated CRF rats were more salt-resistant than NACL-treated CRF rats. Additionally, the NACT-treated CRF group showed less tubulointerstitial damage than the NACL-treated CRF group. The expression and immunoreactivity of NHE3 in the kidney in the NACT-treated CRF group were lower than those in the NACL-treated CRF group. We observed that dietary NACT as alkali therapy in CRF might improve the altered salt-sensitivity and ameliorate the progression of kidney injury compared to the NACL diet, which may be related to reduced renal NHE3 expression.

Shigella flexneri Inhibits Intestinal Inflammation by Modulation of Host Sphingosine-1-Phosphate in Mice

Infection with invasive Shigella species results in intestinal inflammation in humans but no symptoms in adult mice. To investigate why adult mice are resistant to invasive shigellae, 6~8-week-old mice were infected orally with S. flexneri 5a. Shigellae successfully colonized the small and large intestines. Mild cell death was seen but no inflammation. The infected bacteria were cleared 24 hours later. Microarray analysis of infected intestinal tissue showed that several genes that are involved with the sphingosine-1-phosphate (S1P) signaling pathway, a lipid mediator which mediates immune responses, were altered significantly. Shigella infection of a human intestinal cell line modulated host S1P-related genes to reduce S1P levels. In addition, co-administration of S1P with shigellae could induce inflammatory responses in the gut. Here we propose that Shigella species have evasion mechanisms that dampen host inflammatory responses by lowering host S1P levels in the gut of adult mice.

A Waterborne Outbreak and Detection of Cryptosporidium Oocysts in Drinking Water of an Older High-Rise Apartment Complex in Seoul

From May to June 2012, a waterborne outbreak of 124 cases of cryptosporidiosis occurred in the plumbing systems of an older high-rise apartment complex in Seoul, Republic of Korea. The residents of this apartment complex had symptoms of watery diarrhea and vomiting. Tap water samples in the apartment complex and its adjacent buildings were collected and tested for 57 parameters under the Korean Drinking Water Standards and for additional 11 microbiological parameters. The microbiological parameters included total colony counts, Clostridium perfringens, Enterococcus, fecal streptococcus, Salmonella, Shigella, Pseudomonas aeruginosa, Cryptosporidium oocysts, Giardia cysts, total culturable viruses, and Norovirus. While the tap water samples of the adjacent buildings complied with the Korean Drinking Water Standards for all parameters, fecal bacteria and Cryptosporidium oocysts were detected in the tap water samples of the outbreak apartment complex. It turned out that the agent of the disease was Cryptosporidium parvum. The drinking water was polluted with sewage from a septic tank in the apartment complex. To remove C. parvum oocysts, we conducted physical processes of cleaning the water storage tanks, flushing the indoor pipes, and replacing old pipes with new ones. Finally we restored the clean drinking water to the apartment complex after identification of no oocysts.

Cholinesterase Activity in the Dental Epithelium of Hamsters During Tooth Development

Cholinesterase (ChE) is one of the most ubiquitous enzymes and in addition to its well characterized catalytic function, the morphogenetic involvement of ChE has also been demonstrated in neuronal tissues and in non-neuronal tissues such as bone and cartilage. We have previously reported that during mouse tooth development, acetylcholinesterase (AChE) activity is dynamically localized in the dental epithelium and its derivatives whereas butyrylcholinesterase (BuChE) activity is localized in the dental follicles. To test the functional conservation of ChE in tooth morphogenesis among different species, we performed cholinesterase histochemistry following the use of specific inhibitors of developing molar and incisors in the hamster from embryonic day 11 (E11) to postnatal day 1 (P1). In the developing molar in hamster, the localization of ChE activity was found to be very similar to that of the mouse. At the bud stage, no ChE activity was found in the tooth buds, but was first detectable in the dental epithelium and dental follicles at the cap and bell stages. AChE activity was found to be principally localized in the dental epithelium whereas BuChE activity was observed in the dental follicle. In contrast to the ChE activity in the molars, BuChE activity was specifically observed in the secretory ameloblasts of the incisors, whilst no AChE activity was found in the dental epithelium of incisors. The subtype and localization of ChE activity in the dental epithelium of the incisor thus differed from those of the molar in hamster. In addition, these patterns also differed from the ChE activity in the mouse incisor. These results strongly suggest that ChE may play roles in the differentiation of the dental epithelium and dental follicle in hamster, and that morphogenetic subtypes of ChE may be variable among species and tooth types.

Evaluation of Anti-dsDNA Antibody Tests: Crithidia luciliae Immunofluorescence Test, Immunoblot, Enzyme-linked Immunosorbent Assay, Chemiluminescence Immunoassay / 대한진단검사의학회지

BACKGROUND: Anti-double stranded DNA antibody (anti-dsDNA) test is useful for the diagnosis and monitoring of systemic lupus erythematosus (SLE). Although several methods are available, none of them is completely satisfactory and differences among them have been reported. We evaluated the diagnostic performance of 6 commercial kits for anti-dsDNA detection. METHODS: A total of 142 sera (SLE [N=74], other systemic rheumatic diseases [N=50], other diseases [N=18]) were tested by 6 different assay kits using different antigenic sources of DNA: Crithidia luciliae immunofluorescence test (CLIFT), salmon testes (immunoblot, IB), human (ELISA I), salmon testes with nucleosome linker (ELISA II), plasmid (ELISA III), and synthetic oligonucleotides (chemiluminescence immunoassay, CLIA). RESULTS: With manufacturers' cut-off values, 6 test kits showed sensitivities of 55.4-91.9%. ELISA I had a greater sensitivity than the other five assays (P0.05). With cut-off values set at 95% of specificity, ELISA II had a higher sensitivity than ELISA III (63.5% vs. 41.9%, P<0.05). IB had poor concordance rates with other assays (42.0-65.0%). Pearson correlation coefficients among 4 quantitative assays were 0.667-0.798. CONCLUSIONS: Six different assays showed various performances depending on the methods and cut-off values used. Except IB, the other five assays can be used for the detection of anti-dsDNA.

Update in Tissue Engineering Methods for Meniscal Tear of knee Joint / 대한정형외과연구학회지

Meniscal tear of knee joint has been known to be one of the most important risk factors to cause knee osteoarthritis. For meniscal tear, in vascular peripheral zone meniscal repair for healing is recommended to preserve knee articular cartilage and in avascular central zone it is recommended partial meniscectomy that preserves intact meniscal rim as much as possible. Recent strategy for meniscal lesion has been established from meniscectomy to meniscal repair as the role of meniscus for preserving articular cartilage has proved to be critical. Even after total meniscectomy, the efforts to preserve meniscus do not decrease and in these cases, meniscal allograft is transplanted to meniscal deficient knee. Although there are so many methods to preserve meniscus, the clinical results are doubtful about cartilage degeneration due to low regenerative potency of meniscus. Nowdays, tissue engineering is reported to be promising treatment modality for not only stimulating lesion healing but also replacing entire meniscus by tissue engineered prosthesis. The authors introduced recent tissue engineering methods for healing torn meniscus and total replacement of meniscus with respect to substituting cells and stimulating growth factors, scaffolds for meniscal regeneration, tissue engineering for meniscal healing, meniscal prosthesis.

In Vivo Biomechanics Using Dual Orthogonal Fluoroscopy after Posterior Stabilized Total Knee Arthroplasty / 대한정형외과연구학회지

This study investigated the six degrees of freedom (DOF) kinematics and three-dimensional (3D) contact during kneeling after total knee replacement arthroplasty. A total of 16 South Korean female patients (22 knees) after posteriorly stabilized (PS) TKA (LPS-Flex) performed by a single surgeon were randomly recruited. The patients were imaged using a dual fluoroscopic technique while they were kneeling from initial to maximum flexion. The acquired images and 3D models were then used to recreate the in vivo pose of the components Patients flexed their knee, on average, from 107.3degrees to 128.0degrees during the kneeling activity. Changes in kinematics included proximal, medial, posterior translation and varus rotation. Articular contact moved posteriorly by 5.9 mm and 6.4 mm in the medial and lateral compartments, respectively. Contact also moved medially by 3.2 mm and 5.8 mm in the medial and lateral compartments. A decrease in articular contact was observed in both condyles, and lateral condylar lift-off increased with flexion (P=0.0001). The tibiofemoral and cam/post articular contact data acquired in this study further suggest that kneeling may be performed by patients after clinically successful PS TKA who feel comfortable with activity and are free of

Shear bond strength of brackets bonded with different self etching primers / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the clinical usefulness of 4 self etching primers by measuring the shear bond strength of orthodontic brackets and examining the failure pattern of bracket-tooth interfaces. METHODS: Seventy-five, defect-free, premolars were randomly assigned into five groups: control group (37% phosphoric acid + Transbond XT primer) and self etching primer treated groups (Transbond Plus self etching primer, Unifil bond, Clearfil SE bond, and Adhese). The shear bond strength was measured with a universal testing machine and the amount of residual adhesive remaining on the brackets after debonding was assessed by the adhesive remnant index (ARI). RESULTS: The results showed that the groups conditioned with self etching primer had significantly lower shear bond strength than the control group (p 0.05). Evaluation of the ARI scores indicated there was less resin remnant on the teeth in the groups conditioned with self etching primers, although not statistically significant. CONCLUSION: The results of this study suggest that all four of the self etching primers have shown acceptable bond strength for clinical use.

Expression of Uchl1 in the Dental Epithelium during Mouse Tooth Development / 체질인류학회지

Tooth is formed by the reciprocal interactions between the ectoderm and ectomesenchyme derived from neural crest. It has not been clear that neuronal factors involved in the morphogenesis and differentiation of tooth. To identify the roles of neuronal factors during the tooth development, the expression patterns and localization of Uchl1 were investigated in the developing mouse tooth germ by in situ hybridization and immunohistochemistry. Uchl1 transcripts were weakly expressed in the oral epithelium and dental lamina at bud stage. However, expression of Uchl1 was not found in the oral epithelium from cap stage and observed in the inner enamel epithelium, stellate reticulum and dental papilla. From the bell stage, Uchl1 was expressed in the inner enamel epithelium and ameloblasts. Uchl1, was appeared to be localized in the inner enamel epithelium and differentiating ameloblasts of molar and incisors at neonates. Uchl1 was localized strongly in the fully differentiated ameloblasts and adjacent papillary layer whereas localized weakly in the odontoblasts of the molar at postnatal day 5. From these results, Uchl1 was expressed and localized in the differentiating dental epithelium and ameloblasts during tooth development. The results suggest that neuronal protein, Uchl1 may play roles in the histo- and cyto-differentiation of non-neuronal dental epithelium.

PDA Clipping by Using 2mm Thoracoscope / 대한흉부외과학회지

Patent ductus arteriosus(PDA) is a common congenital heart disease encountered in premature neonates infants and children. Patent ductus arteriosus was the first surgically managed congenital heart disease,. Classic surgical interruption of patent ducturs arteriosus was partially replaced by a transcatheter endovascular closure, After a 5-7 mm video-assisted thoracoscopic interruption of the patent ductus arteriosus first applied in 1991, this minimally invasive technique came to be used in many centers, Video-assisted thoracoscopic interruption of the patent ductus arteriosus is feasible in low-weight infants whereas transcatheter endovascular closure of the ductus is usually not possible. We experienced successful outcome for the treatment of patent ductus arteriosus with 2 mm video-assisted thoracoscopic titanium clipping, We believed that this technique is a simple safe and rapid method for closure of the patent arteriosus.

Change of both Palmar Temperature During Thoracoscopic Sympathicotomy for Palmar Hyperhidrosis / 대한흉부외과학회지

BACKGROUND: Thoracoscopic T2 sympathicotomy is an effective method for the treatment of palmar hyperhidrosis. Not only are the symptoms of hyperhidrosis abolished but also the temperature of the ipsilateral palm is elevated due to the sympatholytic vasodilation after the completion of the sympathicotomy on the first side. However little is known about the temperature changes in the contralateral palm. This study was performed to evaluate the changes in both palmar temperatures during the thoracoscopic T2 sympathicotomy for palmar hyperhidrosis. MATERIAL AND METHOD: Thoracoscopic T2 sympathicotomy was performed in 15 patients with primary palmar hyperhidrosis. Surface temperatures of both palms were monitored continuously and were recorded simultaneously during the 7 different stages of the operation. RESULT: When T2 sympathicotomy was performed on the first(left) side, an ipsilateral increase with a contralateral decrease of temperature was observed. The difference in the temperature of both palms was greatest just before the sympathicotomy on the contralateral(right) side(Lt. 34.6+/-0.9degree C vs. Rt. 31.6+/-1.3degree C, p<0.0001). After the sympathicotomy on the second(right) side, temperature of the right palm was elevated. The difference in the temperature of both palms was abolished at the end of the operation(Lt.34.7+/-0.9degree C vs. Rt.34.4+/-1.0degree C, P=0.415). CONCLUSION: When T2 sympathicotomy was performed on the first side, an ipsilateral palmar temperature increased due to the sympatholytic vasodilation. However contralateral palmar temperature decreased due to a vasoconstriction. Although the mechanism of vasoconstriction is still unknown, it is postulated that there may be a cross- inhibitory effect by the post-ganglionic neurons innervating blood vessels of the palm.

Short and Intermediate Term Results of the ATS Heart Valve Replacement / 대한흉부외과학회지

BACKGROUND: ATS mechanical valve is a recently introduced pyrolytic carbon bileaflet prosthesis. This report is to evaluate the results of hemodynamic and anticoagulant therapy after ATS valve replacement. MATERIAL AND METHOD: From May 1995 to October 1998, 53 patients received 65 ATS prosthesis; 38 Mitral(27-33 mm), 27 Aortic(19-25 mm). 2 CABGs and 5 Tricuspid annuloplasty were taken concomitantly. The follow up period was 769 patient-months(mean 16.2+/-10.0), varied from 1 month to 39 months with 92.5% follow up rate. All patients were evaluated with Doppler echocardiography, 7-14 days after operation. RESULT: NYHA functional class was improved significantly, from 2.6+/-0.8 preoperatively to 1.3+/-0.4 postoperatively. The average value of peak and mean transvalvular pressure gradients were 25.7+/-13.5 mmHg, 12.7+/-8.3 mmHg in aortic position. In the mitral position, the average values of peak and mean transvalvular pressure gradient and valve area were 5.9+/-2.5 mmHg, 3.1+/-0.8 mmHg and 2.9+/-0.5 cm2, respectively. In the anticoagulant therapy, mean INR was 2.5+/-0.6 in mitral valve replacement and 1.9+/-0.5 in aortic valve replacement. There was no anticoagulant related complication. During that period, there were 3 hospital death(5.9%) and 1 late death(1.9%). CONCLUSION: The early clinical results of the ATS heart valve replacement is quite satisfactory, and low target INR reginmen is safe. And long term follow of hemodynamic characteristics is also necessary.

Analysis of Age-related Distribution of the Tracheal Diameter and Cross-sectional Area Among Koreans: Compuerized Tomographic Measurement / 대한흉부외과학회지

INTRODUCTION: Understanding the normal distribution of the tracheal diameter and crross- sectional area is one of the key elements in the management of various tracheal pathologies or tracheal reconstruction for the patients in growing age. However, data for Korean standard has been lacking. This study was designed to analyze retrospectively the distribution of tracheal diameter and cross-sectional area in young Koreans, which can afford fundamental data for the management of tracheal diseases. MATERIAL AND METHOD: Of the patients who underwent computerized tomogram of the chest between May 1996 and August 1998, one hundred six young patients(age range: 0-20 years) were included. Patients with any conditions which might affect the tracheal cross-sectional area or diameter, such as tracheal disease, previous operation, mediastinal tumor, or obstructive lung disease were excluded from the study. Gender distribution was 69 males and 37 females. Tracheal diameters, anterior-posterior and transverse, were measured at the level of the thoracic inlet(level I) and the aortic arch(level II). Types of the trachea were divided into round, oval, or horseshoe shaped on cross-sectional view, and the dimension was calculated by using the equation of A=1/4(pi)ab(A; area, (pi); 3.14, a; anterior-posterior diameter, b; transverse diameter). We analyzed the distribution of the diameter at each level and compared the cross-sectional area with respect to age and gender. A p-value lower than 0.05 wa considered significant. RESULT: The trachea of patients less than 5 years old were round in shape at both of level I and II, and no differences in cross-sectional area was observed between the levels(p=NS). As the age increased, the trachea become oval in shape at level I while it remained round in shape at level II(p=0.020). The tracheal diameter and cross-sectional area increased as the age increased with a linear correlation(r>0.9). In patients less than 5 years of age, female patients showed larger cross-sectional area than male patients (p=0.020), and it was reversed in patients older than 15 years of age(p=0.002). CONCLUSION: From the above results, we suggest chest computerized tomogram as a safe and reliable tool in measuring the tracheal diameter and cross-sectional area. We also provide the data as a standard for distribution of the tracheal diameter and cross-sectional area in young Korean population.