• Imaging Science in Dentistry
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• v.52 no.4
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• pp.393-398
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• 2022

Purpose: This study proposed a generative adversarial network (GAN) model for T2-weighted image (WI) synthesis from proton density (PD)-WI in a temporomandibular joint(TMJ) magnetic resonance imaging (MRI) protocol. Materials and Methods: From January to November 2019, MRI scans for TMJ were reviewed and 308 imaging sets were collected. For training, 277 pairs of PD- and T2-WI sagittal TMJ images were used. Transfer learning of the pix2pix GAN model was utilized to generate T2-WI from PD-WI. Model performance was evaluated with the structural similarity index map (SSIM) and peak signal-to-noise ratio (PSNR) indices for 31 predicted T2-WI (pT2). The disc position was clinically diagnosed as anterior disc displacement with or without reduction, and joint effusion as present or absent. The true T2-WI-based diagnosis was regarded as the gold standard, to which pT2-based diagnoses were compared using Cohen's ĸ coefficient. Results: The mean SSIM and PSNR values were 0.4781(±0.0522) and 21.30(±1.51) dB, respectively. The pT2 protocol showed almost perfect agreement(ĸ=0.81) with the gold standard for disc position. The number of discordant cases was higher for normal disc position (17%) than for anterior displacement with reduction (2%) or without reduction (10%). The effusion diagnosis also showed almost perfect agreement(ĸ=0.88), with higher concordance for the presence (85%) than for the absence (77%) of effusion. Conclusion: The application of pT2 images for a TMJ MRI protocol useful for diagnosis, although the image quality of pT2 was not fully satisfactory. Further research is expected to enhance pT2 quality.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.22-30
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• 2024

Objective : This study aimed to determine the frequency of paraclinoid aneurysms among ruptured cerebral aneurysms and compare paraclinoid aneurysms with other aneurysms to clarify the characteristics of ruptured paraclinoid aneurysms. Methods : This study included 970 ruptured cerebral aneurysms treated at our hospital between 2003 and 2020. Results : There were 15 cases (1.3%) of paraclinoid aneurysms with maximum diameters of 5-22 mm (mean±standard deviation [SD], 11.6±5.4 mm). Treatment consisted of clipping in four patients and endovascular treatment in 11. Factors significantly different in multivariate analysis for paraclinoid aneurysms compared with those for other aneurysms were a history of hypertension (odds ratio [OR], 1.2-9.8; p=0.021) and aneurysm ≥10 mm (OR, 7.5-390.3; p<0.001). The sites of paraclinoid aneurysm were ophthalmic artery type in nine patients, anterior wall type in five, medial wall type in one, and ventral wall type in zero. The medial wall type (22 mm) was significantly larger than the ophthalmic artery type (mean±SD, 7.2±2.0 mm) (p=0.003), and the anterior wall type (mean±SD, 12.2±4.8 mm) was significantly larger than the ophthalmic artery type (p=0.024). Conclusion : This study showed a low frequency of paraclinoid aneurysms among ruptured cerebral aneurysms. Most were upward-facing with relatively large aneurysms, and no aneurysms were smaller than 5 mm. With recent advances in endovascular treatment devices, paraclinoid aneurysms are easily treatable. However, the treatment indication of each paraclinoid aneurysm should be carefully considered.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.67-74
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• 2012

Purpose: The purpose of this study to evaluate visual acuity and refractive state and measure and analyze the components of eye's optical system in children and teenagers. Methods: With subjects of 124 (230 eyes) children and teenagers who had no eye diseases, correlation between the correlation between refractive errors and component's of eye's optical system was investigated. The spherical equivalent power of cycloplegic clinical refraction or manifest clinical refraction(SE), corneal power(CP), corneal radius(CR), axial length(AL), anterior chamber depth(ACD) and axial length to corneal radius (AL/CR) ratio were measured and analysed. Results: the SE was negatively correlated with the AL(r = -0.80, p = 0.00), the ACD(r = -0.35, p = 0.00) and the CR(r = -0.11, p=0.00) and positively correlated with the CP(r = +0.11, p=0.00). The AL was positively correlated with the AL/CR ratio (r = +0.84, p = 0.00), the ACD(r = +0.47, p=0.00) and the CR(r = +0.38, p = 0.00) and negatively correlated with the CP(r = -0.38, p=0.00). The CR was negatively correlated with CP(r = -1.00, p = 0.00), the AL/CR ratio(r = -0.19, p = 0.00) and the ACD(r = -0.06, p = 0.39). The CP was positively correlated with the AL/CR ratio(r = +0.19, p = 0.00) and the ACD(r = +0.06, p = 0.39). The ACD was positively correlated with the AL/CR ratio(r = 0.53, p = 0.00). Conclusions: the highest change of refractive errors was shown that the AL/CR ratio was a very important indicator for diagnosing the refractive errors of the children and teenagers.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.3
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• pp.217-227
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• 1992

The purpose of this paper is to investigate changes in soft tissue in 22 patients treated by vertical ramus osteotomy and sagittal split ramus osteotomy for the correction of mandibular prognathism. 22 individuals, 12 males and 10 females, were selected from the patients with mandibular prognathism at the Department of Oral and Maxillofacial Surgery, Colledge of Dentistry, Kyung Hee University. Patient were analyzed with cephalogram taken 1 week before and at least 6 weeks after surgery under the same condition. Measurements were made constructed hard tissue and sop tissue points located on each before-and-after film tracing. Comparision were made of these figures to estimate the amount that the soft tissue followed the hard tissue structures in each surgical procedure : ratio of sop and hard tissue changes were formulated. The results were as follows. 1. The horizontal changes of Pogs and Bs as a ratio of the horizontal changes of Pog and B point were 1.02 and 1.16 respectively. 2. One millimeter of posterior changes at Pog resulted in 0.86mm of posterior change at Li and 0.09mm of posterior change at Ls. The greatest amount of sop tissue change occurred at Pogs, with substantially less posterior displacement at Bs, even less at Li and at least at Ls. 3. The ratio of LI to Li was 1:0.81 and the ratio of LI to Ls was not significant.(1 : 0.17) 4. The ULA(Cm-Sn-Ls) and the relative lower lip projection (LLP) was incnease4 but the relative upper lip projection (ULP) was slightly decreased 5. The angular change of the upper lip inclined angle (Ls-Sn/ANS-PNS) and lower lip inclined angle(Li-Pogs/Me-Go) expressed as a ratio of the posterior change of Pog were 0.57 and 0.20 respectively. 6. The ratio of the lower anterior facial height change of the soft tissue(Sn-Mes) to the hard tissue(ANS-Gn) were 0.78 and and the ratio of vertical height changes of the hard tissue and sop tissue to the posterior change of the Pog were 0.18 and 0.19 respectively. 7. The sop tissue angular change of facial convexity(G-Sn-Pogs) expressed as a ratio of the angular change of the hard tissue angle of facial convexity(N-A-Pog) was 1.24.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.290-298
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• 2018

This study aimed to evaluate surface morphology and resin tag penetration of resin infiltration into primary anterior teeth after enamel deproteinization with sodium hypochlorite (NaOCl) prior to phosphoric acid ($H_3PO_4$) etching. Ninety primary anterior teeth with non-cavitated caries lesion were devided five groups according to enamel pretreatment as follows, group I-15% hydrochloric acid (HCl) 2min. ; group II-5.25% NaOCl 1min., 35% $H_3PO_4$ 1min. ; group III-5.25% NaOCl 2min., 35% $H_3PO_4$ 1min. ; group IV-5.25% NaOCl 1min., 35% $H_3PO_4$ 2min. ; group V-5.25% NaOCl 2min., 35% $H_3PO_4$ 2min. Fifteen teeth were examined etched surface structure using field emission-scanning electron microscope. Seventy five teeth were infiltrated with resin, maximum penetration depth and percentage penetration were analysed using dual fluorescence confocal microscopy. As the application time of NaOCl increased, ratio of enamel type I, II were increased. Percentage penetration (PP) was higher in group V than group II, III (p < 0.05). PP of group IV, V did not show any differences. Non-cavitated caries of primary anterior teeth can be treated with resin infiltration. Enamel deproteinization with NaOCl prior to 35% $H_3PO_4$ etching could be an alternative of 15% HCl etching in resin infiltration.

• The Korean Journal of Mycology
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• v.9 no.4
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• pp.199-207
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• 1981

This investigation was undertaken to establish more accurately the clinical features of the desease as seen in Korea, and to investigate susceptibility factors and to study the ecology of P. orbiculare in this condition. All of 50 new patients with Tinea versicolor attending the Ewha University Hospital, during a period of 6 months were studied personally. 1. Clinical feature: The sex ratio of the whole series was 32 males to 18 females. Twenty of 50 patients (40%) were between the age of 20 to 29 years. The duration of disease was more than 4 months in 37 of 50 patients (74%). The cases of first onset in June, July and August were 33 of 50 patients (66%). Whereas, the developed in December, January and February were only 3 of 50 patients (6%). Seasonal fluctuation was remarkable in 16 of 25 patients (66.7%) who had the duration of more than 1 year. The course of disease was rapid in 33 of 50 patients (66%) and slow in 9 of 50 patients (18%). Thirty-three of 50 patients (66%) had not any subjective symptoms. Thirteen patients (26%) had mild itching sensation and 4 patients (8%) had severe itching. The frequency of the first affected were neck (27.4%), axilla (19.2%) anterior chest (15.0%) and groin (11.0%). 7) Hyperpigmented lesions were observed in 35 of 50 patients (70%) and hypopigmented lesions were observed in 11 of 50 patients (22%). Skin lesions were noticed mainly in the anterior chest, neck, back and axilla, and more severe in the anterior chest, back and abdomen than other areas. Tinea versicolor was particularly prevalent in those persons who had occupations of mental work and who perspired every day or every 2 or 3 days. A positive family history of Tinea versicolor was obtained in 7 of 50 patients (14%). Fourteen of 50 patients (28%) had association with superficial fungal infections. 2. Mycological features: Typical appearance of M. furfur was observed in all scrapings from 25 lesions and only 3 scrapings from 20 clinically skin of the patients. P. orbiculare was seen on direct examination of scrapings from 24 of 25 skin lesions, from 19 of 20. clinically normal skin of patients and from 18 of 29 control normal skin. The quantity of P. orbiculare was greater in skin lesions and clinically normal skin area than in control normal skin surfaces.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.550-555
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• 2009

Distribution of orthodontic patients in pediatric dental clinics has increased recently. So it is worth to study about the present status of orthodontic patients in pediatric dental clinics. The purpose of this study was to recognize the characteristics and orthodontic patterns of orthodontic patients in pediatric dental clinics. The material consisted of distribution and orthodontic analysis records of 792 new patients in the department of pediatric dentistry, Seoul National University Dental Hospital, from 2006 to 2008. Results were as follows 1. In age distribution, 8-year-olds group comprised 22%, 7-year-olds 19%, 9-year-olds 16%, 10-year olds 15%, 11-year-olds 11%, and other age groups comprised 18%. 2. In skeletal patterns, skeletal class I patients comprised 52%, class II 29%, and class III 19%. 3. In vertical facial types mesofacial comprised 41%, brachyfacial 35%, and dolichofacial 24%. 4. Out of 792 patients 218 patients(28%) showed anterior cross-bite, and the occurrence ratio of anterior cross-bite increased as the age decreased.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.404-411
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• 2022

The patient in this case was an 80-year-old female who had lost #16, 13, 26, 37, 36, 35, 44, 45, 46, 47 teeth. The patient showed loss of posterior support, loss of vertical dimension of occlusion, and deep anterior overbite. Her chief complaint was esthetic and functional discomfort. She wanted to restore normal facial aesthetic shape and masticatory function through prosthetic treatment. Clinical evaluation, radiographic examinations, and facial and oral analysis were performed. Interocclusal rest space was excessive than the average. Distance between labial vestibules and zenith of central incisors, and lower facial ratio were below the average. Taken together, occlusal rehabilitation was determined through increasing 4 mm of vertical dimension on premolars. In this case, a patient who lacked restoration space with deep bite in the anterior region due to loss of the posterior teeth support restored a stable occlusal relationship and harmonious anterior and lateral guidance through fixed and removable prosthesis with increased vertical dimension.

• Physical Therapy Korea
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• v.12 no.3
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• pp.22-30
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• 2005

This study was designed to identify the effect of various decline boards and postures of lower extremities on surface electromyographic (EMG) activity of knee muscles during isometric single-leg decline squat exercises. The subjects were twenty young male adults who had not experienced any knee injury and their Q-angles were within a normal range. They were asked to perform single-leg decline squat exercises in five various conditions. The EMG activities of the gluteus maximus (GM), vastus lateralis (VL), vastus medialis (VMO), tibialis anterior (TA), and gastrocnemius (GCM) muscles were recorded in five various single-leg decline squat exercises by surface electrodes and normalized by maximal voluntary isometric contraction (MVIC) values. The normalized EMG activity levels were compared using one-way ANOVA with repeated measures. The results of this study were as follows: 1) Exercises 2 and 4 produced significantly greater EMG activity of VMO than did exercise 1 ($p_{adj}$<.05/10), 2) The VMO/VL ratio of EMG activity of exercise 4 was the highest, producing a significantly greater ratio than exercise 1 ($p_{adj}$<.05/10). These results show that single-leg lateral oblique decline squat exercise is the best exercise for selective strengthening of VMO, and the posture of the contralateral leg does also affect strengthening of VMO, but we'll need to research patellofemoral joint compression for clinical application of single-leg lateral oblique decline squat exercises.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.318-328
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• 1998

The aqua-acupuncture blended with liquid medicine and acupuncture is known to be effective in treating various medical disorders. This study used gallbladders of bear (WoongDam, WD, Ursus arctos Linne) and pig(JeoDam, JD, Sus scrofa domestica Brisson) plus the stones from the ox gallbladder(WooHwang, WH, Bos taurus var, domesticus Gmelin) to produce the liquid medicine. For the acupuncture, acupoint of ST -36 which is located one finger breadth from the anterior crest of the tibia was selected. There were a couple of purposes in this experiment. First, the relationship between aqua-acupuncture and gastric activity was scrutinized. Secondly, the possibility of pig gallbladder as an alternative organ to bear gallbladder for making liquid medicine was evaluated. Thirdly, different injection concentration ratio of liquid medicine was tried to figure out the optimal dosage for the aqua-acupuncture. The data of the present results indicated that the mixtures of WD + WH and JD + WH have a similar hypotonic effect on the stomach. These findings illustrated that aqua-acupuncture or hydroacupuncture showed inhibitory effect on the stomach in addition to its well-known prophylactic value. Also the possible alternative medical organ of pig gallbladder was checked out since two mixtures illustrated very similar trends in suppressing the gastric activity. The injection concentration ratio was not very different between two mixtures in terms of gastric motility except a couple of ratio. In conclusion, the aqua-acupuncture is a promising way to control the gastric activity for better medical purposes and the gallbladder of pig was assessed as a prospective one for making a liquid medicine.