• The Journal of Advanced Prosthodontics
• /
• v.14 no.2
• /
• pp.88-95
• /
• 2022

PURPOSE. This study investigated the accuracy of full-arch intraoral scans obtained by various scan strategies with the segmental scan and merge methods. MATERIALS AND METHODS. Seventy intraoral scans (seven scans per group) were performed using 10 scan strategies that differed in the segmental scan (1, 2, or 3 segments) and the scanning motion (straight, zigzag, or combined). The three-dimensional (3D) geometric accuracy of scan images was evaluated by comparison with a reference image in an image analysis software program, in terms of the arch shape discrepancies. Measurement parameters were the intermolar distance, interpremolar distance, anteroposterior distance, and global surface deviation. One-way analysis of variance and Tukey honestly significance difference post hoc tests were carried out to compare differences among the scan strategy groups (α = .05). RESULTS. The linear discrepancy values of intraoral scans were not different among scan strategies performed with the single scan and segmental scan methods. In general, differences in the scan motion did not show different accuracies, except for the intermolar distance measured under the scan conditions of a 3-segmental scan and zigzag motion. The global surface deviations were not different among all scan strategies. CONCLUSION. The segmental scan and merge methods using two scan parts appear to be reliable as an alternative to the single scan method for full-arch intraoral scans. When three segmental scans are involved, the accuracy of complete arch scan can be negatively affected.

• Journal of Pharmacopuncture
• /
• v.25 no.1
• /
• pp.46-51
• /
• 2022

Objectives: This study was performed to evaluate the skin irritation toxicity of processed sulfur. Methods: All experiments were conducted at Medvill (Korea), an institution authorized to perform non-clinical studies, under the Good Laboratory Practice (GLP) regulations. In order to investigate skin irritation toxicity of processed sulfur, we divided the back of six rabbits into two control sites and two test sites. One of each of the two control and test sites was then designated abraded sites and intact sites. In test sites, 0.5 g of processed sulfur was applied to the back of the rabbit for 24 hours, and in control sites, 0.5 g of sterile distilled water was applied in the same way. We observed and evaluated mortality, weight, general symptoms, and skin irritation toxicity. This study was conducted with the approval of the Animal Ethics Committee (Approval number: IAC2020-1549). Results: In all experiments, no dead animals were observed. In all cases, skin coloration was observed at 24 hours after processed sulfur administration. This coloration lasted up to 48 hours and is believed to be the effect of the administration of test substances. Weight measurement indicated that weight was lost 72 hours after administration in three cases, but this is considered an accidental weight change. Normal weight gain was observed in the remaining subjects. In all animals, no skin irritation toxicity was observed, and the primary irritation index (P.I.I) was calculated as 0.0 according to Draize's evaluation method. Conclusion: The above findings suggest that it is relatively safe to apply a processed sulfur to the skin. Further research on this topic is needed to provide more specific evidence.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.3
• /
• pp.150-161
• /
• 2022

PURPOSE. The purpose of the study was to assess the influence of build orientations and density of support structures on the trueness of the 3D printed removable partial denture (RPD) frameworks. MATERIALS AND METHODS. A maxillary Kennedy class III and mandibular class I casts were 3D scanned and used to design and produce two 3D virtual models of RPD frameworks. Using digital light processing (DLP) 3D printing, 47 RPD frameworks were fabricated at 3 different build orientations (100, 135 and 150-degree angles) and 2 support structure densities. All frameworks were scanned and 3D compared to the original virtual RPD models by metrology software to check 3D deviations quantitatively and qualitatively. The accuracy data were statistically analyzed using one-way ANOVA for build orientation comparison and independent sample t-test for structure density comparison at (α = .05). Points study analysis targeting RPD components and representative color maps were also studied. RESULTS. The build orientation of 135-degree angle of the maxillary frameworks showed the lowest deviation at the clasp arms of tooth 26 of the 135-degree angle group. The mandibular frameworks with 150-degree angle build orientation showed the least deviation at the rest on tooth 44 and the arm of the I-bar clasp of tooth 45. No significant difference was seen between different support structure densities. CONCLUSION. Build orientation had an influence on the accuracy of the frameworks, especially at a 135-degree angle of maxillary design and 150-degree of mandibular design. The difference in the support's density structure revealed no considerable effect on the accuracy.

• Journal of Biomedical Engineering Research
• /
• v.43 no.1
• /
• pp.27-34
• /
• 2022

Drunk driving defines a driver as unable to drive a vehicle safely due to drinking. To crack down on drunk driving, alcohol concentration evaluates through breathing and crack down on drinking using S-shaped courses. A method for assessing drunk driving without using BAC or BrAC is measurement via biosignal. Depending on the individual specificity of drinking, alcohol evaluation studies through various biosignals need to be conducted. In this study, we measure biosignals that are related to alcohol concentration, predict BrAC through SVM, and verify the effectiveness of the S-shaped course. Participants were 8 men who have a driving license. Subjects conducted a d2 test and a scenario evaluation of driving an S-shaped course when they attained BrAC's certain criteria. We utilized SVR to predict BrAC via biosignals. Statistical analysis used a one-way Anova test. Depending on the amount of drinking, there was a tendency to increase pupil size, HR, normLF, skin conductivity, body temperature, SE, and speed, while normHF tended to decrease. There was no apparent change in the respiratory rate and TN-E. The result of the D2 test tended to increase from 0.03% and decrease from 0.08%. Measured biosignals have enabled BrAC predictions using SVR models to obtain high Figs in primary and secondary cross-validations. In this study, we were able to predict BrAC through changes in biosignals and SVMs depending on alcohol concentration and verified the effectiveness of the S-shaped course drinking control method.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.5
• /
• pp.294-304
• /
• 2022

PURPOSE. The purpose of this study was to evaluate the influence of different palatal vault configurations on the accuracy and scan speed of intraoral scans (IO) of completely edentulous arches. MATERIALS AND METHODS. Three different virtual models of a completely edentulous maxillary arch with different palatal vault heights- Cl I moderate (U-shaped), Cl II deep (steep) and Cl III shallow (flat)-were digitally designed using CAD software (Meshmixer; Autodesk, USA) and 3D-printed using SLA-based 3D-printer (XFAB; DWS, Italy) (n = 30; 10 specimens per group). Each model was scanned using intraoral scanner (Trios 3; 3Shape^TM, Denmark). Scanning time was recorded for all samples. Scanning accuracy (trueness and precision) were evaluated using digital subtraction technique using Geomagic Control X v2020 (Geomagic; 3DSystems, USA). One-way analysis of variance (ANOVA) test was used to detect differences in scanning time, trueness and precision among the test groups. Statistical significance was set at α = .05. RESULTS. The scan process could not be completed for Class II group and manufacturer's recommended technique had to be modified. ANOVA revealed no statistically significant difference in trueness and precision values among the test groups (P=.959 and P=.658, respectively). Deep palatal vault (Cl II) showed significantly longer scan time compared to Cl I and III. CONCLUSION. The selection of scan protocol in complex cases such as deep palatal vault is of utmost importance. The modified, adopted longer path scan protocol of deep vault cases resulted in increased scan time when compared to the other two groups.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.4
• /
• pp.103-111
• /
• 2022

Purpose : In recent years, essential oils have been produced using natural extracts for various uses. Their functionality is currently being tested not only for cosmetics and perfumes but also for other categories of products. Therefore, this study verified their antibacterial effects on S. mutans, P. gingivalis, and L. gasseri which are the representative strains that cause oral diseases. Methods : Eighteen types of natural essential oils were made at a concentration of 50 % (v/v) using Tween 20, and their antibacterial effects were verified by applying S. mutans, P. gingivalis, and L. gasseri. The antibacterial effects were measured with the disc diffusion method. All the experiments were repeated three times, and the mean value of three measurement values for each variable was used for data analysis. A one-way analysis of variance was conducted using these mean values. Results : Of the eighteen types of essential oils tested, sixteen types showed antibacterial effects on S. mutans, and sixteen and fifteen types exhibited antibacterial effects on P. gingivalis and L. gasseri respectively. The types of essential oils with high-level antibacterial activities were geranium, may chang, and bergamot for S. mutans, lemongrass, bergamot, and eucalyptus for P. gingivalis, and lemongrass, machan, and geranium for L. gasseri in order of antibacterial effect. This result was statistically significant (p<.001). In addition, in the case of mandarin oil, it was found that there was no antibacterial activity in all three strains. Conclusion : This study proved the antibacterial activities of essential oils, which are used for various purposes in daily life, against dental caries and periodontal diseases. The study results will likely be applied to different prevention programs for oral health and broadly used to develop products such as oral care items and dentifrices.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.35 no.4
• /
• pp.37-56
• /
• 2022

Objectives: The purpose of this study is to assess the effect of electroacupuncture for treating postpartum hypogalactia. Methods: We searched 9 databases on May, 2022, which contained four English, two Chinese, one Japanese, and two Korean databases. Randomized controlled trials (RCTs) were eligible. Measurement of outcome included total effective rate, lactation amount, serum prolactin level, and degree of breast fullness. The risk of bias was assessed by two independent authors using the Cochrane risk of bias tool. Results: 101 trials were screened, 5 RCTs were finally selected. Number of participants per study ranged from 56 to 273. The treatment group was effective of improving total effective rate, lactation amount, serum prolactin level compared with control group, and the result was stastically significant. The quality of the evidence for specific comparisons ranged from low to high. Conclusions: Included studies showed that electroacupuncture on acupoints related to lactation would be effective way to increase milk supply among mothers who are suffering from postpartum hypogalactia. In the future, further high-quality RCTs are needed to prove effectiveness of electroacupuncture for relieving hypogalactia with low risk of bias.

• Journal of the Korean Society of Physical Medicine
• /
• v.18 no.1
• /
• pp.99-110
• /
• 2023

PURPOSE: This study was conducted to suggest a way to easily understand and utilize the International Classification of Functioning, Disability and Health (ICF) or Korean Standard Classification of Functioning, Disability and Health (KCF), a common and standard language related to health information. METHODS: The tools used by physical therapists to evaluate the functioning of neurological patients were collected from 10 domestic hospitals. By applying the ICF linking rule, two experts compared, analyzed, and linked the concepts in the items of the collected tools and the ICF/KCF codes. The frequency of use of the selected tool, the matching rate of the liking results of two experts, and the number of the codes linked were treated as descriptive statistics and the code set was presented as a list. RESULTS: The berg balance scale, trunk impairment scale, timed up and go test, functional ambulation category, 6 Minute walk test, manual muscle test, and range of motion measurements were the most commonly used tools for evaluating the functioning. The total number of items of the seven tools was 33, and the codes linked to the ICF/KCF were 69. Twenty-two codes were mapped, excluding duplicate codes. Ten codes in the body function, 11 codes in the activity, and one code in the environmental factor were included. CONCLUSION: The information on the development process of the code set will increase the understanding of ICF/KCF and the developed code set can conveniently be used for collecting patients' functioning information.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.8
• /
• pp.137-144
• /
• 2023

One of the methods being suggested as a way to address social issues is the utilization of big data analysis techniques. In this study, we utilized keyword network analysis and CONCOR analysis techniques to analyze the research trends on work-related musculoskeletal disorders. The findings of this study are as follows: Firstly, the number of papers on work-related musculoskeletal disorders has been consistently increasing, with an average of over 33 articles published per year since the investigation of musculoskeletal risk factors in 2003. The publication rate showed an increase from 2007 to 2009. Secondly, the frequency of the top keywords identified through text mining were as follows: work (4,940), musculoskeletal disorders (2,197), symptoms (1,836), related (1,769), musculoskeletal system (1,421). Thirdly, the CONCOR analysis resulted in the formation of four clusters: ' Musculoskeletal disorder treatment', 'Occupational health and safety management', 'Work environment assessment', and ' Workplace environment measurement'. It is expected that this study will contribute to the development of research on musculoskeletal disorders and provide various directions for future studies.

• Progress in Superconductivity and Cryogenics
• /
• v.9 no.1
• /
• pp.22-26
• /
• 2007

Superconductor is weak in AC condition. Bifilar geometry provides a solution to reduce AC loss. Bifialr geometry is piled up or wound with more than two layers. When a layer of superconductor abuts on other layers, AC loss is affected by not only self-field, but also magnetic field induced by adjacent layers. In this study, two superconductors are piled up as a series connection so that current flows in different directions. By this method, magnetic field is cancelled. If magnetic field is cancelled, AC loss is reduced. To compare AC loss with respect to piling method, we measured the AC loss difference between the case facing each other with substrate side and the case facing with YBCO side. Measured AC loss is compared with one-way current flow single layer AC loss. In addition, we analyzed how much AC loss was increased, or reduced. All results were compared with those calculated with Norris equation. By this experiment, we concluded that distance between two wires is the important cause of AC loss. The distance between two wires affects magnetic field reduction in YBCO and induced current flow on substrate side.