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Controlling transverse discrepancies is necessary to ensure stable and functional occlusion. Altered molar inclinations can camouflage the transverse relationship. The purpose of this research was to evaluate the maxillomandibular relationship of the center of resistance (CR) of the arch form created by the CR of teeth and compare these CR arch forms by their skeletal patterns.Sixty patients with minor crowding and normal posterior overjet were divided into 3 groups according to ANB angle: skeletal Class I group had ANB angle between 0° and 4° (n = 20), skeletal Class II group had ANB angle 4° (n = 20), and skeletal Class III group had ANB angle 0° (n = 20). The 3-dimensional coordinates of the CR were estimated using cone-beam computed tomography images and projected on the CR occlusal plane to obtain the 2-dimensional coordinates. The CR arch forms were constructed and evaluated using Matlab (MathWorks, Natick, Mass).On comparing maxillomandibular CR arch form widths, the maxilla was significantly larger than the mandible of the canine and first premolar. The mandible was larger in the first molar of the skeletal Class III group. The maxillomandibular CR arch form width ratios were between 0.97 and 1.35. On comparing maxillomandibular CR arch form areas, the maxilla was significantly larger than the mandible in the anterior segment, and the mandible was larger in the posterior segment. The ratios were between 0.86 and 2.25. In between-group comparison, the skeletal Class III group showed significantly greater arch forms in the mandible.CR arch forms had significant maxillomandibular differences throughout the arch. The maxillomandibular ratios could be a reference for site-specific transverse discrepancy analysis.

Objective To identify the most favorable sites that optimize the initial stability and survival rate of orthodontic mini-implants, this study measured hard and soft tissue thicknesses in the median and paramedian regions of the palate using cone-beam computed tomography (CBCT) and determined possible sex- and age-related differences in these thicknesses. Methods The study sample comprised CBCT images of 189 healthy subjects. The sample was divided into four groups according to age. A grid area was set for the measurement of hard and soft tissue thicknesses in the palate. Vertical lines were marked at intervals of 0, 1.5, and 3.0 mm lateral to the midpalatal suture, while horizontal lines were marked at 2-mm intervals up to 24 mm from the posterior margin of the incisive foramen. Measurements were made at 65 points of intersection between the horizontal and vertical lines. Results The palatal hard tissue thickness decreased from the anterior to the posterior region, with a decrease in the medial-to-lateral direction in the middle and posterior regions. While the soft tissue was rather thick around the lateral aspects of the palatal arch, it formed a constant layer that was only 1–2-mm thick throughout the palate. Statistically significant differences were observed according to sex and age. Conclusions The anterolateral palate as well as the midpalatal suture seem to be the most favorable sites for insertion of orthodontic mini-implants. The thickness of the palate differed by age and sex; these differences should be considered while planning the placement of orthodontic mini-implants.

Introduction C-expanders are tissue- and bone-borne maxillary expanders that are anchored by 6 orthodontic miniscrews, 3 on each side of the palate. The purpose of the study was to investigate the effect of C-expanders on the circummaxillary sutures and bucco-palatal axis of teeth in 3-dimensional finite element analyses when anchor screw vectors are different. Methods Five expansion models were studied on the basis of the vertical positions of anchor screws on the palate. Anchor screws for models A, B, and C were placed symmetrically at 4 mm, 7 mm, and 15 mm below the cementoenamel junction (CEJ), respectively. Anchor screws for models D and E were placed asymmetrically at 4 mm and 15 mm below CEJ and 7 mm and 15 mm below CEJ, respectively. Stress, displacement, and angular changes of the bone and teeth were measured in elastoplastic behavior models using a static-nonlinear simulation in an implicit method. Results Symmetrical and asymmetrical anchor screw placement with different vertical vectors were compared using finite element analyses on 5 models. Conclusions Using different vectors of anchor screws for C-expanders does change the pattern of palatal expansion (null hypothesis was rejected). The current investigation presents a promising future of controlled asymmetric skeletal maxillary expansion when asymmetric maxillary architecture needs to be corrected for successful orthodontic outcomes without involving orthognathic surgeries.

Objective To evaluate the accuracy of a multi-stage convolutional neural network (CNN) model-based automated identification system for posteroanterior (PA) cephalometric landmarks. Methods The multi-stage CNN model was implemented with a personal computer. A total of 430 PA-cephalograms synthesized from cone-beam computed tomography scans (CBCT-PA) were selected as samples. Twenty-three landmarks used for Tweemac analysis were manually identified on all CBCT-PA images by a single examiner. Intra-examiner reproducibility was confirmed by repeating the identification on 85 randomly selected images, which were subsequently set as test data, with a two-week interval before training. For initial learning stage of the multi-stage CNN model, the data from 345 of 430 CBCT-PA images were used, after which the multi-stage CNN model was tested with previous 85 images. The first manual identification on these 85 images was set as a truth ground. The mean radial error (MRE) and successful detection rate (SDR) were calculated to evaluate the errors in manual identification and artificial intelligence (AI) prediction. Results The AI showed an average MRE of 2.23 ± 2.02 mm with an SDR of 60.88% for errors of 2 mm or lower. However, in a comparison of the repetitive task, the AI predicted landmarks at the same position, while the MRE for the repeated manual identification was 1.31 ± 0.94 mm. Conclusions Automated identification for CBCT-synthesized PA cephalometric landmarks did not sufficiently achieve the clinically favorable error range of less than 2 mm. However, AI landmark identification on PA cephalograms showed better consistency than manual identification.

Sialolithiasis is one of the most common causes of salivary duct obstruction. In the last 20 years, minimally invasive procedures like sialendoscopy, extracorporeal lithotripsy, and basket snaring are increasingly being used for the treatment of salivary gland duct stones. Sialo-irrigation of the salivary gland is an effective procedure for treating inflammation and providing symptomatic relief. This procedure can be employed for the treatment of sialolithiasis using the back pressure of instilled saline. Sialo-irrigation under ultrasound (US) guidance allows for dynamic studies showing real-time images during diagnostic or surgical procedure and can be used for the removal of sialoliths. In addition, it can also be used to remove primitive sialoliths and microliths by washing out the ductal system, which prevents the recurrence of sialoliths. The aim of this study was to propose a minimally invasive technique for sialolithiasis using US-guided sialo-irrigation.

Nonmineralized cysts and cyst-like lesions that frequently occur in the mandible include ameloblastomas, odontogenic keratocysts, and dentigerous cysts. They have specific features of well-demarcated, unilocular, and radiolucent lesions that are often associated with tooth impaction. Although it rarely occurs, these cysts can become extremely large. Furthermore, cyst enlargement causes additional symptoms that can challenge the success of tooth recovery through orthodontic treatment. This clinical report presents the successful eruption of 2 impacted molars in a large dentigerous cyst treated with marsupialization and orthodontic traction using an orthodontic miniplate anchorage over a 4-year treatment period.

Purpose This report presents a procedure for performing power Doppler ultrasound-guided sialography using the phenomenon of increased blood flow and illustrates its application to practical patient cases. Materials and methods The salivary gland was scanned using ultrasound equipment (GE LOGIQ5 Expert® device; GE Medical Systems, Milwaukee, WI, USA) to identify pathological findings related to the patient's chief complaint. To identify the orifice of the main duct, it should be cannulated using a lacrimal dilator. After inserting the catheter into the cannulated main duct, the position of the catheter within the duct was confirmed by ultrasound. A contrast agent was injected until the patient felt fullness, and ultrasound (B-mode) was used to confirm whether the contrast agent filled the main canal and secondary and tertiary ducts. Then, power Doppler ultrasound was performed to determine whether the salivary gland had increased blood flow. Results In 2 cases in this report, a power Doppler ultrasound scan showed a significant increase in blood flow after contrast medium injection, which was not observed on a preoperative scan. Conclusion Power Doppler ultrasound was found to be a simple, safe, and effective tool for real-time sialography monitoring.

Anchoring miniscrews used for a tissue bone borne maxillary expander (C-expander) can fail if they contact tooth roots or perforate the maxillary sinus. Cone beam computed tomography images were reviewed retrospectively to evaluate the geometric factors of miniscrew placement in the palate that contribute to root proximity (RP) and sinus perforation (SP), and to investigate the differences of miniscrew placement depth (PD) and placement angle (PA) among the groups in each variable from 340 anchoring miniscrews on 70 patients whose C-expanders showed sufficient stability after palatal expansion for orthodontic treatment. Two types of miniscrews were used: a self-tapping miniscrew with 1.8 mm-in-diameter, and a self-drilling miniscrew with 1.6 mm-in-diameter. While the self-tapping larger diameter miniscrew influenced root proximity significantly, the screw location and PD affected the rate of sinus perforation. PA was significantly different between the right and left sides of the palate. The results of this study confirmed that root proximity and sinus perforation of anchoring miniscrews in a tissue bone borne palatal expander occurred due to certain risk factors, even when the palates were expanded successfully. Knowledge of these factors can help the clinician place miniscrews with less risk of root proximity or sinus perforation.

Central odontogenic fibroma (COF) is defined as a fibroblastic odontogenic tumor characterized by varying density of the tooth epithelium. It is an extremely rare benign neoplasm that occurs in the maxilla and the mandible; only a few reports of COF are available in the literature. Diagnosis of the lesion based only on the radiological features of COF is difficult due to variation in the findings regarding this condition. This report describes 2 clinical cases of middle-aged women with COF. Clinical examination revealed palatal mucosal depression; additionally, oral examination, as well as panoramic radiographs, intraoral radiographs, and computed tomography scans, revealed severe root resorption. This report highlights the clinical and radiological imaging features of COF, with the goal of enabling straightforward differential diagnosis of the lesion by the clinician and thereby appropriate treatment of the patient.

OBJECTIVES To evaluate three-dimensional (3D) craniofacial changes induced by a non-surgical tooth-bone-borne rapid palatal expander (TBB-RPE) according to the symmetrical pattern of expansion, to investigate the 3D changes between the sides in patients with asymmetric expansion, and to identify the related factors of asymmetric expansion. SETTING AND SAMPLE POPULATION Sixty-six patients (mean age: 19.3 ± 5.7 years) treated with TBB-RPE were divided into a symmetric expansion group (Group S, n = 46) or asymmetric expansion group (Group A, n = 20). Group S was subdivided into Group Ss (n = 27), with bilateral frontomaxillary suture (FMS) split, and Group Sn (n = 19), with no FMS split. MATERIALS AND METHODS Pre- and post-expansion cone-beam computed tomography images were superimposed, and the common coordinated system was set. All landmarks were designated as coordinate pairs, and treatment changes were automatically calculated. Analysis of variance was conducted for intergroup comparison of craniofacial changes, and logistic regression analysis was performed to identify the related factors of asymmetric expansion. RESULTS The frequency of asymmetric expansion was 30.3%. Group A with unilateral FMS split showed less craniofacial changes than Group Ss and more changes than Group Sn. Group A exhibited different nasomaxillary displacement between the two halves, showing greater changes in the FMS-split side. Among the tested six variables (age, gender, Angle's classification, unilateral crossbite, maxillary cant and chin deviation), chin deviation was uniquely associated with asymmetric expansion. CONCLUSIONS Tooth-bone-borne rapid palatal expander had a risk of asymmetric expansion, especially in facial asymmetric patients with chin deviation, producing different craniofacial changes from symmetric expansion.

Acantholytic squamous cell carcinoma (ASCC) is an uncommon, histopathologically distinct variant of squamous cell carcinoma. ASCC commonly occurs in areas of skin exposed to sunlight and has only rarely been seen on mucosal surfaces such as the oral cavity. Although the World Health Organization has defined ASCC as an original entity, the imaging findings of ASCC have not been adequately described. We herein report a case of ASCC occurring in the oral mucosa with emphasis on the findings of several imaging studies: panoramic radiography, intraoral radiography, contrast-enhanced computed tomography, magnetic resonance imaging, and fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography.

Some craniofacial diseases or anatomical variations are found in radiographic images taken for other purposes. These incidental findings(IFs) can be detected in orthodontic patients, as various radiographs are required for orthodontic diagnosis. To evaluate the rates of IFs in three-dimensional(3D) cone-beam-computed tomography (CBCT) with a large field of view (FOV) and investigate the effectiveness or accuracy of two-dimensional (2D) radiographs for detecting IFs compared to CBCT, the radiographic data of 1,020-orthodontic patients were interpreted. Prevalence in five areas was measured, and sensitivity, specificity, positive predictive value (PPV), negative predictive value(NPV), and accuracy were calculated. The accuracies of various 2D-radiograph were compared through a proportion test. A total of 709-cases(69.5%) of 1,020-subjects showed one or more IFs in CBCT images. Nasal cavity was the most affected area. Based on the CBCT images as a gold standard, different accuracies of various 2D-radiographs were observed in each area of the findings. The highest accuracy was confirmed in soft tissue calcifications with comprehensive radiographs. For detecting nasal septum deviations, postero anterior cephalograms were the most accurate radiograph. A possible improvement in accuracy for detecting IFs is expected by the development of CBCT with a lower radiation dose and higher resolution.

The aim of this study was to present an optimal diagnostic protocol by comparing and analyzing a conventional examination and the quantitative light-induced fluorescence (QLF) technique. Selected were 297 teeth of 153 patients to take QLF images and bitewing radiographs. Occlusal dental caries, proximal dental caries and cracks were evaluated and scored using QLF, X-ray and/or visual criteria. The sensitivity, specificity, and area under the curve (AUC) of a receiver operating characteristic analysis were calculated. Two fluorescence parameters (|ΔFmax| and ΔRmax) were utilized to evaluate the fluorescence pattern according to the severity of lesions based on QLF or X-ray criteria. QLF showed higher scores for detecting occlusal dental caries and cracks than the conventional method. ΔRmax increased more clearly than ΔFmax did with occlusal dental caries. The |ΔFmax| values of occlusal dental caries, proximal dental caries and cracks showed good AUC levels (0.84, 0.81 and 0.83, respectively). The ΔRmax of occlusal dental caries showed the highest AUC (0.91) and the ΔRmax of proximal dental caries showed a fail level (0.59) compared to bitewing radiographs. The QLF image could visualize and estimate the degree of occlusal dental caries or cracks. Consequently, the QLF technique may be an adjunct tool to conventional methods for the detection of occlusal caries and peripheral cracks.

High orthodontic forces and various directions of applied forces can be associated with loosening of the screw anchorage in the bone. Screw designs have been modified to increase the stability of the miniscrews. This research evaluates the influence of three-designs on the stability of orthodontic miniscrews. A conventionally cylinder-type miniscrew design (Bio-Action screw, Jin-Biomed co., Bucheon, Korea) was set as a control, and three conditions were studied based on modifications of this control design. Condition-1 has narrowed threads in the upper part of the screw, Condition-2 has a notch at the middle part, and Condition-3 has the combination of Condition-1 and Condition-2. The moment required to unwind the miniscrew to five degrees is tested, and the moment generated at the cortical bone and the trabecular bone were calculated with finite element analysis. Compared to the control, all three conditions showed a higher moment required to unwind the miniscrew and a higher moment generated at the cortical bone. At the trabecular bone, condition-2 and -3 showed higher moment than the control, and condition-1 showed similar moment to the control. Condition-3 required a higher overall moment to unwind the miniscrew. These findings validate the design modifications used to increase the rotational resistance.

This study was designed to develop and verify a fully automated cephalometry landmark identification system, based on multi-stage convolutional neural networks (CNNs) architecture, using a combination dataset. In this research, we trained and tested multi-stage CNNs with 430 lateral and 430 MIP lateral cephalograms synthesized by cone-beam computed tomography (CBCT) to make a combination dataset. Fifteen landmarks were manually and respectively identified by experienced examiner, at the preprocessing phase. The intra-examiner reliability was high (ICC = 0.99) in manual identification. The results of prediction of the system for average mean radial error (MRE) and standard deviation (SD) were 1.03 mm and 1.29 mm, respectively. In conclusion, different types of image data might be the one of factors that affect the prediction accuracy of a fully-automated landmark identification system, based on multi-stage CNNs.

The aim of this preliminary study was to evaluate the short-term changes of occlusal contacts and muscle activity after orthodontic treatment during the use of a multi-layer clear retainer. Evaluation was done with the T-scan and BioEMG systems. A total of 18 subjects were included, who were evaluated at three time intervals&mdash, T0 at debonding, T1 at one month after retainer delivery, and T2 at four months after retainer delivery. The T-scan and electromyography (EMG) data were recorded simultaneously. The T-scan system recorded the occlusion time, disclusion time and force distribution. The EMG waves were quantified by calculating the asymmetry index and activity index. The time variables changed but not significantly. Occlusal force decreased in the anterior dentition and increased in the posterior dentition during T0&ndash, T2. There was no clear evidence of a relationship between unbalanced occlusal forces and muscle activity. In most subjects, the temporalis anterior muscle was more dominant than the masseter muscle. From this preliminary computerized study, there were no significant changes in the state of the occlusion or muscle activity during the short-term retention period.

Objective This outcome analysis study evaluated the actual positions of the orthodontic miniplate and miniplate anchoring screws (MPASs) and the risk factors affecting adjacent anatomic structures after miniplate placement in the mandibular incisal area. Methods Cone-beam computed tomographic images of 97 orthodontic miniplates and their 194 MPASs (diameter, 1.5 mm; length, 4 mm) in patients whose miniplates provided sufficient clinical stability for orthodontic treatment were retrospectively reviewed. For evaluating the actual positions of the miniplates and analyzing the risk factors, including the effects on adjacent roots, MPAS placement height (PH), placement depth (PD), plate angle (PA), mental fossa angle (MA), and root proximity were assessed using the paired t-test, analysis of variance, and generalized linear model and regression analyses. Results The mean PDs of MPASs at positions 1 (P1) and 2 (P2) were 2.01 mm and 2.23 mm, respectively. PA was significantly higher in the Class III malocclusion group than in the other groups. PH was positively correlated with MA and PD at P1. Of the 97 MPASs at P1, 49 were in the no-root area and 48 in the dentulous area; moreover, 19 showed a degree of root contact (19.6%) without root perforation. All MPASs at P2 were in the no-root area. Conclusions Positioning the miniplate head approximately 1 mm lower than the mucogingival junction is highly likely to provide sufficient PH for the P1- MPASs to be placed in the no-root area.

Oculofaciocardiodental (OFCD) syndrome is a rare genetic disease, first reported by Hayward in 1980. This syndrome presents with various ocular, facial, cardiac, and dental symptoms, including congenital cataract, dysmorphic facial features, congenital heart disease, and enlarged roots, respectively. The most important criteria for the diagnosis of OFCD syndrome are dental abnormalities, especially extreme elongation of canine roots. Here, we report detailed analysis of the dentofacial region, as well as ocular, facial, cardiac, and dental findings in a female with OFCD syndrome. To the best of our knowledge, the patient in this case is the first such patient reported in South Korea.

Purpose This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. Materials and Methods CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. Results Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements (P

Osseointegrated implants are now commonplace in contemporary dentistry. However, a number of complications can occur around dental implants, including peri-implantitis, maxillary sinusitis, osteomyelitis, and neoplasms. There have been several reports of a malignant neoplasm occurring adjacent to a dental implant. In this report, we describe 2 such cases. One case was that of a 75-year-old man with no previous history of malignant disease who developed a solitary plasmacytoma around a dental implant in the left posterior mandible, and the other was that of a 43-year-old man who was diagnosed with squamous cell carcinoma adjacent to a dental implant in the right posterior mandible. Our experiences with these 2 cases suggest the possibility of a relationship between implant treatment and an inflammatory cofactor that might increase the risk of development of a malignant neoplasm.

Introduction To investigate the anatomy of the posterior palatal alveolar process, which is often used for placement of the orthodontic mini-implant (OMI), and to suggest simple guidelines for safe placement of OMI. Methods Cone-beam computed tomography (CBCT) scans of 60 patients (30 men, 30 women; age range, 18-39 years; average age, 25.8 years) was used to measure the palatal interradicular distance, the palatal bone thickness, and the palatal soft-tissue thickness. Measurements were performed on the area from the maxillary canine to the maxillary second molar based on the vertical distance apical from the cementoenamel junction. The CBCT data were analyzed by Bonferroni correction for multiple testing and the multivariable mixed linear model. Results The palatal interradicular distance was the widest between the second premolar and the first molar and the narrowest between the first and second premolars. The palatal bone thickness at interdental sites was the thickest between the first and second premolars and the thinnest between the first and second molars. The interdental palatal soft-tissue thickness from the canine to the second premolar was thicker than any other area. There were minor measurement differences between genders and positive correlations between vertical distance from the cementoenamel junction plane and all of the parameters. Conclusion In this study, we evaluated the anatomy of the posterior palatal area using CBCT scans of adult patients. The data will provide guidelines to the clinicians before OMI placement in the posterior palatal alveolar process.

Table S1. Baseline characteristics of β2AR agonists group by duration

Fibrous dysplasia (FD) is generally considered to be a benign disease that affects the bones, but it has potential to become malignant over time, generally several decades after its initial diagnosis. Radiation therapy can induce malignant transformation of FD; however, reports have indicated a few cases of malignant transformation of FD in the absence of radiation therapy. Angiosarcoma is a particularly rare type of cancer in the oral region, which accounts for less than 1% of all soft-tissue sarcomas. Herein, we reported a case of a 62-year-old man with monostotic FD of the left maxilla of over 50 years’ duration that underwent malignant transformation into an epithelioid-type angiosarcoma. To the best of our knowledge, this is the first report of such case.

Purpose The purpose of this study was to evaluate vertical bone loss and alveolar bone thickness in the maxillary and mandibular incisors of patients with skeletal class III malocclusion. This study also aimed to evaluate the periodontal condition of class III malocclusion patients who had not undergone orthodontic treatment. Materials and Methods The sample included cone-beam computed tomography scans of 24 Korean subjects (3 male and 21 female). Alveolar bone thickness (ABT), alveolar bone area (ABA), alveolar bone loss (ABL), and fenestration of the maxillary and mandibular incisors were measured using 3-dimensional imaging software. Results All incisors displayed an ABT of less than 1.0 mm from the labial surface to root level 7 (70% of the root length). A statistically significant difference was observed between the mandibular labial and lingual ABAs and between the maxillary labial and mandibular labial ABAs. The lingual ABA of the mandibular lateral incisors was larger than that of the mandibular central incisors. ABL was severe on the labial surface. A statistically significant difference was observed between the maxillary and mandibular labial ABL values(21.8% and 34.4%, respectively). Mandibular lingual ABL (27.6%) was significantly more severe than maxillary lingual ABL (18.3%) (P

Purpose The positions of the mandibular foramen (MnF) and the lingula affect the success rate of inferior alveolar nerve block. The objective of this study was to investigate aspects of the MnF and the lingula relevant for mandibular block anesthesia using cone-beam computed tomography (CBCT). Materials and Methods Fifty CBCT scans were collected from a picture archiving and communications system. All scans were taken using an Alphard Vega 3030 (Asahi Roentgen Co. Ltd., Kyoto, Japan). Fifty-eight MnFs of 30 subjects were included in the study. The position of the MnF, the size of the MnF, the position of the lingula, the size of the lingula, and the shape of the lingula were measured and recorded. All data were statistically analyzed at a significance level of P

The aim of this study was to evaluate the effectiveness and shielding performance of a novel recently developed non-lead radiation-shielding fabric containing bismuth oxide (BO-fabric). BO-fabric was fabricated using urethane resin and bismuth nanopowder. A dose-measurement method was employed to evaluate the radiation-attenuation characteristics of the shielding fabric in accordance with the Korean Standards standard. The shielding performances (%) were calculated by measuring the radiation doses after lamination with increasing layers of fabric (1–10 layers). The physical performance of the fabric in terms of flexural and abrasion resistances was evaluated by the Korea Apparel Testing and Research Institute (KATRI). The radiation-attenuation capabilities of one layer of BO-fabric were 58.5, 49.9, and 43.0% at tube voltages of 60, 80, and 100 kVp, respectively. The radiation-shielding performance upon lamination of BO-fabric gradually increased as the number of layers increased. Excellent flexural and abrasion resistances were observed in the KATRI evaluation. A non-lead radiation-shielding fabric based on urethane resin and bismuth was fabricated and examined, revealing an excellent shielding performance. Owing to the flexibility and simple operation of the fabric, it can be employed for various designs of clothing and protective apparel with many purposes.

Background Proton pump inhibitor use is associated with incident chronic kidney disease, chronic kidney disease progression and end-stage renal disease. However, the extent of proton pump inhibitor prescriptions to chronic kidney disease patients is still unclear. Method In a retrospective study, we enrolled patients (>18 years old) who received proton pump inhibitor in the out-patient setting from 2014 through 2015. All data was obtained from electronical medical records of Soonchunhyang Medical Center. The prescription patterns and characteristics of proton pump inhibitors were analyzed according to individual estimated glomerular filtration rate of the patients. Result During the study period 178,228 patients visited the out-patient clinic. Proton pump inhibitors were prescribed to 9,109 (5.11%) patients. In our sample, 50% were females and 9.8% were chronic kidney disease (eGFR

Ultrasound (US)-guided salivary gland irrigation is a popular conservative treatment method that improves the success rate and reduces complications of the sialo-irrigation procedure. US is routinely used for evaluation of various salivary gland diseases because of its easy accessibility and absence of ionizing radiation. US also allows dynamic studies with real-time imaging during diagnostic or surgical procedures. However, conventional US images have limitations in salivary duct visualization. Although US images acquired with saline irrigation have improved visualization because of ductal system dilation by the pulling effect, the resultant image quality remains insufficient for diagnosis. Therefore, contrast agents are required during US-guided sialo-irrigation procedures to produce diagnostic image quality. Air bubbles in saline solution have high echogenicity and enhance image quality by acting as a US contrast agent. The aim of this study was to assess the clinical significance of US-guided sialo-irrigation with a saline-air contrast medium, to estimate its diagnostic and treatment efficacy, and to examine the procedure in two patients. In the study, two patients underwent US-guided salivary gland irrigation with air-bubble mixed saline solution. During the procedure, we were able to visualize the salivary gland duct and subsequently irrigate and clean the inside of the duct. As a result, the patients' symptoms were relieved and saline solution mixed with air bubbles was confirmed to be an effective contrast agent.

Purpose: This study was performed to evaluate the feasibility of visualizing soft tissue lesions and vascular structures using contrast-enhanced cone-beam computed tomography (CE-CBCT) after the intravenous administration of a contrast medium in an animal model. Materials and Methods: CBCT was performed on six rabbits after a contrast medium was administered using an injection dose of 2 mL/kg body weight and an injection rate of 1 mL/s via the ear vein or femoral vein under general anesthesia. Artificial soft tissue lesions were created through the transplantation of autologous fatty tissue into the salivary gland. Volume rendering reconstruction, maximum intensity projection, and multiplanar reconstruction images were reconstructed and evaluated in order to visualize soft tissue contrast and vascular structures. Results: The contrast enhancement of soft tissue was possible using all contrast medium injection parameters. An adequate contrast medium injection parameter for facilitating effective CE-CBCT was a 5-mL injection before exposure combined with a continuous 5-mL injection during scanning. Artificial soft tissue lesions were successfully created in the animals. The CE-CBCT images demonstrated adequate opacification of the soft tissues and vascular structures. Conclusion: Despite limited soft tissue resolution, the opacification of vascular structures was observed and artificial soft tissue lesions were visualized with sufficient contrast to the surrounding structures. The vascular structures and soft tissue lesions appeared well delineated in the CE-CBCT images, which was probably due to the superior spatial resolution of CE-CBCT compared to other techniques, such as multislice computed tomography. (Imaging

Gallstone ileus is a rare complication of the biliary stone, occurring in 0.3-0.5% of patients with cholelithiasis. The mortality rate is high at 12-27% and early diagnosis and prompt management can improve its prognosis. An 83-yearold woman was admitted to the hospital with abdominal pain. The patient previously had a hysterectomy and had received radiation therapy for uterine cancer. Plain abdominal x-ray showed typical findings of small bowel ileus with step ladder patterns. Computed tomography (CT) scan revealed biliary-enteric fistula with a 3-cm-sized gallstone in the jejunal loop. Surgical treatment was planned but due to the patient’s wish, conservative treatment was provided for 10 days. In the follow-up CT scan, the stone had moved to the distal ileum but intestinal perforation was suspected. Ileocecectomy and adhesiolysis were performed and the patient recovered fully. Here we report a case of gallstone ileus that was treated by surgical removal after 10 days of conservative treatment.

Purpose This study was performed to investigate the influence of object shape and distance from the center of the image on the volumetric accuracy of cone-beam computed tomography (CBCT) scans, according to different parameters of tube voltage and current. Materials and methods Four geometric objects (cylinder, cube, pyramid, and hexagon) with predefined dimensions were fabricated. The objects consisted of Teflon-perfluoroalkoxy embedded in a hydrocolloid matrix (Dupli-Coe-Loid TM; GC America Inc., Alsip, IL, USA), encased in an acrylic resin cylinder assembly. An Alphard Vega Dental CT system (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan) was used to acquire CBCT images. OnDemand 3D (CyberMed Inc., Seoul, Korea) software was used for object segmentation and image analysis. The accuracy was expressed by the volume error (VE). The VE was calculated under 3 different exposure settings. The measured volumes of the objects were compared to the true volumes for statistical analysis. Results The mean VE ranged from -4.47% to 2.35%. There was no significant relationship between an object's shape and the VE. A significant correlation was found between the distance of the object to the center of the image and the VE. Tube voltage affected the volume measurements and the VE, but tube current did not. Conclusion The evaluated CBCT device provided satisfactory volume measurements. To assess volume measurements, it might be sufficient to use serial scans with a high resolution, but a low dose. This information may provide useful guidance for assessing volume measurements.

Beta2-adrenergic receptor (&beta, 2AR) agonists can have protective effects targeting macrophage activation, but research on human subjects has not been done. This study was designed to assess the relationship between the use of &beta, 2AR agonists and diabetic vascular complications. Using data from the Korean National Health Insurance Service, adults first diagnosed with diabetes in 2004 (n = 249,222) were followed up until 31 December 2015. Propensity score matching was performed between case and control groups (n = 5179 in each), and multivariate analysis was conducted. The &beta, 2AR agonist group was divided into quartiles according to the duration of &beta, 2AR agonist use. During the follow-up, the incidence of vascular complications gradually decreased as the duration of &beta, 2AR agonist administration increased. Multivariate analysis revealed that the hazard ratio for all composite vascular complications was 0.80 (95% CI, 0.75&ndash, 0.86, p &lt, 0.001) in the longest quartile of &beta, 2AR agonist use as compared with the control group after adjusting for confounding variables. The association between the duration of &beta, 2AR agonist use and the risk of each vascular complication including cerebrovascular, peripheral vascular, peripheral neural, renal, and ophthalmic complications was consistent, and the risks were significantly lower in the longest users than the control group. Long-term use of &beta, 2AR agonists may exert a protective effect against diabetic vascular complications.