• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.19 no.1
• /
• pp.93-107
• /
• 1997

Magnetic resonance imaging has been used in the temporomandibular joint(TMJ) primarily to define morphology and positional relationship of associating structures. This report examines signal intensity characteristics of the posterior attachment as they related to the severity of internal derangement. Fifty six joints in 35 patients with a history of TMJ dysfunction were imaged writ MR using $T_1$-weighted spin echo sequence. According to disk position, ability to reduction, and the presence of osteoarthritis, the joints were categorized into three groups. A group 1 was anterior disk displacement with reduction; a group 2 was anterior disk displacement without reduction; a group 3 was anterior disk displacement without reduction and condyle had osteoarthritic change. The control group was determined by the clinical absence of any signs or symptoms of current or past TMJ pain and dysfunction. Calculated the relative value of MR signal intensity in posterior attachment and disk to cerebral cortex of temporal lobe by means of computer program, we have compared them with each groups. The result showed statistically little significant difference of disk signal intensity among each groups. but, signal intensity from posterior attachment in group 2 and 3 were significantly(p<0.05) decreased than control group. this might reflect an fibrosis or hyalinization of posterior attachment, which was part of remodeling process that occurs in disk displacement without reduction. However, this study could not demonstrate histologic confirmation of the decreased signal intensity in the posterior attachment. So, further investigation could be needed to understand the association between them.

• Journal of Chest Surgery
• /
• v.27 no.3
• /
• pp.226-229
• /
• 1994

VATS is now used by many thoracic surgeons and in various anatomic locations such as lung parenchyme, pleura and mediastinum, etc. VATS of mediastinal masses has special characteristics compared to that of other diseases. Those are no positional changes of the mass during collapse of the lung and close proximity of the mass to major vascular structures, nerves and other vital organs. From 1992. July to 1993. August, 10 mediastinal masses were treated with video assisted thoracoscopy. There were five males and five females, ages ranged from 11 years to 65 years with average 37.7 17.7 years old. Of the 10 patients, 4 were bronchogenic cysts, 2 were teratoma, and the others were thymoma, neurilemmoma, pericardial cyst, and thymic cyst. Needle aspiration was done in large cysts and the working thoracotomy[or utility thoracotomy] was done in large solid masses for the purpose of easy dissection, easy handling and easy delivery of the mass. The average operation time were 155.6 6.8 minutes and the duration of air leakage were 1 2.2 days. The duration of the chest tube drainage were 3.3 2.6 days. The lengths of the postoperative hospitalization were 5.1 2.7 days which were shorter than those of 12 mediastinal masses treated with conventional thoracotomy during the same periods [p<0.05]. There was 1 patient converted to thoracotomy because of a bleeding at innominate vein. 3 postoperative complications were occured. Those were persistent air leakage for 7 days, diaphragmatic palsy and hoarseness which were recovered within 1 month. We conclude that mediastinal mass can be excised with video assisted thoracoscopy and the posthospitalization is reduced. But careful attention is required for avoiding injury to major vascular structures, nerves, and other vital organs.

• Journal of International Society for Simulation Surgery
• /
• v.2 no.1
• /
• pp.13-16
• /
• 2015

Purpose We conducted a study on the reconstruction of the head's shape in 3D using the ToF depth sensor. A time-of-flight camera (ToF camera) is a range imaging camera system that resolves distance based on the known speed of light, measuring the time-of-flight of a light signal between the camera and the subject for each point of the image. The above method is the safest way of measuring the head shape of plagiocephaly patients in 3D. The texture, appearance and size of the head were reconstructed from the measured data and we used the SDF method for a precise reconstruction. Materials and Methods To generate a precise model, mesh was generated by using Marching cube and SDF. Results The ground truth was determined by measuring 10 people of experiment participants for 3 times repetitively and the created 3D model of the same part from this experiment was measured as well. Measurement of actual head circumference and the reconstructed model were made according to the layer 3 standard and measurement errors were also calculated. As a result, we were able to gain exact results with an average error of 0.9 cm, standard deviation of 0.9, min: 0.2 and max: 1.4. Conclusion The suggested method was able to complete the 3D model by minimizing errors. This model is very effective in terms of quantitative and objective evaluation. However, measurement range somewhat lacks 3D information for the manufacture of protective helmets, as measurements were made according to the layer 3 standard. As a result, measurement range will need to be widened to facilitate production of more precise and perfectively protective helmets by conducting scans on all head circumferences in the future.

• Journal of Radiation Protection and Research
• /
• v.44 no.1
• /
• pp.32-42
• /
• 2019

Background: There have been much efforts to develop the proper and realistic machine Quality Assurance (QA) reflecting on real Volumetric Modulated Arc Therapy (VMAT) plan. In this work we propose and test a special VMAT plan of plan-class specific (pcsr) QA, as a machine QA so that it might be a good solution to supplement weak point of present machine QA to make it more realistic for VMAT treatment. Materials and Methods: We divided human body into 5 treatment sites: brain, head and neck, chest, abdomen, and pelvis. One plan for each treatment site was selected from real VMAT cases and contours were mapped into the computational human phantom where the same plan as real VMAT plan was created and called plan-class specific reference (pcsr) QA plan. We delivered this pcsr QA plan on a daily basis over the full research period and tracked how much MLC movement and dosimetric error occurred in regular delivery. Several real patients under treatments were also tracked to test the usefulness of pcsr QA through comparisons between them. We used dynalog file viewer (DFV) and Dynalog file to analyze position and speed of individual MLC leaf. The gamma pass rate from portal dosimetry for different gamma criteria was analyzed to evaluate analyze dosimetric accuracy. Results and Discussion: The maxRMS of MLC position error for all plans were all within the tolerance limit of < 0.35 cm and the positional variation of maxPEs for both pcsr and real plans were observed very stable over the research session. Daily variations of maxRMS of MLC speed error and gamma pass rate for real VMAT plans were observed very comparable to those in their pcsr plans in good acceptable fluctuation. Conclusion: We believe that the newly proposed pcsr QA would be useful and helpful to predict the mid-term quality of real VMAT treatment delivery.

• Progress in Medical Physics
• /
• v.32 no.2
• /
• pp.40-49
• /
• 2021

Purpose: This study aimed to develop a surface-guided radiosurgery system customized for a neurosurgery clinic that could be used as an auxiliary system for improving the accuracy, monitoring the movements of patients while performing hypofractionated radiosurgery, and minimizing the geometric misses. Methods: RGB-D cameras were installed in the treatment room and a monitoring system was constructed to perform a three-dimensional (3D) scan of the body surface of the patient and to express it as a point cloud. This could be used to confirm the exact position of the body of the patient and monitor their movements during radiosurgery. The image from the system was matched with the computed tomography (CT) image, and the positional accuracy was compared and analyzed in relation to the existing system to evaluate the accuracy of the setup. Results: The user interface was configured to register the patient and display the setup image to position the setup location by matching the 3D points on the body of the patient with the CT image. The error rate for the position difference was within 1-mm distance (min, -0.21 mm; max, 0.63 mm). Compared with the existing system, the differences were found to be as follows: x=0.08 mm, y=0.13 mm, and z=0.26 mm. Conclusions: We developed a surface-guided repositioning and monitoring system that can be customized and applied in a radiation surgery environment with an existing linear accelerator. It was confirmed that this system could be easily applied for accurate patient repositioning and inter-treatment motion monitoring.

• The korean journal of orthodontics
• /
• v.30 no.4 s.81
• /
• pp.491-507
• /
• 2000

The purpose of this study was to investigate if there were a significant differences in mandibular position between cephalometric measurements from a centric occlusion tracing compared to those of a acquired centric relation by stabilization splint on malocclusion patient with TMD. 60 malocclusion patients, who had TMD and CO-CR discrepancy beyond normal range, were selected and subdivided into Class I, II, III by Angle's classification and also subdivided into clockwise, straight downward, and counterclockwise group by Jarabak's posterior facial height/anterior facial height ratio. Lateral cephaolmetric radiographs with the mandible in centric occlusion were taken and measured, and for each Patient the stabilization splint with mutually protected occlusal scheme was applied for minimum 3months. After each patient's CO-CR discrepancy was in normal range, lateral cephalometric radiographs were retaken and measured. The comparison of the difference between CO-CR cephalometric measurements in all sample, Class I, II, III groups, and Clockwise, Straight downward, Counterclockwise groups were studied. The finding of this study can be summarized as follows: 1 In all sample, the value of cephalometric measurements was significantly different between CO-CR. The mandible rotated to down and posterior position and the vertical change was greater than the horizontal change (overjet-1.3mm increase, overbite-1.9mm decrease). 2. In Class II malocclusion group, most of the mean difference value between CO-CR is higher than that of the other groups and more measurements was statically significant. 3. In clockwise and counterclockwise group, some of the mean difference value is higher than that of straight downward group and more measurements was statically significant. 4. There ware no measurements that explain centric relation measurements from the type of malocclusion, facial pattern and centric occlusion measurements. Henceforth, it is strongly recommended that stabilization splint therapy for orthodontic treatment on TMD patient should be excuted upon overall facial types prior to orthodontic diagnosis and treatment planning.

• The korean journal of orthodontics
• /
• v.25 no.4
• /
• pp.375-401
• /
• 1995

Cause of skeletal Class III malocclusion in growing patients can be classified into maxillary deficiency, mandibular overgrowth, and combination of the two. Use of Protraction Head Gear(P.H.G.) has been recommended for treatment of growing Class III malocclusion patients, for it results in forward & downward movement of maxilla and backward & downward rotation of mandible. Numerous animal experiments were performed and clinical study data have been reported ; nevertheless, studies on soft tissue profile change and comparison of treatment effects among the patients who had undergone treatment are considered to be somewhat insufficient. The author selected 93 patients, who had been diagnosed as skeletal Class III malocclusion with maxillary deficiency and then treated with P.H.G. ; the sample group was divided according to sex, treatment beginning age, palatal suture opening(intraoral appliance), and facial growth pattern. For each group, changing patterns of hard and soft tissue profile observed, and comparision with 20 normal group(Angle's Class I) patients of statistical significance in amount of growth and treatment of hard and soft tissue was done. The following results were obtained. 1. Skeletal, dental, and soft tissue measurements indicated that more growth changes was induced in the sample group that used P.H.G. compared to the growth amount of normal group. 2. No statistical significance was observed in the amounts of maxillary forward movement and mandibular backward & downward rotation depending on treatment beginning age in both sex group. 3. R.P.E. showed more significant maxillary forward movement and less protrusion of upper incisor than La-Li. 4. There was no statistical significance in the amount of maxillary forward movement depending on facial growth pattern. On the other hand, measurements indicating mandibular downward & backward rotation indicated greater change in counterclockwise growth pattern group than the clockwise. 5. Changes in upper and lower lip thicknesses showed a close relationship with positional changes in underlying bone tissue and upper and lower teeth, and upper lip height and nasolabial angle increased and mentolabial angle decreased.

• Korean Journal of Biological Psychiatry
• /
• v.19 no.3
• /
• pp.128-133
• /
• 2012

Objectives : Located on chromosome 10q22-q23, the human neuregulin 3 (NRG3) is suggested as a strong positional and functional candidate gene involved in the pathogenesis of schizophrenia. Several case-control studies examining the association between polymorphisms on NRG3 gene with schizophrenia and/or its traits (such as delusion) have been reported recently in cohorts of Han Chinese, Ashkenazi Jews, Australians, white Americans of Western European ancestry and Koreans. Thus, this study aimed to investigate the association of one SNP in exon 9 (rs2295933) of NRG3 gene with the risk of schizophrenia in a Korean population. Methods : Using TaqMan assay, rs2295933 in the exon 9 of NRG3 was genotyped in 435 patients with schizophrenia as cases and 393 unrelated healthy individuals as controls. Differences in frequency distributions were analyzed using logistic regression models following various modes of genetic inheritance and controlling for age and sex as covariates. Results : Subsequent analysis revealed that the frequency distribution of rs2295933 of NRG3 was not different between schizophrenia patients and healthy controls of Korean ethnicity. Conclusions : This study does not support the role of NRG3 in schizophrenia in a Korean population.

• The korean journal of orthodontics
• /
• v.28 no.1 s.66
• /
• pp.113-122
• /
• 1998

Stabilization splint therapy Precedes orthodontic intervention to enable the operator to find a 'true' centric(which is stable and comfortable), to test the patient's response to a change in the occlusion, prior to embarking upon a complex course of occlusal therapy : and finally, to see if the centric relation position can be stabilized. For this study, 47 malocclusion Patients enrolled for orthodontic treatment at the Department of Orthodontics, College of Dentistry, Chosun University comprised the malocclusion group, little variation of growth factor by the second molar eruption. They had Cr-Co discrepancy beyond normal range. For each patients the stabilization splint with mutually protected type of occlusal scheme was applied for 3 months. Condylar positions in CR and CO were measured using Penadent articulators, Panadent condylar position indicator(CPI), and transcranial projection before & after stabilization splint therapy. On the basis of this study, the results of this study were as follows 1. In all samples using CPI, there were statistical significances in CR-CO discrepancy(p<0.001) both before 8t after stabilization splint therapy. 2. In Rt and Lt+Rt/2 of superior joint space using transcranial projection, there were statistical significances in CR-CO discrepancy({<0.05) before & after stabilization splint therapy. 3. In supero-inferior components using CPI, there were statistical significances in CR-CO discrepancy(p<0.01) before & after stabilization splint therapy. 4. In all components except Rt using transcranial projection, there were no statistical significances in CR-CO discrepancy(p>0.05) before & after stabilization splint therapy. To sum up, CPI might be more effective than transcranial projection to reveal the changes between CR-CO discrepancies and stabilization splint might be more useful appliance for displaying the vertical changes, than the antero-posterior changes, of condylar position.

• The Journal of Korean Society for Radiation Therapy
• /
• v.15 no.1
• /
• pp.53-60
• /
• 2003

I. Purpose It is essential to have the correct body contour information for the calculation of dose distribution. The role of CT images in the radiation oncology field has been increased. But there still exists a method to use cast or lead wire for the body contour drawing. This traditional method has drawbacks such as in accurate and time consuming procedure. This study has been designed to overcome this problem. II. Materials and Methods A digital camera is attached to a pole which stands on the opposite side of the gantry. Positional information was acquired from an image of the phantom which is specially designed for this study and located on the isocenter level of the simulator Laser line on the patients skin or on the phantom surface was digitized and reconstructed as the contour. Verification of usefulness this technique has been done with various shape of phantoms and a patients chest III. Results and Conclusions Contours from the traditional method with the cast or lead wire and the digital image method showed good agreement within experimetal error range. This technique showed more efficiente in time and convenience. For irregular shaped contour, like H&N region, special care are needed. The results suggest that more study is needed. To use of the another photogrammatory techinique with two camera system may be better for the actual clinical application