• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.675-681
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• 2005

The Horseshoe appliance was introduced by Dr. Schwarz, and it is used to correct sagittal relationships by elastic force in class III malocclusion. It minimizes the increment of lower anterior facial height and allows the mandible to be repositioned harmoniously with the soft tissue and muscle matrix of the jaw It has the advantages of better patient cooperation, easier construction, and more effective modification. In the patients who were treated with Horseshoe appliance, forward growth of maxilla and counterclockwise rotation of occlusal plane with labioversion of maxillary incisors and linguoversion of mandibular incisors were obtained. Minimum downward and backward rotation of mandible was accepted, so increasing of lower anterior facial height was minimized.

• Archives of Craniofacial Surgery
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• v.13 no.1
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• pp.4-10
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• 2012

Purpose: The objective of this retrospective study was to assess the skeletal stability after orthognathic surgery for patients with cleft lip and palate. The soft tissue changes in relation to the skeletal movement were also evaluated. Methods: Thirty one patients with cleft received orthognathic surgery by one surgeon at the Craniofacial Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Osseous and soft tissue landmarks were localized on lateral cephalograms taken at preoperative (T0), postoperative (T1), and after completion of orthodontic treatment (T2) stages. Surgical movement (T0.T1) and relapse (T1.T2) were measured and compared. Results: Mean anteroposterior horizontal advancement of maxilla at point A was 5.5 mm, and the mean horizontal relapse was 0.5 mm (9.1%). The degree of horizontal relapse was found to be correlated to the extent of maxillary advancement. Mean vertical lengthening of maxilla at point A was 3.2 mm, and the mean vertical relapse was 0.6 mm (18.8%). All cases had maxillary clockwise rotation with a mean of 4.4 degrees. The ratio for horizontal advancement of nasal tip/anterior nasal spine was 0.54/1, and the ratio of A' point/A point was 0.68/1 and 0.69/1 for the upper vermilion/upper incisor tip. Conclusion: Satisfactory skeletal stability with an acceptable relapse rate was obtained from this study. High soft tissue to skeletal tissue ratios were obtained. Two-jaw surgery, clockwise rotation, rigid fixation, and alar cinch suture appeared to be the contributing factors for favorable results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.15-22
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• 2002

This paper introduces a compensating system for machining error, which is resulted from chucking with separated jaws. In machining the chucked cylindrical workpiece, the deterioration of machining accuracy, such as out-of-roundness is inevitable due to the variation of the radial compliance of the chuck workpiece system which is caused by the position of jaws with respect to the direction of the applied force. To compensate the chucking compliance induced error, firstly roundness profile of workpiece due to chucking compliance after machining needs to be predicted. Then using this predicted profile, the compensated tool feed trajectory can be generated. And by synchronizing the cutting tool feed system with workpiece rotation, the chucking compliance induced error can be compensated. To satisfy the condition that the cutting tool feed system must provide high speed and high position accuracy, brushless linear DC motor is used. In this study, firstly through the force-deflection experiment in workpiece chucked lathe, the variation of radial compliance of chuck workpiece system is obtained. Secondly using the mathematical equation and cutting experiment result, the predicted profile of workpiece and its compensation tool trajectory are generated. Thirdly the configuration of compensation system using linear motor is introduced, and to improve the system performance, PID controller is designed. Finally the tracking performance of system is examined by experiment. Through the real cutting experiment, roundness is significantly improved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.4
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• pp.301-314
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• 1990

This paper is an attempt to use vision-pattern recognition technique to analyzation on a hidden rigid body motion. Specially shaped rod, rigidly connected to the hidden body is extended to the ouside of hiding object so that a camera may catch the motion data. Every motion can be described with translatio and rotation. But translation can be explanied with ratation with a infinitly far centroid. Motion analysis is to find the instantaneous centroid and ratation angle. With this theory jaw motion is analyzed in this paper.

• The korean journal of orthodontics
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• v.37 no.4
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• pp.245-259
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• 2007

Improvements in jaw relationship through clockwise rotation of the mandible may be desirable in some Class III patients with short low facial height. The aim of this study was to examine the treatment effect of face mask for Class III malocclusion patients according to their low facial morphology. Methods: Class III patients in their pubertal growth period were divided into two groups (Group 1, high LFH; Group 2, low LFH) according to lower facial height (LFH) by Ricketts (norm, 47). treatment changes between groups after face mask treatment was compared not only for hard tissue but also for soft tissue. Results: There were no significant differences between the two groups for the skeletal and soft tissues of the maxilla. There were no significant differences between the two groups for the skeletal posterior movement of the mandible, but posterior movement of the mandibular soft tissues in group 2 was larger than group 1. There were no significant differences between the two groups for the vertical hard tissue proportion changes of the mandible, but the vertical soft tissue proportion changes of the mandible in group 2 was larger than group 1. There was a significant correlation between the sagittal hard tissue and soft tissue changes of the maxilla and mandible, but there was no significant difference in the vertical changes. Conclusion: The clockwise rotation of the mandible occurred from use of the face mask, and posterior movement of soft tissues of the mandible was higher in Cl III patients with low LFH than with high LFH.

• The Journal of the Korean dental association
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• v.48 no.5
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• pp.379-390
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• 2010

The aim of this study was to investigate clinical and cephalometric characteristics of patients with anterior open bite and mandibular condylar resorption. Total of 45 subjects were recruited from the patients who visited the Department of Oral Medicine, Kyungpook National University Hospital in 2006 for treatment of temporomandibular dysfunction. After taking patient's history concerning temporomandibular joint dysfunction, clinical examination was performed and panoramic, transcranial, and lateral cephalometric radiographs were obtained. The cephalometric data were compared to those of normal Korean population. The results were as follow: 1. Clinical characteristics 1) Female was 4.6 time more prevalent than male, and 82.2% of the subjects were in second and third decade. 2) Angle's Class I occlusal type was 51%, Class II was 29%, and Class III was 20%. 3) The mean value of the overjet and overbite were 3.2mm and -1.1mm, respectively. 4) Most of the patients had parafunctional oral habits. 2. Cephalometric characteristics 1) SNA showed no significant difference between condyle resorption and normal group. However, in female resorption group, SNB was lesser and ANB was greater than those in normal group. 2) SN-GoMe and FMA increased in resorption group. 3) Palatal plane angle did not show significant difference between resorption and normal group. 4) Total posterior facial height was significantly smaller and total anterior facial height showed no significant increase as compared with those of the normal group. 5) Mandibular body length did not show any significant difference between resorption and normal group.

• The korean journal of orthodontics
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• v.46 no.6
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• The Journal of the Korean dental association
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• v.55 no.6
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• pp.400-410
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• 2017

Approximately 30% of adult patients who want orthodontic treatment have transverse discrepancy with insufficient width of the maxilla. Particularly, in Class III patients requiring orthognathic surgery, the frequency of insufficient width of the maxillary arch related to respiratory problems is high. We report a case of non-surgical maxillary expansion using a Hyrax type expander with an orthognathic surgery, based on the reports that the ratio of non-fused midpalatal suture is not high in adults. A 30 years and 2 months old woman with a long face showed an Angle Class III with a vertical growth pattern. Class III molar and canine relation, anterior edge bite, and mandibular incisor compensatory lingual inclination were observed. The posterior buccal overjet seemed to be appropriate, but I diagnosed that there was a transverse discrepancy, for the following reasons. The inter-canine and inter-molar widths were sufficient but excessive lingual inclination of the mandibular molars was observed when assessing the bucco-lingual inclination based on the center of resistance of the maxillary and mandibular first molar. For this reason, it was expected that intercuspal interference would occur during orthodontic decompensation. Therefore, slow maxillary expansion using Hyrax type expander was performed and 2-jaw rotation surgery was performed to improve aesthetic and occlusion. Adults can also improve width discrepancy by non-surgical methods, which can avoid SARPE requiring additional surgery or segmental surgery lacking stability and predictability.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.103-116
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• 2021

PURPOSE: This study examined the effects on the upper extremity function, muscle strength, and hand function of a task-oriented training approach using a percussion instrument for patients with chronic stroke. METHODS: Twenty-four chronic stroke patients accompanied with upper extremity hemiplegia were selected for research and were classified randomly into 12 experimental groups and 12 control groups. The experimental group performed a task-oriented approach, and the control group performed upper extremity occupational therapy. Stroke upper extremity test, Jebsen-Taylor Hand Function test, upper extremity muscle strength test, and hand muscle strength test were measured before and after training in the evaluation process. RESULTS: In the upper extremity test and Jebsen-Taylor test, there were no significant differences between the groups. In the upper extremity muscle strength test, there were significant differences in shoulder flexion, internal rotation, and elbow flexion in the experimental group. In the hand muscle strength test, there were significant differences in the grip, tip Pinch, lateral Pinch, and 3-jaw chuck in the experimental group and significant differences in only grip, tip pinch, and lateral pinch in the control group. In addition, there were significant differences in the lateral pinch compared to the amount of change. CONCLUSION: Task-oriented approach using percussion instruments for upper extremity rehabilitation in stroke patients is effective in the upper extremity function and strength, hand function, and strength.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.2
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• pp.43-61
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• 2004

Purpose : For qualify improvement in radiotherapy, it is important to set up and evaluate equipment (linac) accurately. In addition, technicians are needed to be fully aware of the equipment's detailed quality and its manual. Therefore, the result of ATP is evaluated and introduced, in order that the technicians are skilled by participating in quality assurance (QA) and understanding the quality of the equipment before clinical use. Method and Material : QA for LINAC 21EX (Varian, US) was done with suppliers its procedure was divided into radiation survey, mechanical test, radiation isocenter test, bean performance, dosimetry, and enhanced dynamic wedge and using X-omat film (Kodak), multidata, densitometer, and electrometer. QA of MLC (Millennium, 120 leaf) attached to LINAC and EPID (Portal vision) were done separately. Result : The leakage dose by survey meter was below the tolerance. In mechanical test, collimater, gantry, and couch rotation were less than 1mm, and the angles were ${\pm}0.1^{\circ}$ for digital and ${\pm}0.5^{\circ}$ for mechanical. The alignment test of the light field and crosshair were evaluated less than 1mm. The (a)symmetrical jaw field was less than ${\pm}0.5mm$. The radiation isocenter test using X-mat film was less than 1mm. The consistency of light field and radiation field was less than ${\pm}0.1mm$. PDD for photon energy was less than ${\pm}1\%$ and for electron energy of $90\%,\;80\%,\;50\%,\;and\;30\%$ were evaluated within the tolerance. Flatness for photon and electron energy was evaluated $2.3\%$ (tolerance $3\%$) and $3\%$ (tolerance $4.5\%$), respectively, and symmetry was $0.45\%$ (tolerance $2\%$) and $0.3\%$ (tolerance $2\%$), respectively. Dosimetry test for short term, MU setting, rep rate, and dose rate accuracy of photon and electron energy was within the tolerance depending on energy, MU, and gantry angle. Conclusion : Accuracy and safety for clinical use of Clinac 21EX was verified through customer acceptance procedure and the quality of the equipment was found out. These can reduce the difficulties in using the equipment. Furthermore, it is useful for clinically treatment of patients by technicians' active participations.