• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.5
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• pp.87-96
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• 2005

In this paper, a mesh simplification algorithm using face constriction is proposed which considers the conservation of the volume of a 3D model. The face constriction method replaces three vertices of the candidate triangle with a new vertex, removing four faces at once. We propose a modified method, compensating an existing method, of considering curvature in the decision of the removing order of triangles. We also propose a method of determining a new vertex replacing the candidate triangle, which reflects curvature difference of the three surrounding areas of the three vertices of the triangle, while conserving the volume. It is shown by simulation that the proposed method conserves the volume and shows good constriction performance comparable to the other methods.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.3
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• pp.171-177
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• 2017

Amniotic constriction band is a rare clinical entity with varied manifestations that range from a combination of congenital malformations to isolated malformations that are unique to each patient. The etiology of this entity remains unknown. Herein, we highlight two cases of amniotic constriction band that presented to our unit with unique clinical characteristics. To the best of our knowledge, an isolated circumferential band of scarring on the face with ocular involvement, as demonstrated by the first case, and a combination of bilateral complete cleft lip and palate with bilateral microphthalmia, auto-amputation of the right thumb, and a constriction band on the left thumb, as demonstrated by the second case, are extremely rare presentations of amniotic constriction band that were not previously reported in the literature and therefore necessitate a special mention. We discuss potential etiologies for these cases and review the existing literature on this entity.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.171-181
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• 2009

The objective of this study was to analyse stress distribution of maxillary complex by use of face mask. The construction of the three-dimensional FEM model was based on the computed tomography(CT) scans of 13.5 years-old male subject. The CT image were digitized and converted to the finite element model by using the mimics program, with PATRAN. An anteriorly directed force of 500g was applied at the first premolar 45 degrees downwards to the FH plane and at the first molar 20 degrees downwards to the FH plane. When 45 degrees force was applied at maxillary first premolar, there were observed expansion at molar part and constriction at premolar part. The largest displacement was 0.00011mm in the x-axis. In the y-axis, anterior displacement observed generally 0.00030mm at maximum. In the z-axis, maxillary complex was displaced 0.00036 mm forward and downward. When 20 degrees force was applied at maxilla first molar, there were observed expansion at lateral nasal wall and constriction at molar part. The largest displacement was 0.001mm in the X-axis. In the Y-axis, anterior displacement observed generally 0.004mm at maximum. In the Z-axis, ANS was displaced upward and pterygoid complex was displaced downward. The largest displacement was 0.002mm.

• The korean journal of orthodontics
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• v.53 no.1
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• pp.54-64
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• 2023

This case report describes skeletal anchorage-supported maxillary protraction performed with the Alternate Rapid Maxillary Expansion and Constriction (AltRAMEC) protocol over a treatment duration of 14 months in a 16-year-old female patient who was in the late growth-development period. Miniplates were applied to the patient's aperture piriformis area to apply force from the protraction appliance. After 9 weeks of following the Alt-RAMEC protocol, miniplates were used to transfer a unilateral 500-g protraction force to a Petit-type face mask. A significant improvement was observed in the soft tissue profile in measurements made both cephalometrically and in three dimensional photographs. Subsequently, the second phase of fixed orthodontic treatment was started and the treatment was completed with the retention phase. Following treatment completion, occlusion, smile esthetics, and soft tissue profile improved significantly in response to orthopedic and orthodontic treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.53-60
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• 2009

Maxillary deficiency, anterior cross bite, constriction of maxillary arch, malaligned teeth are frequently observed in patients with cleft lip and palate. Surgery and orthodontics, combined intervention are needed to correct maxillary deficiency. Distraction osteogenesis that currently used has many advantages like less relapse tendency, more advancement of maxilla, capable in growing patients. In case 1, 18 years old girl with BCLP had severe midfacial deficiency and multiple missing of teeth. LeFort I osteotomy, followed by maxillary distraction osteogenesis utilizing rigid external distraction device(RED) system, was performed. After a 6-day latency period, distraction proceeded at a rate of 1mm per day (at 1st week, 1.5mm/day). Total advancement was 19mm. The RED device left in place for the additional 4 weeks for consolidation. After the RED device was removed, face mask was applied with elastic traction for 5 weeks. After achieving acceptable facial appearance and occlusion, orthodontic appliance was removed. The results after 4 years follow-up was sustained pretty well without aggravation of velopharyngeal function. In case 2, 22 years old man with UCLP had severe midfacial deficiency and palatally erupted upper 2nd premolars due to arch length discrepancy, but the anterior segment of maxillary did not show constriction and crowding. patient had no arch width discrepancy, crowding was concentrated on premolar region. Segmental LeFort I osteotomy was performed. After a 6 - day latency period, using internal distraction device, distraction proceeded at a 0.5mm per day(at 1st week, 0.75 - 1 mm/day). Total advancement was 15mm. After internal distraction device was removed, face mask was applied with elastic traction for 4 weeks. After surgical-orthodontic treatment, facial appearance and occlusion was improved pretty good, and after 46 months follow-up the result was retained well.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.20.1-20.6
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• 2016

Background: Most of cleft lip and palate patients have the esthetic and functional problems of midfacial deficiencies due to innate developmental tendency and scar tissues from repeated operations. In these cases, maxillary protraction is required for the harmonious facial esthetics and functional occlusion. Case presentation: A 7-year old boy had been diagnosed as severe maxillary constriction due to unilateral complete cleft lip and palate. The author tried to correct the secondary deformity by early distraction osteogenesis with the aim of avoiding marked psychological impact from peers of elementary school. From 1999 to 2006, repeated treatments, which consisted of Le Fort I osteotomy and face mask distraction, and complementary maxillary protraction using miniplates were performed including orthodontics. But, final facial profile was not satisfactory, which needs compromising surgery. Conclusions: The result of this study suggests that if early distraction treatment is performed before facial skeletal growth is completed, an orthognathic surgery or additional distraction may be needed later. Maxillofacial plastic and reconstructive surgeons should notify this point when they plan early distraction treatment for cleft maxillary deformity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.577-580
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• 2003

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along single of several shear surfaces. separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests new approach to the constriction of slip-line field, which Implies uniform compression in chip formation zone. On the base of given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination have been considered. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model could be useful in solution of various problems of machining.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.173-178
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• 1977

A 51 year old man was admitted to the Thoracic and Cardiovascular Department of Kyungpook University Hospital on April 7, 1976, with chief complaints of orthopnea and the chest pain for about 3 months. Physical examination showed narrow pulse pressure, puffy face, engorged neck veins at sitting position, distant heart sound, enlarged liver and edematous upper extremities. The chest roentgenogram demonstrated markedly enlarged cardiac silhouette. Low voltage and the low to diphagic T`s were noted on the electrocardiogram. Paroxysmal ventricular tachycardia was developed intermittently and was subsided spontaneously. Repeated pericardiocentesis were performed each of which yielded from 100 to 300ml. but intractable cardiac failure was progressed. The bacteriology and cytology of the pericardial fluid were not revealed any specific findings. The pericardiectomy was performed to release the intractable cardiac tamponade. Pericardium was found to be thickened and cardiac constriction was noted. The thickened pericardium was easily removed. A large hen`s egg sized dark blue tumor mass occupied the anterior wall of the right atrium and two thumb tip sized pearl gray tumors were placed at the just below portion of the main pulmonary artery. The biopsy report revealed primary fibrosarcoma of the heart. The patient was improved from the symptoms of the cardiac failure during the postoperative course.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.3
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• pp.24-28
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• 2005

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along one of several shear surfaces, separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests a new approach to the constriction of slip-line field, which implies uniform compression in chip formation zone. Based on the given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination has been considered as well. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model would be useful in understanding mechanistic problems in machining.

• Journal of Oral Medicine and Pain
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• v.45 no.4
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• pp.97-109
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• 2020

Purpose: Cervicogenic headache (CGH) is pain referred to the head/ face from the structures in vicinity of upper cervical spinal nerves via trigeminocervical pathway. Ponticulus Posticus (PP) and Elongated Styloid Process (ESP) are anatomical structures that cause compression of vasculature present around upper cervical nerve plexus. Recently, computational fluid dynamics (CFD) has shown to play an essential role in identification of these high-pressure zones in the brain. The aim of this research is to study the association of ESP and PP in patients with CGH and to develop a hypothesis by CFD to analyse vertebrobasilar insufficiency as a contributing factor in occurrence of CGH. Methods: Retrospective analysis of 4500 full skull CBCT scans was done for the presence of partial or complete PP and length of Styloid Process (SP). Research was divided into two phases; In first Preliminary Phase, 150 scans that showed the presence of PP and ESP were analysed, and only 134 patients gave consent to fill the questionnaire containing 96 question items pertaining to symptoms associated with CGH. In the second phase, simulation of Vertebral and Carotid Artery was done using Fluent 14.5 Software and by CFD, pressure distribution on arteries was obtained that helped to identify high pressure regions. Results: Both PP and ESP showed a statistically significant association with CGH (p<0.001). By CFD analysis, both steady and transient phases of simulation showed drop in pressure due to constriction of internal carotid and vertebral artery by ESP and PP respectively and were found to decrease the volume of blood reaching the brain, 0.12 /0.13 mL and 0.06 mL respectively. Conclusions: Our analysis proves ESP and PP as contributing factors towards CGH. Hence for proper diagnosis and management of headache disorders, clinicians should have adequate knowledge about these anatomical structures and their resulting clinical symptoms.