• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.26 no.1
• /
• pp.58-62
• /
• 2015

Xanthoma disseminatum (XD) is a benign, non-Langerhans cell histiocytosis characterized by disseminated xanthomatous lesions with face, flexures, and mucosa. Most of XD develops in mucocutaneous lesions including skin, oral cavity and pharynx, however laryngeal involvement is uncommon. While the natural course of XD is usually benign and often self-limiting, but XD develop in critical anatomical locations may result in morbidity and mortality. Localized mucous lesions in oropharynx and larynx lead to dysphagia, dyspnea and air way obstruction. The diagnosis of XD was based on clinical, histological and immunohistochemical findings. The treatment is complex and non-consensual. Local treatment with cryotherapy, radiotherapy, surgery, and carbon dioxide lasers have been attempted with various results. Systemic medication with peroxisome proliferator-activated gamma receptors, statins, fenofibrate, chlorodeoxyadenosine, cyclophosphamide, doxycycline, and cyclosporine have also been reported, but none have proven particularly successful. A 59-year-old man presented with respiratory symptoms because of laryngeal involvement of XD. We had to remove the obstructive lesion for relieving the symptoms. We experienced XD in Larynx that was rare in otorhinolaryngology. So we report this case with review of literatures.

• Archives of Craniofacial Surgery
• /
• v.22 no.4
• /
• pp.183-192
• /
• 2021

Background: The purse-string suture (PSS) is a simple and rapid wound closure method that results in minimal scarring. It has been used to treat circular or oval skin defects caused by tumor excision or trauma. However, due to obscurity, it is not widely used, especially for the head and neck. This study aimed to modify the PSS to obtain predictable and acceptable results. Methods: A total of 45 sites in 39 patients with various types of skin and soft tissue defects in the head and neck were treated with PSS. We used PDS II (2-0 to 5-0), which is an absorbable suture. Minimal dissection of the subcutaneous layer was performed. The suture knot was hidden by placing it in the dissection layer. Depending on the characteristics of the skin and soft tissue defects, additional surgical interventions such as side-to-side advancement sutures, double PSS, or split-thickness skin graft were applied. Results: All wounds healed completely without any serious complications. Large defects up to 45 mm in diameter were successfully reconstructed using only PSS. Postoperative radiating folds were almost flattened after approximately 1-2 months. Conclusion: PSS is simple, rapid, and relatively free from surgical design. Owing to the circumferential advancement of the surrounding tissue, PSS always results in a smaller scar than the initial lesion and less distortion of the body structures around the wound in the completely healed defect. If the operator can predict the process of healing and immediate radiating folds, PSS could be a favorable option for round skin defects in the head and neck.

• Korean Journal of Head & Neck Oncology
• /
• v.2 no.1
• /
• pp.49-59
• /
• 1986

The surgical reconstruction of major defects of the head and neck such as those following accidental injuries or resection of tumors has been facilitated and advanced by the development of myocutaneous flaps which provide both muscle bulk and skin coverage. Of the many available myocutaneous flaps, the pectoralis major myocutaneous flap has many advantages such as abundant tissue with an excellent vascularity, anatomic proximity, long arc of rotation, reliability and versatility, so it is used most frequently in head and neck reconstruction. It is the purpose of this paper to present our experiences with two cases of pectoralis major myocutaneous island flaps used in reconstruction of major defects of face; one is after resection of very large basal cell carcinoma of the left oral commissure and the other is after resection of a huge fibrous mass and destructed facial bones caused by chronic osteomyelitis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.603-607
• /
• 2004

The vision-based driver fatigue detection is one of the most prospective commercial applications of facial expression recognition technology. The facial feature tracking is the primary technique issue in it. Current facial tracking technology faces three challenges: (1) detection failure of some or all of features due to a variety of lighting conditions and head motions; (2) multiple and non-rigid object tracking and (3) features occlusion when the head is in oblique angles. In this paper, we propose a new active approach. First, the active IR sensor is used to robustly detect pupils under variable lighting conditions. The detected pupils are then used to predict the head motion. Furthermore, face movement is assumed to be locally smooth so that a facial feature can be tracked with a Kalman filter. The simultaneous use of the pupil constraint and the Kalman filtering greatly increases the prediction accuracy for each feature position. Feature detection is accomplished in the Gabor space with respect to the vicinity of predicted location. Local graphs consisting of identified features are extracted and used to capture the spatial relationship among detected features. Finally, a graph-based reliability propagation is proposed to tackle the occlusion problem and verify the tracking results. The experimental results show validity of our active approach to real-life facial tracking under variable lighting conditions, head orientations, and facial expressions.

• Journal of the Korean Geotechnical Society
• /
• v.28 no.5
• /
• pp.67-76
• /
• 2012

This study is a research about cutter bits arrangement of shield-TBM and carried out a scale model test and numerical analysis according to a space of cutter bits. A cutter head pressures and an advance time are measured to be followed by the space of cutter bits with an advance speed through the scale model test. We conducted the numerical analysis to verify the result of the scale model test, and to compare with the scale model test. There are three cases of space : unification 1.0D and 1.5D. In case TBM is excavated and space is 1.0D, the advance speed is much faster than the other cases, and pressure of face of ground deformation and cutter head is maintained stably. If additional researches about bits arrangement of cutter head of sand ground based on the result of this research are performed, substantial results may be obtained.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.2 no.3
• /
• pp.53-60
• /
• 2009

The vision-based driver fatigue detection is one of the most prospective commercial applications of facial expression recognition technology. The facial feature tracking is the primary technique issue in it. Current facial tracking technology faces three challenges: (1) detection failure of some or all of features due to a variety of lighting conditions and head motions; (2) multiple and non-rigid object tracking; and (3) features occlusion when the head is in oblique angles. In this paper, we propose a new active approach. First, the active IR sensor is used to robustly detect pupils under variable lighting conditions. The detected pupils are then used to predict the head motion. Furthermore, face movement is assumed to be locally smooth so that a facial feature can be tracked with a Kalman filter. The simultaneous use of the pupil constraint and the Kalman filtering greatly increases the prediction accuracy for each feature position. Feature detection is accomplished in the Gabor space with respect to the vicinity of predicted location. Local graphs consisting of identified features are extracted and used to capture the spatial relationship among detected features. Finally, a graph-based reliability propagation is proposed to tackle the occlusion problem and verify the tracking results. The experimental results show validity of our active approach to real-life facial tracking under variable lighting conditions, head orientations, and facial expressions.

• The korean journal of orthodontics
• /
• v.31 no.1 s.84
• /
• pp.25-38
• /
• 2001

The purpose of this study was to compare the force, the displacement and the stress distribution on the maxillary first molars altered by the application of various asymmetric head-gear. For this study, the finite element models of unilateral Cl II maxillary dental arch was made. Also, the finite element models of asymmetric face-bow was made. Three types of asymmetric face-bow were made : each of the right side 15mm, 25mm and 35mm shorter than the left side. We compared the forces, the displacement and the distribution of stress that were generated by application of various asymmetric head-gear, The results were as follows. 1. The total forces that both maxillary first molars received were similar in all groups. But the forces that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow shortened. 2. In lateral force comparison, the buccal forces that normally positioned tooth received were increased as the length of the outer-bow shortened, and the buccal fortes that mesially positioned tooth received were decreased as the length of the outer-bow shortened. Though the net lateral force moved to the buccal side of normally positioned tooth as the length of the outer-bow shortened, both maxillary first molars received the buccal force. That showed 'Avchiai Expansion Effect' 3. The distal forces, the extrusion forces and the magnitudes of the crown distal tipping that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow was shortened. 4. The magnitude of the distal-in rotation that normally positioned tooth received were increased as the length of the outer-bow was shortened. But, mesially positioned tooth show two different results. For the outer-bow 15mm shortened, mesially positioned tooth showed the distal-in rotation, hut for the outer-bow 25mm and 35mn shortened, mesially positioned tooth showed the distal-out rotation. Thus, the turning point exists between 15mm and 25mm. 5. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the compressive stress in the distobuccal root of the normally positioned tooth moved from the palatal side to the distal side and the buccal side successively as the length of the outer-bow shortened. 6. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the magnitudes of stress were altered but the total stress distributions were not altered in the mesiobuccal root and the palatal root of normally positioned tooth, and also three roots of mesially positioned tooth as the length of the outer-bow shortened.

• Korean Journal of Head & Neck Oncology
• /
• v.17 no.2
• /
• pp.190-193
• /
• 2001

Background and Objectives: Reliable and versatile free flap has become a mainstay in reconstruction of the head and neck. But until now pectoralis major myocutaneous flap (PMMCF) as workhorse is useful and has some advantages such as good viability, one-stage reconstruction and carotid protection. The objective of this study was to review the role and indication of PMMCF in this era of potent free flaps for head and neck reconstruction. Patients and Methods: Sixty one PMMCF and one hundred forty six free flaps used for head and neck reconstruction between 1991 and 2001 were reviewed retrospectively. We compared the applied sites of flap, the flap failure rate and complications. Results: Contrary to the free flap, use of PMMCF has gradually decreased after the middle of 1990s. PMMCF were mainly used for mucosal defect(33cases, 54.1%) and cervical skin defect(22cases, 36.1%) and free flap were mainly used for mucosal defect(129cases, 88.4%). In point of use of PMMCF according to years, from 1991 to 1997, 30cases(70%) are used to reconstruct mucosal defect and 12cases(29%) are used to reconstruct skin defect. But from 1998 to 2001, only 2cases(10.5%) are used to reconstruct mucosal defect and 13cases(68.4%) are used to reconstruct neck skin defect. In case of free flap, from 1991 to 1997, 41cases (87%) are used to reconstruct mucosal defect and from 1998 to 2001 88cases(89%) are used as same purpose. Three major necrosis (more than 50%) deveolped in 61 PMMCF (4.9%) and three major necrosis developed in 146 free flaps(2.1%). Conclusion: PMMCF is no longer flap of choice for primary reconstruction but it is a still one of a good tool in some head and neck reconstruction such as covering single wide defect of face or neck skin, back-up procedure of free flap, postoperative status, treatment of pharyngocutaneous fistula and covering vital structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.870-874
• /
• 2007

Golf ball spin rate after impact with club is created by the contact force, which is greatly influenced by ball and club mass, material, impact speed, and club loft angle. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of the ball, and the tangential force creates the spin. Especially, the tangential force takes either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail. It is shown in this work that the linear impulse of the tangential force is directly related to generation of back spin rate of golf ball. The linear impulse can be calculated from the tangential force, which depends upon many factors such as ball and club mass, material, impact speed, and club loft angle. In this research, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and the contact time at impact between golf club head and ball are computed using FEM.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.11
• /
• pp.1127-1132
• /
• 2007

Golf ball spin rate after impact with club is created by the contact force, which is greatly influenced by ball and club mass, material, impact speed, and club loft angle. Previous studies showed that the contact force is determined as the resultant force of the reaction forces normal and tangential to the club face at the contact point. The normal force causes the compression and restitution of the ball, and the tangential force creates the spin. Especially, the tangential force takes either positive or negative values as the ball rolls and slides along the club face during impact. Although the positive and negative tangential forces are known to create and reduce the back spin rate, respectively, the mechanism of ball spin creation has not yet been discussed in detail. It is shown in this work that the linear impulse of the tangential force is directly related to generation of back spin rate of golf ball. The linear impulse can be calculated from the tangential force, which depends upon many factors such as ball and club mass, material, impact speed, and club loft angle. In this research, the influence of the contact force between golf club and ball is investigated to analyze the mechanism of impact. For this purpose, the contact force and the contact time at impact between golf club head and ball are computed using FEM.