• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.4
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• pp.314-318
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• 2011

Purpose: The purpose of this study is to evaluate the results of alveolar bone grafting in patients with various types of cleft lip and to compare the success rates according to the lateral incisors and canines. Methods: The postoperative radiographs of 20 patient with a cleft lip and alveolar process alone (CLAP), complete unilateral cleft lip and palate (UCLP) and complete bilateral cleft lip and palate (BCLP) were retrospectively analyzed. The alveolar bone height was classified according to ${\AA}$byholm (1981) and Bergland (1986) and we evaluated the dentition at the time of surgery and the existence of a lateral incisor and impacted canines. Results: 16 (80%) of the 20 patients were assigned to Type I & II and they were considered successful. In the UCLP group, the success rate was significantly better than that of the UCLP and BCLP groups. The success rate was significantly better than when the cleft was grafted with the existence of a lateral incisor and before the eruption of the canines. Conclusion: The severity of the deformity influenced the success rate. The timing of the operation was a critical variable that affected the outcome in patients with cleft lip and palate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.636-642
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• 2007

Background: CpG DNA plays an important role in immune cell function. This study examined whether the temporal control of toll-like receptor (TLR)9 by CpG DNA can regulate the expression of matrix metalloproteinase-9(MMP-9). Methods and materials: Macrophages were cultured in the presence of 10% FBS. For the various MMP genes analysis, RT-PCR and real-time PCR were performed. In addition, zymography assay performed for the MMP activity. The phosphorylation assay did for the ERK1/2 and NF${\kappa}B$ activation, and luciferase promoter assay was for the NF${\kappa}B$ activity. Results: CpG DNA induced the mRNA expression of MMP-2, MMP-9, and MMP-13, but not of MMP-7, MMP-8, and MMP-12, in a time-dependent manner. Especially, the mRNA expression of MMP-9 was strongly induced by CpG DNA using real-time RT-PCR. The TLR9 inhibitor, chloroquine, suppressed CpG DNA-induced MMP-9 expression and its activity. Moreover, CpG DNA induced the phosphorylation of ERK and the inhibition of ERK by U0126 suppressed CpG DNA-induced MMP-9 expression and its activity. CpG DNA stimulated $I{\kappa}B-{\alpha}$ degradation and luciferase activity. In addition, pretreatment of SN-50, the inhibitor of NF${\kappa}B$, strongly blocked the CpG DNA-induced MMP-9 expression and activity. Conclusion: These observations suggest that CpG DNA may play important roles in the activation of macrophages by regulating the production of MMP-9 via the sequential TLR9-ERK-NF${\kappa}B$ signaling pathway.

• Journal of Yeungnam Medical Science
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• v.21 no.2
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• pp.242-250
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• 2004

In general, the skeletal class III has the characteristics of mandibular overgrowth with a normal maxillary growth or maxillary undergrowth with a normal mandibular growth And clinical and radiographic evaluations of the patient are needed. However, the treatment plan is not dependent on these evaluations alone, because patient's general condition and hope for aesthetics varies. The aim of this report is to consider the treatment of a medically compromised patient with an anterior open bite and skeletal class III, which showed a severe mandibular overgrowth. In 2003, a 17-year-old boy with epilepsy, mental retardation presented at our clinic complaining of concave profile. A clinical examination showed severe mandibular prognathism with an anterior open bite. The radiographic examination revealed a short cranial base, a moderate maxillary overgrowth, severe mandibular overgrowth and skeletal open bite tendency. In 2004, he was verified to have no potential of growth by hand-and-wrist radiographs and an endocrine examination. He completed the preoperative orthodontic treatment and orthognathic surgery (sagittal split ramus osteotomy, genioplasty). He was evaluated on the first visit, the preoperative period and the postoperative period with a clinical and radiographic examination. At the first visit, the patient showed moderate overgrowth of the maxilla, severe overgrowth of the mandible, and a subsequential skeletal open bite. After the preoperative orthodontic treatment (preoperative period), the patient showed the same skeletal problem as before and a decompensated dentition for orthognathic surgery. After orthognathic surgery, his profile had improved, but he had still a skeletal openbite tendency because the maxillary orthognathic surgery was not performed. Severe mandibular prognathism with a maxillary overgrowth and anterior open bite should be treated by bimaxillary orthognathic surgery. However, one-jaw orthognathic surgery on the remaining the skeletal open bite tendency was performed for his medical problem and facial esthetics. This subsequential open bite should be resolved with a postoperative orthodontic treatment.

• Journal of Yeungnam Medical Science
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• v.25 no.2
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• pp.108-116
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• 2008

Background : When surgeons plan mandible ortho surgery for patients with skeletal class III facial asymmetry, they must be consider the exact method of surgery for correction of the facial asymmetry. Three-dimensional (3D) CT imaging is efficient in depicting specific structures in the craniofacial area. It reproduces actual measurements by minimizing errors from patient movement and allows for image magnification. Due to the rapid development of digital image technology and the expansion of treatment range, rapid progress has been made in the study of three-dimensional facial skeleton analysis. The purpose of this study was to conduct 3D CT image comparisons of mandible changes after mandibular surgery in facial asymmetry patients. Materials & methods : This study included 7 patients who underwent 3D CT before and after correction of facial asymmetry in the oral and maxillofacial surgery department of Yeungnam University Hospital between August 2002 and November 2005. Patients included 2 males and 5 females, with ages ranging from 16 years to 30 years (average 21.4 years). Frontal CT images were obtained before and after surgery, and changes in mandible angle and length were measured. Results : When we compared the measurements obtained before and after mandibular surgery in facial asymmetry patients, correction of facial asymmetry was identified on the "after" images. The mean difference between the right and left mandibular angles before mandibular surgery was $7^{\circ}$, whereas after mandibular surgery it was $1.5^{\circ}$. The right and left mandibular length ratios subtracted from 1 was 0.114 before mandibular surgery, while it was 0.036 after mandibular surgery. The differences were analyzed using the nonparametric test and the Wilcoxon signed ranks test (p<0.05). Conclusion: The system that has been developed produces an accurate three-dimensional representation of the skull, upon which individualized surgery of the skull and jaws is easily performed. The system also permits accurate measurement and monitoring of postsurgical changes to the face and jaws through reproducible and noninvasive means.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.3
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• pp.195-199
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• 2013

Pseudoaneurysms are rare complications of orgthognathic surgery, trauma or other surgical procedures in the head and neck regions. Surgical approach is a routine procedure of bleeding control. However, bleeding control using angiography and embolization can also be an excellent method. We experienced pseudoaneurysm of the inferior alveolar artery occurring after surgical curettage of cystic lesion. The 33-year-old man who underwent surgical curettage of keratocystic odontogenic tumor was presented with severe bleeding in the right mandible ramal inner surface 14 days after the surgical curettage. After hemostasis with vaseline gauze packing and pressure, bleeding temporarily stopped. However, bleeding started after 14 days and soon it has been continued. Finally, the patient was diagnosed as pseudoaneurysm of the inferior alveolar artery from the enhanced-computed tomography images, and angiographic embolization was performed successfully. We report a rare case of pseudoaneurysm of the inferior alveolar artery after benign tumor curettage and review of the previewer's literature.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.271-279
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• 1985

The authors treated a case of bimaxillary dentoalveolar protrusion corrected by anterior segmental osteotomies: As presurgical treatment & process, closing of the upper anterior spacing with fixed appliances was worked out, cephalometric predicition & model surgery was done, and fabrication of intra-arch acrylic resin splints were made. It was not necessary to make an intermaxillary fixation with wire after surgery. Only intramaxillary fixation of anterior retracted mobile segment with resin plate was required for 8 weeks. After surgical treatment, leveling of the upper and lower arch with rectangular arch wire were accomplished as the Intrusion of anterior teeth proceeded. We will continue to improve the class II molar relationship by using class II elastics and have a good occlusiion through the orthodontic treatment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.1
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• pp.72-78
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• 2015

Recently, the usage of the satellite is increased more and more in the areas that are communication, weather, marine, optical, radar etc. The functions of the Satellite are evolving from passive transponder to active transponder by the developing of a technology. Advanced countries in satellites install the DCAMP for increase of bandwidth efficiency, improvement of QoS by interference rejection. DCAMP includes many digital components in order to implement functions. Thus, these kinds of active transponders consume much more power compared to passive transponder and then increase the heat. In this paper, we discuss the TVAC test result of DCAMP in EQM(Engineering Qualification Model) level. The paper shows the test results of digital gain control in order to verify DCAMP status under the TVAC test. In addition, the temperature and heat condition of main components from viewpoint of derating will be treated through the official environment test for qualification.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.3
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• pp.263-268
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• 2002

DFDM is a good candidate for beyond-3G high-speed wireless communication application because of the robustness to the intersymbol interference and multipath fading. However. an OFDM signal has a serious problem of the high PAPR, which results in the significant nonlinear distortion when it passes through a nonlinear high power amplifier. We propose a new PAPR reduction method using pre-emphasis and clipping. Via the proposed method, the OFDM output signal can have a low PAPR and BER improvement. Then. de-emphasis process is requisite in OFDM receiver. PAPR is reduced to about 5.7 ㏈ at the CCDF= 10$\^$-3/ when the subcarrier number is 16, QPSK modulation is used. pre-emphasis change point Is 3/9 of the peak amplitude of the IFFT output and clipping level is 11 in the IFFT output amplitude. The required SNR at BER=10$\^$-3/ the proposed system is improved by 2 dB than that of the original OFDM system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2A
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• pp.159-166
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• 2008

In this paper, we proposed an algorithm to solve the problem that can't maintain hop synchronization using only early-late gate tracking loop due to the drift of geo-stationary satellite in frequency hopping satellite communication system. When the signal is transferred to downlink through DRT(Dehop-Rebop Transponder), the problem with synchronization loss is occurred periodically when using only early-late gate tracking loop, because of energy loss in each side portion of hop due to orbital variation of the satellite. To solve this problem, we have developed Anti-Shrink synchronization tracking algorithm which uses the prediction value of transmission timing and the structure of inner-outer gate instead of early-late gate with the ranging information. Through simulations, we showed that the performance of the Anti-Shrink algorithm is better than that of simple inner-outer energy ratio algorithm and similar to that of conventional early-late tracking loop algorithm with ranging information. No synchronization failure in the proposed algorithm was occurred because of less energy loss and robustness without the ranging information.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.208-214
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• 2001

Background: When we make treatment plan of class III malocclusion children, it is difficult to determine whether we treat it with orthognathic surgery or without orthognathic surgery. To determine that, we must consider many factors, such as cephalometric analysis, growth pattern, family history, and skeletal age. A Harvold cephalometric analysis is useful in determining the amount of discrepancy by comparing the maxillary unit length with mandibular, unit length. We tried this study to help the decision of treatment planning in class ill malocclusion children by comparison in class III malocclusion and normal occlusion children using a Harvold analysis. Materials and Methods: The materials for this study consisted of 20 class III malocclusion children. Cephalometric tracing and measurements were performed by one investigator. The control group consisted of 18 normal occlusion children and lateral cephalograms were obtained from 8.5 to 14.5 years old children biannually. The relationships between class III malocclusion group and normal occlusion group were evaluated statistically. Results: The lower anterior facial heights between two groups were not significantly different, although the lower anterior facial heights of class III malocclusion group was higher than those of normal occlusion group in all age groups. The Maxillary-mandibular unit length differences of class III malocclusion group were significantly higher than those of normal occlusion group(p<0.05). Conclusion: A Harvold analysis was useful to make treatment planning for class III malocclusion children.