• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.38
• /
• pp.22.1-22.6
• /
• 2016

Background: The aim of this study is to quantitatively evaluate the effect of rhBMP-2 for repair of bone defects after cyst enucleation using the osteogenesis index (OI). Methods: Under general anesthesia, 10 patients (12 lesions) underwent oral or maxillofacial surgery for cyst enucleation. Postoperatively, 12 lesions were divided into two groups: group A (six lesions) was treated with absorbable collagen sponge (ACS) in combination with rhBMP-2, and group B (six lesions) was treated with ACS alone. After 3 months, cone-beam computed tomographic scans were obtained to measure changes in the volume of the lesions. We then calculated the OI of each group at two different Hounsfield units to determine any statistically significant difference between these two groups (Mann-Whitney U test). Results: As tested at the level of new bone, the mean OI was 72.37 % in group A and 55.08 % in group B -a statistically significant difference (p = 0.041). As tested at the level of mature bone, the mean OI was 27.47 % in group A and 18.88 % in group B, but the difference was not statistically significant (p = 0.394). Conclusions: The application of rhBMP-2 after maxillofacial cyst enucleation accelerated new bone formation in the bone defects. Thus, the use of rhBMP-2 in combination with ACS may be considered an alternative to conventional bone grafting in some patients with postoperative bone defects.

• Archives of Craniofacial Surgery
• /
• v.14 no.2
• /
• pp.129-132
• /
• 2013

Cutaneous squamous cell carcinoma is the second-most common skin cancer and represents 20% of all skin cancers. Cutaneous squamous cell carcinoma often spreads to the parotid gland through lymph nodes, but, direct invasion of an adjacent organ may also occur. We present the case of 78-year-old man with ulcerated mass on the right infra-auricular area. The histopathologic finding was squamous cell carcinoma. There was no evidence of distant metastasis, but the mass was found to invade the superficial lobe of the right parotid gland. The mass was widely excised and superficial parotidectomy was performed while preserving the facial nerve. The defect was covered by primary closure. Postoperative radiotherapy was performed. At 20 months after surgery, our patient had no facial palsy, local recurrence, or metastasis. Cutaneous squamous cell carcinoma involving the parotid gland is an aggressive, rapidly advancing lesion, which if not recognized and treated early will result in high morbidity and mortality. Squamous cell carcinoma of the parotid gland has shown that patients who receive adjuvant radiotherapy have a lower recurrence rate and a higher survival rate than patients treated with surgery alone. The role of elective neck dissection remains controversial.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.29 no.2
• /
• pp.182-186
• /
• 2007

A cyst is a pathologic lesion characterized by a cavity filled with fluid, celluar products, air, or a combination of these. Dentigerous cysts were formed around the crown of unerupted teeth. The reduced enamel epithelium persists around the crown after it has formed. Proliferation of the epithelium in a fluid-filled sac may be induced by osmotic pressure. In the first decade the most frequent location is the premolar site. In each subsequent decade the largest number of cysts are in the mandibular third molar site, with the second most frequent site being the maxillary canine. The treatment of odontogenic cyst can be mostly classified into three types of cyst enucleation, marsupialization and decompression. We should consider age of patient, anatomic structure, location and size for choosing a treatment method. Advantage of cyst enucleation is fast healing, but a injury of a surrounding structure is highly. Marsupialization is conservative treatment that can reduce the damage of a adjacent structure, but it is only limited at superficial lesion. Decompression also is conservative treatment, but it has the difficulty of the oral hygiene and the troublesome of the lavage. We present the possibility that reduces the defect of decompression and cures the lesion efficiently. We report a male patient with the dentigerous cyst developed at left mandibular third molar in this study. We used the decompression for a treatment and created special appliance to treat the lesion efficiently. We report a case of the cyst treatment that is association with efficiency of decompression appliance.

• Earthquakes and Structures
• /
• v.10 no.5
• /
• pp.1089-1109
• /
• 2016

Modified two-surface model (M2SM) is one of the steel elasto-plastic hysteretic constitutive models that consider both analysis accuracy and efficiency. However, when M2SM is used for complex strain history, sometimes the results are irrational due to the limitation of stress-strain path judgment. In this paper, the defect of M2SM was re-modified by improving the judgment of stress-strain paths. The accuracy and applicability of the improved method were verified on both material and structural level. Based on this improvement, the nonlinear time-history analysis was carried out for a deck-through steel arch bridge with a 200 m-long span under the ground motions of Chi-Chi earthquake and Niigata earthquake. In the analysis, we compared the results obtained by hysteretic constitutive models of improved two-surface model (I2SM) presented in this paper, M2SM and the bilinear kinematic hardening model (BKHM). Results show that, although the analysis precision of displacement response of different steel hysteretic models differs little from each other, the stress-strain responses of the structure are affected by steel hysteretic models apparently. The difference between the stress-strain responses obtained by I2SM and M2SM cannot be neglected. In significantly damaged areas, BKHM gives smaller stress result and obviously different strain response compared with I2SM and M2SM, and tends to overestimate the effect of hysteretic energy dissipation. Moreover, at some position with severe damage, BKHM may underestimate the size of seismic damaged areas. Different steel hysteretic models also have influences on structural damage evaluation results based on deformation behavior and low cycle fatigue, and may lead to completely different judgment of failure, especially in severely damaged areas.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.13 no.2
• /
• pp.203-216
• /
• 1991

Nerve allografts as a bridge of regeneration is useful in the repair of peripheral nerve defect resulting from trauma, and leprosy. But immunological rejection and complicated scar formation is an unavoidable problem in the application of allogeneic nerves. This article is intended to study of the regeneration of allogeneic nerve grafts in rats with histopathologically, scanning electron microscopically. 24 adult male Sprague-Dawley rats were used as the experimental animals. A 2cm skin incision was made on the lateral aspects of limb, parallel to femur. Segments of sciatic nerve trunk taken from rats, 10mm was resected at the middle of the thigh, nerve graft was inserted between the ends of gaps with perineural and epineural suture method with 10-0 prolene. Obsrevation was made simultaneously at 3 day, 1, 2, 3, 4, 5, 6, 8 weeks after surgery. The results were as follows. 1. In light and electronic microscopic studies, marked degenerative change of the graft nerves were observed at 2 weeks after surgery. 2. After surgery, blood clot fromation was observed at 3 day, granualtion tissue formation was observed at 2 week, and fibrous tissue proliferation was observed at 3 week. 3. In change of nerve fiber, there were Wallerian degeneration at early stage, decrease in degeneration at 4 week but degeneration of myeline was continuded at 8 week. 4. At 4 week, schwann cells proliferate at its cut ends to join with the distal and proximal stump of the damaged nerve. 5. Fibrous scar tissues are formed at 2 weeks and increased progressively in 8 weeks, which was interrupted the regeneration of grafted nerve.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.34 no.4
• /
• pp.286-292
• /
• 2012

The lateral upper arm flap (LUAF) was initially described by in 1982 by Song et al. as a simple skin flap, addressing the availability of cutaneous nerves for anastomoses. Katsaros et al., reported the use of a lateral upper arm skin flap, but also considered using it as a composite graft. The LUAF for the oral and maxillofacial reconstruction has several advantages over other flaps, such as constant anatomy, good color match and texture, thin design and plasticity. There is no functional limitation in the donor arm, such as strength and extension, and donor defects can be closed primarily with a linear scar, even when a flap of up to 8 cm in width is taken. For a better understanding of LUAF as a routine reconstructive option in moderate defect of maxillofacial region, the constant anatomical findings must be learned and memorized by young doctors during the specialized training course for the Korean national board of oral and maxillofacial surgery. This article review the anatomical basis of LUAF with Korean language.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.34 no.5
• /
• pp.367-375
• /
• 2012

Midfacial reconstruction following resection of extensive malignant oral cavity tumors constitutes a challenging problems for reconstructive surgeons. Rectus abdominis muscle free flap (RAMFF) can be considered as the optimal reconstructive option in this case, because this flap has some advantages including consistent deep inferior epigastric artery anatomy, easy to dissect with well defined skin boundaries, acceptable donor site morbidity and the ability to perform simultaneous flap harvest with oral cancer ablation surgery. The rectus abdominis muscle forms an important part of the anterior abdominal wall and flexes the vertebral column, which is a long strap-like muscle divided transversely by three tendinous intersections, fibrous bands which are adherent to the anterior rectus sheath, which is thickly enclosed by the rectus sheath, except for the posterior part below the arcuate line that is usually located midway between the umbilicus and symphysis pubis. Below the arcuate line, this muscle lies in direct contact with the transversalis fascia and parietal peritoneum. For the better understanding of RAMFF as a routine reconstructive procedure in oral and maxillofacial surgery, the constant anatomical findings muse be learned and memorized by the young doctors in the course of the special curriculum periods for the Korean national board of oral and maxillofacial surgery. This review article will discuss the anatomical basis of RAMFF with Korean language.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.5
• /
• pp.337-343
• /
• 2017

As a shop practice, a strength estimation method for die cast parts is suggested, in which various defects such as pores can be allowed. The equivalent porosity is evaluated by combining the stiffness data from a simple elastic test at the part level during the shop practice and the theoretical stiffness data, which are defect free. A porosity equation is derived from Eshelby's inclusion theory. Then, using the Mori-Tanaka method, the porosity value is used to draw a stress-strain curve for the porous material. In this paper, the Hollomon equation is used to capture the strain hardening effect. This stress-strain curve can be used to estimate the strength of a die cast part with porous defects. An elastoplastic theoretical solution is derived for the three-point bending of a die cast beam by using the plastic hinge method as a reference solution for a part with porous defects.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.37
• /
• pp.20.1-20.7
• /
• 2015

Background: The objectives of the present study were to investigate the reliability and outcomes of computer-assisted techniques in mandibular reconstruction with a fibula flap and verify whether the surgical navigation system was feasible in mandible reconstructive surgery. Methods: Eight cases were enrolled in the computer assisted surgery (CAS) group and 14 cases in the traditional group. The shaping and fixation of the fibula grafts were guided by computer assisted techniques, which could be monitored with the BrainLAB surgical navigation system. The variation of mandible configuration was evaluated by CT measurement in the Mimics software, including the variation of length, width, height and gonial angle of the mandible. The 3D facial soft tissue alteration was also analyzed in 3D chromatogram by Geomagic software. Results: All 22 fibula flaps survived. The mandibular configurations and facial contours had a better clinic result in the CAS group. The length, width, height and gonial angle of the reconstructive mandible were more similar to the original one. The Wilcoxon rank sum test analysis suggested significant differences in the measurements. The chromatographic analysis also visually showed superiority over the traditional group. Conclusions: The computer assisted surgical navigation method used in mandibular reconstruction is feasible and precise for clinical application. The contour of the reconstructed mandible and facial symmetry are improved with computer techniques.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.36 no.1
• /
• pp.25-29
• /
• 2014

The purpose of this study is to report on five cases treated with bone graft using recombinant human bone morphogenetic protein-2 (rhBMP-2) on jaw defects after cyst enucleation. We performed bone graft with BMP (rhBMP-2+${\beta}$-tricalcium phosphate/hydroxyapatite) wrapped with a collagen sponge on jaw defects after cyst enucleation. Postoperative panoramic radiographs were taken periodically. After 1 to 12 months, bone remodeling was observed in the jaw defect area. In our cases, there were few signs or symptoms of recurrence of the cyst during the follow-up period.