Showing papers in "Journal of The Korean Association of Oral and Maxillofacial Surgeons in 2006"

Endoscopic-assisted open reduction and internal fixation (EAORIF) for condylar fracture.

Abstract: The endoscopic-assisted approach for the treatment of condylar fracture are a less invasive alternative and overcomes the limited access to the operation field to obtain an accurate reduction and fixation. Nine condylar fracture patients underwent the endoscopic-assisted open reduction and internal fixation through the transoral approach at the department of oral and maxillofacial surgery, Seoul National University Dental Hospital. The endoscope was inserted through an intraoral incision and the reduction of fracture fragment was performed via a transbuccal approach with two transcutaneous stab incisions. Five patients showed anatomic reduction without any complications. Three patients, whose fracture site was fixed with a single plate, showed fratured condylar segment displacement during the follow-up period and one of them resulted in postoperative malocclusion. No patient had any facial nerve damage.

Development of biocompatible dressing material made of collagen and amniotic membrane and wound healing experiment in rat

Abstract: Purpose of study: Partial thickness skin graft is the golden standard regimen for full-thickness skin defect caused by burn or trauma. However, in case of extensive burns of more than 50% of total body surface area, the donor site is not sufficient to cover all defects. As a second choice, allograft, xenograft and synthetic materials have been used to treat skin defect. Among them the amniotic membrane(AM) was used as a biological dressing for centuries because of its potential for wound healing. In this study, quantification of EGF in AM and effect of AM-collagen complex on full thickness skin defects was examined. Materials & Methods: The concentration of EGF in fresh, deep frozen and freeze-dried AM was evaluated by ELISA. EGF-R immunostaining was performed in freeze-dried AM. SD rats weighing 250~300g was used for wound healing experiment. Three full thickness skin defects(28㎜ diameter) were made on dorsal surface of SD rat. The control group was covered by Vaselin gauze and AM-collagen complex and Terudermis was grafted in two other defects. Healing area, Cinamon's score were evaluated before biopsy. Grafted sites were retrieved at 3 days, 1 week, 2 weeks and 4 weeks after operation. H & E and Factor Ⅷ immunohistochemical stain was performed to evaluate the microscopic adhesion and structural integrity and microvessel formation. Results: 1. EGF concentration of fresh, deep frozen and freeze-dried AM showed similar level and EGF-R was stained in epithelial layer of freeze-dried AM. 2. At 4 weeks after grafting, the healing area of AM-collagen and Terudermis group was 99.29±0.71% and 99.19±0.77 of original size. However, that of control group was 24.88±2.90. 3. The Cinamon's score of AM-Collagen and Terudermis group at 4 weeks was 15.6±1.26 and 14.6±3.l3 and that of control group was 3.7±0.95. Significant difference was observed among control and experimental groups(p＜0.05). 4. Histologic examination revealed that AM protected leukocyte infiltration and epithelial migration was nearly completed at 4 weeks. Terudermis group showed mild neutrophil infiltration until 2 weeks and completion of epithelization at 4 weeks. Control group showed massive leukocyte infiltration until 4 weeks. 5. Microvessels were increased sharply at 1 week and control group at 1 and 4 week showed significant differences with Terudermis group of same interval(p＜0.05) but no differences were found with AM group(p＜0.05). Conclusion: EGF and EGF-R were well preserved in freeze-dried AM. AM attached to collagen acted as excellent biologic dressing which had similar effect with Terudermis. AM showed anti-inflammatory action and healing was completed at 4 weeks after full-thickness skin defect.

The most appropriate antimitotic treatment of ara-c in schwann cell-enriched culture from dorsal root ganglia of new born rat

Abstract: Schwann cell, one of important components of peripheral nervous system, interact with neurons to mutually support the growth and replication of embryonal nerves and to maintain the different functions of adult nerves. The Ara-C, known as an antimitotic agent, have been used to have high effectiveness in eliminating fibroblasts during Schwann cell culture period. This enrichment effect is also known to be cummulative with each successive pulse of Ara-C applied and is due to a progressive loss of fibroblasts. But the cytotoxicity by Ara-C is also cummulative and noticeable over the period To determine the most effective application time and interval of Ara-C in the Schwann cell culture, we observed the Schwann cell purity and density with the Ara-C treatment in plain and three-dimensional culture from dorsal root ganglion of new born rat. By culturing dispersed dorsal root ganglia, we can repeatedly generate homogenous Schwann cells, and cellular morphology and cell count with mean percentages were evaluated in the plain culture dishes and in the immunostainings of S-100 and GFAP in the three-dimensional culture. The Ara-C treated cultures showed a higher Schwann cell percentage (31.0%±8.09% in P4 group to 65.5%±24.08%, in P2 group), compared with that obtained in the abscence of Ara-C (17.6%±6.03%) in the plain culture after 2 weeks. And in the three-dimensional culture, S-100 positive cells increased to 56.22%±0.67% and GFAP positive cells to 66.46%±1.83% in G2 group (p＜0.05), higher yield than other groups with Ara-C application. Therefore, we concluded that the Ara-C treatment is effective for the proliferation of Schwann cells contrast to the fibroblasts in vitro culture, and the first application after 24 hours from cell harvesting and subsequent 2 pulse treatment (P2 group in plain culture and G2 group in three-dimensional culture) was more effective than other application protocols.

Finite Element Stress Analysis according to Apical - coronal Implant Position

Abstract: Purpose: The purpose of this study was to evaluate the influence of apical-coronal implant position on the stress distribution after occlusal and oblique loading. Materials and Methods: The cortical and cancellous bone was assumed to be isotropic, homogeneous, and linearly elastic. The implant was apposed to cortical bone in the crestal region and to cancellous bone for the remainder of the implant-bone interface. The cancellous core was surrounded by 2-㎜-thick cortical bone. An axial load of 200 N was assumed and a 200-N oblique load was applied at a buccal inclination of 30 degrees to the center of the pontic and buccal cusps. The 3-D geometry modeled in Iron CAD was interfaced with ANSYS. Results: When only the stress in the bone was compared, the minimal principal stress at load Points A and B, with a axial load applied at 90 degrees or an oblique load applied at 30 degrees, for model 5. The von Mises stress in the screw of model 5 was minimal at Points A and B, for 90- and 30-degree loads. When the von Mises stress of the abutment screw was compared at Points A and B, and a 30-degree oblique load, the maximum principal stress was seen with model 2, while the minimum principal stress was with model 5. In the case of implant, the model that received maximum von Mises stress was model 1 with the load Point A and Point B, axial load applied in 90-degree, and oblique load applied in 30-degree. Discussion and Conclusions: These results suggests that implantation should be done at the supracrestal level only when necessary, since it results in higher stress than when implantation is done at or below the alveolar bone level. Within the limited this study, we recommend the use of supracrestal apical-coronal positioning in the case of clinical indications.

Clinical and radiological comparison between titanium and biodegradable miniplate monocortical osteosynthesis in mandibular angle fractures.

Abstract: J. Kor. Oral Maxillofac. Surg. 2006;32:222-225) CLINICAL AND RADIOLOGICAL COMPARISON BETWEEN TITANIUM AND BIODEGRADABLE MINIPLATE MONOCORTICAL OSTEOSYNTHESIS IN MANDIBULAR ANGLE FRACTURES Eun-Joo Choi, Woong Nam, Young-Soo Jung, Ki-Ho Kim, Hyung-Jun Kim Department of Oral & Maxillofacial Surgery, College of Dentistry, Yonsei University The treatment objective of mandibular fracture is a return to normal function. According to Champy, a rigid fixation of mandibular angle fracture is performed by using 4 or 6 holes titanium miniplates on the external oblique ridge of mandible. However, the limitations of metal plate such as hypersensitivity, interference with the cranio-facial growth of growing child, secondary bone resorption around the plate, foreign body reaction, declination of primary callus formation, and bone atrophy due to the lack of normal stress reaction of the bone have been reported. Recently, biodegradable miniplate has been introduced and used as an alternative to the metal plate despite its lower strength than that of the titanium plate and the side effect caused by the resorption in the body. In this study, 61 patients diagnosed as mandibular angle fracture and treated from Jan. 1998 to Dec. 2004 in our department have been reviewed. Metal plate fixation was used in 50 patients and biodegradable plate fixation in 11 patients on the external oblique ridge around the fractured mandibular angle according to the principle of monocortical osteosynthesis by Champy. We compared the incidence of side effects and the degree of bony union at the mandibular inferior border in two different fixation methods. In conclusion, we have found that one miniplate regardless of matter could provide enough strength to grasp bony fragments of the tension site and compress the inferior border of mandible without any complications.

경부 및 이하부에 발생한 침습성 지방종의 치험례

Abstract: The lipoma is the neoplasm of mesenchymal origin. Although most lipomas occur on the trunk and the proximal portion of the extremities, lipomas of the oral and maxillofacial regions are relatively rare, approximately 13% of all cases. Lipomas have been found in all age, but usually found between 40 and 60 years of age. Clinically the lipoma is a painless, slowly growing, nearly always benign soft mass. The treatment of choice is a surgical excision, and the recurrence is rare. But the infiltrating lipoma originated from muscle has high recurrence rate. It has ill-defined border and little or no evidence of encapsulation. Histologically there is a consistent infiltration with dissociation of the surrounding muscle fiber. The infiltrating lipoma should be excised with surrounding normal muscle and tissue to prevent the recurrence. This case was a 57-year-old female with a painless swelling of the right cervical and parotid areas which was diagnosed as large infiltrating lipoma by clinical examination and radiographic findings. The patient was treated by surgical excision and showed good functional and esthetic results. Histologically the tumor was diagnosed as infiltrating lipoma with no evidence of malignancy.

Preliminary study on the effect of inflamed TMJ synovial fluid on the intracellular calcium concentration and differential expression of iNOS and COX-2 in human immortalized chondrocyte C28 / I2

Abstract: Objective. The objective of this study was to examine the hypothesis that inflammatory synovial fluid from TMJ internal derangement initiates a transient increase in intracellular calcium concentration ([Ca²+]i) in chondrocytes and the induced Ca2+ signaling affects iNOS/COX-2 gene expression patterns following exposure to inflamed synovial fluid. Materials and Methods. Two female adult patients with symptoms of TMD who agreed to participate in the study were selected for this study. Immortalized human juvenile costal chondrocyte C-28/I2 was grown to 80% con fluency and synovial fluids from two patients were added respectively to culture media for 24 hours at the concentration of 100ng/10ml. Confocal laser scanning microscope (CLSM) was used to examine changes of intracellular calcium concentration ([Ca²+]i). RT-PCR was performed to identify the expression profile of IL-1α, iNOS, COX-2. Results. Increased [Ca²+]i was observed in chondrocytes subjected to inflamed synovial fluid compared to control cultures and in respective cultures exposed to inflamed synovial fluids from each patient, IL-1β, COX-2 mRNA were detected. However, in neither case iNOS mRNA was expressed. IL-1α, COX-2, and iNOS mRNA were expressed in control culture. Conclusion. Our results show that immortalized chondrocytes cultured with inflamed synovial fluids from patients diagnosed as disc displacement without reduction and limitation in mouth opening showed increased calcium concentration and expression of COX-2 while inhibiting the production of iNOS, which in turn could adversely affect the chondrocytes in at least short term by hindering physiologic role of NO against inflammatory cascades. These findings suggest that inflamed synovial fluid may differentially regulate the transcriptomes of relevant inflammatory mediators, especially iNOS/COX-2 axis in chondrocytes through adjusting calcium transients.

Changes of transverse mandibular width after intraoral vertical ramus osteotomy

Abstract: OBJECTIVE The purpose of this study was to analyze the long-term changes in the horizontal transverse mandibular width (TMW) between the angles of mandible after intraoral vertical ramus osteotomy (IVRO) with respect to hard and soft tissues. STUDY DESIGN A total of 107 from a pool of 207 patients with mandibular prognathism who had undergone bilateral IVRO were retrospectively evaluated radiographically and photographically. A comparison study of the changes of horizontal transverse width in hard and soft tissues after surgery was performed using preoperative, and 1-, 3-, 6-, and 12-month postoperative posteroanterior (PA) cephalograms and clinical photos. Three groups were divided according to the amount of mandibular setback performed (Group 1: <5 mm, Group 2: 5-10 mm, Group 3: >10 mm). RESULTS The overall average amount of mandibular setback in all patients was 8.58 mm. Statistically significant increases of TMW in hard and soft tissue from preoperative to postoperative 1 month were seen. TMW in hard tissue showed a gradually decreasing pattern postoperatively from 1 month to 1 year, and the changes were statistically significant at 1 year postop. TMW in soft tissue was not changed uniformly after 1 month, and showed less than 1% change at 1-year postoperatively compared with preoperatively. The amount of increase in the TMW postoperatively was not proportional or statistically significant to the amount of mandibular setback performed. CONCLUSIONS The results show that mandibular setback using BIVRO did not significantly influence the TMW changes in soft tissue. Therefore, IVRO technique can be safely used without compromising esthetic results through soft tissue TMW increase.

Sympathetic and parasympathetic regulation of sodium transporters and water channels in rat submandibular gland

Abstract: The present study was aimed to explore the role of sympathetic and parasympathetic nerves in the regulation of sodium transporters and water channels in the salivary gland. Rats were denervated of their sympathetic and parasympathetic nerves to the submandibular gland, and the glandular expression of sodium transporters and water channels was determined by Western blot analysis. The expression of either α1 or β1 subunit of Na, K-ATPase was not significantly affected either by the sympathetic or by the parasympathetic denervation. The expression of subunits of epithelial sodium channels was significantly increased both in the denervated and contralateral glands either by the sympathetic or by the parasympathetic denervation. Neither the sympathetic nor the parasympathetic denervation significantly altered the expression of aquaporin-1 (AQP1). Nor was the expression of AQP4 affected significantly by the parasympathetic or the sympathetic denervation. On the contrary, the expression of AQP5 was significantly increased not only by the parasympathetic but also by the sympathetic denervation. These results suggest that sympathetic and parasympathetic nerves have tonic regulatory effects on the regulation of certain sodium transporters and AQP water channels in the salivary gland.

Accuracy of preoperative assessments for cervical lymph node metastasis in oral cancer

Abstract: There were some limits on the accuracy of clinical and radiologic assessments in the preoperative detection of the cervical lymph nodes in oral cancer. To improve the accuracy, it is important to communicate between clinician and radiologist, and adjunctive diagnostic measures, ultrasound and fine needle aspiration cytology, were helpful increasing the overall efficiency. In the high risk sites (oral tongue and floor of the mouth) the false negative value is higher and the overall efficiency in radiologic evaluation is lower than those of the low risk sites (gingiva and alveolar ridge, retromolar trigone and buccal mucosa). The elective neck dissection should be considered in the high risk sites.

Application of bioabsorbable plates in orthognathic surgery

Abstract: Backgrounds: Though they are considered as reliable devices, titanium plates and screws have limitations due to some potential problems. To overcome these problems, researches on bioabsorbable materials for internal fixation have been continuing. Recently, there are many clinical trials to apply biodegradable internal fixation devices in oral and maxillofacial surgery. The purpose of this study was to evaluate the clinical results of application of bioabsorbable plates and screws in orthognathic surgery. Methods: Fifty-four patients with dentofacial deformity (17 male patients and 37 female patients) were selected in this study. The patients were treated by internal fixation using bioabsorbable plates and 2.4-㎜, 2.0-㎜ pretapped screws (Biosorb FX, Bionix Implants, Inc., Finland). The patients were evaluated for complications during the follow-up period. Results: Five patients(9.3%) experienced complications. All complications in these cases were infection. No other complications related with physical or mechanical properties of bioabsorbable plates were found such as malunion or nonunion, fractures of plates and loosening of screws. All complications were minor and adequately managed with drainage and supportive care with antibiotics coverage. Conclusions: From the results, the use of these fixation systems in orthognathic surgery will provide a promising alternative titanium fixation in appropriate cases.