• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.631-635
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• 2007

Purpose: The classic technique for open reduction of subcondylar fractures is the submandibular approach. The aim of this study was to evaluate clinical result of retromandibular approach to displaced subcondylar fractures. Material and methods: During a period of 24months we perfomed a prospective study with a retromandibular approach in 23 patients with displaced subcondylar fractures. In this article we describe clinical result in 23 patients with follow ups for 3 months after surgery. Preoperatively all patients had malocclusion and radiology demonstrated displacement. Result: The retromandibularl approach for ORIF was good in all case. Mouth opening(M/O) was 49mm. Occlusion was good too. Permanent facial nerve palsy was not detected. Conclusion: Our findings indicate that the retromandibular approach is a safe technique for subcondylar fractures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.262-269
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• 2010

Introduction: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. Materials and Methods: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. Results: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. Conclusion: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.1
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• pp.57-61
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• 2010

In the presence of acute pericoronitis of mandilbular third molar, antibiotic therapy and early incision and drainage are the method of choice, followed by definitive surgical extraction of the tooth as soon as it becomes subacute. If excision of the overlying tissues is decided on, it should be done adequately. All overlying tissues must be throughly excised, and the crown portion of the unerupted tooth should be completely exposed. After excision has been completed, the wound should be managed with a surgical dressing. This should be allowed to remain approximately 7 days. And then, surgical extraction of the impacted mandibular third molar can be done usually. In this operation, there are many complications, such as, postoperative bleeding, infection, trismus, dysphasia and paresthesia. The surgeon are discredited and medicolegal problem may be occurred in the presence of many distressed complications. Therefore, the relatively nonsurgical treatment is the method of choice. So, authors selected the conservative treatment methods of incision and drainage, primary endodontic drainage, operculectomy without surgical extraction of the mandibular third molars. The results were more favorable without the postoperative complication in Wonju old offender prison.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.375-380
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• 2007

The purpose of this study is to understand anxiety in patients undergoing third molar extraction and care patients of third molar extraction. The subjects in the study were Sixty-three patients who visited the department of dentistry at Pusan Paik Hospital from May 2006 to September 2006 and who underwent third molar extraction. Patients' anxiety(state anxiety and trait anxiety) to use Spielberger's state-trait anxiety inventory(STAI) were measured. They were asked to fill out STAI question paper immediately before third molar extraction(pre-extraction) and on the day after the extraction(post-extraction). And visual analog scale(VAS) to measure patient's postoperative pain on the day after extraction(postextraction day) was used. Then Differences in anxiety before and after extraction, between men and women, between the first and second extraction, with impacted versus non impacted third molar extraction, between extraction time and anxiety, and between postoperative pain and anxiety were evaluated. The anxiety status of patients undergoing third molar extraction could be quantitatively evaluated using the STAI-KYZ. There were significant difference before and after third molar extraction. Especially women and patients of more severe postoperative pain was more anxious. We need to alleviate patient's anxiety(especially women) and to control postoperative pain throughout the tooth removal process.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.1
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• pp.53-56
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• 2010

Carcinoma ex pleomorphic adenoma is transformed at the incidence of 1-20% in pleomorphic adenoma and frequently recurred. It accounts for 10% of all malignant salivary tumors and its average age of occurrence is 60s. It will present in a large, long-standing pleomorphic adenoma or in one that was previously treated but has recurred. According to cell composition in malignant cell carcinoma, and clear cell adenocarcinoma. Most (75%) occur in parotid gland, while about 20% occur in the minor gland of the oral mucosa. The metastasis rate to regional lymph node is about 25%, and to distant organs about 33% and the 5-year survival rates are 40%. Though the treatment of the carcinoma ex pleomorphic adenoma is not established, it is treated ideally with and extensive resection, neck dissection, postoperative radiotherapy, and chemotherapy. When occurred in parotid gland, facial paralysis is reported. With a review of literatures, we report a case of carcinoma ex pleomorphic adenoma which operated with total parotidectomy and supraomohyoid neck dissection.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.314-319
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• 2010

Odontogenic infections are a normally locally confined, self-limiting process that is easily treated by antibiotic therapy and local surgical treatment. However, it may spread into the surrounding tissues through a perforation of the bone, and into contiguous fascial spaces or planes like the primary or secondary fascial spaces. If the infection extends widely, it may spread into the lateral pharyngeal and retropharyngeal space. The retropharyngeal space is located posterior to the pharynx. If an odontogenic infection spreads into this space, severe life-threatening complications will occur, such as airway obstruction, mediastinitis, pericarditis, pleurisy, pulmonary abscess, aspiration pneumonia and hematogenous dissemination to the distant organs. The mortality rate of mediastinitis ranges from 35% to 50%. Therefore, a rapid evaluation and treatment are essential for treating retropharyngeal space abscesses and preventing severe complications. Recently, we encountered two cases of a retropharyngeal space abscess due to the spread of an odontogenic infection. In all patients, early diagnosis was performed by computed tomography scanning and a physical examination. All patients were treated successfully by extensive surgical and antibiotic therapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.1
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• pp.39-42
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• 2010

Maxillary sinus lift and bone graft are used to reconstruct atrophic maxilla molar area for endosseous dental implants. Many different grafting materials and techniques can be used for maxillary sinus bone graft. Bio-$Oss^{(R)}$ has been proposed as bone substitute and successfully utilized as osteoconductive filler. Platelet rich plasma (PRP) is an autologous material with many growth factors, such as PDGF, TGF-$\beta$, IGF, VEGF, facilitating bone healing process. And Platelet poor plasma (PPP) is the by-product in procedure of producing PRP. Six rabbits were used as experimental animal. Both maxillary sinus were grafted with Bio-$Oss^{(R)}$ and PRP, and Bio-$Oss^{(R)}$ and PPP. Rabbits were sacrificed at 4, 8 and 12 weeks. The grafting sites were evaluated by histomorphometric analysis. As a result, using PRP showed excellent bone formation in the early stage, but no further significant effect after that. In late stage, the ability of bone formation of using PRP was even worse than using PPP. The further studies need to be considered in this case.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.325-330
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• 2010

Introduction: Mini-implant system is applicable to areas of narrow space and area requiring temporary loading support. The purpose of this study was to evaluate the clinical outcome of a mini-implant system as well as the application of mini-implant system in the dental clinical field. Materials and Methods: The patients who had been operated from Jan 2007 to Dec 2007 in the four dental facility including Seoul National University Bundang Hospital were enrolled. To evaluate the factors associated with the clinical outcome, the patients were classified according to gender, age, area of surgery, type of implant, diameter and length of the implant, and the purpose of the mini-implant system application. Results: From 147 implants, only three implants failed, one of them was for temporary loading. There were no serious surgical or prosthetic complications in this study. Conclusion: An analysis of the preliminary data revealed a satisfactory clinical outcome. However, more long-term evaluation of narrow ridge type as well as the patient’s satisfaction on the use of a provisional type mini-implant system is needed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.255-261
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• 2010

Introduction: To evaluate the skeletal stability after a bilateral sagittal split osteotomy (BSSO) setback of the mandible fixed with a biodegradable internal fixation device or metal internal fixation device. Materials and Methods: Thirty consecutive patients underwent mandibular setback via BSSO. Fifteen patients were fixed with a biodegradable internal fixation device or metal internal fixation device respectively. Posteroanterior (PA) and lateral cephalograms were taken preoperatively and at two days, 5.5 months and 14.5 months postoperatively. The relevant skeletal points were traced and digitized to evaluate the skeletal changes postoperatively. The relapse rates were analyzed and compared statistically. Results: There was no statistically significant differences in postoperative stability between the two groups.(P<0.05) Conclusion: The biodegradable internal fixation device may make an effective device alternative to a metal internal fixation device for setback BSSO.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.1
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• pp.23-27
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• 2010

The purpose of this study was to evaluate the reliability of 6-axis model surgery simulator (6AMSS) for orthognathic surgery. A rectangular parallelepiped plastic block was assembled to model-mounting plate of 6AMSS. Left-right (X), anterior-posterior (Y), up-down (Z) translation and pitching (${\phi}X$), rolling (${\phi}Y$) and yawing (${\phi}Z$) rotation was planned and performed using 6AMSS. The actual translation and rotation were measured with dial gauge and precisional protractor, respectively. Comparison between the planned and actual movements of plastic block for each variable were made using paired t- test. Statistical analysis for X, Y, Z, ${\phi}X$, ${\phi}Y$ and ${\phi}Z$ movement have shown no significant differences between planned and actual movement (P > 0.05). This indicate that model surgery performed with the aid of the 6AMSS is accurate in 3D translation and rotation. The 6AMSS is practically useful for accurate fabrication of surgical splint for orthognathic surgery.