• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권6호
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• pp.491-497
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• 2001

Polymethylmethacrylate(PMMA) is currently commonly used material for the reconstruction of bone defects and fixation of joint prosthetics following congenital and acquired causes. Although PMMA has widespread use, it does not possess the ideal mechanical characteristics with osteoconductivity and osteoinductivity required. In order to overcome these problem, addition of bovine bone drived defatting demineralized bone(BDB) powders to a PMMA bone cement was done for improvement of physical property and bone forming characteristics of composite. In order to investigate the influence of BDB reinforcement on the PMMA, we measured physical property of compressive, tensile, flexural strength, and scanning electron microscopic examinations. The results were obtained as follows: 1. The PMMA forms a solid cellular matrix with open cells about $100{\mu}m$ in variable size and incorporating BDB. BDB aggregates inside the cells form a porous network that is accessible from the outer surface. 2. The physical properties were compressive strength of mean $22.74{\pm}1.69MPa$, tensile strength of mean $22.74{\pm}1.69MPa$, flexural strength of mean $77.53{\pm}6.93MPa$. Scanning electron microscopic examinations were revealed that there was DBD particles form a highly porous agglomerates. BDB can be added PMMA in the form of dried powders, the composites are applicable as bone substitutes. BDB and PMMA mixture is shown to produce a class of composites that due to their microstructure and improved mechanical properties may be suitable for application as bone subsitutes. The mechanical and material properties of the BDB-PMMA bone substitute composites are competitive with those properties of a porous ceramic matrix of other hydroxyapatite and with those of natural bones.

• Journal of Korean Dental Science
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• 제10권1호
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• pp.35-44
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• 2017

In case of loss of many teeth due to dental caries or periodontal disease, improvement of masticatory function and aesthetics can be obtained through implant treatment. However, if the patient does not have a normal intercondylar relationship, it is difficult to achieve an ideal occlusal relationship with only prosthetic treatment. In particular, oral reconstruction with orthodontic treatment or orthognathic surgery is necessary for patients with mandibular prognathism. However, if the posterior occlusion collapses due to severe caries or periodontal disease, orthognathic surgery may be difficult. The occlusal vertical stop is very important for the stability of the mandibular position during occlusal reconstruction through orthognathic surgery. The patient in this case had posterior occlusion collapsed due to the caries of a large number of posterior teeth, and showed mandibular prognathism and long face. We planned a full arch restoration with orthognathic surgery and extracted the hopeless teeth. To secure the vertical stop required for orthognathic surgery, the implant was placed before surgery. After the orthognathic surgery and the final prosthesis application, the results were satisfactory for the improvement of the aesthetics and the restoration of the masticatory function.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.41.1-41.11
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• 2020

Background: Orthognathic surgery such as bilateral sagittal split ramus osteotomy (BSSRO) for the treatment of mandibular deformities is one of the most common procedures in maxillofacial operations that may lead to neurosensory disturbance. In this study, we aimed to evaluate the effectiveness of low-level laser therapy (LLLT) on augmenting recovery of neurosensory disturbance of inferior alveolar nerve (IAN) in patients who underwent BSSRO surgery. Methods: A comprehensive literature search was conducted by two independent authors in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Embase, and Google Scholar electronic databases. Besides, a manual search of all textbooks and relevant articles were conducted. Searches took place in August 2020 and were limited to published and peer-reviewed articles from 2000 to 2020. All analysis was performed using the comprehensive meta-analysis (CMA) and the STATA MP (version:16) software. The weighted mean difference (WMD) using the inverse variance method and the standard mean difference (SMD) was considered for continuous variables. Results: Seventy-four papers were retrieved after removing duplicate studies and finally, eight studies were assessed for qualitative synthesis and five for meta-analysis. Totally, 94 patients were included in the meta-analysis. Based on the meta-analysis, it was shown that LLLT was not effective in a short interval (0 to 48 h) after surgery, but in a period of more than 1 month after surgery, the positive results of treatment can be observed strikingly. Also, LLLT side/group showed no significant difference in some aspects of neurosensory recovery such as thermal sensation compared to the placebo side/group. Conclusions: The meta-analysis of randomized controlled trials revealed that LLLT generally improves IAN sensory disturbance caused by BSSRO. Further high-quality clinical trials with longer follow-up periods and larger sample sizes are recommended.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.153-157
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• 2002

Purpose : This study was performed to determine the proper reference line for taking axial computed tomograms from which the good cross-sectional views can be reformatted by multiplanar reconstruction. Methods : Three dry mandibles with implanted gutta percha cones in the extracted socket were scanned axially according to 6 reference lines of 2 mandibular positions with computed tomogram Hitachi W550. The accuracy of measurements of the lengths of implanted gutta perch a cones in the each cross-sectional view reformatted from axial computed tomogram by multiplanar reconstruction was evaluated. Results: The difference between the measurements and the real length of implant was smallest in the bucco-lingual views reformatted from the axial views scanned according to the reference line of group V-a. The smaller the angle difference between reference line and occlusal line was, the smaller the difference between the measurements in the bucco-lingual views reformatted from axial views and the real length of implant. The majority of measured widths of implants in the bucco-lingually reformatted views were larger than the actual values. Conclusions : When the mandible is inclined within the limitation of gantry angle and scanned with the reference line coincident with occlusal plane, the bucco-lingual view can be reformatted without deformation of images from the axially scanned images.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권4호
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• pp.300-305
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• 2005

Purpose: For the reconstruction of maxillofacial defect created by trauma, infection, or tumor etc, the role of microvascular anastomosis or vessel graft has been increased. Many methods has been tried to increase the success rate of microvascular anastomosis. Various anticoagulants and thrombolytic agents have been used to reduce the failure rate of microvascular anastomosis and avoid re-operation. Many drugs, however, have been used in the limited cases because most of these drugs may cause complications, such as allergy, fever or systemic bleeding. This study was performed to evaluate the influence of the Argatroban on patency and thrombosis in microvascular anastomosis when it is used for local irrigation or general administration. Materials & methods: Eight mature rabbits, weighing 2kg, were used. After exposing both femoral veins, the artificial thrombotic model was made by crushing injury using a smooth needle holder, and the transverse incision were made on femoral vein. The animals were divided into 4 groups according to Argatroban administration methods; control group (n=4), topical irrigation of lumen with saline solution; experimental group 1 (n=4), topical irrigation of lumen with Argatroban saline solution; experimental group 2 (n=4), topical irrigation of lumen with heparin followed by intravenous injection of Argatroban; experimental group 3 (n=4), topical irrigation of lumen with Argatroban followed by IV of Argatroban. Microvascular anastomosis was done with 10-0 Ethilon. The patency was evaluated by empty-and-refill test 30 minutes and 3 days after microanastomosis. The thrombus formation was examined 3 days after microanastomosis by surgical microscope. The histologic findings were also examined. Results: 1. Thirty minutes after microvascular anastomosis, the patency of all experimental groups was better than that of control group, but there was no significant difference among groups. 2. Three days after microvascular anastomosis, the patency of all experimental groups was more improved than that of control group (p<0.05). There was no significant difference among experimental groups. 3. Three days after microvascular anastomosis, the amount of thrombus in all experimental groups was less than that of control group (p<0.05). There was no significant difference among experimental groups. 4. Histologically, a lot of luminal thrombus was observed around sutured area in control group. Few luminal thrombus was observed in all experimental groups. The necrotic changes were observed on the sutured vein wall in all specimens. Conclusion: These results indicate that topical irrigation and/or intravenous administration of Argatroban is effective in improving patency and preventing thrombus formation after microvascular anastomosis.

• 대한구순구개열학회지
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• 제3권1호
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• pp.23-31
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• 2000

전방 기저 설피판은 비교적 큰 구개 결손을 폐쇄하는데 안전하고 효과적이었으며 후에 장골 이식을 위한 건전한 피복을 제공하였다. 그리고 치조열 결손의 순측면까지 완전히 피복하기 위한 목적으로 양측성 치조열에 적용되도록 재단된 Y-형의 변형은 결과가 믿을 만하였으며 합병증도 무시할 만 하였다.

• 대한치과의사협회지
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• 제54권10호
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• pp.799-810
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• 2016

Orbital fractures have a significant portion in facial bone trauma. The important thing in treatment of orbital fractures is variable depending on the patient. Reconstruction of orbital wall demands an understanding of the anatomy and function of the orbit, including the orbital tissues, and the approacheds, materials, and methods available.

• 대한치과보철학회지
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• 제57권4호
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• pp.448-455
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• 2019

법랑모세포종은 치성 상피성 양성 종양으로 재발률이 높아 주변 조직의 광범위한 절제 및 결손부의 재건을 필요로 한다. 술 후 치아 결손 부위의 보철치료 시에 재건 부위의 해부학적 한계로 인해 임플란트 식립을 동반한 보철 치료가 추천된다. 본 증례에서는 법랑모세포종으로 인해 하악골 분절 절제술 및 장골을 이용한 하악골 재건술을 시행한 환자에서 재건 부위 상실치를 임플란트 고정성 보철물로 수복하였고 임플란트 보철물을 장착 완료 한 14개월 뒤 원인 미상의 인접치 정출로 인해 임플란트를 포함한 전방부 치아에서 1 mm 가량의 개방 교합이 발생하였다. 성인에서 상악 전치부 임플란트 식립 후 잔존 성장으로 인해 임플란트 저위 교합이 발생하는 경우는 보고된 바 있으나 본 증례는 구치부에서 인접한 자연치의 정출로 인해 임플란트 보철물을 포함한 전방 치열의 개방 교합이 발생한 것으로 그 유사 보고가 흔하지 않다. 이에 정출된 치아를 압하 하는 교정 치료를 동반한 전체 치료 과정을 보고하고 원인 미상의 자연치 정출이 발생한 원인에 대해 고찰해보고자 한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권3호
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• pp.241-249
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• 2006

Purpose For the reconstruction of craniofacial deformities, the distraction osteogenesis is an useful method which can make new soft tissues as well as new bone. Although the distraction osteogenesis is an effective procedure in quantitative aspects, the new bone formed by this procedure can be coarse in qualitive aspects sometimes. Materials and methods Twelve rabbits, weighing about 2 kg, were included and the prefabricated distraction device were used. After a latency period of 5 days, in the experimental group (n=6), the mandible was distracted at the rate of 1.0 mm/day for 2 days and then compressed with 1.0 mm for the next 3rd day, therefore distracted totally to a length of 1.0 mm for 3 days. This procedure was repeated 5 times and, as a result, the experimental group was distracted to a length of 5.0 mm for 15 days finally. In the control group (n=6), the mandible was distracted totally to a length of 5.0 mm at the rate of 1 mm/day. At 2 weeks and 8 weeks of consolidation in the control group, 3 rabbits in each group were sacrificed and their biopsy specimens from the distracted mandible were taken. Results All animals showed the mandibular elongation clinically and radiographically. Histologically, many blood vessels, osteoblasts and immature bones formed by osteoid deposition were observed in the experimental group at 2 weeks. At 8 weeks, the bony trabeculae were thicker than the ones in the control group and were composed of lamella bones and woven bones in the experimental group. On histomorphometric analysis, the bone deposition area of the distracted site was broader in the experimental group $(273.8{\pm}115.7\;cm^2)$ than the one in the control group $(199.4{\pm}101.4\;cm^2)$. Futhermore, the modified rate of bone deposition area was higher in the experimental group (48${\pm}$20%) than the one in the control group (35${\pm}$18%). However, these data showed no significant differences statistically. Conclusion These results suggest that the distraction osteogenesis by using an alternating distraction/compression protocols is an effective method for increasing new bone formation in distracted areas.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권4호
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• pp.315-323
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• 2005

For reconstruction of the bony defect, distraction osteogenesis has many advantages in comparison with bone graft. However, it needs long consolidation period for sufficient bone maturity. This study is performed to evaluate the effect of PRP injection into the distracted mandible on bone formation in rabbits. Twelve house rabbits, weighing 2 kg, were used. All animals underwent bilateral mandibular osteotomy under general anesthesia. A internal distractor divice was positioned along a plane perpendicular to the line of osteotomy. After 5 days of latency period, distraction osteogenesis was started at a rate of 1 mm/day for 9 days which was distracted 9 mm totally. After completion of distraction, 0.5 ml of PRP which collected in rabbit blood was injected into the distracted mandible on experimental group, whereas no injection was done in control group. Macroscopical, radiographical, and histological, and histomorphometric examinations were performed 2, 4 and 8 weeks after distraction. All animals showed distracted mandible and severe anterior cross-bite. In radiographical findings 2 weeks after distraction, more radiopacity in the distracted gap was found in experimental group than that of control group. At 4 weeks after distraction, distracted bone was similar to normal bone in experimental group. In histological findings, 1) At 2 weeks after distraction, number of osteoblasts and angiogenesis in the distracted gap was found in experimental group than that of control group. 2) At 4 weeks after distraction, more active and distinct bone in the distracted gap was found in experimental group than that of control groups. 3) At 8 weeks after distraction, more dense and matured lamellated bone in the distracted gap was found in experimental group than that of control group. In histomorphometrical findings 8 weeks after distraction, more bone formation was observed in experimental group than control group (p<0.01). These results indicate that administration of PRP into the distracted mandible can promote bone formation.