• Imaging Science in Dentistry
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• 제33권4호
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• pp.239-244
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• 2003

Malignant fibrous histiocytoma (MFH) is a pleomorphic soft tissue sarcoma. Three cases of MFH were reported in our study. The first case involved in the right infratemporal fossa of a 32-year-old female was presented. MR imaging revealed a 5.0 × 3.3 cm soft tissue mass of inhomogeneous high signal intensity. The second case was found in the right hard palate of a 66-year-old male. CT demonstrated bone destruction and MR imaging showed a 4 × 4 cm sized soft tissue mass of heterogeneous high signal intensity. The final case was found in the left masticator space of a 37-year-old male. The CT image showed a large mass with massive bone destruction of the left mandibular ramus, while the MRI displayed a soft tissue mass, 8 cm diameter. Our cases exhibited the general features of MFH. MRI is essential in the imaging of MFH, namely to depict tumor borders and demonstrate relationships with adjacent structures.

• 치과방사선
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• 제17권1호
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• pp.271-278
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• 1987

The purpose of the present study was to investigate associations between periapical and bitewing techniques by assessing the crestal alveolar bone. This article also reports the ability of these two techniques to correctly detect evidence of interproximal dental caries, and comparison between the interproximal overlapping of teeth. Bitewing and periapical radiographs were used from posterior quardants of 243 dental students in Seoul National University. The distance from cemento-enamel junction to the alveolar crest (CEJ-AC) was measured for each proximal surface from the distal of cuspid to the distal of second molar. Data were arranged according to the proximal surface examined, and bitewing and periapical measurements were compared using paired tests. The obtained results were as follows: 1. In maxilla, a significant t ratio with a P value of 0.05 or less reached for 100% and in mandible, reached for 94%. 2. The anatomic limitations imposed on periapical radiographic technique, most often result in somewhat foreshortened radiographic images. This situation would tend to be accentuated by the anatomical restrictions of the hard palate. 3. Consequently, since the significant differences frequently exist between measurements obtained from bitewing and periapical techniques, it is important to define which technique is used. 4. The number of the interproximal overlapping was the largest medial side of the maxillary second molar, while the smallest at the distal side of the mandibular second premolar. And the overall number of the interproximal overlapping was more (538) in the periapical technique than in the bitewing technique (372). 5. The interproximal dental carious lesions were detected more (74) on the bitewing films than on the periapical ones (23). The fact was resulted from the small number of interproximal overlapping and relative easi- ness of obtaining horizontal angulation in taking the bitewing radiographs.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.229-234
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• 2016

PURPOSE. The purpose of this study was to investigate the demographic patterns of maxillofacial prosthetic treatment to identify the characteristics and geographic distribution of patients with maxillofacial prosthetics in the capital region of Korea. MATERIALS AND METHODS. This retrospective analytical multicenter study was performed by chart reviews. This study included patients who visited the department of prosthodontics at four university dental hospitals for maxillofacial prosthetic rehabilitation. Patients with facial and congenital defects or with insufficient medical data were excluded. The patients were classified into three categories based on the location of the defect. Patients' sex, age, and residential area were analyzed. Pearson's chi-square test with a significance level of 0.05 was used to analyze the variables. RESULTS. Among 540 patients with maxillofacial prosthetics, there were 284 (52.59%) male patients and 256 (47.41%) female patients. The number of the patients varied greatly by hospital. Most patients were older than 70, and the most common defect was a hard palate defect. Chi-square analysis did not identify any significant differences in sex, age, and distance to hospital for any defect group (P>.05). CONCLUSION. The results of this study indicated that there was imbalance in the distribution of patients with maxillofacial prosthetic among the hospitals in the capital region of Korea. Considerations on specialists and insurance policies for the improvement of maxillofacial prosthetics in Korea are required.

• 한국임상수의학회지
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• 제23권3호
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• pp.361-365
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• 2006

A spayed female, 5-year-old, weighing 2.7 kg, domestic short hair cat was referred to Veterinary Medical Teaching Hospital, Seoul National University. The clinical signs of this patient were weight loss, sneezing, respiratory distress, nasal discharge, epistaxis, ocular discharge, left exophthalmos, and left facial edema and deformity. The laboratory tests represented mild leukocytosis. On the skull radiographs, soft tissue density filled nasal cavity with loss of turbinate detail was found. Destructive and lytic changes of the left nasal bone with soft tissue swelling were identified. On the thorax radiographs, there were a tracheobronchial lymph node swelling and a soft tissue round mass in the left caudal lung field. On computed tomographic scan images, asymmetrical destruction of turbinate and nasal septum and increased soft tissue opacity in the nasal cavity were identified. Destruction of the lateral maxillary bone, invasion to the left retrobulbar region, and craniodorsal deviation of the left eye were seen. Also, there was lysis of hard palate and cribriform plate. Invasion to the brain was found. The patient was diagnosed as nasal lymphoma by cytology and histopathology.

• 한국임상수의학회지
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• 제23권3호
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• pp.355-360
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• 2006

Four dogs with similar respiratory signs were referred to Veterinary Medical Teaching Hospital, Seoul National University. The clinical signs observed in these cases were anorexia, nasal discharge, sneezing, epistaxis, ocular discharge, and exophthalmoses. The routine laboratory tests revealed leukocytosis in two cases. On the skull radiographs, soft tissue density filled nasal cavity with loss of turbinate detail and increased density in frontal sinuses were found in all cases. Lysis of nasal bone was seen in two cases. Lysis of zygomatic arch was seen in one case. On computed tomography scan images, asymmetrical destruction of turbinate and nasal septum, and the superimposition of a soft tissue mass over the turbinate with peripheral contrast enhanced effect were identified in all cases. Destruction of ipsilateral orbital bone and invasion to retrobulbar region were visualized in all cases. In addition, all cases had lysis of cribriform plate. Lysis of nasal bone and destruction of hard palate were seen in two cases. Swelling of submandibular lymph node and salivary gland was seen in a case. Invasion to brain was identified in a case. All cases were diagnosed as nasal adenocarcinoma by cytology with fine needle aspiration and curettage.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권4호
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• pp.339-342
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• 2009

Adenoid cystic carcinoma(ACC) is the second most common malignant neoplasm in the salivary gland. In spite of ACC shows slowly growing nature, it is sometimes highly detrimental that it readily invades adjacent tissues and metastasize to distant organs at the early stage of disease. Hence, treatment outcome may be misfortunate due to wide regional infiltration, pathognomonic perineural spread and the tendency of hematogenous metastasis. We present a unusal case of ACC of the scalp in which the patient initially presented with bumpy mass of the scalp who had been diagnosed as the primarily developed ACC of the right hard palate that extended to infratemporal fossa, nasal cavity, and paranasal sinuses and had been treated by total excision and post-operative chemotherapy and radiation therapy for 10 years ago. Although this lesion occured at the scalp, which is a frequent site of primary dermatologic ACC, its histomorphology was the same with that of previous tumor. Complete clinical examination showed no recurrence sign at the primary site and suggested the scalp as a sole treatment failure site. Accordingly, it would be reasonable to consider the present case as either a scalp metastasis or a second primary lesion of salivary gland ACC.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.391-395
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• 2000

Malignant tumors of the maxilla represent about 3-4% of head and neck malignant neoplasm and the origins are maxillary gingiva, hard palate and maxillary sinus. We are to investigate clinical features and results according to various treatment modalities of maxillary malignant tumor to get information for better treatment results. Sixty patients with malignant maxillary tumors treated at Yonsei medical center from 1992 to 1997 were studied retrospectively. They are evaluated according to clinical signs & symptoms, stages at first diagnosis, primary site, histopathologic features, treatment method, recurrence and survival rate with clinical records, biopsy results and CT radiograph. The most common primary site was maxillary sinus and most common histopathology was squamous cell carcinoma. The local recurrence rate was 18% at 5 years, neck failure was 3% and distant metastasis was 18%. Overall survival rate was 78% at 2 years and 69% at 5 years. Failure at primary site is the main problem in the curative treatment. So, to improve survival in these patients efforts should be directed toward improvement of local control.

• 대한두개안면성형외과학회지
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• 제18권1호
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• pp.50-53
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• 2017

Trichilemmal cysts are common fluid-filled growths that arise from the isthmus of the hair follicle. They can form rapidly multiplying trichilemmal tumors-, also called proliferating trichilemmal cysts, which are typically benign. Rarely, proliferating trichilemmal cysts can become cancerous. Here we report the case of a patient who experienced this series of changes. The 27-year-old male patient had been observed to have a $1{\times}1cm$ cyst 7 years ago. Eight months prior to presentation at our institution, incision and drainage was performed at his local clinic. However, the size of the mass had gradually increased. At our clinic, he presented with a $5{\times}4cm$ hard mass that had recurred on the posterior side of his neck. The tumor was removed without safety margin, and the skin defect was covered with a split-thickness skin graft. The pathologic diagnosis was a benign proliferating trichilemmal cyst. The mass recurred after 4months, at which point, a wide excision (1.3-cm safety margin) and split-thickness skin graft were performed. The biopsy revealed a trichilemmal carcinoma arising from a proliferating trichilemmal cyst. This clinical experience suggests that clinicians should consider the possibility of malignant changes when diagnosing and treating trichilemmal cysts.

• Imaging Science in Dentistry
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• 제45권1호
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• pp.23-29
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• 2015

Purpose: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) $60{\times}60mm$ FOV, $0.125mm^3$ ($FOV_{60}$); 2) $80{\times}80mm$ FOV, $0.160mm^3$ ($FOV_{80}$); and 3) $100{\times}100mm$ FOV, $0.250mm^3$ ($FOV_{100}$). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.

• 대한두개안면성형외과학회지
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• 제20권6호
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• pp.370-375
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• 2019

Background: Some parts of a maxillary fracture-for example, the medial and posterior walls-may remain unreduced because they are unapproachable or hard to deal with. This study aimed to investigate the self-healing process of unreduced maxillary membranous parts of fractures through a longitudinal computed tomography (CT) analysis of cases of unilateral facial bone injuries involving the maxillary sinus walls. Methods: Thirty-two patients who had undergone unilateral facial bone reduction surgery involving the maxillary sinus walls without reduction of the medial and posterior walls were analyzed in this retrospective chart review. Preoperative, immediate postoperative, and 3-month postoperative CT scans were analyzed. The maxillary sinus volume was calculated and improvements in bone continuity and alignment were evaluated. Results: The volume of the traumatized maxillary sinuses increased after surgery, and expanded significantly by 3 months postoperatively (p< 0.05). The significant preoperative volume difference between the normal and traumatized sides (p= 0.024) resolved after surgery (p> 0.05), and this resolution was maintained at 3 months postoperatively (p > 0.05). The unreduced parts of the maxillary bone showed improved alignment and continuity (in 75.0% and 90.6% of cases, respectively), and improvements in bone alignment and bone continuity were found to be correlated using the Pearson chi-square test (p= 0.002). Conclusion: Maxillary wall remodeling through self-healing occurred concomitantly with an increase in sinus volume and simultaneous improvements in bone alignment and continuity. Midfacial surgeons should be aware of the natural course of unreduced fractured medial and posterior maxillary walls in complex maxillary fractures.