• Imaging Science in Dentistry
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• v.32 no.2
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• pp.89-97
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• 2002

Purpose: The objective of this study is to find the differentiating characteristics of ameloblastomas and odontogenic keratocysts of the jaw by analyzing computed tomography (CT) images of the lesions, clarify radiological characteristics associated with jaw lesions, and to make a diagnsis based on these findings. Materials and Methods : Test subjects were chosen among the patients who were diagnosed as having an odontogenic keratocyst or ameloblastoma at the Yonsei University Dental Hospital from January 1996 to December 2000 and had CT scans taken preoperatively. The subject pool was comprised of 51 cases of odontogenic keratocyst and 37 cases of ameloblastoma. The following measures were used for image analysis of the lesion: the anatomic location, CT pattern, mesiodistal width, buccolingual width, the ratios between mesiodistal width and buccolingual width, height, CT number, homogeneity of radiodensity, the appearance of a sclerotic rim, continuity of adjacent cortical bone, and displacement and resorption of adjacent teeth. Results: Comparing the CT patten, mesiodistal width, buccolingual width, height, CT number, homogeneity, appearance of sclerotic rim, continuity of adjacent cortical bone, there were statistically significant differences between ameloblastoma and odontogenic keratocyst test subjects (p<0.05). Comparing the ratios between mesiodistal width and buccolingual width, displacement and resorption of adjacent teeth, there were no statistically significant differences (p>0.05). Conclusion: We compared odontogenic keratocysts and ameloblastomas in CT scans. They occurred most frequently in the posterior to the ramus of the mandible. The findings of patterns of the CT images showed that size and border of lesions were more aggressive in ameloblastomas than in odontogenic keratocysts. The internal contents represented an increased attenuation area (IAA) in odontopenic keratocyst. Odontogenic keratocysts were shown to have higher CT numbers than ameloblastomas.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.477-482
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• 2011

Introduction: Bone regeneration of cystic defects of the jaws after a cyst treatment requires lengthy healing periods. Generally, the bony changes are observed periodically through a visual radiographic reading as well as by the clinical opinion and radiographic images (panorama, periapical view), but it is difficult to compare the objective bony changes using only the radiographic density. In addition, it is difficult to observe minute bony changes through a visual radiographic reading, which can lead to a subjective judgment. This study exmined the bone density after the enucleation of a jaw cyst by fractal analysis. Materials and Methods: Eighteen patients with a cystic lesion on the jaw were assessed. Panoramic radiographs were taken preoperatively, immediately postoperatively, and 1, 3, 6 and 12 months after cyst enucleation. The images were analyzed by fractal analysis. Results: The mean fractal dimensions increased immediately after surgery and 3, 6 and 12 months postoperatively. The postoperative 6 and 12 months fractal dimension was similar to the controls. Conclusion: Fractal analysis was used to overcome the limit of a subjective reading during an assessment of bone regeneration after cyst enucleation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.588-593
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• 2006

Cyst is pathologic disease develops in hard tissue as well as soft tissue, which is lined by epithelium filled with liquid, semi-liquid, or air. Origins and symptoms of the cyst are various according to region, and symptoms are malocclusion, diversion of root, tooth mobility, periapical swelling, discoloration and lesion expansion, because the odontogenic cysts begin in the numerous rests of odontogenic epithelium. But almost cysts produce no symptoms unless secondary infection occurs. Treatment of small cysts may include extraction, endodontic therapy, and apical surgery. Treatment of a large cysts usually involves surgical removal (enucleation), Marsupialization(a method of decompression) or combination of two before mentioned. Bone graft is done for helping of bone defect healing at the same time of enucleation This clinical research from January 2000 to December 2005, analyzed by the age, sex, classification, size, region, treatment method, whether or not of bone graft of cyst in the jaw in Daegu Catholic University Hospital.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.94-102
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• 2007

The ameloblastoma is a common odontogenic tumor of the jaw bone and represents approximately 1% of tumor in the jaw. However, it might be able to infiltrate into the adjacent tissue, causing bony destruction and high recurrent rate. In this study, expression of RANKL and OPG in ameloblastoma in relation to age and gender of patient and recurrence, location of the lesion were examined through immunohistochemisry study. The RANKL and OPG antibody staining were used. The obtained result were as follow. 1. Positive immunoreactivity to RANKL/OPG in all specimens was found. 2. 1n recurrenc, location of ameloblastoma and age, gender of patients using immunohistochemical expression of RANKL. There was not significant difference. 3. 1n recurrence, location of ameloblastoma and age, gender of patients using immunohistochemical expression of OPG. There was not significant difference. In summary, it is suggested that activation of osteoclasts by RANKL is an important mechanism by which ameloblastomas cause bone destruction.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.94-100
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• 1996

Ossifying fibroma is one of a group of fibro-osseous lesions which arises typically within the jaw bones and only rarely affects the long bones. Ossifying fibroma of the long bones almost involve exclusively the tibia but may also involve the fibula. Ossifying fibroma of the long bones is distinct from fibrous dysplasia, adamantinoma and nonossifying fibroma with regard to age of the patient, site, radiographic appearance, histological features, and clinical course. We are reporting the cases of seven patients with a tumor-like lesion that named osteofibrous dysplasia. It is most commonly found in the tibia and fibula of a child ten years of age or younger. Of the seven cases reported in this study, only one patient was younger than ten years. In all cases, the lesions were usually located in the tibial diaphysis. The average duration of clinical manifestation was 5.2 years. The clinical symptoms were anterior bowing of the tibia in 2 cases, buldging of the tibia in 2 cases, and mass overlying the tibia in 3 cases. On the roentgenography, it shows multiple radiolucent lesion with intervening sclerotic rim of the tibial diaphysis. In seven patients, 6 cases were confirmed with biopsy. We had done curettage and bone graft in three cases, VFG was done in one case. The other three cases underwent conservative management.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.341-355
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• 1999

Squamous cell carcinoma is the most common type of oral cancer and odontogenic myxoma is relatively uncommon benign tumor of mesenchymal origin. There are, to our knowledge, no prior reports of simultaneously occurring squamous cell carcinoma and odontogenic myxoma of the jaw bones. In this case, at first, the plain films and computed tomograms revealed a large expansile multilocular radiolucent lesion on left mandible and marked expansion of cortical plate. In addition this radiograms revealed also infiltrative bony destruction of anterior and medial border of ascending ramus of left mandible and alveolar bone of left maxilla, floating teeth on left lower molar area and metastatic enlargement of left submandibular, jugular digastric and spinal accessory lymphnodes. Magnetic resonance imaging of this patient revealed infiltrative growth of tumor on alveolar bone of left maxilla, left retromolar fat pad. left masseter and left medial pterygoid muscle. Intraoral presurgical biopsy presented typical features of squamous cell carcinoma. After chemotherapy with radiation therapy during 6 months. this central lesion was diagnosed as odontogenic myxoma by the postsurgical biopsy. After 3 months, this patient presented multiple metastatic signs at lumbar spines, rib and liver. Consequently, our case is simultaneous occurrence of squamous cell carcinoma and odontogenic myxoma.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.418-422
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• 2002

Cyst is a cavity filled with fluids and semi-fluids that is lined with epithelial cells. Odontogenic cysts are those that form within the jaw which origin from dental follicles, enamel epithelium remnants of the crown, Malassez epithelial cell rest and basal cell layer of the oral epithelium. In such cases, treatment methods such as enucleation, marsupialization, decompression, surgical excision etc. can be used according to the lesion's characteristics, size, relationship with the surrounding tissue, patient's age and developmental status. This case was to report an odontogenic cyst caused by an impacted immature permannent tooth and its treatment. The cyst was removed by decompression. Cystic cavity was healed with bone tissue and the impacted permanent tooth erupted without any recurred cystic lesion.

• Imaging Science in Dentistry
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• v.53 no.1
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• pp.27-34
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• 2023

Purpose: The aim of this study was to clarify the influence of training with a different kind of lesion on the performance of a target model. Materials and Methods: A total of 310 patients(211 men, 99 women; average age, 47.9±16.1 years) were selected and their panoramic images were used in this study. We created a source model using panoramic radiographs including mandibular radiolucent cyst-like lesions (radicular cyst, dentigerous cyst, odontogenic keratocyst, and ameloblastoma). The model was simulatively transferred and trained on images of Stafne's bone cavity. A learning model was created using a customized DetectNet built in the Digits version 5.0 (NVIDIA, Santa Clara, CA). Two machines(Machines A and B) with identical specifications were used to simulate transfer learning. A source model was created from the data consisting of ameloblastoma, odontogenic keratocyst, dentigerous cyst, and radicular cyst in Machine A. Thereafter, it was transferred to Machine B and trained on additional data of Stafne's bone cavity to create target models. To investigate the effect of the number of cases, we created several target models with different numbers of Stafne's bone cavity cases. Results: When the Stafne's bone cavity data were added to the training, both the detection and classification performances for this pathology improved. Even for lesions other than Stafne's bone cavity, the detection sensitivities tended to increase with the increase in the number of Stafne's bone cavities. Conclusion: This study showed that using different lesions for transfer learning improves the performance of the model.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.72-76
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• 2010

Osteochondroma is the one of the most benign tumors of the axial skeleton, but is rarely found in the facial bones. Typical facial features of condylar osteochondroma include striking facial asymmetry, malocclusion with openbite on the affected side, and prognathic deviation of the chin and crossbite to the contralateral side. In this case, twenty four year-old female showed facial asymmetry, chin deviation, openbite on the affected side but have no symptoms of pain or dysfunction. Concomitantly she had maxillary occlusal cant and hemimandibular hypertrophy. Panoramic radiograph showed radiopaque mass on right mandibular condyle extended along the lateral pterygoid muscle. Computed tomogram demonstrated enlarged condylar head and bony spur on posteromedial side of condyle and 99Tc bone scintigraphy showed a focal hot image. These findings were correspond with osteochondroma. The lesion was treated with condylectomy and residual facial asymmetry was corrected with 2-jaw orthognathic surgery. Herein, we report a case of osteochondroma of the mandibular condyle and accompanying facial asymmetry.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.86-88
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• 2010

Oral metastatic tumors are uncommon and account for about 1% of malignant oral neoplasm. The metastatic lesions are common in breast, lung, kidney and thyroid cancer. About 20% of oral mucosal metastasis is founded before detection of primary lesions. Usually, the metastatic lesions of the oral cavity are involved in the jaw bone, especially mandible more than the oral soft tissues. We report a case diagnosed as the stomach cancer with mandible metastatic lesion looking like TMJ abscess.