• International Journal of Oral Biology
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• v.49 no.1
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• pp.18-25
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• 2024

Despite advancements in therapeutic approaches, radiotherapy and cisplatin-based chemotherapy remain primary noninvasive treatments for patients with oral squamous cell carcinoma (OSCC). Moreover, the 5-year survival rate for patients with OSCC has remained almost unchanged for several decades, and many side effects of chemotherapy still exist. In this study, three-dimensional (3D) models of OSCC were established using fibroblasts, and the efficacy of various biological inhibitors was evaluated. A culture of epithelial cells with two types of fibroblasts (hTERT-hNOFs and cancer-associated fibroblasts) within a type I collagen matrix resulted in the formation of a continuous layer of tightly packed cells compared to models without fibroblasts. Furthermore, the effects of biological chemicals, including Y27632, latrunculin A, and verteporfin, on these models were investigated. The stratified formation of the epithelial layer and invasion in OSCC 3D-culture models were effectively inhibited by verteporfin, whereas invasion was weakly inhibited by Y27632 and latrunculin. Collectively, the developed OSCC 3D-culture models established with fibroblasts demonstrated the potential for drug screening, with verteporfin showing promising efficacy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.39.1-39.5
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• 2020

Background: Head or scalp injury is a life-threatening and typically accidental human injury. Most medical departments require immediate medical treatment and proper treatment with specialized medical personnel and facilities. However, in low-resource environments, such as the rural region of West Africa, the authors have treated emergency trauma patients and provided immediate treatment despite lack of resources. Case presentation: We reviewed three cases of scalp injury patients, with representative clinical information, and used these cases to outline feedback on scalp trauma treatment based on the specialty knowledge of general and emergency surgeon. Conclusions: Oral and maxillofacial surgeons are medical specialists that can immediately diagnose and treat these scalp injuries based on their medical knowledge and experience with the maxillofacial region.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.263-271
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• 2003

The purpose of the present study was to evaluate the patterns of hybrid layer according to the application time and the frequency and its effects on the shear bonding strength of All-In-One system in primary teeth. A single bonding agent(Scotchbond Multi-Purpose Plus, 3M) and an All-In-One system(Prompt L-pop, 3M ESPE) were applied on the dentin varying the application time and the frequency in primary teeth. Shear bond strength was measured and the patterns of hybrid layers were observed by SEM. The following results were obtained ; 1. The shear bonding strength of single bonding agent was significantly higher than that of All-In-One system(P<0.05). 2. The shear bonding strength of All-In-One system applied twice or 3 times were higher than that of applied once (P<0.05). And thickness of the hybrid layer was increased when applied twice or 3 times compared to once. 3. The shear bonding strength of All-In-One system when applied for 15 second and 30 second were higher than that of 7 second (P<0.05). And the hybrid layer thickness of 15 second and 30 second's application time were higher than that of 7 second. 4. Thickness of hybrid layer applied with single bonding agent was $2-4{\mu}m$ and that of All-In-One system was $1-2{\mu}m$.

• Imaging Science in Dentistry
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• v.30 no.3
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• pp.169-181
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• 2000

Purpose: To investigate the expression of bone morphogenetic protein (BMP)-2/4 during eary tooth development after irradiation and calcium-deficient diet. Materials and Methods: The pregnant three-week-old Sprague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group (Group 1), and the experimental groups were irradiation/normal diet group (Group 2) and irradiation/calcium-deficient diet group (Group 3). The abdomen of the rats at the 9th day of pregnancy were irradiated with single dose of 350 cGy. The rat pups were sacrificed at embryonic 18 days, 3 days and 14 days after delivery and the maxillae tooth germs were taken. The tissue sections of specimen were stained immunohisto-chemically with anti-BMP-2/4 antibody. Results: At embryo-18 days, immunoreacivity for BMP-2/4 of the Group 1 was modetate in stratum intermedium of dental organ and weak in dental papilla and dental follicle, but that of Group 2 was weak in cell layer of dental organ, and no immunoreacivity was shown in dental papilla and dental follice of Group 2 and in all tissue components of the Group 3. At postnatal-3 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in cell layer of dental organ, odontoblasts and developing alveolar bone, but that of Group of 2 and Group 3 was weak in odontoblasts and developing alveolar bone. At postnatal-14 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in newly formed cementum, alveolar bone and odontoblasts, but that of Group 2 was weaker than that of Group 1. In the Group 3, tooth forming cell layer showed weak immunoreactivity, but other cell layers showed no immunoreactivity. Couclusion : The expression of bone morphogenetic protein (BMP)-2/4 during early tooth development was disturbed after irradiation and calcium-deficient diet.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.79-85
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• 2003

The purpose of this study is to observe histopathologic changes in the bilateral craniomandibular joints after allowing 6 weeks of consolidation by varying the amount of distraction in rabbit mandible. Eight rabbits weighing about 2 to 3 kg were used. After corticotomy was performed on the left mandibular body between the first premolar and the second premolar region, a unilateral fixation device was placed. Then, a 7-day period was allowed without distraction of the device. The mandible was lengthened 0.5 mm/day. Corticotomy and lengthening of mandible were not performed in control group. After the completion of the lengthening process, a 6-week-consolidation period was allowed. Then, the rabbits were sacrificed, and histologic examination of the craniomandibular joints was performed. Proliferative changes were observed in the craniomandibular joints in all groups. With the increasing amount of distraction, hypertrophy of the cartilage layer became more severe, bone formed was dense and enchondral ossification was clearly shown in subchondral bone. Hypertrophy of the cartilage layer was also seen in the non-distracted side as the distracted side in the experimental group. These results indicate that when physical force is applied constantly to joints, the proliferation of articular cartilage and bone formation are present. When more than 6 weeks of consolidation period is allowed at the time of performing distraction for more than 5 mm, articular changes, especially, in the contralateral side should also be noted.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.161-168
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• 2011

Purpose: The odontogenic keratocysts demonstrated a high recurrence rate and a biologically aggressive nature. This might be due to unknown factors inherent in the epithelium or enzymatic activity in the fibrous wall. Bcl-2 protein is characterized by its ability to inhibit apoptosis. The aim of this study was to evaluate the expression and distribution of bcl-2 in the OKCs, its possible relationship with the tumorous characteristics, such as the aggressive nature and high recurrence rate, and its usefulness to differentiate OKCs from dentigerous cysts. Materials and Methods: Formalin fixed paraffin-embedded tissue sections of 53 OKCs, and 44 dentigerous cyst were immunohistochemically analyzed quantitatively for the immunoreactivity of the bcl-2 protein with i-solution. Results: More Bcl-2 expression was observed in the OKCs (mean34.387%) than dentigerous cyst (mean11.144%) with statistical significance (P<0.001). Seventeen and 15 of the 32 OKCs in this study showed positivity in the basal layer and basal/suprabasal layers, respectively. In dentigerous cyst, 2 of 3 showed positivity in the basal cell layer. Conclusion: Considering that bcl-2 over expression may lead to the increased survival of epithelial cells, this study demonstrated a possible relationship between the aggressive nature of OKC and the intrinsic growth potential of its lining epithelium. Furthermore, the basal/suprabasal distribution of bcl-2 positive cells was observed in some OKCs, which might have a significant impact on the behavior of cysts. The bcl-2 expression of OKCs can be useful for differentiating OKCs from dentigerous cysts.

• Journal of Oral Medicine and Pain
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• v.9 no.1
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• pp.147-156
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• 1984

In spite of the radical increase of chemical poisoning cases caused by prevalent of oranic chlorine like endosulfan, the study of detection of chemical poisoning has seldom been attempted; the study of poisoning in teeth, which is more secure physiochemically, and in all the oral tissues has been even less attempted. The author has administered endosulfan into the month of a rabbit, causing its death, and tried to detect endosulfan in the teeth, jaws, and oral tissues through forensic chemical and histopathological tests. The result obtained is as follows : 1. By thin layer chromatography, endosulfan was detected in the jews, dental hard tissues, dental pulp, blood, and the liver. 2. By gas chromatography, it was also detected in the jaws, dental hard tissues, dental pulp, blood, and the liver. 3. The congestion and hemorrhage in buccal mucosa, palatal mucosa, and dental pulp was detected.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.4
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• pp.194-197
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• 2015

The amniotic membrane is the innermost layer of fetal membrane and is attached to the chorion in the placenta. This membrane has been used for nearly a century in varied fields such as ophthalmology, reconstructive surgery, and burn treatment. In this case report, we used a human amniotic membrane to repair an iatrogenic oroantral communication that occurred during the extraction of the patient's right upper second molar. A splint was given after the perforation was covered with human amniotic membrane and healing was clinically evaluated at various intervals. The outcome of the study revealed that the human amniotic membrane was an efficient graft material for repairing the defect caused by an iatrogenic oroantral communication following tooth extraction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.4
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• pp.214-217
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• 2023

Objectives: This case series aims to introduce the nasal floor approach for extracting inverted mesiodens. Materials and Methods: Through a retrospective chart review between January 2022 and February 2023, we included the mesiodens patients using nasal floor approach, and analysis the location of mesiodens from the anterior nasal spine (ANS), total operation time, and complications. Results: Each mesiodens was located 10 to 12 mm from the ANS and was covered with a cortical layer of the nasal floor. All mesiodens were successfully extracted without exposing the adjacent incisors or nasopalatine nerve within 30 minutes from draping to postoperative dressing. Conclusion: The nasal floor approach is an efficient extraction method that reduces bone removal and prevents anatomical damage while removing the mesiodens just below the nasal floor bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.3
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• pp.191-198
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• 2007

The p53 which is well known as tumor suppressor gene is located at 17p13. p53 is a sequence-specific DNA binding transcription factor that responds to certain cytotoxic stresses, such as DNA damage, by enhancing the transcription of genes that regulate cell-cycle progression as well as programmed cell death. The p63 gene that is located at 3q27-29, is recognized members of the p53 family, and responsible for the transcription of 6 isoforms. Three isoforms ($TAp63{\alpha}$, $TAp63{\beta}$, $TAp63{\gamma}$) contain an N-terminal transactivation (TA) domain and can induce apoptosis. The other 3 isoforms (${\Delta}Np63{\alpha}$, ${\Delta}Np63{\beta}$, ${\Delta}Np63{\gamma}$) lack the TA domain and may function in a dominant-negative fashion by inhibiting the transactivation functions of p53 and TAp63 proteins, and thus act as oncoproteins. A number of studies have investigated the role of p63 in human squamous cell carcinomas from different organs. Only a few studies have examined ${\Delta}Np63$ isoform in oral squamous cell carcinoma including normal epithelium. This study aimed to evaluate expression of ${\Delta}Np63$ isoform in human oral squamous cell carcinoma tissue and normal mucosa. The 3 cases of well differenciated oral squamous cell carcinoma specimen including adjacent normal mucosa were examined, and immunohistochemical study with monoclonal antibody(4A4) and tumor cell apoptosis analysis with Transmission Electon Microscopy were studied. And, RT-PCR analysis was done for expression of ${\Delta}Np63$ isoform. The results were as followed. 1. Normal gingiva showed the restricted p63 expression in basal cell layer. 2. Well differentiated squamous cell carcinoma showed mainly p63 expression in overall area of malignancy, especially in basal cell layer to adjacent stromal tissue. 3. Tumor cells around keratinized area with no p63 expression disclosed less micro-organelle in decreased size cytoplasm and severe chromatin margination with nuclear destruction that means apoptosis. 4. Comparison of mRNA expression of ${\Delta}Np63$ isoform by RT-PCR showed variable expression of ${\Delta}Np63$ isoform, but ${\Delta}Np63{\alpha}$ was most highly expressed in all 3 tumor specimen. From theses results, it should be suggested that ${\Delta}Np63$ isoform expression in well differentiated squamous cell carcinoma was closely related to tumor oncogenesis, expecially overexpression of ${\Delta}Np63{\alpha}$ is a most important factor in tumor genesis of oral squamous cell carcinoma.