• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.4
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• pp.277-286
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• 2006

In the present study, I investigated the effects of N-methyl-D-aspartate (NMDA), arachidonic acid (AA), and Nitric Oxide Synthase Inhibitor (NOS-I), alone or in combination, on the viability of cultured primary normal human oral keratinocytes (NHOK). Specifically, we examined whether AA and NOS-I could protect primary NHOK from glutamate cytotoxicity. The purpose of this study was therefore the preliminary study for the examination of the interaction between these agents and NHOK in order to elucidate the mechanisms by which epithelial growth and regeneration are regulated. NHOK were obtained from gingival tissue of 20 individuals aged 20 to 29, and third passage (P3) cells were used for this study. Cell viability was measured by the MTT assay. NMDA and NNA, a calcium dependent NOS inhibitor, induced an initial increase in cell number, which subsequently decreased by the $7^{th}$ day. Low concentration of AA ($0.5\;{\mu}M$ & $1\;{\mu}M$) induced an increase in cell number while high concentrations of AA ($5\;{\mu}M$ & $10\;{\mu}M$) induced a decrease in cell number. The decrease in cell number induced by NMDA at the $7^{th}$ day was abolished by the addition of low concentrations of AA ($0.5\;{\mu}M$ & $1\;{\mu}M$) or NOS inhibitors. Low concentrations of AA ($0.5\;{\mu}M$ & $1\;{\mu}M$) or NOS inhibitors may protect the NHOK from NMDA induced cytotoxicity. These reactions might be related to the NMDA receptor in the cell and the change of the intracellular calcium ion concentration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.2
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• pp.124-136
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• 2001

Heat shock protein (HSP) expression is unregulated in tumor cells and, HSP expression is likely marker of the malignant potential of oral epithelial lesion. Furthermore, the 70kDa HSP is implicated in the degree of tumor differentiation, the rate of tumor proliferation and the magnitude of the anti-tumor Immune response. Accordingly, the distribution and intensity of HSP70 and HSP47 expression was assessed in the DMBA induced oral carcinogenesis in hamster. Golden Syrian hamsters which were 3 months-age and $90{\sim}120g$ were collected. 9,10-dimethyl -1,2-benzanthracene (DMBA) in a 0.5% solution in mineral oil was painted on the buccal pouch mucosa 3 times per week in the study group. In each control and experimental groups of 6, 8, 10, 12, 14, 16, 18, 20 weeks, specimen were sectioned for immunohistochemical study with anti-HSP47 and anti-HSP70 antibody. The following results were obtained. 1. HSP47 positive cells were race or negative of normal oral mucosa, increased mildly in basal and suprabasal basal layer, and spinous cell layer after experimental 6 weeks (dysplastic or CIS stage). In CIS stage, HSP47 expression is prominent in dysplastic free or normal adjacent epithelium. 2. HSP47 positive cells in connective tissue were mainly inflammatory cells, which is gradually increased from control to precancerous and cancer stage. But HSP47 positive cells after 14 weeks were decreased, especially normal and cancer adjacent epithelium. 3. The positive staining cells of HSP70 in control, dysplastic, and CIS stage were not seen. But they were mild findings in basal layer and moderate findings in spinous layer after experimental 14 weeks (cancer stage). 4. HSP70 positive cells were increased in precancerous and cancer stage than control group in connective tissue. After experimental 16 weeks, we could not find the HSP expression in cancer cells according to cancer differentiation or cancer stage. It is concluded that HSP70 or HSP47 expression is not a definitive marker of oral malignancy or malignant potential. However, with further development, HSP immunoreactivity may be valuable as an adjunct to conventional histology for assessing the malignant potential of oral mucosal lesions.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.57-61
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• 2010

Objective: Second primary malignancy (SPM) that occur in various period and region are important factors that deteriorate long-term survival rate in patients who recovered from oral cancer. Researches such as chemoprevention are being tried to reduce occurrence of SPMs. Only if analysis of clinical features of patients who develop SPM such as period, region and factors precedes, adequate prevention and treatment of SPM is possible. But, there are few researches about clinical features of SPMs that have primary lesion in oral cavity. In this study, we analysis that occurrence rates, regions that happen, risk factors and effect to survival rates of 2nd primary malignancies in oral cancer patients. From this survey, we willing to collect basic data for prevention and early diagnosis of SPMs. Methods: The medical records of 139 patients of oral oncology clinic of National Cancer Center who had up to 2-years follow up records after surgical or radiological treatment due to squamus cell carcinoma of oral cavity were reviewed. In these patients, survey of occurrence rate of SPMs, duration, survival rate and risk factors about occurrence of SPMs such as history of smoking, body mass index, age, sex, stage of primary lesion and history of radiologic treatment were achieved. Results: There are 15 patients who developed SPM in 139 cases. The actual occurrence rate of SPM was 10.79% and SPM were more likely to occur in male patients with 11 male Vs 4 female patients. Median age of these patient is 61.47 within 32 to 74 range. The regions that develop SPM are oral cavities (2 cases), stomach (4 cases), esophagus (2 cases), lung (2 cases) and others (1 case each breast, larynx, cervix, liver and kidney). In addition, metachronous cancers were 11 cases which happened more common than 4cases of synchronous cancers. Surveys of risk factors that relate to development of SPMs, such as sex, age, history of radiologic treatment, body mass index, history of smoking and stage of primary disease were done. Among them, factor of sex is only appear statistically significant (P=0.001), but rest are not significant in statistically. Conclusion: Occurrence rates of SPMs were reported from 10% to 20% by precede study. In this study, occurrence rate of SPMs is 10.79% that is similar to results of precede research. In comparison of 5-yr survival rates of groups that develop SPMs or not, there is statistically significance between two groups. Present treatment modalities of SPMs are surgical operation, radiotherapy, chemotherapy and combination of these modalities. In choosing the treatment modality, we must consider the first treatment modality, region of primary disease, region of SPMs and general conditions of patient. Because development of SPMs have big effect on prognosis, prevention of SPMs must regard to important objective of treatments in patients of SCCa in oral cavity.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.544-550
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• 2010

Purpose: The result of all malignant neoplasms including oral cancer is decided by long-term prognosis. However, until now, there are only a few reports about long-term prognosis of cancer secluded in the oral cavity. So, we investigated all patients that visited our clinic for oral squamous cell carcinoma (SCCa) for the last 10 years. From this survey, we hope to find important factors that influence prognosis of the disease. Patients and Methods: A retrospective study was performed for patients that visited the oral oncology clinic for oral cancers from Jan. 2001 to Feb. 2010. We selected the patients that were diagnosed with SCCa and received curative treatment. In these patients, we investigated basic epidemiology, smoking history, body mass index, recurrence rate, treatment methods, pathologic data and 5-yr survival rate. Results: There was a total of 185 patients (115 males, 70 females and mean age: 57.3 years) that visited the oral oncology clinic for oral SCCa. Areas of primary lesion were tongue (105 cases, 57%), lower gum (19 cases, 10%), floor of mouth (16 caess, 8%), retromolar trigone (12 cases, 6.5%), and buccal cheek (11 cases, 6%). Other involved areas were upper gum, palate, lip, and salivary glands-of 1 case each. The overall 5-year survival rate was 63.7%. The factors that influenced prognosis of the disease were stage of the disease, status of differentiation, recurrence, metastasis of cervical lymph node and age. Conclusion: The factors that influence prognosis of disease are stage of the disease, status of differentiation, recurrence, metastasis of cervical lymph node and age. To point out a current trend, the mean age of patients that developed oral cancer was lower than that of before. Secondly, the prevalence of oral cancer in non-smoker are on the rise. Thus, further studies on etiology and epidemiology should be done.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.5
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• pp.277-283
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• 2013

Purpose: Well vascularized pectoralis major myocutaneous flap (PMMF) had been a commonly used versatile flap in reconstructive oromaxillofacial surgery since the 1970s. However, after the advent of microvascular surgery in the 1980s, the PMMF was used less frequently. But, to date, PMMF has been useful and has some advantages such as covering wide defects, covering vital structures, back-up procedure in cases of free flap failure, and reconstruction for radiotherapy patients. The purpose of this study is to evaluate the role, indication, complications, functional, and aesthetic results of this flap in the era of free flap with a literature and chart review. Methods: A retrospective study was conducted of 16 oral cancer patients undergoing reconstructive surgery with PMMF for reconstruction of defects from 2001 to 2012 at Kyungpook National University Hospital. The male to female ratio was 10:6, with a mean age of 63 years (16~79 years). Basic demographic data, previous treatment history, indications, dimension of the flap, site of reconstruction, postoperative complications, and patients' final status were systemically analyzed from chart review. Results: The pathology of the disease included squamous cell carcinoma in the majority of cases (n=14). The remaining cases were fibrosarcoma and mucoepidermoid carcinoma. Of the 16 PMMF reconstructions, 13 flaps were applied as primary reconstructive procedures, whereas three flaps were; salvage; procedures (vascularized free flap failure). Twelve patients had complications such as wound dehiscence, infection, hematoma, fistula, flap bulkiness, and partial flap necrosis. The higher complication rates showed an association with utilization of the flap in preoperative radiotherapy cases. However, all patients were discharged without failure. Conclusion: In reconstructive oromaxillofacial surgery, the PMMF is still a useful flap for huge defects. In addition, the PMMF can be used as a salvage procedure after vascularized free flap failure and reconstruction for patients with a history of preoperative radiotherapy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.227-235
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• 2013

Purpose: High risk human papillomavirus (HPV) is the main source of cervical cancer, nearly up to 100%. Because there are no affordable data regarding the incidence of HPV in different sites of oral cavity, the purpose of this study is to review the previous article and to find out about the incidence and types of HPV in specific areas of oral cavity. Methods: We examined a total of 106 patients with oral cavity cancer for HPV detection. Available DNA chip (MY-HPV chip kit$^{(R)}$, Mygene Co., Korea) was used for the detection of low risk HPV types (6, 11, 34, 40, 42, 43, 44) and high risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 54, 56, 58). Patients were previously diagnosed as invasive cancer of oral cavity. Specimen used for HPV detection was extracted from the main mass during resection and were tested for HPV type, performed by a DNA chip method. Results: Histologic results showed that there were squamous cell carcinomas, mucoepidermoid carcinomas, cystadenocarcinomas, leiomyosarcoma and etc. Among HPV positive cancer, 2 patients showed positive for high risk HPV type 16, 3 patients showed positive for low risk HPV type 6 and the other 2 patients were positive for other types of HPV. Of the 7 patients with HPV positive, 4 patients were on the tongue, 3 on the lower gingiva. Conclusion: Most of the HPV positive cancers were on the tongue in our study. Cervical cancer of HPV infection is reported to be increasing in our society and because HPV infection largely spreads by sexual contact, the incidence of oral cancer with HPV infection is greatly assumed to be on the increase, simultaneously. Because the incidence of HPV on specific areas of oral cavity among oral cancer patients is not identified, more studies are ongoing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.111-117
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• 2001

There are three designs of thread form in screw type implants: V-thread, Reverse buttress thread and Square thread. The purpose of this study was to find out how thread form designs have an influence on the equivalent stress, equivalent strain, maximum shear stress and maximum shear strain and which design of thread form generates more maximum equivalent stress and strain. 3-D finite element analysis was used to evaluate the stress and strain patterns of three tread types. The results of this study were as follow. 1. Under the 200N of axial load, the value of maximum equivalent stress is smallest in square thread and there is no significant difference between that of V thread and reverse buttress thread. 2. Under the 200N of axial load, the value of maximum equivalent strain is largest in V thread and smallest in square thread. 3. Under the 200N of axial load, the value of maximum shear stress is smallest in square thread and there is no significant difference between that of V thread and reverse buttress thread. 4. Under the 200N of axial load, the value of maximum equivalent strain is largest in V thread and there is no significant difference between that of square thread and reverse buttress thread. 5. Above results show that the square thread has special advantages in stress and strain compared with other thread types, especially in shear stess which is most determinant to implant-bone interface. Considering the superior biomechanical properties of square form implant, we presume that square form implant has better clinical results than the other types of implants in the same clinical conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.129-134
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• 2001

Since NNK is one of the most abundant tobacco-specific alkaloids and a strong carcinogenic nitrosamine, it has been used for evaluating a potential of carcinogenicity in the animal models. The present study has attempted to examine the potential of carcinogenicity of NNK in human epithelial cells, from which the cell type the most of cancers including oral cancer and nasal cavity cancer are originated. The cellular model used for the study is a human keratinocyte cell system immortalized by Ad12-SV40 hybrid virus. The cellular system has successfully been used for the carcinogenicity studies because of its limitless life span, epithelial morphology and nontumorigenicity. When cells were treated with a variety of NNK concentrations, levels of saturation density and soft agar colony formation were increased in a dose-dependent fashion. Colonies of large cell aggregates were above 5 at the higher doses. The results indicate that exposure of human cells with NNK induced loss of contact inhibition and increases of anchorage independence and cellular adhesion, which are typical characteristics of the neoplatically transformed cells. When cells were exposed with 100uM NNK for 2hr, mRNA levels of IL-1 and PAI-2 were increased in a dose-dependent manner, but expression of TGF- 1 was not affected. While expression of growth regulatory factors were altered with a short-term exposure, there was no alteration of these factors in the NNK-transformed cells. However, mRNA levels of fibronectin were increased both in the short-term treatment and in the transformation. The results suggest that altered expression of extracellular matrix such as fibronectin following short-term exposure might be fixed in the genome and these altered properties be continuously transfered throughout the cell division. Western blot analysis showed a translocation of PKC- from cytosolic fraction to the particulate fraction, indicating a possible role of NNK in the signal transduction pathway. The present study provided an evidence that NNK in the smoking may be associated with epithelial origin cancer such as oral and nasal cavity cancers. In addition, this study suggested that altered expression of extracellular matrix and PKC may play an important role in the carcinogenic mechanism of NNK.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.167-173
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• 2001

Cystic lesion of the jaw are frequently encountered clinically. Although they rarely lead to development of tumors, they can result in resorption of the jaw bone or asymmetry of the face may occur. The purpose of this study is to find the clinical and histopathological pattern of cysts and to help better understanding for the diagnosis and treatment of jaw cysts. The hospital chart, out-patient chart, panorama X-ray, histopathological report and operation report of 246 patients were reviewed who had been diagnosed as cyst. Sex distribution, age distribution, classification, anatomic distribution, clinical sign & symptoms, treatment, post-operation complications, recurrence rate were studied. Then significant difference between the diameter of cyst with bone graft and none-bone graft was calculated with SAS program. The results were as follows. 1. Among the total patient of 246 cases, male were 163 case(67.0%), and female were 83 case(37.0%), male predominated by the ratio of 1.98. 2. By age group, the 20's accounted for the largest proportion of the cases(27.2%) and the 30' accounted for the 2nd largest proportion of the case(19.5%). 3. Radicular cyst and dentigerous cyst were most common cysts, irrespective of 166 case(67.5%) and 62 case(25.2%). 4. Clinical sign & symptoms were swelling(167case), pain(85case), pus discharge(53case), teeth discoloration(28case), indicating that most complaints were related to inflammation and facial asymmetry. 4.9% of the total cases were discovered accidentally. 5. The primary site of cysts were maxillary anterior area(43.9%), the others were, in descending order, mandibular posterior area(25.6%), maxillary posterior area(14.6%). 6. Enucleation with endodontic treatment was a main treatment method(133 case, 54.1%) and 38 cases(15.4%) were enucleation with extraction, and 37 cases(15.0%) were only enucleation, and 21 cases(8.5%) were enucleation with bone graft. 7. The average diameter of cysts with bone graft was significally greater than with non-bone graft(p<0.05). 8. Post-operation complications occurred in 10 case(4.1%), all of this were due to secondary infection.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.324-329
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• 1999

The facial esthetics are much affected by nasal changes due to especially its central position in relation to facial outline and so appropriately evaluated should be the functional and esthetic aspects of the nose associated with the facial appearance. Generally, a maxillary surgical movement is known to induce the changes of nasolabial morphology secondary to the skeletal repositioning accompanied by muscular retraction. These changes can be desirable or undesirable to individuals according to the direction and amount of maxillary repositioning. We investigated the surgical changes of bony maxilla and its effects to nasal morphology through the analysis of the lateral cephalogram in the Le Fort I osteotomy. Subjects were 10 patients(male 2, female 8, mean age 22.3 years) and cephalograms were obtained 2 weeks before surgery(T1) and 6 months after surgery(T2). The surgical maxillary movement was identified through the horizontal and vertical repositioning of point A. Soft-tissue analysis of the nasal profile was performed employing two angles: nasal tip projection(NTP), columellar angle(CA). Also, alar base width(ABW) was assessed directly on the patients with a slide gauge. The results were as follows; 1. Both anterior and superior movement above 2mm of maxilla rotated up nasal tip above 1mm. Either anterior or superior movement above 2mm of maxilla made prediction of the amount & direction of NTP changes difficult. Especially, a correlation between horizontal movement of maxilla and NTP rotated-up was P<0.01. 2. Both much highly anterior and superior movement of maxilla is accompanied by more CA increase than either highly. Especially, the correlation between horizontal movement of maxilla and CA change was P<0.05. 3. Anterior and/or superior movement of maxilla was accompanied by the unpredictable ABW widening. 4. The amount of changes of NTP, CA, and ABW is not in direct proportion to amout of anterior and/or superior movement of maxilla. 5. Nasal morphologic changes following Le Fort I osteotomy are affacted by not merely bony repositioning but other multiple factors.