• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.101-109
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• 2012

Objectives: The inactivation of the tumor suppressor gene $p16^{INK4a}$ plays an important role in the development of malignant tumors, including oral squamous cell carcinoma. The p16 gene is involved in the p16/cyclin-dependent kinase/retinoblastoma (Rb) gene pathway of cell cycle control. The p16 protein is considered a negative regulator of this pathway. The p16 gene encodes an inhibitor of cyclin-dependent kinases 4 and 6 which regulate the phosphorylation of the retinoblastoma gene and G1 to S phase transition in the cell cycle. However, the p16 gene can lose its functionality through point mutations, loss of heterozygosity or methylation of its promoter region. Materials and Methods: In this study, the authors analyzed the correlation between various clinicopathological findings- patient age, gender and smoking, disease recurrence, tumor size, stage, and differentiation- and p16 protein expression or p16 promoter hypermethylation in 59 cases of head and neck squamous cell carcinoma. Results: The results revealed p16 protein expression and p16 promoter hypermethylation in 28 cases (47.5%) and 21 cases (35.6%), respectively, of head and neck squamous cell carcinoma. However, neither p16 protein expression nor p16 promoter hypermethylation had any statistical influence on clinicopathological findings or survival rate. Conclusion: This data, and a review of the literature, suggest that p16 promoter hypermethylation cannot yet be used as an independent prognostic factor influencing carcinogenesis, but must be considered as an important factor along with other genetic alterations affecting the pRb pathway.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.241-244
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• 2011

Introduction: Intravenous sedation is performed to ensure smooth and safe surgery. Dental anxiety is a reaction to an unknown danger. The Spielberger's state-trait anxiety inventory (STAI) can be used to simultaneously evaluate the levels of state and trait anxiety. State anxiety is defined as subjective feelings of nervousness. This study assessed the presurgical anxiety using STAI and performed intravenous sedation for patients whose level of state anxiety was > stage IV. Based on our clinical experience, it is believed that higher doses of sedatives are needed to induce the desired levels of sedation in patients with a high level of state anxiety. Objectives: This study examined whether the sedative consumption of the patient with a high anxiety level increased. Patients and Methods: Patients with state anxiety scores of ${\geq}$51 were included in Group V, and those with state anxiety scores ranging from 42 to 50 were placed in Group IV. To induce sedation, intravenous access was established, and a bolus dose of 3.0 mg midazolam was administered intravenously. Sedation was maintained by administering a continuous infusion of propofol, which was aimed at achieving an Observer's Assessment of Alertness/Sedation scale of 10-12/20. In this study, midazolam was initially administered when the body movements appeared to occur or the blood pressure increased. This was followed by the administration of higher doses of propofol if low sedation was observed. Results: There were no significant differences in the patient demographics, duration of sedation, and doses of local anaesthetic agents between Groups IV and V. The midazolam dose and mean propofol dose needed to maintain comparable levels of sedation were significantly higher in Group V than in Group IV. Conclusion: In female patients, whose level of preoperative state anxiety is more than Stage V of STAI, a large quantity of sedatives is needed for intravenous sedation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.90-95
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• 2012

Objectives: This study was conducted in order to assess the efficacy of 1st generation cephalosporin as use as a single-dose preoperative prophylactic antibiotic for surgical wound infections resulting from intra-oral bone grafting procedures. Materials and Methods: A total of 23 patients who were to undergo intra-oral bone graft procedures participated in this study. After randomization, 2 grams of 1st generation cephalosporin was orally administered to both the experimental and placebo groups one hour prior to surgery in a double-blind fashion. Post-operatively, the experimental group (12 patients) was orally administered placebo three times a day for three days. The control group (11 patients) was orally administered 1st generation cephalosporin three times a day for three days. The postoperative course was observed for one month including the clinical parameters associated with infection. Results: Postoperative infections were noted in 1 out of 11 patients in the experimental group. No infections occurred in the control group. Conclusion: There was no significant difference in the incidence of postoperative infections between the two groups. Two grams of 1st generation cephalosporin administered orally one hour before surgery served as an effective prophylactic antibiotics therapy for intra-oral bone graft surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.85-89
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• 2012

Objectives: This study was to evaluate the effect of vertical bone gain and success rate and analyze the failure cases using the hydrodynamic piezoelectric internal sinus elevation (HPISE) technique. Materials and Methods: Patients who had been operated in the three centers including Daegu Catholic University Medical Center were selected for this study. The mucoperiosteal flap was elevated, and the sinus floor was then broken by specially designed piezoelectric insert, with hydraulic pressure applied to the sinus membrane for even elevation. Afterward, implants were placed. Panoramic radiogram or computed tomogram was taken before and after surgery and at the second operation and prosthesis placement. Later, changes in vertical height were measured and compared. The survival rate was based on the criteria of Buser et al. and Cochran et al. Results: In this study, 8 implants failed out of a total of 169 implants, resulting a success rate of 95.3%. These failure cases were due to insufficient initial stability or sinus membrane perforation. The mean of radiographic vertical height change at prosthesis placement was 5.7 mm (0.5-10.5 mm). Conclusion: In this study, HPISE technique was found to be a predictable treatment for atrophic maxilla and an alternative technique to the lateral approach.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.78-84
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• 2012

Objectives: Odontogenic keratocysts (OKCs) have a tendency to recur and possess an aggressive nature. the aim of the present study was to evaluate cytokeratin (CK) expression patterns as a method for the differentiation between dentigerous cysts (DCs) and OKCs, as their histomorphologic appearance are often indistinguishable. Materials and Methods: Formalin-fixed, paraffin-embedded tissue sections of 43 OKCs and 38 DCs were immunohistochemically analyzed with i-solution in a quantitative manner in order to evaluate the immunoreactivity of CK 10, 16 and 17. Results: CK 10 expression was evident in 79.1% of OKCs but found in only 18.4% of DCs (P<0.05), and CK 10 expression was observed to occur more frequently in OKCs (mean 25.45%) than in DCs (2.19%) (P<0.05). The expression of CK 16 was evident in 79.1% of OKCs but found in only 7.9% of the DCs (P<0.05) and CK 16 expression was observed to occur more frequently in OKCs (mean 4.33%) than in the DCs (0.61%) (P<0.05). The expression of CK 17 was evident in 88.4% of OKCs but seen in only 15.7% of the DCs (P<0.05) and CK 17 expression was observed to occur more frequently in OKCs (mean 31.11%) than in the DCs (2.37%) (P<0.05). Conclusion: The immunohistochemical detection of CK 10, 16 and 17 can be utilized as a valuable biomarker for use in distinguishing between OKCs and DCs, which have clinically significant differential diagnoses.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.71-77
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• 2012

Objectives: This study sought to investigate the positioning of the posterior superior alveolar artery in relation to the performance of the maxillary sinus bone graft procedure in a Korean population. Materials and Methods: We identified the position of the posterior superior alveolar artery relative to 93 maxillary sinuses in 58 patients and determined the distance from the inferior border of the artery in the premolar and molar areas to the alveolar ridge and sinus floor. Results: The mean distance from the alveolar ridge to the posterior superior alveolar artery in the dentate group ($20.62{\pm}3.05mm$ in the premolar region, $17.50{\pm}2.84mm$ in the molar region) was greater than as compared to the edentulous group ($18.83{\pm}2.79mm$ in the premolar region, $15.50{\pm}1.64mm$ in the molar region), and this difference was statistically significant (P<0.05). In contrast, there was no statistically significant difference (P>0.05) between the mean distance from the sinus floor to the posterior superior alveolar artery in the dentate group ($8.21{\pm}2.79mm$ in the premolar region, $7.52{\pm}2.07mm$ in the molar region) or in the edentulous group ($7.75{\pm}3.31mm$ in the premolar region, $7.97{\pm}2.31mm$ in the molar region). Conclusion: Prior to surgery, it is important to evaluate the position of the posterior superior maxillary artery by using computed tomography scans. The premolar area is safer than the molar area for performing the maxillary sinus bone graft without bleeding.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.234-236
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• 2011

Traditional surgery to remove foreign bodies in the face carries a risk of postoperative morbidity with an injury to various anatomical structures, particularly the facial nerve and parotid duct and gland. Endoscopy can be a great aid in the removal of foreign bodies in the maxillofacial region. Surgical intervention using endoscope and/,or intraoperative images can be minimized, allowing the safe and precise removal of foreign bodies, and saving operating time. We report a case of the use of an endoscope and C-arm fluoroscopy guidance system to remove a very small foreign body.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.121-126
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• 2012

Aberrations on the short arm of chromosome 8 (8p) are frequently observed in several human cancers. In this study, 20 squamous cell carcinoma (SCC) specimens from the tongue were examined in order to evaluate the role of 8p in SCC of the tongue. Microsatellite analysis using 14 markers demonstrated two commonly deleted regions (CDRs) on 8p. Reverse transcription-polymerase chain reaction (RT-PCR) revealed frequent down-regulation of the FEZ1 gene, mapped to 8p22, and frequent over-expression of the cathepsin B gene, mapped to 8p-21-22. These results suggested that genetic aberrations are involved in the development of SCC of the tongue. However, no significant relationship was observed to be established between the genetic alterations and clinicopathological features. Thus, further investigation is necessary in order to clarify the clinical role of 8p in carcinoma of the tongue.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.116-120
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• 2012

The buccal fat pad is specialized fat tissue located anterior to the masseter muscle and deep to the buccinator muscle. Possessing a central body and four processes it provides separation allowing gliding motion between muscles, protects the neurovascular bundles from injuries, and maintains facial convexity. Because of its many advantageous functions, the use of the buccal fat pad during oral and maxillofacial procedures is promoted for the reconstruction of defects secondary to tumor resection, and those defects resulting from oroantral fistula caused by dento-alveolar surgery or trauma. We used the pedicled buccal fat pad in the reconstruction of intraoral defects such as oroantral fistula, maxillary posterior bone loss, or defects resulting from tumor resection. Epithelization of the fat tissue began 1 week after the surgery and demonstrated stable healing without complications over a long-term period. Thus, we highly recommend the use of this procedure.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.205-213
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• 2011

Introduction: The enlargement and deformation of the orbit give rise to a visible enophthalmos. As a consequence, a disturbance of eye motility together with double images is likely to occur. This study examined the degree of enophthalmos according to the extent of orbital wall fracture and volume of herniated orbital tissue in blowout fractures of the medial and inferior orbital wall. Materials and Methods: This study was performed on patients diagnosed with medial and inferior orbital wall fractures at the Department of Oral and maxillofacial surgery, Chonbuk National University Hospital from 2007 to 2009. The patients' age, gender, etiology of fracture and degree of enophthalmos were investigated. The changes in the degree of enophthalomos, diplopia and ocular motility restriction after operation were examined. Results: The degree of enophthalomos increased with increasing extent of orbital wall fracture and volume of herniated orbital tissue. Conclusion: Whether to perform the operation is decided after measuring the extent of the orbital wall fracture and volume of herniated orbital tissue using computed tomography (CT), time for the decision of operation can be shortened. This can cause a decrease in the complications of orbital wall fractures.