Hee-Kyun Oh

EGCG induces apoptosis in human laryngeal epidermoid carcinoma Hep2 cells via mitochondria with the release of apoptosis-inducing factor and endonuclease G

(-)-Epigallocatechin-3-gallate (EGCG), a major green tea polyphenol, was tested for in vitro cytotoxicity against human laryngeal epidermoid carcinoma of the larynx Hep2 cells. EGCG-induced apoptotic cell death accompanied by a change in the cell cycle. However, EGCG did not result in caspase activation, nor did a caspase inhibitor block cell death. Furthermore, EGCG caused no change in the intracellular levels of reactive oxygen species (ROS). The levels of p53 were increased in the EGCG-treated cells, with a corresponding decrease in Bcl-2 and Bid protein levels as well as an increase in the Bax level. In addition, EGCG induced the cytoplasmic release of cytochrome c from the mitochondria accompanied by a decreased mitochondrial membrane potential, and subsequently upregulated translocation of apoptosis-inducing factor (AIF) and endonuclease G (EndoG) into the nucleus during the apoptotic process. Taken together, these findings indicate that the p53-mediated mitochondrial pathway and the nuclear translocation of AIF and EndoG play a crucial role in EGCG-induced apoptosis of human laryngeal epidermoid carcinoma Hep2 cells, which proceeds through a caspase-independent pathway.

Reduction Malarplasty Using Modified L-Shaped Osteotomy

t m Zygomatic bone, which protrudes on both sides of the midface, plays an important role in determining the facial impression. Many esthetic differences regarding the malar prominence exist between Asians and whites. In the West, augmentation malarplasty s performed mainly because a slightly prominent alar is believed to be esthetically pleasing. In ontrast, in the East, a prominent malar is believed o project an aggressive and unpleasing impression, articularly for women. Therefore, many reduction alarplasty procedures have been developed. For eduction malarplasty, bone shaving, infracture, and I-shaped and L-shaped osteotomy methods ave been used. Of these techniques, an I-shaped osteotomy can e used for a moderate or severe malar promience. This is an effective and safe method for educing the anterior zygoma with no damage to he maxillary sinus. This method, however, can esult in insufficient bone reduction ( 5 mm) and isturb the middle 0.333 of the zygoma (the most rominent area). An L-shaped osteotomy can be used for severe malar protrusion. The fracture line

Gene induction by glycyrol to apoptosis through endonuclease G in tumor cells and prediction of oncogene function by microarray analysis.

Glycyrrhiza uralensis (Leguminosae) has long been known as an antiinflammatory agent for gastric ulcers, arthritis, and rheumatism. The flavonoid glycyrol (GC) (10 μg/ml) isolated from G. uralensis dramatically inhibits phorbol ester (phorbol 12-myristate 13-acetate)-induced nuclear factor (NF)-κB-dependent transcriptional activity, as determined by luciferase reporter activity in human kidney epithelial 293T cells. To investigate global gene expression profiling in cells by GC, we performed high-density oligonucleotide microarrays. Our microarray analyses showed that GC inhibited phorbol ester-induced NF-κB-dependent transcriptional activity in inflammatory-related gene expression. RT-PCR analysis, based on microarray data, showed that NF-κB-dependent genes (such as CCL2, CCL7, CD44, and HSPB8 in addition to NF-κB itself) were significantly downregulated by GC. Treatment with GC (10 μg/ml) inhibited I-κB degradation induced by phorbol 12-myristate 13-acetate. The microarray data also suggested that GC induces gene expression to p53-dependent apoptosis through endonuclease G, instead of CAD/DFF and AIF/PDCD8, as a downstream-apoptosis factor in human kidney epithelial 293T tumor cells, and induces oncogenes with a suppressor role as an added function.

Effect of magnesium and calcium phosphate coatings on osteoblastic responses to the titanium surface

PURPOSE The aim of this study was to evaluate the surface properties and in vitro bioactivity to osteoblasts of magnesium and magnesium-hydroxyapatite coated titanium. MATERIALS AND METHODS Themagnesium (Mg) and magnesium-hydroxyapatite (Mg-HA) coatings on titanium (Ti) substrates were prepared by radio frequency (RF) and direct current (DC) magnetron sputtering.The samples were divided into non-coated smooth Ti (Ti-S group), Mg coatinggroup (Ti-Mg group), and Mg-HA coating group (Ti-MgHA group).The surface properties were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy (AFM). Cell adhesion, cell proliferation and alkaline phosphatase (ALP) activity were evaluated using MC3T3-E1 cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed. RESULTS Cross-sectional SEM images showed that Mg and Mg-HA depositionson titanium substrates were performed successfully. The surface roughness appeared to be similaramong the three groups. Ti-MgHA and Ti-Mg group had improved cellular responses with regard to the proliferation, alkaline phosphatase (ALP) activity, and bone-associated markers, such as bone sialoprotein (BSP) and osteocalcin (OCN) mRNA compared to those of Ti-S group. However, the differences between Ti-Mg group and Ti-MgHA group were not significant, in spite of the tendency of higher proliferation, ALP activity and BSP expression in Ti-MgHA group. CONCLUSION Mg and Mg-HAcoatings could stimulate the differentiation into osteoblastic MC3T3-E1 cells, potentially contributing to rapid osseointegration.

Odontogenic infection involving the secondary fascial space in diabetic and non-diabetic patients: a clinical comparative study.

OBJECTIVES This retrospective study was performed to evaluate the clinical impact of diabetes mellitus on the prognosis in secondary space infection. MATERIALS AND METHODS Medical records, radiographic images, computed tomography, and microbial studies of 51 patients (25 diabetic patients and 26 non-diabetic patients) were reviewed. Patients were diagnosed as secondary fascial space infections with odontogenic origin and underwent treatment at Chonnam National University Hospital, in Department of Oral and Maxillofacial Surgery, from January 2007 to February 2009. RESULTS COMPARED TO PATIENTS WITHOUT DIABETES, PATIENTS WITH DIABETES WERE PRESENTED WITH THE FOLLOWING CHARACTERISTICS: older age (diabetic patients: 62.9 years, non-diabetic patients, 47.8 years), more spaces involved (diabetic patients, 60%; non-diabetic patients, 27.3%), more intense treatment, longer hospitalization (diabetic patients, 28.9 days; non-diabetic patients, 15.4 days), higher white blood cell and C-reactive protein values, higher incidence of complication (diabetic patients, 40%; non-diabetic patients, 7.7%), and distinctive main causative microorganisms. CONCLUSION These results suggest that the prognosis of diabetic patients is poorer than that of non-diabetic patients in secondary space infections since they had greater incidence rates of involved spaces, abnormal hematologic findings, more complications, and additional procedures, such as tracheostomy.

Vector control of malpositioned segment during alveolar distraction osteogenesis by using rubber traction.

PURPOSE In this study we discuss how to control and maintain the vector of the malpositioned segment, which had occurred in post-distraction, and suggested treatments. PATIENTS AND METHODS We studied a patient who had undergone alveolar distraction osteogenesis and revealed a complication at the end of the distraction period; namely, the malpositioned segment. We treated this patient by removing the screw from the base plate and attaching a wire splint on the adjacent teeth during osseous consolidation as an anchorage to fix the malpositioned segment toward the desired direction. RESULTS At the end of traction application, a normal arch shape was observed. After the completion of distraction, implants were inserted in the ideal position. CONCLUSION The described treatment strategy appears to have good potential for providing an ideal final position of the lingually or palatally inclined bone segment.

Comparative study of the sinus septa between dentulous and edentulous patients by cone beam computed tomography.

Purpose:The purpose of this study was to conduct radiographic comparison of maxillary septa in dentulous and edentulous patients using 3-dimensional cone-beam computed tomography (CBCT). Materials and Methods:From November- 2008 to August 2010, the CBCT of full dentulous 100 patients was conducted randomly at the Department of Radiology, Chonnam National University Dental Hospital. Septa in the maxillary sinus were analyzed. Also, CBCT of 51 patients with partial or full edentulous dentition on maxillary posterior area was obtained. The height of the maxillary sinus septa was measured from the sinus floor, the location divided by the anterior, middle, and posterior portion, and the direction was determined to be the buccopalatal, sagittal, and transverse course. Results:In dentulous patients, sinus septa were found in 27% with 6.01 ± 2.21 mm mean height. The mean age of these patients was 24 years and 9 months, and most septa were found in anterior portion with a buccopalatal course. In cases of edentulous patients, the prevalence of edentulous patients with septa was 25.8% with 5.30 ± 1.90 mm mean height. The mean age of the patients was 63 years and 4 months, and most of septa were in the middle portion with a buccopalatal direction. Conclusion:There was no significant difference in the prevalence, incidence, height, location, and direction of maxillary sinus septa between dentulous and edentulous patients (P > 0.05).

Acute Airway Obstruction Secondary to Lingual Hematoma after Lower Third Molar Extraction: A Case Report

Few dental procedures are potentially life-threatening. Note, however, that a dental extraction can result in preventable death. Severe post-extraction bleeding can occur, which may give rise to an alarming situation if there is any delay in detecting and managing the problem. The most immediate danger for a healthy patient with severe post-extraction hemorrhage is airway compromise. Acute airway obstruction from post-extraction hematoma is relatively uncommon, but it may occur with fatal consequences if there is any reluctance to maintain the airway clearance. Therefore, dentists and oral and maxillofacial surgeons should have clear understanding of the problem and measures to control it. Active bleeding that is not controlled by local measures in a dental office should be referred to the nearest hospital emergency department as soon as possible for appropriate management.

A multicenter prospective study in type IV bone of a single type of implant.

Purpose:To analyze the success and survival rates of the Osstem GSII (Osstem, Busan, Korea) implant in type IV bone. Materials:A prospective, multicenter (5 centers) study was conducted by examining the relationship between implant success and survival rates, and several patient and surgical parameters. The implants were placed in 82 patients who visited several nationwide dental hospitals and clinics between 2007 and 2008, followed by clinical and radiographic analyses. Results:In type IV bone, the implant success and survival rates were 93.23% and 95.83%, respectively. The maxillary premolar and mandibular anterior tooth areas showed success rates of 100%. The most widely used implant diameter and length was 5.0 and 13 mm, respectively, but the diameter and length had no effect on success rates. However, success rates appeared to decrease with age. Conclusions:The results indicated that the Osstem GSII implant is highly effective in poor-quality type IV bone.

A Simple Technique for the Treatment of Inferior Orbital Blow-Out Fracture: A Transantral Approach, Open Reduction, and Internal Fixation With Miniplate and Screws

PURPOSE Infraorbital blow-out fracture (IOBF) is an uncommon midfacial trauma, and impairs eyeball function and causes esthetic problems. The extraoral approach can lead to some complications such as scarring, ectropion, and entropion. The intraoral approach, such as a transantral approach, has advantages such as no visible scaring, it can be used to simultaneously treat a zygomaticomaxillary complex fracture (ZMCF), and the procedure is relatively easy. PATIENTS AND METHODS IOBFs were reduced from the maxillary sinus, and fixated internally using miniplates and screws with/without Medpor (Porex, Newnan, GA) via a transantral approach. We used this technique in 11 patients who had an inferior blow-out fracture. Patients records and CT scans were reviewed. RESULTS The mean age of the patients was 37 years (ranging between 15 years and 68 years). The mean follow-up period was 9.8 months, which ranged from 1 to 24 months. Before the operation, the patients had orbital symptoms: diplopia in 3 patients; enophthalmos in 4; and gaze limitation in 3. All the patients showed periorbital swelling and ecchymosis. After surgery, none of the patients had diplopia, gaze limitations, and enophthalmos. There were no orbital symptoms or sinus symptoms due to an infection or allergic reaction after surgery except in 1 patient. In 1 patient, maxillary sinusitis developed at 4 months after surgery which subsided with antibiotic therapy after plate removal. CONCLUSION We think this technique offers an easy approach, and produces reliable, satisfactory results in IOBF.