Analysis of Factors Related to Distal Proximal Caries on the Distal Surface of the Mandibular Second Molar Induced by an Impacted Mandibular Third Molar.

OBJECTIVE: To analyze the factors related to distal proximal caries of the mandibular second molar (MSM) induced by an impacted mandibular third molar (MTM). METHODS: A total 500 panoramic radiographs of patients with impacted MTMs who were treated in the Department of Stomatology of the Affiliated Hospital of Yanbian University between October 2017 and October 2019 were selected. Descriptive and bivariate analyses were conducted, and the diagnosis of caries in the MSM and the position of the MTM were evaluated. RESULTS: The posterior margin space of the MSM was larger in males (13.5 mm) than females (11.1 mm, P < 0.001) and correlated with the MTM's impacted depth and eruption degree (P < 0.001). The prevalence of distal proximal caries of the MSM was 37.6%, and a χ 2 test showed that age, impacted depth, impacted direction, impacted angle, degree of occurrence, and CEJ distance were correlated with caries in the distal adjacent surface of the MSM (P < 0.001). Logistic multivariate analysis showed that the impacted depth was at position A or B, the impacted direction was mesioangular, and the impacted angle was <80°. Distal adjacent caries of MSMs were prone to occur when entirely or partially emergent. CEJ distance was not an independent factor for caries. The severity of caries in an MSM's distal adjacent surface had statistical significance on the impacted depth and impacted angle (P < 0.001). CONCLUSION: The posterior margin space of the MSM influences the impacted condition of the MTM. Preventive extraction can be considered if the impacted angle is <80°, especially in the case of a fully or partially emergent MTM at position A or B and mesioangular impacted areas.

Apigenin Inhibits Proliferation, Migration, and Invasion of Human Tongue Carcinoma Tca8113 Cells Through Regulating the MAPK Signaling Pathways.

OBJECTIVE: This study aimed to examine the effects of apigenin (API) on the proliferation, migration, and invasion of human tongue squamous cell carcinoma Tca8113 cells and explore its probable mechanisms. METHODS: After treating Tca8113 cells with API, the cell proliferation, migration, and invasive capacities were identified by tetrazolium salt colorimetry (MTT) assay, cell scratch test, and Transwell chamber test. Cellular immunofluorescence staining was used to localize mitogen-activated protein kinase 1 (MAPK1) and extracellular regulated protein kinase (ERK) 1/2 proteins. Western blot was used to detect the variations of the related protein expression levels. RESULTS: 1)Through the MTT assay, API significantly inhibited cell proliferation (P<0.01). 2) In the cell scratch test, the distance of lateral migration after the API treatment was significantly shorter compared to the control group (P<0.01). 3) The invasion rate in the lower chamber of the Transwell chamber was lower in the API group (P<0.01). 4) Cellular immunofluorescence staining presented that the total-MEKK1 was localized in the cytoplasm, p-MEKK1 was localized in the nuclear membrane and cytoplasm, and p-ERK1/2 was localized in the cytoplasm and nucleus. ⑤ After API was applied to cells, the expressions of p-MEKK1 and p-ERK1/2 proteins significantly reduced (P<0.01). CONCLUSION: Apigenin (API) significantly inhibits the proliferation, migration, and invasion of Tca8113 cells and its mechanism may be associated with the MAPK signaling pathway.

TGF-ß downregulation overcomes gemcitabine resistance in oral squamous cell carcinoma.

OBJECTIVE: The aim of this study was to explore the mechanisms by which oral cancer acquires resistance to gemcitabine. METHODS: Oral squamous cell carcinoma (OSCC) cells were treated with gemcitabine upon infection or with a lentivirus harboring short hairpin RNA (shRNA) targeted to transforming growth factor-ß (TGF-ß). Then, Western blot, ELISA, migration assay, MTT assay, and animal experiments were used to explore the mechanism of resistance to gemcitabine treatment. RESULTS: After the treatment of non-transfected cells with gemcitabine, NF-κB and AKT activities were increased, which may have induced the OSCC resistance to gemcitabine. Then, we found that TGF-ß downregulation effectively reduced NF-κB and AKT phosphorylation levels after the administration of gemcitabine and increased the OSCC sensitivity to gemcitabine, resulting in cell death and the blunting of OSCC resistance to gemcitabine. The EMT was also reduced by TGF-ß downregulation combined with gemcitabine treatment. CONCLUSION: Cellular levels of TGF-ß constitute an important factor in gemcitabine resistance and TGF-ß silencing might represent a novel and potent strategy for overcoming OSCC resistance to gemcitabine.

Osteoblastic behavior to zirconium coating on Ti-6Al-4V alloy.

PURPOSE: The purpose of this study was to assess the surface characteristics and the biocompatibility of zirconium (Zr) coating on Ti-6Al-4V alloy surface by radio frequency (RF) magnetron sputtering method. MATERIALS AND METHODS: The zirconium films were developed on Ti-6Al-4V discs using RF magnetron sputtering method. Surface profile, surface composition, surface roughness and surface energy were evaluated. Electrochemical test was performed to evaluate the corrosion behavior. Cell proliferation, alkaline phosphatase (ALP) activity and gene expression of mineralized matrix markers were measured. RESULTS: SEM and EDS analysis showed that zirconium deposition was performed successfully on Ti-6Al-4V alloy substrate. Ti-6Al-4V group and Zr-coating group showed no significant difference in surface roughness (P>.05). Surface energy was significantly higher in Zr-coating group than in Ti-6Al-4V group (P<.05). No difference in cell morphology was observed between Ti-6Al-4V group and Zr-coating group. Cell proliferation was higher in Zr-coating group than Ti-6Al-4V group at 1, 3 and 5 days (P<.05). Zr-coating group showed higher ALP activity level than Ti-6Al-4V group (P<.05). The mRNA expressions of bone sialoprotein (BSP) and osteocalcin (OCN) on Zr-coating group increased approximately 1.2-fold and 2.1-fold respectively, compared to that of Ti-6Al-4V group. CONCLUSION: These results suggest that zirconium coating on Ti-6Al-4V alloy could enhance the early osteoblast responses. This property could make non-toxic metal coatings on Ti-6Al-4V alloy suitable for orthopedic and dental implants.

[Cephalometric study with Steiner analysis on normal occlusion of Korean adults in Yanbian China].

OBJECTIVE: The aim of the study was to establish a cephalometric normal standard value for Korean in Yanbian China by means of Steiner analysis. METHODS: 72 cases of Korean adults in Yanbian with normal occlusion were selected, standard lateral cranial X-ray films were taken and cephalometric Steiner analysis was performed. The data was compared with Korean in Soul of Republic of Korea with normal occlusion. RESULTS: 1) Cephalometric Steiner normal standard values, standard deviation and Cheveron analysis chart were established. 2) 1-NB angle of male was significantly bigger than that of female, while GoGn-SN angle of female was significantly bigger than that of male (P<0.05), respectively. 3) There were significant differences on SNA, SNB, ANB, SND, [symbol: see text]-NA (mm),1-NB (except woman) compared with same age group Korean presented by In-Chool Park (P<0.05). CONCLUSION: There is a significantly different between male and female Koreans with normal occlusions in Yanbian China. This experiment filled in the blank of stomatology research in Yanbian Korean autonomous region. In the mean while, it completed and supplemented the normal occlude data of different nations in China. The present paper also provided the reference for clinic and scientific research on orthognathic surgeon. At the same time, the experiment provided the evidence for the further research.

[A case of vertebral traumatic pseudoaneurysm].

Pseudoaneurysm often occurred after trauma and infection. It was seen commonly on limb arteries but rarely on vertebral artery. The case was diagnosed two months after trauma. The pulsatile mass and vascular murmur found through preoperative examination confirmed from the vertebral artery. No complication was observed after surgery.