Objective: To examine the level of serum Cyfra21-1 in patients with oral squamous cell carcinoma(OSCC) and to explore the potential application of serum Cyfra21-1 detection in the diagnosis of OSCC. Methods: The serum Cyfra21-1 concentrations were detected by ELISA. Results: The preoperative serum Cyfra21-1 concentration in patients with OSCC was (1.12±0.61) ng/ml, which was significantly higher than that in healthy persons (0.34±0.20) ng/ml and that in patients with oral benign tumor (0.50±0.27) ng/ml. The sensitivity rate and specificity rate of the test were 83.9% and 89.3%, respectively. For 10 patients with OSCC, the serum Cyfra21-1 concentrations were decreased from (1.31±0.25) ng/ml preoperatively to (0.65±0.14) ng/ml postoperatively. Conclusion: Cyfra21-1 may be a good marker in diagnosis of OSCC.

Objective: To examine the microbial flora within the root canals with failed root canal therapy by PCR test, to identify detection rate of bacteria and the predominant bacteria species, and to determine the association of the various species with clinical features. Methods: Forty roots with failed root canal therapy were selected for this study. According to clinical features the roots were divided into three groups: pain, fistula and symptomless. After removal of the root filling material, the microbial samples were taken from the canal and detected by PCR test. Results: The microbial flora within root canals of teeth with failed root canal therapy was found to be mixed, six kinds of bacteria were detected. Enterococcus faecalis was the most commonly recovered bacteria species. Significant associations were observed between Prevotella nigrescens and pain, while dependablity was observed between Actinomyces israelii and fistula. Conclusion: The main cause of root canal treatment failure is the persistent microorganisms. The composition of bacteria in teeth with failed root canal therapy has its own specificity.

Objective: To observe the behavior therapy efficacy in dental fear patients for dental extraction using video eyewear and N_2O inhalation. Methods: 100 patients were divided into two groups, one group only used N_2O and other group used N_2O with video eyewear. Compared two groups′ Frankl behavior rating scale and Houpt scale after dental extraction. The HR and SpO_2 were measured during dental extraction. Results: Using video eyewear and N_2O showed a significant good sedative effect on patients with dental fear. There were statistical difference in the Frankl behavior rating scale and Houpt scale between experiment group and control group(P<0.01). There were no significant changes in heat rate and SpO_2 before and after in two groups. Conclusion: Video eyewear and N_2O inhalation sedation is good for dental fear patient during dental extraction.

Objective: To establish a cephalometric norms of Downs analysis for Korean population in China. Methods: 72 Korean adults in Yanbian with normal occlusion and harmonious face were selected. Lateral cephalometric radiographs were taken and analyzed with Downs analysis. The data was compared with the norms of the Korean in Seoul, Republic of Korea, which reported by Park. Results: Means, standard deviation of Downs polygon of our samples were presented. Differences between males and females were found in our samples: Facial angle in males group was smaller than that in females group. Angle of Yaix, L1 to mandibular plane, L1 to occlusal plane and U1 to AP plane in male group were larger than female group(P<0.05). Statistically significant differences were detected between our samples and Park's: Facial angle in Yanbian group was smaller than Soul group, while, Yaxis and occlusal plane was larger in Yanbian group. Angles of convexity of Yanbian males were larger than Soul males(P<0.05). Statistically significant differences were detected between our sample and Han group in Northeast China: Facial angle and AB-NP angle were larger than Han group. Angle of mandibular plane, angle of Yaix, L1 to mandibular plane, L1 to occlusal plane, angle of U1 to L1were smaller than Han group (P<0.05). Conclusion: Korean males in Yanbian district tend to have more convex profiles than females. Compared with Korean population in Seoul, Korean in Yanbian have more convex facial profile. Facial characteristics of Korean in Yanbian are between Korean population in Soul and Han population in Northeast China.

Objective: To explore the operation method and clinical effect of treatment for bilateral cleft lip with improved straight line closure. Methods: On the basis of straight line closure, the vermilion and anterior lip pear were repaired with the muscle-vermilion labial flap of lateral lip. In order to close nasal floor, flap-C from lateral wall of anterior lip and flap-G from nasal wing base were designed, meanwhile, nasal mucosa flap-D and flap-H from two sides of nasal base fissure were designed. The function of the orbicularis oris was repaired by cutting off the anomaly adhesion of the orbicularis oris. Results: The post-operational upper lip was thickened together with good shape and vermilion color, there was no obvious dynamic abnormality, nasal floor was closed well. Conclusion: The improved straight line closure can obtain good shape of lip, reduce the whistling deformities, oronasal fistula and dynamic abnormality.

Objective:To compare the quality of root-end preparation quantitatively between ultrasonic retrotips and traditional slow-speed handpiece. Methods: 27 maxillary second bicuspid teeth with two canals and an isthmus were randomly assigned to 3 groups.Root-end preparations were made respectively using ultrasonic diamond tip Berutti and niti tip RE2, ultrasonic 40~#K file and slow-speed handpiece with No.2 round bur. Image processing and analysis system were used to measure the preoperation and postoperation parameters for further evaluating the difference between the two techniques. Results: The cutting volume of ultrasonic instruments was less than slow-speed handpiece(P<0.000 1). Conclusion: Ultrasonic instrument is better in the root-end preparation than traditional slow-speed handpiece.

Objective: To determine the inhibitory effects of maltitol-gum on Streptococcus mutans, Lactobacilli and Actinomyces viscosus in dental plaque. Methods: Thirty 13-15 years old children with DMFS>4 were divided into three groups, maltitol chewing gums group(A group), xylitol chewing gum group(B group) and blank gum base group (C group). The plaque samples were collected and colony forming units were counted. Results: The levels of three-species cariogenic pathogens in three groups were statistically down-regulated when compared with the baseline(P<0.001).Moreover, A group and B group resulted in a higher decrease of Streptococcus mutans levels compare with C group(P<0.05). The levels of Lactobacilli and Actinomyces viscosus were not statistically different between groups(P>0.05). Conclusion: Maltitol-gum can lead to a significant suppression on Streptococcus mutans levels in dental plaque,while the inhibitory effect of the maltitol-gum on Lactobacilli, Actinomyces viscosus is not obvious.

Objective: To investigate the effects of hyperbaric oxygen(HB0_2) on black pigmented bacteroides groups(BPB), obligately and facultatively anaerobes of periodontitis. Methods: 60 periodontitis cases were divided into 2 groups. The HB0_2 group(gingival scaling was done at the first visit)was exposed in 0.25 MPa pure oxygen 90 minutes each day, and treated 10 days continuously. The control group received gingival scaling at the first visit. The clinical indices of each group were measured. The microorganisms in periodontal pocket were incubated and analyzed. The number of subgingival anaerobes as well as the number of BPB,obligately and facultatively anaerobes were measured and counted by routine anaerobic culture. Results: Highly significant differences in Gingival Indices (GI), Probing Depth (PD), Attachment Loss (AL), and also significant differences in Plaque Index (PLI),and teeth mobility were seen between the HB0_2 group and the control group. There were significant difference of PLI, GI,PD,AL, teeth mobility in HB0_2 group pre-therapy and post-therapy. There were significant difference of subgingival anaerobes amounts, obligately and facultatively anaerobes sorts between pre-therapy and post-therapy. The positive rate of BPB of group HB0_2 post-therapy were reduced more than that of pre-therapy(P<0.01). Conclusion: HB0_2 has beneficial therapeutic effects on chronic and aggressive periodontitis. The mechanism of the HB0_2 therapy might inhibit the growth of subgingival obligately and facultatively anaerobes and BPB of human periodontitis, especially the obligately anaerobes and BPB in periodontal pockets.

Objective:To study the feasibility of extraction of impacted mandibular wisdom teeth using turbine drill and new instruments. Methods: 600 patients with impacted mandibular third molars were divides into 2 groups. A group used turbine drill and new instruments to extract the impacted mandibular third molar. B group used the dental chisel to extract the impacted mandibular third molar. The operation time, intraoperative and postoperative complications were recorded to assess the effects of the methods. Results: The operation time of group A and group B was (22.285±12.025 01) min and (16.115±12.078 62) min respectively. The operation time of group A was shorter(P<0.05). The intraoperative and postoperative complication incidence rate was lower(P<0.05). Conclusion: Turbine drill and new instruments method is superior to dental chisel method in the extraction of impacted mandibular wisdom teeth.

Objective:To investigate the treatment effect of combined forsus appliance on young people's Angel Ⅱ~1 malocclusion. Methods:13 Angel Ⅱ~1 cases during pre-peak or peak period was chosen, treated with combined forsus appliance for an average period of 5.5 months, evaluated treatment effect through cephalometric and cast measurement. Results: All canines and molars have reached class Ⅰ or over-class Ⅰrelations, 13 patients' mandibular retrognathia face have gained significant improvement. Conclusion: The combined forsus appliance can be used in early functional treatment, improve class Ⅱ face type and decrease the difficulty of the second period and enhanced treatment effect.