Objective:To propose a novel neural network to achieve tooth instance segmentation and recognition based on cone-beam computed tomography(CBCT)voxel data.Methods:The proposed methods included three different convolutional neural network models.The architecture was based on the Resnet module and built according to the structure of"Encoder-Decoder"and U-Net.The CBCT image was de-sampled and a fixed-size region of interest(ROI)containing all the teeth was determined.ROI would first through a two-branch"encoder and decoder"structure of the network,the network could pre-dict each voxel in the input data of the spatial embedding.The post-processing algorithm would cluster the prediction results of the relevant spatial location information according to the two-branch network to realize the tooth instance segmentation.The tooth position identification was realized by another U-Net model based on the multi-classification segmentation task.According to the predicted results of the net-work,the post-processing algorithm would classify the tooth position according to the voting results of each tooth instance segmentation.At the original spatial resolution,a U-Net network model for the fine-tooth segmentation was trained using the region corresponding to each tooth as the input.According to the results of instance segmentation and tooth position identification,the model would process the correspon-ding positions on the high-resolution CBCT images to obtain the high-resolution tooth segmentation re-sults.In this study,CBCT data of 59 cases with simple crown prostheses and implants were collected for manual labeling as the database,and statistical indicators were evaluated for the prediction results of the algorithm.To assess the performance of tooth segmentation and classification,instance Dice similarity co-efficient(IDSC)and the average Dice similarity coefficient(ADSC)were calculated.Results:The ex-perimental results showed that the IDSC was 89.35％,and the ADSC was 84.74％.After eliminating the data with prostheses artifacts,the database of 43 samples was generated,and the performance of the training network was better,with 90.34％for IDSC and 87.88％for ADSC.The framework achieved ex-cellent performance on tooth segmentation and identification.Voxels near intercuspation surfaces and fuzzy boundaries could be separated into correct instances by this framework.Conclusion:The results show that this method can not only successfully achieve 3D tooth instance segmentation but also identify all teeth notation numbers accurately,which has clinical practicability.

Objective To investigate the risk factors and etiology in young adults with ischemic stroke.Methods From June 2014 to June 2017,consecutive patients with first-ever ischemic stroke aged from 18 to 45 years and admitted to the Department of Neurology,the Third People's Hospital of Chengdu were collected retrospectively.The demographic data,vascular risk factors,National Institutes of Health Stroke Scale score,location of infarction,and etiological subtypes were documented.They were divided into either a male group or a female group according to the gender,and they were divided into 2 age groups of 18-35 years and 36-45 years.Results A total of 103 young adults with ischemic stroke were enrolled during the study.Among them,the proportion of men was higher than that of women (73.8％ vs.26.2％).The most common 5 risk factors were smoking,abnormal lipid metabolism,drinking alcohol,hypertension,and large atherosclerosis,respectively.The proportions of abnormal glucose metabolism (37.2％ vs.11.8％),hypertension (46.5％ vs.11.8％),and large artery atherosclerosis (37.2％ vs.11.8％) in the age group of 36-45 years were significantly higher than those in the age group of 18-35 years (all P＜0.05).The proportions of smoking (67.1％ vs.14.8％) and drinking alcohol (51.3％ vs.18.5％) in the male group were significantly higher than those in the female group (all P＜ 0.05).In the etiological aspect,the proportion of cryptogenic stroke in the age group of 18-35 years was significantly higher than that in the age group of 36-45 years (47.1％ vs.15.1％;P=0.006),while the proportion of the large artery atherosclerotic stroke was significantly lower than that in the age group of 36-45 years (11.8％vs.41.9％;P =0.019).There were no significant differences in the etiological subtypes between different sex groups.Conclusion The distribution of risk factors and etiological subtypes in young patients with ischemic stroke have some differences in different gender and age groups.Some common modifiable risk factors (such as smoking,drinking,abnormal lipid metabolism,etc.) still account for a higher proportion in young adults with ischemic stroke.

BACKGROUND:The post space cleaning using ultrasonic file can improve the bonding strength of fiber postscemented with the self-adhesive resin cement, but the effect on apical sealing ability is stil unclear. OBJECTIVE:To evaluate the effect of the post space cleaning using ultrasonic file on apical microleakage fol owing treatment with two kinds of root canal sealers at two different residual lengths of root canal fil ing. METHODS:Eighty extracted human maxil ary anterior teeth with single-rooted canal were selected, and equivalently randomized into groups A and B (n=40 per group), fol owed by fil ed with Cortisomol or AH-plus, respectively. Groups A and B were randomly subdivided into four groups according to the residual length of root canal fil ing and with or without ultrasonic cleaning (n=10 per group):A1, B1 groups:residual 5 mm, no ultrasonic cleaning;A2, B2 groups:residual 5 mm, ultrasonic cleaning;A3, B3 groups:residual 3 mm, no ultrasonic cleaning;A4, B4 groups:residual 3 mm, ultrasonic cleaning. Subsequently, the apical microleakage was measured using dye method and transparent specimen technique under stereomicroscope. RESULTS AND CONCLUSION:The apical microleakage of each group was as fol ows:A1 (0.73±0.21) mm, A2 (1.37±0.55) mm, A3 (1.18±0.36) mm, A4 (2.05±0.62) mm, B1 (0.34±0.18) mm, B2 (0.47±0.14) mm, B3 (0.59±0.23) mm, B4 (1.39±0.50) mm. The three-factor analysis of variance revealed that the ultrasonic cleaning, root canal sealers and residual length of root canal fil ing al had a significant effects on the apical microleakage (P<0.05), and there were significant differences in the apical microleakage between groups A1 and A2, groups A3 and A4, groups B3 and B4, groups A2 and A4, groups B2 and B4 (P<0.05). These results indicate that the ultrasonic cleaning increases the apical microleakage fol owing the use of Cortisomol at 5 and 3 mm residual length, as wel as the use of AH-Plus at 3 mm residual length. Moreover, for the same root canal sealer, the longer residual length of root canal fil ing indicates, the less microleakage after ultrasonic cleaning.

OBJECTIVE To observe the effect of baicalin on Aβ25-35 induced learning and memory deficits and changes in autophagy-related genes in mice so as to explore the related mechanisms of Alzheimer disease (AD) treatment . METHODS C57 mice were administered with 3μL Aβ25-35 3 mmol·L-1 by intracerebroventricular injection to establish an AD model. Baicalin was given by intracerebroventricular injection at the dose of 25, 50 and 100 mg · kg-1 for 15 d, respectively. The total distance and the central grid residence time were measured in the open-field test. The escape latency and the time to reach the platform were monitored in the Morris water maze trial. The autophagic vacuoles in the hippocampus of the mice were observed by transmission electron microscopy before the protein expressions of microtu?bule-associated protein 1 light chain 3 (LC3) and Beclin1 in brain tissue were analyzed by Western blot?ting assay. RESULTS Intracerebroventricular injection of Aβ25-35 could reduce the total distance from (3984±321)cm to (2790±306)cm and extend central grid residence time from (3.6±1.2)s to (8.8±2.9)s in the open-field test. The escape latency of water maze also increased from (22.0 ± 1.9)s to (38.8 ± 2.2)s. Autophagic vacuoles or late autophagic vacuoles and increased Beclin1 and LC3 and protein level were observed in the hippocampus after Aβ25-35 injection. Intraperitoneal injection of Baicalin 50 and 100 mg · kg-1 for fifteen consecutive days extended the total distance in open-field test to (3705 ± 337)cm and (3968 ± 448)cm, respectively, while the central grid residence time was reduced to (5.6 ± 1.8)s and (3.9±1.5)s, respectively. The total time taken to reach the platform in water maze test was reduced to (28.6± 1.9)s, (22.9 ± 1.7)s. Mitochondrial swelling, vacuolar membrane structure or autophagic vacuoles were visible in the hippocampus. LC3 and Beclin1 protein expression was significantly up-regulated(P<0.01). CONCLUSION Baicalin shows protective effect against Aβ25-35 induced learning and memory deficits, and this effect may be related to the activation of autophagy in the mouse hippocampus.

Objective To investigate the effects of S-allylcysteine ( SAC ) , on nitric oxide ( NO ) production and antioxidant enzyme activities in hyperlipidemic rats. Methods Male Wistar rats were randomly divided into seven groups. Five groups including normal control group ( normal diet) , model control group ( high-fat diet, HFD) and SAC low,medium,high treated group (high-fat diet +25,50,100 mg·kg-1 SAC) were sacrificed after 4 weeks dosing,while the other two groups including L-arginine group (normal diet+ 20 mg·kg-1 L-arginine) and SAC+L-arginine group (50 mg·kg-1 SAC+20 mg·kg-1 L-arginine) were sacrificed at 4 h after dosing. The serum, livers and kidneys were collected. The levels of NO, the activities of nitric oxide synthase ( NOS ) , antioxidant enzymes in vivo and L-arginine contents in serum were determined. Results Comparing with model control group, the activities of total NOS in serum and liver were significantly reduced in SAC-treated groups (P<0. 05). The level of L-arginine in SAC-treated groups was (8. 25 ± 1. 15), (7. 76 ± 1. 24) and (7. 22 ± 1. 64)μg·mL-1 , respectively. Compared with model control group, the level of L-arginine were significantly reduced in SAC-treated groups (P<0. 05). Comparing with L-arginine group, the activities of total NOS (T-NOS) and iNOS were reduced in SAC+L-arginine group. SAC treatment (100 mg·kg-1) significantly increased the activities of superoxide dismutase (SOD) (P<0. 01) and the level of glutathione (GSH) (P<0.01), and decreased the level of malondialdehyde (MDA) in serum and liver of hyperlipidemic rats. Conclusion These data suggest that SAC inhibits the NO production by reducing iNOS activity, arginine concentration and exhibited antioxidant activity, which may play a pharmacologically important role in protection from oxidative injury and pathogenesis of atherosclerosis.

Objective To observe the effects of Er-YAG and surgical resection in the treatment of oral cav-ity mucous cyst. Methods A total of 63 patients with oral cavity mucous cyst ,selected in our hospital from March 2013 to May 2014,were divided into control group(n=31)and experimental group(n=32)based on dif-ferent therapies. The oral cavity mucous cysts in the experimental group and the control group were treated with Er-YAG and surgical resection ,respectively. The two groups were compared in terms of therapeutic effect. Results The cure rate in the two groups had no significant difference (P>0.05). The operation time in the experiment group was significantly shorter than the control group(P<0.05). In the experiment group,the incidence of intra-operative blood loss,postoperative edema and postoperative scarring were significantly lower than those of the con-trol group(P<0.05),but the two-year recurrence rate in the two groups had no significant difference(P>0.05). The SAS scores had no significant difference between the two groups at 1 week after operation (P > 0.05),but they were significantly higher in the experiment group than in the control group before operation and 3 days after op-eration(P < 0.05). In HAD emotional determination,the numbers of patients who had the manifestation of anxi-ety and depression in the experiment group were smaller than control group before operation and 3 days after opera-tion(P<0.05),but there was no significantly difference between the two groups at 1 week after operation(P >0.05). Conclusions The curative effect of Er-YAG in the treatment of oral mucous cysts is close to that by the conventional surgery,but the former is advantageous for easier operation,less postoperative complications and alle-viation of patientspsychology pressure,worthy of clinical spreading.

Objective To study the morphological variations of maxillary sinus and to provide anatomical basis for maxillary posterior teeth implantation and extraction usingcone-beam computed tomography (CBCT) scan-ning. Methods CBCT images from 403 patients were reviewed. The minimal distance from sinus floor to alveolar ridge wasmeasured and the number of patients with clinical features such as having sinus septum , mucosal thicken-ing and posterior teeth roots extend into maxillary sinus were counted. Results The mean value of the minimal dis-tance from maxillary sinus floor to alveolar ridge was about 8.3 mm, there was no significant statistical difference between sex, but there was a significant statisticalsignificant difference between the left sides and the right sides. Occurrences of sinus septum, mucosal thickening and roots into sinus were 98.6%, 31% (in which 56.3% of mu-cosal thickening were related to apical periodontitis) and 47%. there was no significantstatisticaldifference between the two sides in males females. Conclusions The morphological variations of maxillary sinus are significant. Chron-ic inflammation in maxillary sinuis is closely related to the position of maxillary posterior teeth roots and periapical lesions.

Objective:To determine the expression profile and potential roles of CD24 in oral squamous cell carcinoma and explore the values of CD24 function as a potential target of clinical therapy.Me-thods:Semi-quantitative immunohistochemistry was used to construct the expression profile of CD24 in 78 human oral tissues and 59 Hamster buccal pouch tissues.Real-time RT-PCR and Western blot were used to analyze the CD24 expression levels in oral DOK4 cells,oral cancer CAL-27 and WSU-HN6 cells. Then these two cancer cell lines were selected to evaluate the effect of all-trans retinoic acid (ATRA)and CD24 antibody on CD24 expression,and the proliferation and tumorsphere formation capacity of these two cell lines.Results:CD24 expression was found significantly elevated in both human and animal tissues compared with normal and benign tissues (P<0.05),as well as in oral cancer CAL-27 and WSU-HN6 cells compared with DOK cells (P<0.05).CAL-27 and WSU-HN6 cells possess increased proliferative and specific tumorsphere formation capability compared with DOK cells (P<0.05 ).Both ATRA and CD24 antibody were able to effectively inhibit the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells (P<0.05).Among them ATRA at least involved partially in the proliferation by down-regulating the CD24 expression (P<0.05 ),while CD24 antibody blocking had no effect on the CD24 expression.Conclusion:CD24 was upregulated in oral cancer and functioned as a potential factor that promoted the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells.Both ATRA and CD24 antibody might effectively inhibit the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells and function as a potential therapy target.

Objective:To study the vertical and horizontal proportions in facial area and the difference between Han and Kazak normal adults in Xinjiang area.Methods:According to certain standards,the adult Han and Kazak college students in Urumqi were randomly selected.Frontal photographs were taken for the subjects in accordance with the same standards.The data were imported into computer, and 20 standard anthropometric marks were determined,then 1 5 measurements were performed by photoshop soft ware,1 9 proportion i-tems of the mesurements was established.Independent sample t-test was applied for statistic analysis by SPSS1 9.0.Results:The face of the males was shorter and wider than that of the females.The males have smaller fissure width and bigger alar width than the females. However,the Han subjects have smaller fissure width and mouth width,bigger alar width and intercanthal width than the Kazak.Con-clusion:This study suggests that facial proportions were significantly different between the two nationalities and between sexes in Xin-jiang.

Objective:To observe the effect of “bulk-fill”flowable resin in filling deep wedge-shaped defects.Methods:50 pa-tients with totally 85 pairs of premolars with deep wedge-shaped defects(depth >2 mm)were included.Each pair of the defects was randomly divided into the test group and the control group,the defects were treated by “bulk-fill”flowable resin with single cure tech-nique and conventional flowable resin with incremental layering technique respectively,the tooth sensitive rate 1 week after filling,the filling failure rate,the edge coloring and secondary caries rate 2 years after filling of the 2 groups were compared.Results:There was no significant difference between the 2 groups in the sensitive rate 1 week after filling,the failure rate and the edge coloring and sec-ondary caries rate 2 years after filling(P >0.05).Conclusion:The “bulk-filled”flowable resin using single cure technique can ac-quire the same clinical effect as conventional flowable resin using incremental layering technique in filling deep wedge-shaped defects.