Caries risk assessment (CRA) involves a combination and analysis of factors including individual’s age, biolo-gical factors, and protective and clinical findings. CRA significantly guides pediatric dentists and oral health caregivers in their decision-making plan for clinical treatment. The following is an introduction on the aspects of harmfulness of childhood caries and CRA for children of different ages.

Objective To evaluate the inhibitory effect of high mobility group chromosomal protein N2 (HMGN2) on human tongue carcinoma tumor in nude mice. Methods A transplantation tumor model in nude mice was constructed by injecting Tca8113 cells. After a week, negative control groups, masculine control groups, and HMGN2 groups were esta-blished. Cell culture of the three groups were separately injected with washing buffer Ⅱ, cis-dichlorodiamineplatinum (DDP), and HMGN2 protein. The tumors were moved after four treatments, and then analyzed by hematoxylin-eosin (HE) staining. Results A transplanted tumor model was established successfully. The volumes of HMGN2 groups and masculine control groups were smaller than those of the negative groups. Mouse weight did not differ among the three groups. Average tumor weight of the negative group was (0.38±0.19) g, that of the HMGN2 group was (0.21±0.15) g, and that of the DDP group was (0.23±0.16) g. These factors indicated no statistically significant difference among the three groups. The tumor inhibitory rate of HMGN2 group was 45.71%, and that of the positive group was 39.44%. Based on evaluation by naked eye, the tumor in the negative group was larger than that in other groups. Inaddition, cell necrosis was observed during HE staining. Conclusion HMGN2 could significantly inhibitgrowth of the transplanted tumor in nude mice.

Objective Through a simulation of interstitial fluidpressure (IFP), we developed an in vitro model to explore the change law of biological characteristics of adenoid cystic carcinoma (ACC) under different IFP. Methods A pressure cooker was refitted into a controllable pressure device. Cultured ACC-2 cells were subdivided into different groups, namely, negative control (untreated ACC-2) and experimental group (stressed for 3, 6, 12, 24 h under pressure of 7.551, 7.649, 7.747kPa). CCK-8 and immunofluorescence of Ki67 were used to reflect proliferation ability. Transwell chamber assay was performed to observe the invasion ability of cells. Results The proliferation ability was positively correlated with treatment time, and the peak value was obtained after the cells were subjected to 7.649 kPa of stress for 24h. The invasion ability of ACC-2 cells was upregulated under stress. Conclusion We successfully developed an in vitro model of IFP and found that highIFP canstimulate cell proliferation abilityandupregulate invasion ability.

Objective To evaluate the effect of taper and inserting angle on stability of micro-implants in type Ⅱ bone and toprovidetheoretical evidencefor clinical selectionoftaper andinsertingangle. Methods Three-dimensionalfinite element models of type Ⅱ bone sections and micro-implants were fabricated. They were designed using different tapers (diameter between 1.1 to 1.6 mm, taper between 0 to 0.062 5) and different inserting angles ranging from 30° to 90° (30°, 45°, 60°, 75°, 90°). Effects on the maximum von Mises stresses in mandible and micro-implants, as well as on the maximum displacements inmicro-implants, were analyzedunder an applied 2N horizontalforce. Results Theinserting anglehadasignificant effect on stresses and displacements, with lower distribution of stresses and displacements occurring at 60°. The effect of the taper wasalsorelatedtotheinsertingangle.Theminimumstresseswere5.0134MPa(corticalbone)and25.1310MPa(micro-implant) in modelD at 60°. The displacements of micro-implantswere proportional to the taper. Conclusion The insertingangle has a significant effect on stability of micro-implants, and the recommended inserting angle is 60°. The influence of taper on the stability of micro-implants is related to the inserting angle. The micro-implant with 0.037 5 taper(maximum diameter is 1.6 mm, minimum diameter is 1.3 mm) ismoresuitablefor type Ⅱ bones.

Objective To study the biological characteristics of p75 neurotrophin receptor positive (p75NTR+) tongue squa-mous cell carcinoma cells which were separated by flow cytometry cell sorting. Methods To determine the biological cha-racteristics of p75NTR+ cells which were separated from Tca-8113 and Cal-27 tongue squamous cell carcinoma cells by flow cytometry cell sorting, including study the capacity of cloning, 3-(4,5)-demethylthiazo(z-y1)-3,5-diphenytetrazoliumromide (MTT) assay, wound healing assay. p75NTR+ cells with non-sorted cells were as control group. Results In Tca-8ll3 and Cal-27 tongue squamous cell carcinoma cell lines, the percentage of p75NTR+ cells were 3.1％ and 1.9％. Compared with p75NTR+ cells with non-sorted cells, p75NTR+ cells possess higher capacity of cloning (Tca-8113, P=0.024; Cal-27, P=0.009). The per-centage of p75NTR+cells of the progeny cells generated from monoclonal p75NTR+ cells decreased to 14.5％ (Tca-8113) and 5.8％ (Cal-27) after cultured two weeks. p75NTR+ cells possessed higher proliferation ability and higher metastasis ability than non-sorted cells. Conclusion p75NTR+ cells isolated from tongue squamous cell carcinoma have the characteristics of cancer stem cells.

 Objective  To evaluate the effects of carbon monoxide releasing molecule-2 (CORM-2) on experimental perio-dontitis inrats. Methods  Forty-two Wistarratswere divided into three groups.Ratsin the normal group (NL group)did not undergo any procedure, whereas the other rats were ligatured and treated with saline solution (NaCl 0.9%) (LO group) or treated with CORM-2 (10 mg• kg-1 per day) (CO group). A 3-0 silk suture was placed around the mandibular first molars. Rats were sacrificed after 3, 7, and 10 d. Blood samples were collected from all animals for tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) analysis. Changes in alveolar bone levels were measured clinically, and periodontal tissues were histopathologically examinedto assess the infiltration of inflammatory cells. Results  Ligature placement increased alveolar bone loss and inflammatory cell infiltration in periodontal tissue. Alveolar bone loss in CO group was significantly higher than that in NL group, but was lower than that in LO group (P<0.05). The ratio of inflammatory cell infiltration in LO group was significantly higher than that in CO and NL groups, and that in CO group was lower than in LO group (P<0.05). Serum levels of TNF-α and IL-1β in the LO group were significantly higher than those in the CO and NL groups, and those in CO group were lower than in LO group (P<0.05). Conclusion  Systemic administration of CORM-2 reduced periodontal inflam-mation andalveolar bone loss in experimental periodontitis in rats.

Objective To prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material. Methods  Sodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope(SEM)and its porosity wasmeasured byliquiddisplacement method.The fifth passage of bonemarrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted micros-cope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquidextractstoconducthemolysistest,thespectrophotometerwasusedtodeterminetheopticaldensity(OD)andtocalculate the hemolysis rate. Results Sodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6±4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials. Conclusion  The composite material fabricated in
thisstudyhashighporosityandgoodbiocompatibility.

 Objective To evaluate remineralization efficacy of an arginine containing dentifrice on initial enamel carious lesions in vitro. Methods  Human enamel blocks with early lesions were prepared and randomly divided into three treatment groups: negative control group (distilled and deionized water), positive control group (fluoride containing dentifrice and 0.14% sodiummonofluorophosphate), and test dentifrice group (8.0% arginine and 0.14% sodium monofluorophosphate). The lesions were subjected to a pH-cycling regime for 10 days. Surface enamel microhardness of the enamel blocks from each group was measured before and after pH cycling, and the surface microhardness recovery was calculated. Then, specimens were analyzed for enamel fluoride uptake (EFU) through acid etching method, after which they were treated in demineralization solution for a 2 h period of acid challenge. The other specimens were sectioned and examined through polarized light microscopy. Results  In the test dentifrice group, microhardness recovery and EFU were significantly higher than those in the negative control and positive groups. The test dentifrice group was significantly resistant to the acid challenge compared with the other groups. Conspicuous remineralization of enamel subsurface lesions was observed under polarized light microscopy among samples treated with test dentifrice, whereas the control groups showed no significant changes on enamel subsurface lesions. Conclusion This study presents the potential superiority of Pro-Argin dentifrice over conventional fluoride dentifrice in promoting the remineralization of initial enamellesions.

Objective To investigate the feasibility and accuracy of length measurement of in vivo teeth by using cone beamCT (CBCT). Methods Before orthodontic extraction, 109vitalpremolars from 40 participantswere scannedby using CBCT and reconstructed by using InVivoDental software. Buccal-lingual sectional images along the long axis of teeth were then acquired, and the crown, root, and tooth length were measured separately. After careful extraction and fixation, the cor-responding length of thesametooth was measured byusing a digitalcaliper. CBCT measurement accuracywas then verified by using physical measurements as reference. Results  CBCT and the physical method did not obtain significantly different measurements of the root, crown, and tooth length of experimental teeth (P=0.790, P=0.621, P=0.657, respectively), and the measurements were found to be consistent. The 95% limits of agreement of root, crown, and tooth length were -1.10 mm to
1.13mm, -1.00 mm to 0.96mm, and -1.00 mm to 1.05 mm, respectively. Conclusion  The difference between CBCT and the physical method was not significant, and good consistency was shown. CBCT could be applied in noninvasive measure-ment of in vivo teeth.

Objective  To observe the short-term clinical effectiveness of bone ring graft technique and to summarize the key points of related surgical operation to provide comprehensive clinical guidelines. Methods Fifteen patients with severe alveolar bone absorption were selected to receive bone ring grafting and immediate dental implant. Final fixed prostheses were cemented   five  months after initial  implantation. Cone beam CT scans were conducted on all subjects before the procedure,as well as four months post-operation to evaluate alveolar bone height and level of bone height and absorption around the implants. Four to six months after prosthesis installation, each implant’s Jemt classification,gingiva attachment, and probing depth (PD) were analyzed. The difference of PD between implants and adjacent teeth, as well as the difference of the bone absorption between labial and lingual sides, was compared. The survival rate of the bone ring and the retention rate of implants were calculated. Complications and patient satisfaction were also investigated. Results  Bone graft survival rate was 94.4% and dental implantation retention rate was 100% four months post-operation. Average bone level increase was (6.06±1.06) mm, average bone absorption was (1.33±0.84) mm, and average bone thickness at the neck of the dental implant body was(6.94± 0.73) mm. Approximately 4 to 6 months after crown restoration, average bone level increase was (5.62±1.03) mm, average bone absorption was(1.51±1.02) mm, and average bone thickness at the neck of the dental implant body was(6.77±0.72) mm. The PD around the implant body and the adjacent teeth was statistically insignificant. No major post-operative complication was observed, restorations were successful,and patient satisfaction level was high.Conclusion  Bone ring graft technique and immediate dental implantation are relatively simple to perform, and these techniques facilitate reduction in required treatment time. Short-term effectis reliable and satisfactory, whereas long-term outcomes require further follow up and study.

Objective  To investigate the difference in mental health status of oral tumor patients and their spouses, and explore the differences on the basis of relevant materials. Methods  Forty patients with oral cancer, eighteen spouses, and thirty-five patients with oral benign tumor were diagnosed in the West China Hospital of Stomatology between December 2011 and August 2012 and assessed with symptom checklist-90(SCL90) (the 5-grade scoring). Participants were assessed independently according to their conditions. Blood samples were obtained from the participants by syringe on the second admission day. A method was developed to determine the concentrations of catecholamine and glucocorticoid in the serum using high performance liquid chromatography-tandemmassspectrometry(HPLC-MS/MS). Results  The scores for compel,depression and rests in the cancer group and benign tumor group were statistically significant (P<0.05). The scores for compel, dread and stubborn in the cancer group and their spouses were statistically significant(P<0.05). The differences  between the total and other monomial factor scores were not statistically significant. However, the contents of epinephrine, norepinephrine, cortisone and hydrocortisone in the serum, as determined by HPLC-MS/MS, were significantly different (P<0.001). Conclusion  Psychiatric factors do not show a simple factor effect on patients. Symptoms of patients may be based on tumorigenesis and developed in small molecules.Further research is required.

Objective  This study aimed to compare the treatment effects of simultaneous surgical treatment and stage ope-ration for patients with craniomaxillofacial fracture combined with other injuries. Methods Fifty patients with maxillofacial fractures combined with other injuries were chosen and divided into simultaneous (28 patients) and staging (22 patients) operation groups. In simultaneous operation group,maxillofacial fracture reduction,internal fixation,and other parts of  the surgery were simultaneously operated by relevant departments jointly. In the staging operation group, maxillofacial fracture reduction and internal fixation were performed after treatment of other injuries. Data on the treatment efficacy and associated injuries of the two groups were statistically analyzed. Results In the simultaneous operation group, 26 patients had good occluding relation, the maximum mouth opening was (34.5±3.7)mm, the symmetry and shape of hard tissues recovered well, and the bone plate of one patient was removed because of internal fixation infection. In the staging operation group, 14 patients had good occluding relation,the maximum mouth opening was(28.5±3.5)mm,the symmetry and shape of hard tissues poorly recovered, and the bone plates of 5 patients were removed because of internal fixation infection. Statistical significance was determined among occluding relation, maximum mouth opening, postoperative complications, and length of stay of the two groups (P< 0.05). Treatment of the simultaneous operation group was more effective than that of the staging operation group. Conclusion When a patient’s condition is relatively stable, simultaneous surgical treatment of multiple specialties should be conducted to treatcraniomaxillofacial fracture   combined with other injuries.

 Objective  To determine the factors affecting post-operative velopharyngeal function of cleft palate patients aged over two years old. Methods  The data on 245 patients, including first visit case records and those in the database, were searched and recorded. Post-operative velopharyngeal function and clinical features, such as cleft ratio, adequate ratio, diagnosis, operative age and method,were analyzed retrospectively. Results Cleftratio and adequate ratio in the velopharyngeal competence (VPC) group were not statistically different from those in the velopharyngeal incompetence (VPI) group. The difference in VPC rate in different age groups and diagnosis was not significant. The post-operative VPC rates under different methods were significantly different. Conclusion  The current therapeutic schedule for patients younger than two years old is inappropriate for patients older than two years old. Cleft ratio is not the main factor affecting postoperative velopharygeal function. Sommerlad-Levator Veli Palatini reconstructional operation combined with sphincter pharyngoplasty can obviously improve the velopharyngeal function of patients aged  2 years old and up.This method should be applied in primary palatoplasty.

 Objective To provide reference data on frequency and distribution of bone islands (BIs) and investigate their relationship with age, gender, and localization. Methods  A population who received a pretreatment and at least one follow-up panoramic radiograph in the Department of Oral Radiology, West China Hospital of Stomatology, Sichuan University, were selected for this retrospective study. A sample population of 29 556 patients (12 824 males and 16 732 females) with different dental complaints and ages ranging from 8 to 80 years (mean age: 23.95 years) were included. Results  In the radio-graphic evaluation, BIs appeared as localized, well-defined, non-expansile, radiopaque masses which were round, elliptic, or irregular in shape. Their sizes varied from a few millimeters to about 2 cm in diameter. A total of 598 radiopacities were detected, and 545 patients of 29 556 patients (1.84%) had BIs. Among subjects with multiple lesions, 49 patients had 2 BIs and 2 patients had 3 BIs. The BIs had immense mandibular predilection, with presentation primarily in the premolar/molar region. The condition appeared to have no tendencies based on sex. Conclusion  Recognition of BIs variation is significant indentalexaminations.

 Objective  This study aimed to compare the crown color match of implant-supported zirconia restorations and porcelain-fused-to-metal (PFM) restorations in the anterior maxillary region through spectrophotometric evaluation. Methods Eighteen patients with 29 implant-supported single crowns in the anterior maxillary area were recruited. Eleven of the implant crowns were zirconia restorations and 18 were PFM restorations. Color matching of the implant crown with contra-lateral/ neighboring tooth at the position of body 1/3 of the crown was assessed using a spectrophotometer (SpectroShadeTM) in CIE L﹡a﹡b﹡ coordinates. Subjective crown color match scores were evaluated. Independent sample t test of SPSS 17.0 was used to compare the difference between zirconia restoration and PFM restoration. Spearman correlation was used to analyze the relationship between the spectrophotometric color difference and the subjective crown color match score. Descriptive statistics was used to analyze the distribution of color coordinates of natural anterial teeth. Results  The crown color of the implant-supported zirconia restorations and PFM restorations were both lighter than that of natural teeth (ΔL, 4.5±3.2, 1.0±2.6). The lightness difference induced by zirconia restorations was significantly larger than that induced by PFM restorations (P=0.004). The spectrophotometric crown color difference (ΔE) induced by zirconia restorations (7.0±2.8) was significantly larger than that induced byPFM restorations (4.0±1.9) (P=0.002), and both values were beyond the clinical thresholds (3.7). Conclusion  The spectrophotometric crown color difference induced by zirconia restorations was significantly larger than that induced by PFM restorations. However, they were indistinguishable in subjective evaluation.

 Objective  To evaluate the effects of periodontal treatment on the clinical response, systemic inflammatory parameters, and metabolic control of type 2 diabetes patients with moderate to severe periodontitis. Methods  A total of 56 patients with mean clinical attachment level (CAL)>3 mm were included in the subgroup analysis. A repeated-measures ANOVA (group factor: treatment group and control group; time factor: initial visit, 1.5, 3, and 6 months) was used to analyze the probing depth (PD), CAL, bleeding on probing (BOP), high-sensitivity C-reactive protein(hsCRP), glycated hemoglobin (HbA1c), and fasting plasma glucose. Results Significantly lower PD (F=62.898，P=0.000), CAL (F=51.263，P=0.000), BOP (F=75.164，P=0.000), hsCRP (F=6.391, P=0.010), HbA1c(F=4.536, P=0.011), and fasting plasma glucose level (F=3.073，P=0.031) were observed after therapeutic periodontal improvement. The inter-group differences for PD (t=-2.050， P=0.045), BOP (t=-4.538，P=0.000), and hsCRP (t=-2.261, P=0.028) were statistically significant after therapy. Conclusion Non-surgical periodontaltreatmentcan effectivelyimproveperiodontalstatus,circulating inflammatory status, andmetabolic controlof diabetic patients with moderate to severe periodontitis.

 Objective To investigate the changes in the quantity of colonizing Streptococcus mutans(S. mutans) and Acti-nomyces on the root surface plaque before and after post-core crown restoration of the mandibular first molars in the elderly patients. Methods  A total of 30 elderly patients, each with one post-core crown restoration of the mandibular first molar, were randomly chosen to participate in the studies. Patients with mandibular first molars with post-core crown restoration and those with healthy contralateral mandibular first molars were divided into the test and control groups, respectively. Root surface plaques of the two groups were collected before tooth preparation, 72 h after preparation, one week afterpreparation, and one month after restoration. S. mutans, Actinomyces naeslundii (A. naeslundii) and Actinomyces viscosus (A. viscosus), were identified using colony morphology, biochemical techniques, and polymerase chain reaction (PCR). Plaque count was measured usingmicrobial colony count. Results  The number of S. mutans and A. viscosus and A. naeslundii in the test group, whichwas statistically significant (P<0.05), increased 72 h after preparation. The quantities of S. mutans, A. viscosus, and A. naeslundii one week after preparation were significantly different (P<0.05). The plaque count of S. mutans, A. viscosus, and A. naeslundii in the test group decreased one month after restoration (P<0.05). Conclusion  The quantities of S. mutans, A. viscosus and A. naeslundii increase one week after preparation but decrease one month after restoration. The finding suggests that dentists shouldeducatepatientsabout plaquecontrol during the earlyperiod after tooth preparation.

 Objective  To evaluate the effect of different subgingival root exposure methods, namely, crown lengthening or forced eruption, and different ferrule lengths on fracture resistance of a residual root restored with a carbon fiber post-and-core system. Methods Fifty-sixextracted endodontically-treated mandibular first premolars were sectioned 1.0 mm coronal to the buccal cementoenamel junction. All the models were divided randomly into seven groups that each consist of eight roots. Group A was given non-ferrule as control. Simulated crown lengthening was performed for the dentin ferrule design in the cervical tooth structure for Groups B, C, and D with a ferrule length of 1.0, 2.0, and 3.0 mm, respectively. Simulated forced eruption was performed with a ferrule length of 1.0, 2.0, and 3.0 mm in the cervical tooth structure for Groups E, F, and G, respectively. After restoration with prefabricated carbon fiber post-and-core system, each specimen was embedded in a self-cured acrylic resin block from 2.0mm apical to the margins of a cast Ni-Cr alloy crown, then loaded at 150° from the long axis in a universal testing machine at a crosshead speed of 1.0mm•min-1 until fracture. Data of failure loads and fracture mode were recorded and analyzed. Results  Mean failure loads for Groups A to G were (1.13±0.15), (1.27±0.18),(1.02±0.11), (1.05±0.12), (1.63±0.14), (1.92±0.19), and (1.93±0.15) kN, respectively. The effects of root exposure method and ferrule design differed significantly,and two factors exhibited significant interaction(F=33.396，P<0.0001). When the ferrule lengths
were the same, fracture loads in the simulated forced eruption groups were significantly higher than those of the simulated crown lengthening groups (P<0.001). No statistical differences in fracture mode were observed among all groups (P=1.00). Conclusion  More than 1.0 mm ferrule placement on the apical crown margin by using forced eruption significantly increases fracture resistance.

 Objective  To explore the effect of silencing protein kinase D (PKD)-2 on Tca8113 cell proliferation, programmed cell death,and chemosensitivity. Methods  The stable celllines of pkd-2 gene silencing and empty vector plasmid group were established. The proliferation and 50% inhibitory concentration (IC50) of shRNA-mediated Tca8113 chemotherapy drugs were detected through methyl thiazolyl tetrazolium assay (MTT). The programmed cell death rate and sensitivity to Tca8113 chemotherapy drugs before or after pkd-2 gene silencing were measured through flow cytometry. P-glycoprotein (P-gp) expression of pkd-2 silencing cells was identified by immunohistochemical methods. Results Stable cell lines of pkd-2 gene silencing were established. Compared with parental cells, the proliferation of shRNA-mediated Tca8113 was not significantly different,but its IC50 was lower. Meanwhile,cell programmed death rate and sensitivity to chemotherapeutic drugs of shRNA-mediated Tca8113 significantly increased. Compared with wild group Tca8113, a significant decrease in P-gp ex-pression was induced by chemotherapy drugs with shRNA-pkd-2 gene silencing. Conclusion  The pkd-2 gene of shRNA interference silencing Tca8113 promotes programmed cell death of Tca8113, reduces the IC50 of the chemotherapy drugs, and significantly improves the sensitivity of Tca8113 to chemotherapeutic drugs while reducing the expression of P-gp.

 Objective  To investigate the effect of different length and diameters on the stability of mini implant and to select optimal length and diameter using continuous variation of parameters. Methods  To perform 3-dimensional finite element analysis, finite element models of a maxilla, and mini implants with length of 6-12 mm and diameters of 1.2-2.0 mm were generated. Load of two different forces were applied to the head of mini implant. One type was horizontal force (HF), the other was composite force (CF). The maximum equivalent stress (Max EQV) in maxilla and the maximum displacement (Max DM) of mini implant were evaluated. Results  The Max EQV in maxilla and Max DM of mini implant decreased as length and diameter increased. When length was more than 9 mm, the evaluation indexes were small and had a less change. Datas indicated that diameter played a more important role in reducing target, and was a more effective parameter in re-ducing Max EQV when CF was loaded. Conclusion  From biomechanical point of view, the choice of the length should not be more than 9 mm. When CF is loaded using the mini implant, diameter exceeding 1.2 mm are optimal design for mini implant.

 Objective  This paper aims to study the effects of gossypol acetic acid (GAA) on proliferation and methylation level of human MutL homologue 1 (hMLH1) gene in human tongue cancer cell line Tca8113. Methods The MTT assay was used to determine the effects of the acid on the proliferation inhibition in Tca8113 cells treated with different GAA concen-trations. Nested methylation-specific polymerase chain reaction (nMSP) was used to detect the change in the methylation level of hMLH1 after 48 and 72 h with 30 and 15 μmol•L-1 GAA treatment. Results  MTT assay results showed the growth and proliferation inhibition of Tca8113 cells in the experimental GAA group after 24h to 72 h of GAA treatment. The nMSP results indicated that the average optical density of hMLH1 in the Tca8113 cells significantly changed after the GAA treat-ment (30 μmol•L.1 GAA for 48 h and 15 μmol•L.1 for 72h) (P<0.05) compared with that of the control group. Conclusion  GAA does not only inhibit Tca8113 proliferation but also has a demethylation effect on the hMLH1 gene. These phenomena may be part of an underlying tumor-suppression mechanism of GAA.

Tongue osteocartilaginous choristoma isthe diseasethat there are well-developed bone and cartilage in the tongue. This article reported a case of tongue osteocartilaginouschoristomainthe oral-cavity,which israre.

 Impacted teeth are usually involved in permanent dentition but not in primary dentition. This paper reports a clinical case of uneruptedmandibular second deciduous molarinferior to the second premolar.

Dentalfear isacommon problemin pediatric dentistry. Therefore, sedation for pediatric patients is anessential tool for anxiety management. Nitrous oxide/oxygen inhalation sedation is a safe, convenient, effective way to calm children. The review is about the technology of nitrous oxide/oxygen inhalation sedation and its clinical application in pediatric den-tistry.