Comparing of dental clinical management in the USA, the authors would like to make some suggestions to Chinese colleagues in the following five aspects. They are included disadvantages of using disposable examination kit, using chair side X-ray machine, stopping using chair side spittoon, using topical anesthesia instead of using topical disinfection, patient management in the university hospital setting. The aims of this article were to open discussion and improve Chinese dental clinical management.

Objective The purpose of this article was to evaluate the influence of cobalt-chromium（Co-Cr） alloy as the material of inner crown on periodontal tissue through detecting the weight of diseased teeth and the concentration of aspartate transaminase（AST） and alkaline phosphatase（ALP） of the gingival crevicular fluid（GCF）after Co-Cr alloy ceramics repairing. Methods In this study, thirty cases of clinical diseased teeth were chosen from thirty patients based on patients’consent. Each tooth conformed to the inclusion criteria. All of the thirty teeth were repaired with Co -Cr alloy ceramics according to the indications. Then GCF of each diseased tooth was collected and weighed at the time of the day before prosthesis, the first and third month after repairing respectively in order to detect the concentration of AST and ALP. Furthermore, comparative analysis for different periods was performed after the data statistics. Results To the weight of GCF and the concentration of AST after the respective comparison of three indexes which was of different periods, numerous of each index increased in accordance with the rule of preoperation, postoperative first month, and postoperative third month（P<0.05）. To the concentration of ALP at three time points, the compared results showed that the preoperative numerous was less than that of third month after operation and there was significant difference between them（P<0.05）. To the weight of GCF and the concentration of AST and ALP, after the respective comparison of three indexes which was the diseased teeth and the contralateral teeth with the same name in the periods of pre-operation, all the differences had no statistical significance（ P>0.05）, but all the differences had statistical significance in the periods of postoperative third month（P< 0.05）. Conclusion During the next three months after operation, GCF weight, concentration of AST and ALP of diseased teeth was gradually increased after their Co-Cr alloy ceramics crown repairing. This increase is somewhat harmful to periodontal health.

Objective To investigate the effect of serum biochemistry on the development of periodontitis. Methods 225 participants without any system disease were involved in the study. Case group consist of 145 chronic peri-odontitis and was divided into gentle group （clinical attachment loss<3 mm）, moderate and severe group（clinical attachment loss≥3 mm）. Control groupconsist of 80 periodontal healthy persons. Peripheral blood sample was obtained from each subject by venipuncture. Serum chemistry variables including glucose, lipid and calcium were analyzed. SPSS 12.0 software package was adopted to analyze the investigation results. Results There’s no statistically significant difference of serum, lipid and calcium between case group and control group（P>0.05）. But case group had a higher percentage of people with abnormal glucose, lipid and calcium than control group（P<0.05）. Moderate and severe group had a significantly higher serum glucose, triglyceride and lipoproteins-cholesterol than gentle group（P<0.05）. Conclusion Abnormal level of serum glucose, lipid and calcium may increase the affectability of host to periodontitis and promote the inflammation in paradentium.

Objective To investigate the association between fibroblast growth factor 3（FGF3） gene rs4980700 and rs4631909 polymorphism and non -syndromic oral clefting（NSOC）. Methods Blood samples from 186 NSOC patients, patients’parents and 200 controls were collected. DNA was extracted and PCR-restriction fragment length polymorphism（PCR-RFLP） was used to identify genotypes of the samples. Case -control analyses and transmission disequilibrium test（TDT） and family based association test（FBAT）analyses were also carried out. Results In casecontrol analysis, there were significant differences in rs4980700 genotype and allele among NSOC patients compared with the control group（P<0.05） and there were significant differences in rs4631909 genotype and allele among NSOC patients compared with the control group（P<0.05）, but no difference in cleft palate only（P=0.49）. In TDT, the G allele of rs4980700 had an overtransmission（P<0.05） and the C allele of rs4631909 had an overtransmission（P<0.05） in NSOC. FBAT analysis also showed a significant association between FGF3 gene rs4980700, rs4631909 polymorphism and NSOC. Conclusion FGF3 gene rs4980700 and rs4631909 polymorphism were associated with NSOC.

Objective To investigate the effect of celecoxib on adhesion, invasion, migration and matrix metalloproteinase- 2（MMP-2） expression of tongue squamous cell carcinoma cell line Tca8113 cells. Methods Following 24 h incubation with celecoxib, the Tca8113 cells were detected for cell adhesion and migration using cell adhesion as-say and Boyden chamber invasion assay. The expression of cyclooxygenase-2（Cox-2） protein in Tca8113 cells was detected with SP immunohistochemistry staining. The MMP -2 level in supernatant was detected with enzyme -linked immunosorbent assay. Results The adhesion and Boyden chamber invasion assays showed that, after treatment with celecoxib, the ability of adhesion and migration of Tca8113 cells was significantly inhibited. Celecoxib could decrease the expression of Cox-2 protein in Tca8113 cell and decrease the MMP-2 level in supernatant. Conclusion Cox-2 inhibitor celecoxib can significantly inhibit the adhesion and migration of Tca8113 cells. The inhibitory effect on adhesion and migration may be correlative with its effect on decrese of Cox -2 protein expression and secretion of MMP-2 in Tca8113 cells.

Objective To evaluate the orbital bone quantity by spiral computer tomography（CT） for orbital implant operation. Methods Fifty -two normal skull specimens with marks received spiral CT scan and their multiplanar images were obtained. The quantity （length×width） were measured on multiplanar images. Results The right orbital bone quantity at 7∶00 was the highest, average 11.91 mm×8.38 mm, and at 3∶00 was the lowest, average 2.31 mm×1.34 mm. The left orbital bone quantity at 5:00 was the highest, average 12.03 mm×8.56 mm, and at 9∶00 was the lowest, average 2.44 mm×1.29 mm. There had no significance correlation with gender at the same position in both sides. Conclusion Useful data had been obtained for the selection of the placement sites, direction, length, and diameter of orbital implants.

Objective To determine the role of 1,25（OH）2D3 on the secondary dentin formation and mineralization of the mice. Methods The differences of the mandible mineralization between the wild-type and 1-α-hydroxylase gene knockout mice at 6 weeks old were assessed by hematoxylin-eosin（HE） staining, immunohistochemistry, alkaline phosphatase（ALP） histochemistry staining. Results The ratio of caries were increased significantly, while the secondary dentin was reduced significantly, the deposition of type Ⅰ collagen and osteocalcin on the secondary dentin of occlusion surface was decreased significantly, but the deposition of the Biglycan on the dentin was increased significantly, the active of ALP on the odontoblasts were reduced significantly in 1-α-hydroxylase gene knockout mice compared to that in the wild-type littermates. Conclusion 1,25（OH）2D3 deficiency lead to a defect in the secondary dentin formation and mineralization and caries of the mice.

Objective The purpose of this study was to evaluate the rugosity with both of the bioactivity and the wear coating of a new type titanium implant material Ti-Zr-Sn-Mo-Nb（TZS）, and to investigate the adhesion of osteoblasts on different coating surface. Methods Both surface topography of bioactivity and wear coating were examined with scanning electron microscope（SEM）. The average roughness of two kinds coating were measured by portable roughometer. We examined the dynamic behavior of early adhesion of the osteoblasts, which were cultured on different coating surface of titanium alloy. As a marker of cell adhesions, cytoskeleton proteins were tagged by F-actin agent. Additionally, the number of adhesion cells was investigated by biological assay MTT. These results were compared with those founds in the control. Results Bioactivity -coating with pore structure and wear -coating with irregular pitting corrosion were observed. Roughometer examination revealed that the roughness of different disc was increased. The control bioactivity-coating surface was the most rough, followed by wear-coating and then the control. Bioactivity coating had best cell biocompatibility, in that the highest cell adhesion ratio was detected. It was very likely that bioactivity coating possessed of biomimetic character and roughness surface. Wear coating had similar biocompatible in comparison with bioactivity coating. The cytoskeleton protein of cell formed a fibrillar structure on bioactivity and wear coating. Cytoskeleton tensin was heterogeneously distributed on variety of surface depending on different surface topography. Conclusion The new titanium alloy shows rough surface after surface treatment, and then cell adhesion and morphology, cytoskeleton protein present wea on bioactivity-coating and wear-coating.

Objective To evaluate effect of root canal curvature and location of the fragment on the removal of broken file from root canal. Methods Sixty extracted mandibular premolars were divided equally into six groups according to location of fragment（2 mm or 8 mm below root canal orifice） and root canal curvature（20°, 30° or 40°）. Broken files were removed using ultrasonic tips combined with dental operating microscope. Number of successfully removed case and operating time were recorded. Pre- and post-operative digital radiographs were input into image analyzing software to calculate diameter variance of root canal at the level of tip of broken file. Results All the 6 groups of broken files were successfully removed with out perforation. Among same fragment location groups, diameter variance was increased in greater curvature groups and the difference was significant（P<0.05）, while operation time was not significantly different（P>0.05）. Among same root canal curvature groups, the deeper the fragment, the longer operation time, difference being significant（P<0.05）, while difference of diameter variance was not significant （P>0.05）. Conclusion The more curvature of root canal, the more dentine removal amount at the level of broken file tip. Location of fragment has no effect on dentine removal amount. Safe straight-line access and adequate thickness of dentine are essential to removal of broken file from root canal.

Objective To evaluate the clinical outcome of periodontal initial therapy on the patients with aggressive periodontitis. Methods A total of 48 patients with aggressive periodontitis, including 20 patients with localized aggressive periodontitis （LAgP） and 28 patients with generalized aggressive periodontitis （GAgP）, were chosen for the study from the patients referred to the Department of Periodontology of the School of Stomatology of China Medical University from September 2006 to December 2008. All subjects were performed periodontal initial therapy. Probing depth（PD）, clinical attachment loss（CAL）, bleeding index（BI） and tooth mobility were recorded at baseline and 1, 3 and 6 months after initial treatment. Results At 1, 3 and 6 months after periodontal initial therapy, there were significant improvements in PD, CAL, BI and tooth mobility of patients with LAgP and GAgP than those in the baseline （P<0.05）. In patients with LAgP, statistical differences were detected in PD and CAL between 1 and 3 months after periodontal initial therapy（P<0.05）. And in patients with GAgP, statistical differences were detected in PD and CAL between 3 and 6 months after therapy（P<0.05）. At 1, 3, and 6 months after therapy, first molars of all patients showed more significant therapeutic effects than central incisors（P<0.05）. Conclusion Periodontal initial therapy showed effectiveness in treatment of aggressive periodontitis. In the mid-term, there were differences in therapeutic effect between patients with LAgP and GAgP.

Objective To study the allocation of embedded teeth in jaws using the three-dimensional reconstruction technique of 64-slices spiral CT. Methods 27 cases were examined by helical scanning of axial view volume scan CT. The exact localization of the embedded teeth in jaws was acquired by using volume rendering（VR）, maximum intensity projection（MIP）, multiplanar reformation（MPR） and curve plane reconstruction（CPR）. Results The localization, morphous, size, erupted orientation and relationship between surrounding tissues of the 41 embedded teeth in 27 patients were displayed by effectually using the images of VR, MIP, MPR and CPR. The election of orthodontic treatment or surgical intervention was decided by using 64-slices spiral CT. Conclusion The exact data and objective evidence of the treatment plan could be provided by 64-slices spiral CT which will have important clinical application.

Objective To explore the magnetic resonance imaging（MRI） characteristics of temporomandibular joint （TMJ） disc including sequence and parameters of the film imaging modalities by means of 3T MRI. To provide morphological and functional reference images for clinical study of temporomandibular joint disc lesions. Methods Fifteen normal volunteers and seven patients with TMJ soft tissue injuries after condylar fractures were imaged by using GE Signa HD 3T MRI system and bilateral TMJ surface coils with oblique sagittal and oblique coronal section. Oblique sagittal and oblique coronal images of mouth close were performed with FSE-XL/T1WI, FLAIR/T1WI, FSEXL/ PDWI, FSE/PDWI+FS, FRFSE-XL/T2WI, FRFSE/T2WI+FS, and oblique sagittal images of mouth open with FSEXL/ T1WI, FSE-XL/PDWI. All MRI findings were analyzed by three senior radiologists and three senior surgeons respectively. Results PDWI showed the best effect in showing articular disc and surrounding structures clearly. T2WI showed articular disc lesions best, including articular disc injury, split, perforation, fluidify of articular capsule. For the displace of articular disc, PDWI showed the best effect. Conclusion 3T MRI can clearly show changes of articular disc during exercise and disease involvement, and play an important role in diagnosis of soft tissue injuries of TMJ in condylar fractures. T1WI, PDWI and T2WI should be routine scan method.

Objective To investigate the effects of speech training on velopharyngeal insufficiency（VPI） in patients with cleft palate. Methods Classify 30 non -syndrome cleft palate patients into Group VPI who was performed levator veli palatini reconstruction surgery at Department of Cleft and Palate Surgery, West China College of Stomatology, Sichuan University and who was performed speech training for 3-6 months after surgery. These patients were diagnosed as mild VPI by speech estimation and demonstrated a velopharyngeal distance between 1 and 5 mm through photography of pharyngeal cavity. VS-99 audio frequency analyzing system was applied to measure the second （F2） and third formant（F3） frequency of vowel [i] of 30 VPI patients before and after speech training, obtained data was compared with those of 30 normal people（Group C）. Results The formant frequency of Group VPI before speech training was F2（1 958.95±431.40）Hz and F3（3 059.84±330.09）Hz. The formant frequency of Group VPI after speech training was F2（2 322.95±213.02）Hz and F3（3 293.84±215.08）Hz. The formant frequency of Group C was F2（2 430.47±223.05）Hz and F3（3 345.97±180.83）Hz. The comparison of F2 and F3 between Group C and Group VPI before speech training showed significant difference（P<0.05）. The comparison of F2 and F3 between Group C and Group VPI after speech training showed no significant difference（P＞0.05）. The comparison of F2 and F3 before and after the speech training in Group VPI showed significant difference（P<0.05）, in which data was higher after speech training. Conclusion Speech training is first recommended for those patients who received the cleft palate surgery at an elder age. It can improve the velopharyngeal insufficiency significantly, which may eventually keep the patients away from a second surgery.

Objective To describe the dental caries of 15 -year -old adolescents in Hubei province, and to determine the influence of various social-behavioral risk factors on dental caries in the population. Methods The survey employed a multistage, stratified, non -geometric proportional randomized sampling, representing adolescents aged 15-year-old in Hubei province. The epidemiological investigation of dental caries was made by clinical oral health examination. Oral health knowledge, attitude and behavior investigated by questionnaire. Results The prevalence and mean DMFT in 1 080 15-year-old adolescents in Hubei province was 24.4% and 0.45, respectively. 11.4% of the adolescents brushed their teeth at least twice a day, 33.1% of the adolescents ever visited the dentists. A significant higher prevalence of dental caries was observed in girls（OR=1.70）. In addition, those who visit dentists and those who the scores of the consumption of sugar drink were high tended to have a higher prevalence of dental caries. Conclusion The dental caries prevalence of adolescents in Hubei province is low, but oral health habit of adolescents seems poor. Gender and consumption of sugar drink may be risk factors of dental caries.

Objective To compare the efficacy and radiographic changes after arthrocentesis followed or not followed by intra -articular corticosteroid injection in patients with temporomandibular disc displacement without reduction  Methods Ninty patients were enrolled in the randomized clinical trial. After receiving arthrocentesis, either 0.5 mL triamcinolone acetonide plus 0.5 mL saline（experimental group，n=46） or 1 mL saline solution as control（control group, n=44） was injected. Patients were assessed by visual analogue scale（VAS） pain scores and Fricton temporomandibular joint（TMJ） index at first visit before treatment, 3-4 weeks and 6 months after treatment respectively. Transpharyngeal and lateral transcranial projections for temporomandibular joints were taken for imaging evaluation. The pain score of patients with pain complaint were recorded everyday for 1 week after treatment. Results Glucocorticoid injection showed more effective pain control over the first week（P<0.05）, and both groups reported symptom and clinical sign relief significantly after treatment（P<0.001）. However, quantitative evaluation for pain reduction, maximal mouth opening improvement and Friction TMJ index showed no significant difference between two groups at 3-4 weeks and 6 months after the treatment. Also there was no significant difference for condylar bone changes radiographically between the two groups. Conclusion Arthrocentesis is an effective treatment for temporomandibular joint disc displacement without reduction, but it is not necessary to inject corticosteroid after arthrocentesis. Intra -articular corticosteroid injection after arthrocentesis is indicated for only those patients with severe pain.

Objective To measure the utility value of different skeletal malocclusion for patients receiving or - thodontic treatment. Methods Utility value of different skeletal malocclusion for patients was measured by rating scale and time trade-off. Results The youth group had higher utility values than adult group for skeletal malocclusion Class Ⅱ（protruding facial type） with median mandibular angle. The utility value of skeletal malocclusion Class Ⅲ（concave facial type） with low mandibular angle was the lowest, and the utility value of skeletal malocclusion Class Ⅱ（protruding facial type） with median mandibular angle was the highest. There was no difference in the utility values by rating scale and by time trade-off. Conclusion For some skeletal malocclusion, the youth had different utility values with the adult.

Objective To investigate the hard and soft tissue changes following the treatment of Class Ⅱ division 1 malocclusion using Twin-block appliance. Methods 50 Class Ⅱ division 1 malocclusion subjects whose handwrist radiographs were in FG-G stage were selected. One group（27 patients） was treated with Twin-block appliance, the other group（23 patients） was observed without treatment. The acquired data of cephalometric of two groups were analyzed statistically with SPSS 11.0. Results Soft tissue changes, Ls-E, Li-E, U1-Stms, Stms-Stmi, NsLs-FH, LsNsLi, LsNsPg’, the angle of H decreased. Sn-Stms, Stmi-Me’, Ns-Me’, Sn-Me’, NsLi-FH, NsPg’-FH, A’Ls-FH, B’Li- FH, LiB’Pg’, CmSnLs, GSnPg’, the angle of Z increased, there was statistically significant difference（P<0.05）. Hard tissue changes, SNB, L1-NB, IMPA increased, ANB, U1-SN, U1-NA, FMIA decreased, there was statistically significant difference（P<0.05）. Conclusion Sagittal relationship between upper- and lower-jaws is effectively improved after orthopedics with Twin-block appliance. Lower face height increases. Soft tissue profile tends to be straight-styled.

Objective To evaluate the therapeutic effect of teeth with large periapical lesions followed apical surgery. Methods 59 patients（59 periapical lesions, 91 teeth） with large periapical lesions ranging in size from 6 mm to 21 mm in diameter were included in this study. All teeth were treated by root canal therapy and apical surgery, and the surgical procedure was completed with microsurgical technology and ultrasonic root -end preparation. The outcomes were evaluated clinically and radiographically at 1, 3, 6, 9, 12 and 24-month intervals, and the various factors which may affect the success rate were analyzed statistically. Results 52 cases（88.1%） of 59 patients were considered success, 6 cases（10.2%） were considered failure, and 1 case（1.7%） was considered in progress. The success rate of elderly patients group（63.6%） was significantly lower than that of the youth group（87.5%） and middle-aged group（95.0%）（P=0.037；P=0.017）. The success rate of molar group（75.0%） was significantly lower than that of the anterior group（92.6%） and the premolar group（90.0%）（P=0.041, P=0.047）；however, there was no significant difference in the gender, the number of teeth invaded in lesions, the size of periapical lesion（P>0.05）. Conclusion It is an effective therapy for the teeth with large periapical lesions by apical surgery after root canal treatment.

Objective To investigate the genotypic diversity of Actinomyces naeslundii in aged people and the elationship between the genotypes of Actinomyces naeslundii and root caries. Methods According to the inclusion riteria, 20 aged people with root caries and 20 without root caries were chosen into two groups for this study. Two ites were chosen in subjects with root caries: One site was the exposed sound root surface, and the other site was he root caries. In subjects without root caries the sampling site of root surface was exposed. Bacteria were cultured nd then identified. Repetitive extragenic palindromic sequence -based polymerase chain reaction（REP -PCR） was sed to analyze the genotypic diversity of the Actinomyces naeslundii clinic isolates. Results 299 strains were isolated rom the groups, 156 strains were chosen to analyze, belonged to 61 different genotypes. At the site of sound oot surface in the subjects with root caries, there were 57 strains with 25 different patterns. At the site of root aries and of sound root surface in subjects without caries, there were 34 strains with 25 different patterns and 65 trains with 26 different patterns respectively. There was the genotypic diversity within Actinomyces naeslundii. here was significant difference in the genotypes in every individual site. Conclusion Many different genotypes of ctinomyces naeslundii concerned with occurrence of root caries.

Objective To investigate morphological change of osteoblasts cultured on titanium plates with different microarchitecture structure when exposured to fluid shear stress. Methods 14 dynes·cm-2 fluid shear stress was applied on osteoblasts cultured on 3 different commercially pure titanium plates: Polished treatment（PT）, sandblast （SB）, sandblasting and acid-base（SB-AB） surfaces. Scanning electron microscope（SEM） was adopted to observe the morphological changes after 0.5, 4, 7.5 h time point respectively. Results Morphologically, no significant changes were observed after 0.5 h and few osteoblasts were seen after 7.5 h on all 3 type of different surfaces, and significant changes could only be observed after 4 h. Osteoblasts were elongated and rearranged along the flow way on different levels on PT surface. Shape of cells was altered, from long fusiform suspending over depressed areas into polygon stretching out many synapsises tightly attachedto pits on SB-AB surface. Osteoblasts on SB surface displayed similar change as SB-AB surface, besides, some cells were elongated along the way of flow, stretching out threadlike synapsises attached to edges of pits. Conclusion Morphological change of osteoblast responding to fluid shear stress in physiological range depends on substrate microarchitecture and varies with the time of fluid shear stress application.

Objective The determination method of histatins 5 in human saliva with reversed-phase high performance liquid chromatography（HPLC） was developed. Methods Salivary samples were collected and diluted with phosphate buffer（pH2.5）. The upper solution was determined with HPLC. Phosphate buffer（pH 3.5） of the mobile phase and C18 column was used throughout the experiment. The detection wavelength was 276 nm. Results The linear ranges were 1.0-50.0 μg·mL-1. The detection limit was 0.12 μg·mL-1. The relative standard derivations（RSD） of standard solution for reserved time and peak area were 0.68% and 4.13% respectively. The proposed method was applied for analysis of salivary samples and the satisfactory results were obtained. RSD for sample determination was 4.41% and the average recoveries were 88.4%-109.0%. Conclusion The method was quick, simple and accurate. Analytical time was less than 15 min. It was adapted for analysis of salivary histatins 5 in salivary samples.

Objective To observe the effects of oxymatrine on the expression of interleukin-6（IL-6）, interleukin- 1β（IL-1β）mRNA of human periodontal ligament cell（PDLC） stimulated by lipopolysaccharides（LPS）, and to discuss oxymatrine’s inhibition mechanism on periodontal inflammation stimulated by LPS. Methods Firstly, isolate PDLC externally and culture them; for oxymatrine experimental group we used different combination of LPS and oxymatrine in different concentration, and for the matched group we use DEME nutrient solutions of 1% FBS. Then reverse transcription -polymerase chain reaction（RT -PCR） for checking the level of IL -6 and IL -1β mRNA. Results 25 μg·mL-1 LPS can significantly enhance the expression of both IL-6 and IL-1β mRNA’s level, and oxymatrine could restrain above phenomena. Conclusion Oxymatrine can restrain the expression of IL-6 and IL-1β mRNA of human PDLC stimulated by LPS.

Objective To analyze the relationship between periodontal condition and premature rupture of membrane（PROM） in order to provide basis to keep pregnant women from oral diseases. Methods 18 cases of preterm pregnant women with PROM（Group PPROM）and 20 cases of full term pregnant women with PROM（Group PROM）were selected as the study group, and 28 cases of full term normal pregnant women were selected as the control group. Everyone’s plaque index（PLI）, probing depth（PD） and sulcular bleeding index（SBI） were checked and recorded. Meanwhile, immunohistochemical method was used to detect the distribution and expression of matrix metalloproteinase-9 （MMP -9） in fetal membrane of cervix. The relationship between the expression of MMP -9 and PROM was analyzed. Results The expression of MMP-9 in the pregnant women with PROM（Group PPROM and Group PROM） was higher than that in the control group. There was no relationship between the expression of MMP-9 in chorion and PD（r=0.053, P=0.075）. The expression of MMP-9 in chorion had direct correlation with SBI（r=0.433, P<0.05） and PLI （r=0.310, P<0.05）. The expression of MMP-9 in amniotic membrane hadn’t dependence with PD（r=0.077, P=0.597）, while had direct correlation with SBI（r=0.430, P<0.05） and PLI（r=0.324, P<0.05）. Conclusion MMP-9 was involved in the pathological process of PROM and periodontal inflammation.

Objective To observe the changes of blood flow volume in mental artery of dog before and after osteocompression. Methods 16 adult dogs were selected and the osteocompressors were fixed on the right buccal side of the mandible. The osteocompressor was used to compress the mandible 1.0 mm per 3 days for totally 15 days. On the 1st, 15th, 45th and 90th day after osteocompression, the 4 MHz prober of color Doppler flow imaging machine was put on the surface of the mucosa below which there was the mental artery. The color Doppler flow imaging was used to measure the blood flow volume in the mental artery of both experimental and control sides. Results 1）The blood flow value in the mental artery was the lowest on the 15th day after osteocompression, however there was not significantly different before and after osteocompression. 2）Compared with the control, the blood flow value of the mental artery on the 1st day after experiment was significantly decreased. 3）Compared with the data before experiment, the deduction of the blood flow values between experimental side and control on the 1st, 15th and 45th day after osteocompression had significant differences. On the 90th day, the deduction of the blood flow value was similar to normal. Conclusion The osteocompression influences blood flow volume in mental artery temporarily, however, the influence is reversible and can be recovered by times after osteocompression.

Objective Carboplatin（CBP）-resistant cell line（Tca8113/CBP） and pingyangmycin（PYM）-resistant cell line（Tca8113/PYM） were established in vitro. Ginkgolic acids’influence over multidrug resistance（MDR） of drug-resistant cells was discussed by ginkgolic acids coupled with chemotherapy drugs. Methods The expression of P-glycoprotein（P-gp） was detected by immunohistochemistry. MTT assay was applied to ascertain the resistance index of drug-resistant cells. The effect of different concentrations of ginkgolic acids on the proliferation of drug-resistant cells and parental cell was measured by MTT assay. Making sure the non-toxic concentration of ginkgolic acids and observing the reversal effect of ginkgolic acids on drug-resistant cells. Resistance index was redetermined by MTT assay after ginkgolic acids coupled with chemotherapy drugs induced the cell lines for some time. Results Immunohistochemistry showed that P-gp positive expression rate of drug-resistant cells was significantly higher than parental cells. The non-toxic concentration of ginkgolic acids which was determined by MTT assay was 10 μg·mL-1. The reversal folds of Tca8113/CBP cell line to CBP and Tca8113/PYM cell line to PYM were 2.94 and 2.43 respectively. Before coupled with ginkgolic acids, the resistance indices of Tca8113/CBP and Tca8113/PYM cell lines were 3.24 and 11.9 respectively. When ginkgolic acids was added with chemotherapy drugs for some time, the resistance indices of Tca8113/CBP and Tca8113/PYM cell lines were 2.18 and 4.43 respectively. Conclusion This experiment successfully induced the drug-resistant cell lines of Tca8113/CBP and Tca8113/PYM. The method of chemotherapy drugs coupled with ginkgolic acids further confirmed the effect on proliferation of Tca8113/CBP and Tca8113/PYM cell lines was reducing. Non-toxic concentration of ginkgolic acids can partially reverse the drug resistance of Tca8113/ CBP and Tca8113/PYM cell lines. Furthermore, MDR level of drug-resistant cells decreased somewhat when they were induced by ginkgolic acids coupled with chemotherapy drugs for some time.

Objective To compare the therapeutic efficacy both apexification and revascularization in the immature anterior teeth of animal model with apical periodontitis, and observe the histological situation of revascularization in the root canal. Methods Six immature anterior teeth of one animal model（dog） aged approximately 4.5 months was selected. Afterwards, periapical periodontitis pattern were established, the samples were randomly divided into the experimental group（revascularization, 3 teeth） and the control group（apexification, 3 teeth）. To compare the development of root and the healing of periapical inflammation, the involved teeth were respectively radiographed 1, 4, 8 weeks after surgery. The animals were sacrificed after 8 weeks, and the closure of apical foramen and the content of root canal were observed by hematine-eosine（HE） staining. Results The postoperative radiography after 1 week and 4 weeks, the apical foramen size and the periapical radiolucency of the samples was shown no perceptual change. After 8 weeks, the experimental group periapical radiolucency area was obviously more narrowing, and had a apical closure tendency whereas the thickness of the root canal walls had imperceptible changed. While the control group periapical radiolucency change varied. The granulation tissue could be seen within the lumen of the experimental group, which contained a large number of irregular calcification, the calcification was obvious in the apical and adjacent the root canal wall. A small quantity of hard tissue was deposited in the apical of the control group. Conclusion Revascu -larization may increase the recovery of immature anterior teeth with chronic periapical inflammation, the vital regenerative tissue within root canal is the granulation tissue contained calcification.

From March 2009 to October 2009, three pediatric patients with parotid tumor were cured. Preoperative physical examination showed regional swelling in parotid area, the surface skin was in moderate reddish purple, the border was vague, and the swelling was inactive. The patients’IgE were significantly increased. B ultrasound examination demonstrated the focus was an isoecho with ringlike dark band around, which was concluded as bull’s-eye sign. Magnetic resonance imaging（MRI） examination  indicated a cystic mass between the skin and parotid. Preoperative diagnosis was eosinophilichyperplastic lymphogranuloma（Kimura’s disease） and the  ranuloma was excised by operation. Pathological examination revealed the capillary vessel hyperplasia in local tissue with a plenty of eosinophils and lymphocytes infiltrating. The disease was confirmed. Although the disease is rare, the diagnosis still could be made by preoperative physical examination, laboratory and imaging examinations.

The main type of four root canals in maxillary second molar is two -mesiobuccal. Incidence rate of maxillary second molar with two palatal root canals is especially rare. A case of maxillary second molar with two palatal root canals was reported in this article.

Tumors of synchronous benign and malignant in unilateral salivary glands have rarely been reported. A case of 21-year-old girl who was diagnosed as synchronously adenoid cystic carcinoma of the left parotid and pleomorphic adenoma of the left submandibular gland. The classification, clinic pathology, diagnosis, possible mechanism were discussed based on similar literatures.

Cemento-ossifying fibroma is a rare benign tumor from periodontium, which usually occurs in mandible body and mandible ramus. It consists of collagen fibrils, fibroblast, and cementoblast. This article reported a case of giant cemento-ossifying fibroma and discussed the clinical features and treatment.