Human papillomavirus （HPV）,a doublestranded circular DNA virus,is a member of papillomaviridae family.HPVrelated human diseases have been studied for more than one hundred years.However,at present,HPVassociated diseases of the oral mucosa have been studied only in the startup stage.In this review,we focused on HPV infection of the oral mucosal and provided insight into the prevalence,pathogenic mechanism,prevention,treatment and other areas,so as to serve as a spur to induce more valuable contributions.

Objective To construct cancellous scaffold of calciumphosphate cement （CPC） and hydrolyzed collagen gelatin,and to observe the effect of substance P （SP） on mandibular bone defect repair by using the scaffold.Methods Hydrolyzed collagen gelatin sponge was prepared by acidolysis and lyophilization of the rattail collagen type Ⅰ.Three groups of CPC based scaffolds were prepared by using 8 mm×2 mm mold.Group one was pure CPC scaffold,Group two was compound scaffold of CPCgelatin,and Group three was compound scaffold of CPCGelatinSP.Criticalsized round bone defect of 8 mm diameter was prepared in rabbit mandible.The scaffolds filled in the defects and bone healing were examined by Xray and MicroCT after 12 weeks.Results Electron microscopy showed that the CPCGelatin scaffold had cancellousbone mimic ultrastructure; Animal experiments showed CPCGelatinSP scaffold merged with the surrounding bone in the 12th week,and new bone regeneration inside the scaffold was significantly better than the other two groups.Conclusions The compound scaffold of CPCgelatin has advantages of easy preparing,easy shaping and selfsetting,and its structure is close to cancellous bone.Besides,substance P can promote the bone repair effect of the scaffold in vivo

Objective To investigate the dentofacial changes caused by retractive force with zygomatic implant anchorage to the maxilla of rhesus monkeys.Methods Three male rhesus monkeys with mixed dentition were randomly assigned to 2 groups： 2 monkeys for experimental group,and 1 for control group.The implants in anterior maxilla were loaded by retractive forces with zygomatic miniplates through NiTi coilsprings.A backward force of 2.94 N was exerted on each side of maxilla for 3 months.Facial characters,model measurements,and Xray cephalometric results were compared before and after treatments.Results The implants kept stable during the whole experiment.The anterior overjet and the length of upper dental arch significantly decreased in experimental group,while the width of upper dental arch increased; SNA and ANB angles reduced and maxillary A point was moved 2mm backward for both monkeys in the experimental group.The angle of palatal plane was increased in both groups,and maxilla rotated clockwise slightly.Conclusions Retracting maxilla with intraoral implant anchorages can inhibit the forward maxillary growth in growing rhesus monkeys,providing experimental basis for a new method of treating maxillary protrusion in mixed dentition.

Objective To observe the expression of PDGFRα in the development stages of mouse embryo palatal shelves.Methods Palatal shelves of C57BL/6J inbred mouse embryos were obtained on the day of GD13.5,GD14.5 and GD15.5 respectively by using stereoscope microscope.The expression location of PDGFRα protein in the palatal shelf was observed by immunohistochemistry（IHC） staining; and the quantities expression of PDGFRα protein were examined by Western blot（WB） analysis.Results IHC staining showed that PDGFRα was specifically expressed in mouse palatal shelves.In GD13.5,PDGFRα expressed mainly in the palatal epithelium; but in GD14.5,GD15.0,and GD15.5,the PDGFRα expressed both in mesenchymal cells and epithelial cells.The WB analysis showed that proteins expression of PDGFRα in different developmental stages of palatal was consistent with IHC results.In GD14.5，the expression level of PDGFRα reached the peak.The proteins expression in GD13.5,GD15.0 or GD15.5 was significantly different compared with that of in GD14.5.Conclusions The study showed PDGFRα had spatiotemporal expression features during the development stages of mouse embryo palatal shelves.PDGFRα gene may be associated with the development of palatal shelves.

Objective To evaluate the color stability of resin infiltration after ultraviolet （UV） aging.Methods 60 intact premolars were selected from orthodontic extraction,which were placed in the artificial demineralization solution for 3 days to form initial artificial enamel caries.The teeth were divided into 3 groups randomly： control （CON）,resin infiltration （RI） and fluoride treatment （FLU）.Changes in color of test samples were determined before and after UV aging for 8,16 and 24 h using the CIE L* a* b* system by a colorimeter.Results After being treated with resin infiltration or fluoride treatment,the ΔE* of 3 groups was RI

Objective To investigate the expression of specific sequence AT protein 2（SATB2）,NANOG,octamerbinding transcription factor（OCT4） in oral squamous cell carcinoma （OSCC） and its relationship with clinical pathological characteristics of oral squamous cell carcinoma.Methods Immunohistochemistry was used to examine the expression of SATB2,NANOG and OCT4 in oral squamous cell carcinoma and normal oral mucosa.Results The expressions of SATB2,NANOG and OCT4 were higher in OSCC than in normal oral mucosa,and the difference was statistically significant （P>0.05）.The expression of SATB2,NANOG and OCT4 protein was unrelated with tumor grade,clinical stage,neck lymphnode metastasis（P>0.05）,and the expression of SATB2,OCT4 protein was unrelated with local invasion （P>0.05）.The expression of NANOG protein was related with local invasion （P<0.05）.Conclusions SATB2,NANOG and OCT4 were highly expressed in oral squamous carcinoma tissues,which could be a tumor marker and used as targets of treatment.The expression of NANOG was associated with tumor invasion ability; it may play an important role in promoting the invasion and metastasis of OSCC.

Objective To evaluate the occluding effect of bioactive glass combined with Er laser irradiation on abrasion cutting dentine model.Methods 45 dentine discs were prepared and the treating sides were roughly grinded,finely grinded and polished.They were randomly divided into 5 groups with different treatments： Group A （no treatment as a control）,Group B （bioactive glass）,Group C （Er,Cr：YSGG laser irradiation）,Group D （bioactive glass followed by Er,Cr：YSGG laser irradiation）,and Group E （Er,Cr：YSGG laser irradiation followed by bioactive glass）.The occluding effect and mineral content were examined by scanning electron microscopy （SEM） and Xray energy spectrum analysis （EDXA）.Results Micrographs of SEM showed excellent occluding effect in Group B,C,D and E,and the dentinal tubule exposure rates were D （0.044%±0.003%）

Objective To construct a threedimensional finite element model of implantretained overdenture with magnetic attachments for analyzing the stress distribution of overdenture with implant magnetic attachments.Methods After using DICOM modeling method based on CT scaning,medical image 3D reconstruction Mimics software,Geomagic studio reverse engineering software and SolidWorks 3D design software the threedimensional finite element model of implant magnetic overdenture was constructed.Results The threedimensional finite element model of implantretained overdenture with magnetic attachments was constructed.〗Conclusions The 3D FEA models of implant magnetic overdenture can be constructed to analyze the stress distribution.

Objective To establish a three-dimensional finite element model of a mandibular first molar with single and combined crown after separation prosthodontic therapy for biomechanical analysis of crown prosthesis. Methods The 3-D finite element model was established with CBCT scanning method. Mimics software was used to read and deal with the tomography data preliminarily, Geomagic software was for precise modification, and UG software was utilized to assemble all of the modules and Ansys software to divide gridding. Result The 3-D finite element models of the mandibular first molar with normal structure and the molar treated with separation prosthodontic therapy were established. Conclusions It was feasible, fast and effective to use the modeling approach of CBCT scan combined with reverse engineering software Mimics and Geomagic, modeling software UG, the finite element analysis software Ansys to establish the 3D finite element model.

Objective To evaluate the effect of H2O2 surface treatments on the bond strength between fiber posts and resin cement.Methods 25 POPO glass fiber posts were randomly separated into five groups： Group A （control; no treatment）,Group B （silanization）,Group C （etching with 10% H2O2 and silanization）,Group D （etching with 20% H2O2 and silanization）,Group E （etching with 30% H2O2 and silanization）.The posts were positioned into a mold to allow adhesive resin cement to be inserted,and to form resin blocks.Then resin block was cut to obtain 1mmthick specimens.The pushout tests were done at a crosshead speed of 0.5 mm/min with a universal testing machine until failure occurred and data were analyzed using oneway ANOVA.The failure mode of each specimen was observed with stereomicroscope.Results The micropushout bond strength values of fiber post from group A to group E： （12.36±1.66） MPa,（12.76±1.59） MPa,（16.10±2.55） MPa,（19.19±2.81） MPa,（21.95±2.95） MPa.Significant difference （P<0.05） was found between each two groups except for Group A and Group B （P>0.05）.Conclusions Silanization as the only surface treatment did not improve the bond strength,but the combination of H2O2 and silanization can enhance the bond strength,and with the concentration increased,the bond strength increased.

Objective To establish a 3D image classification system for maxillary canine impactions based on spiral CT.Methods A retrospective sample of 102 subjects with maxillary canine impaction （121 impacted canines） were selected.All subjects received standard CT scans and all data （DICOM files） were reconstructed through MIMICS10.01 by the means of Surface Shaded Display （SSD） to show the 3D position of the impacted canines.Based on the analysis of 121 impacted canines,a 3D CT image classification system for maxillary canine impactions was established.Results A database for 3D CT images of different maxillary canine impactions was established.The data showed that the type of mesial cusp tip with normal root apex of maxillary canine was most common on the Xaxis while there were only three types on the Yaxis which were high root apex with high,middle or low cusp tip of maxillary canine.And the type of buccal cusp tip with buccal root apex of maxillary canine （about 1/3） was most common on the Zaxis.Conclusions A 3D image classification system for maxillary canine impactions based on spiral CT was established with certain diagnostic value.

Objective To compare treatment impacts on oral healthrelated quality of life （OHRQOL） among Gemini MBT,Damon Q and Invisalign aligner.Methods 60 adult orthodontic patients at the age of 1828 years old were divided into group C （treated with Gemini MBT brackets）,group S （treated with Damon Q brackets）,and group I （treated with Invisalign aligners）,20 in each group.The patients were asked to complete the oral health impact profile （OHIP14） at five intervals： before treatment （T0）,after insertion of the fixed appliance or the first aligner of Invisalign at 1 week （T1）,1 month （T2）,3 months （T3）,and 6 months （T4）.Results were analyzed using software SPSS 18.0.Results No significant differences of overall OHIP14 scores were found between Gemini MBT brackets and Damon Q brackets.Moreover,in Damon Q group，overall scores at T1,T2 and T3 were significantly higher than those in Invisalign aligners group （P<0.05）.Conclusions Invisalign aligners could have less negative influence on oral healthrelated quality of life than fixed appliances within 3 months after treatment.

Objective After the teeth were etched with 35% phosphoric acid,the first permanent molars were sealed by 3M flowable composite resin and common pit and fissure sealant so as to compare the retention rate and caries prevalence rate of dental caries by the two kinds of sealing material.Methods 240 permanent mandibular first molars with deep fissures and with no caries among 120 children of 7-9 years old were selected.The self export control method was used.According to the result of coin tossing,one side was chosen as the phosphoric acid +3M flowable resin group,and the other side the phosphoric acid etching +3M pit and fissure sealant group.After 3 months,6 months,12 months,and 24 months,pit and fissure sealant retention and caries rates were respectively examined.Results In the 3rd and 6th months,pit and fissure sealant retention,and caries decrease rate between two groups were different with no statistical significance （P>0.05）.In the 12th and 24th months,retention and caries decrease rates in the flowable composite resin group were higher than those in the pit and fissure sealant group,while caries incidence rate was lower than that in the pit and fissure sealant group.The differences were statistically significant （P<0.05）.Conclusions The clinical effect of the phosphoric acid etching combined with flowable composite resin is better than that of phosphoric acid etching combined with pit and fissure sealant.The former method can increase retention rate of sealing materials,thus lowering prevalence rate of dental caries.

Objective To evaluate the effect of orthodontic treatment combined with the alveolar corticotomy surgery on the correction of lingual inclination of molars.Methods 40 patients with a unilateral scissors bite caused by lingual inclination of the second molar in mandible were divided into 2 groups （20 patients in each）.All of them were treated with intermaxillary elastics as to correct the scissors bite.20 patients were treated with the alveolar corticotomy surgery （Group 1）,and another 20 were in the control group without the alveolar corticotomy surgery （Group 2）.The treatment time of correcting the scissors bite in both groups was observed,and cone beam CT of root absorption before and after the treatment were compared.Results The treatment time was significantly shorter in G1 than in G2,and no obvious root absorption in G1 was detected.Conclusions Alveolar corticotomy surgery is effective in correcting the scissors bite in that it can shorten the treatment time and lower the occurrence of root absorption.

Objective To study the retention effect of the insertiontype separate inlay crown on the molar residual crowns with low occlusogingival distance.Methods 43 cases of molar residual crowns with low occlusogingival distance after RCT were restored by the insertiontype separate inlay crown.After two years,the clinical effects were judged by Modified USPHS Criteria.Results The numbers of fracture,marginal gingivitis,failure were 2,5,and 2,respectively.All the other restorations were perfect with good marginal fit,stable retention and fine occlusion.Conclusions The insertiontype separate inlay crown is a clinically reliable method in the restoration of molar residual crowns with low occlusogingival distance.

Objective To explore the range of the distance between the dental implant tip and mandibular canal.Methods 15 dental implants （including soft tissue level and bone level implants） from 12 patients whose distance between the tip of dental implant and the superior border of mandibular canal was less than 2 mm were selected and the real distance was measured and after surgery the inferior alveolar nerve symptoms were recorded.Results The average distance between the tip of dental implant and the superior border of mandibular canal in 15 implants was (0.94±0.50)mm（0.24~1.52 mm） and one patient experienced numbness of the chin in one week.Conclusions Considering the possible problems such as mandible infection,inferior alveolar nerve damage,periimplantitis、Retrograde PeriImplantitis，the safe range of distance may be less than 2 mm.

Objective To explore the domestic epidemiology characteristics and risk factors of nonsyndromic cleft lip with or without palate,so as to provide basis for for its early prevention.Methods A casecontrol study recruiting nonsyndromic cleft lip with or without palate patients and healthy controls from Jiangsu,Anhui and its surrounding areas was designed.A questionnaire （a total of 14 factors,including family history,parental educational level,childbearing age,pregnancy reaction,parity,drug use during pregnancy,infections,active and passive smoking during pregnancy,alcohol consumption during pregnancy,nutritional status,etc） was investigated and further analyzed by chisquare test and logistic regression analysis.Results 352 nonsyndromic cleft lip with or without palate cases as well as 602 healthy controls were recruited in the final study.Univariate analysis showed pregnant reaction,passive smoking during pregnancy,educational level of the father and family history were associated with nonsyndromic cleft lip with or without palate.These factors together with educational level of mother and vitamin intake were also significant in multivariate analysis.Conclusions Pregnancy reaction,passive smoking during pregnancy,parental educational level,vitamin intake and family history may be related factors of nonsyndromic cleft lip with or without palate in Jiangsu,Anhui and its surrounding areas.

Objective To analyze the prevalence and distributing feature of oral malignant tumor in Nanjing and its surrounding areas, so as to provide reference for the prevention and treatment of oral malignant tumor.Methods 1 267 cases of oral malignant tumor treated from 2010 to 2013 in Nanjing Stomatological Hospital were collected and analyzed. Results The average age of 1267 cases was 60.94 years old, and the incidence rate of male was higher than that of female, which was 1.3∶1.0. Males also had a longer smoking and drinking history than females. The high risk age was 60-69 and over 70 years old. Males at 60-69 years old and females over 70 years old suffered from the highest incidence rate. There was a significant difference between different ages (P<0.001). The most common oral malignant tumor was oral cancer, in which the most common was squamous cell carcinoma with the rate of 64.56% (818 cases). The most common site was tongue (27.55%), followed by buccal, gingiva, soft and hard palate, jaw, salivary glands. The percentage of oral ulcer, oral mucosal lesions and dental disease was 73.56% (932 cases). Conclusions The prevalence of male patients with oral malignant tumor was higher than female in Nanjing Stomatological Hospital. The high risk age was over 60 years old, and the most common oral cancer was squamous cell carcinoma, which suggests that oral health care of old people should be strengthened.

Objective To improve the quality of practice teaching of stomatology through the reform of clinical practice skills examination mode.Methods Objective structured clinical examination mode was used in oral clinical practice examination.The effect of this mode was investigated by comparative analysis and questionnaires.Results The objective structured clinical examination mode was accepted and adapted by students.It evaluated students practice ability objectively and comprehensively.And it helped to improve the quality of practice teaching.Conclusions Objective structured clinical examination is good model of stomatological practice examination,which is worth popularization and application in the stomatological practice teaching.

Digital 3 dimensional photogrammetry (3dMD) is a useful and effective method to assess and calculate maxillofacial soft tissue by gaining the information from threedimensional images that traditional twodimensional images can not provide.Compared with other 3 dimensional photogrammetries like CBCT and laser scanning,3dMD captures 3 dimensional images quickly with no radiation and injury,thus it is preferred in oral and maxillofacial region.This paper reviewed its application in oral and maxillofacial soft tissue assessment.

The traditional treatments of tissue defects caused by oral and craniomaxillofacial diseases are obturator prosthesis or bone transplantation,which have many drawbacks,such as infection and inflammation,secondary damage of the donor site,etc.In recent years,with the development of in situ tissue engineering technique,some researchers have begun to try various methods to induce cells within the local defect site to migrate,proliferate and differentiate,which may result in new tissue formation,thus achieving oral and craniomaxillofacial tissue regeneration.Approved by the FDA,parathyroid hormone（PTH） is the unique bone anabolic drug for the treatment of osteoporosis,which is seen as an important regulatory factor in the process of bone formation and bone remodeling that can promote the proliferation and differentiation of bone progenitor cells.This article reviewed the mechanisms of parathyroid hormone on osteogenesis and its impact on craniomaxillofacial and periodontal tissue regeneration.

Treated with a fatal dose of antibiotic,most microbial population will soon die,while some subpopulation cannot be eliminated and thus survive.Different from the traditional resistant mutants,these bacterial strains do not change as to their gene sequence.After the collection and reincubation of the bacterial strains,its been found that their minimal inhibitory concentration （MIC） remains the same.The subpopulation that cannot be eliminated thoroughly is known as persisters.More and more studies suggest that persisters seem to play the main role in the recalcitrance of chronic infections.This paper reviewed the biological characteristics and the generation mechanism of persisters and their tolerance mechanism to antibiotic,as well as the strategy to eliminate them.