Objective To evaluate the influence of the phosphate eater monomer 10metacryloxydecyl dihydrogen phosphate (MDP) on resin bonding of yttriastabilized tetragonal zirconia polycrystals (YTZP)， performed in various solvent environments. Methods Ethanol， acetone and ethanol/acetone(1∶1) solution containing MDP were prepared as experimental primers respectively. Shear bond strength testing was performed to compare the efficacy of the three kinds of experimental primers in improving resinzirconia bond strength. The group conditioned with no primers was taken as the negative control and another with a commercially available MDPcontaining primer served as the positive control. Xray photoelectron spectroscopy (XPS)was used to investigate the formation of chemical bond on the surface of YTZP treated with the three experimental primers containing MDP. Results The negative control group presented the lowest SBS， whereas the three groups conditioned with experimental primers showed higher values， which were not significantly different from one another (P>0.05). The XPS spectra analysis detected POZr bond on the surface of YTZP treated with the MDP ethanol solution or acetone solution. Conclusion No matter ethanol， acetone， or the mixing of the two as the solvent， the MDP can improve the resin bond strength of zirconia. 

Objective To compare the initial adhesive ability of osteoblast which adheres to calcium magnesium phosphate cement (CMPC) and calcium silicate compound with calcium magnesium phosphate cement (CMPSiC). Methods The ions concentrations of the extract from CMPC and CMPSiC were detected. The initial attachment effects of MG63 on CMPC and CMPSiC were performed by MTT and cell morphometric evaluations. Results Concentrations of calcium， magnesium and phosphorus ion of the CMPC and CMPSiC extract significantly increased after immersion for 24 hours（P<0.05）. And concentration of silicon ion significantly increased in CMPSiC extract（P<0.05）. The result of MTT experiment indicated that the number of osteoblasts increased over time， and the number adhering on CMPSiC surface was significantly more than that on CMPC surface (P<0.05). After 6 h inoculation， cells adhering on CMPC surface were shrinked， and those on CMPSiC surface were spreading. Cell morphological parameters such as cell surface area， perimeter and Fred diameter of CMPSiC group were significantly larger than those of CMPC group（P<0.05）. Conclusion Compared with CMPC， CMPSiC is more conducive to initial adhesion and spread of osteoblast.

Objective To study the expression of midkine(MK) in salivary adenoid cystic carcinoma(SACC) and its relationship with perineural invasion(PNI). Methods Immunohistochemistry staining(SP method) for MK was performed on 35 SACC and 20 normal salivary gland tissues(NSG). Then， the correlation between the expression of MK and PNI was analyzed. Results In SACC， MK was highly expressed and the positive rate was 82.9%（29/35）while it was lowly expressed and the positive rate was 10.0%（2/20）in NSG， which showed significant difference (P<0.01). There was no relationship between the expression of MK and age， sex， pathologic types (P>0.05). However， there was significant difference between PNI cases and nonPNI cases(P<0.05). Conclusions MK may be associated with generation of SACC， and its overexpression may be contributed to the perineural invasion in SACC patients.

Objective To investigate the effect of rich platelet plasma (PRP) and PRP composite osteoinduction active material (PRP/OAM) on the repair of bone defect around implant. Methods Four adult Beagle dogs were selected which weight 10 ~ 13 kg， and each dogs left and right mandibular fourth molar teeth were randomly divided into group A and group B， the first and second molar teeth in the same side with group B as control group. In group A， bone defect around the implant was implanted with PRP/OAM， group B was implanted with PRP/ calcium phosphate， and the control group was implanted with calcium phosphate. The contents of Ca2+ on the implant bone interface of each group were analyzed by energy spectrum， and the histological patterns of 8 and 16 weeks after implantation were observed. Results Ca2+ content on the planting body bone surface of group A and group B planting after 8 and 16 weeks was significantly higher than that of the control group (P<0.05); Ca2+ content on the planting body bone surface of group A planting after 8， 16 weeks were (26.01±3.28)% and (44.10±7.11)%， which were significantly higher than that in group B (P<0.05); 8 weeks after implantation， in group A new bone and implant formed sectional osseointegration， in group B new bone formed at the implant edge， and the control group implant edge was fibrous interface; 16 weeks after implantation， in group A and group B new bone and implant formed bone integration， in the control group it was only fibrous combination. Conclusion PRP and PRP/OAM in the repair of bone defects around implants can effectively promote the repair of bone defects.

Objective To investigate the effects of bone marrow mesenchymal stem cells (BMSCs) and fibrin glue (FG) as seed cells and scaffold materials in repairing alveolar bone defect in rats. Methods 30 SD rats were selected to establish the alveolar bone defect model， randomly divided into observation group， negative control group and blank control group， with 10 rats in each group. In the observation group， BMSCs and FG were implanted to repair the alveolar bone defect of the rats; while the negative control group was implanted with FG， and the blank control group was not implanted. HE staining and MicroCT scanning were used to observe the osteogenesis effect of each group. Results After 6 weeks in the observation group， the bone healing was good， and the healing surface was smooth; while in the negative control group and blank control group， the bone defect still existed， and there was no obvious bone formation. The percentage of new bone area in the observation group was (76.23±7.11)%， significantly higher than that of the negative control group and blank control group， and the difference was statistically significant (P<0.05). MicroCT scanning showed that in the observation group， new bone formed in the area where bone defect existed， bone defect basically healed， and there was no obvious boundaries around. The negative control group and blank control group had no obvious osteogenesis， and the bone defect was still obvious. Conclusion BMSCs and FG as seed cells and scaffold materials for repairing alveolar bone defects have good effects， which can improve the new bone quantity， and are the ideal materials for the repair of alveolar bone defects.

Objective To evaluate the effects of different sand particle sizes of polishing disc on composite resin surface roughness and bacterial adherence. Methods Specimens of resins were randomly divided into five groups and polished with polishing burs (group A)， and polishing discs of different particle sizes:70 μm particle size (group B)， 50 μm particle size (group C)， 30 μm particle size (group D) and 5 μm particle size (group E) respectively (n=10 for each group). Scanning electron microscopy (SEM) was used to observe the roughness and surface structure of the specimens. Bacterial adhesion on the surface of the specimens was calculated by CFU counting. Results Scanning electron microscopy (SEM) showed that with the decrease of particle size of polishing disc to 30 μm(group D)， the grooves on the surface became shallower， and the number of pits were reduced in group D and E. There was a significant difference in bacterial adhesion between group D， E and that of group A (P<0.005). No significant difference was detected between group A，B and C (P>0.005). Conclusions With the decrease of the particle size of the polishing disc， lower surface roughness and fewer bacterial adhesion will be observed. Polishing disc with at least 30μm particle size can reduce bacterial adhesion of composite resin.

Objective To establish Zucker diabetic fatty rats with periodontitis model， to explore the effect of periodontitis on the severity of diabetesrelated complications in models， and to analyze its mechanism. Methods 48 female Zucker diabetic fatty (ZDF， fa/fa) rats were included and randomly divided into Group A and B， each group further randomized into Group 1 and 2. Group A was made model of periodontitis， in which Group A1 was given high fat diet， in order to induce insulin resistance (IR)， while Group A2 was given low fat diet. Group B was not made model of periodontitis， in which Group B1 was given high fat diet， while Group A2 was given low fat diet. Glucose tolerance test was carried out， fasting insulin and blood glucose were measured every week. 13 weeks later， the rats were sacrificed， and the health condition of periodontal tissue was detected， in order to evaluate the reliability of modeling. Serum TNFα， IL1β， CRP and pathological changes in aorta， fundus， pancreatic tissues were detected and analyzed statistically. Results ① The modeling scheme is reliable. Fasting blood glucose， fasting insulin， and HOMAIR in Group A1 and B1 were respectively higher than in Group A2 and B2， and the difference was statistically significant (P<0.05). There was obvious periodontal inflammation， periodontal soft tissue destruction， and bone resorption in Group A. ② The serum TNFα， IL1β， CRP in Group A1 and B1 were respectively higher than in Group A2 and B2， and the difference was statistically significant (P<0.05). There was a positive correlation between the above indexes and HOMAIR (P<0.05). ③ The pathological changes of aorta， fundus and pancreatic tissue were significantly higher in A1 group than in other groups， and the difference was statistically significant (P<0.05). Conclusion Periodontitis can lead to the increase of IR degree and the severity of diabetesrelated complications in Zucker diabetic fatty rats， which may be related to the increase of serum inflammatory factors in rats with periodontitis.

Objective To compare tooth glue cleaning effect and root tip chipping removing amount in root canal retreatment among methods of G bore+manual K file， Protaper Universal retreatment and Reciproc. Methods 60 invitro single root solenoglyphic teeth were selected and root canal preparation was made， glass ionomer was filled and sealed for the teeth lasting for 30 days. Then they were divided into three groups at random， 20 in each group. Grub root canal filler was cleaned respectively with G bore+stainless manual K filing（group A）， Protaper Universal retreatment(group B) and Reciproc single filing(group C). The condition of filler removal was evaluated by root tip Xray film and scanning electron microscope. The cleaning effect of 3 groups root canal filler was compared， filler elimination operating time was recorded and the total amount of tooth glue chipping of apical foramen in each group was calculated by weighing method. Results Filler residues existed in all root canal walls of the 3 sample groups. Root canal wall filler residues in Group B and Group C were obviously less than those in Group A (P<0.05)， and eliminating effect of Group C was superior to that of group B (P<0.05). Compared to Group A， both Group B and Group A could reduce retreatment time (P<0.05). Group A removed the largest amount of root tip chipping， Group B took the second place and that of Group C was the least. Conclusion Nickeltitanium instrument is superior to manual instrument not only in cleaning effect， operating time but also in apical foramens chipping amount. Reciproc single killing as well is superior to Protaper retreatment killing.

Objective To investigate the clinical application of minimally invasive extraction and immediate implant replacement and compare the differences between immediate implant and delayed implant. Methods 127 patients(127 singletooth implants) were included in this research. After the complete examination 127 teeth in the maxillary anterior region were extracted without flap reflection and 59 implants were replaced immediately，68 implants were replaced after alveolar ridge preservation. The day when stagetwo operation was done， gingival contour was induced using implantsupported temporary crowns prior to restoration till permanent prostheses delivered. The periimplant bone level and probing depth were measured immediately after the permanent restoration and 3，6，12 months later the clinical effect was evaluated. Results The implant stability quotient (ISQ) value of the 2 groups showed no significant difference before permanent restoration(P>0.05). The PD of the 2 groups also showed no significant difference(P>0.05).In all the cases after loading 1 year， the periimplant bone loses of the immediate group and delayed group in the mesial side were (0.37±0.34) mm and (0.39±0.43) mm respectively， while in the distal side were (0.41±0.31) mm and (0.43±0.32) mm respectively. All these indicators showed no significant difference between the 2 groups(P>0.05). Conclusions Both the protocols can achieve great therapeutic effects. And the therapy of minimally invasive extraction and immediate implant replacement is a sensitive technique through which patients can shut down their treatment time and acquire great aesthetic effect. To obtain ideal results， the operators need to be trained professionally and control the indications strictly.

Objective Three dimensional finite element method analysis is used in stress analysis of the temporomandibular joint in patient under treatment of junior classⅡmalocclusion with AdvanSync appliance to explore whether the temporomandibular joint has adaptive remodeling under localized stimulus. Methods An 11yearold classⅡDivision 1 malocclusion patient was selected as a volunteer in this research. CBCT was used in scanning the head of the patient. And the data was output as graphic data， which was established into threedimensional finite element model of appliances maxilla mandible and dentition by mimics17.0 software. ANSYS workbench 15.0 software was used in threedimensional model boundary and loading force valued 5.7 N， and making the stress analysis of the temporomandibular joint. Results Threedimensional model of AdvanSync functional appliances was established. When the appliance was leaded force，the left side and the right side of the temporomandibular joint stress distribution were basically the same. Equivalent stress mainly concentrated in front of the condylar slope near the neck of condyle， condylar cartilage，， and articular disc cavity. The maximum principal stress distribution of equivalent stress analysis results were basically the same， mainly bear tensile force; the minimum principal stress mainly concentrated on the top of condyle and condylar cartilage at the top， which is mainly bear compressive stress. Conclusion When AdvanSync functional appliance leads submaxila forward， condylar process and condylar chondrocyte have the adaptive trend under pressure. But articular disc and fossa have little effect.

Objective To study the occurrence time and the characteristics of the joint vibration from TMJs in both of the patients with anterior disc displacement with reduction(ADDR)and controls， thus to provide the basis for quantitative clinical diagnosis. Methods The joint vibration pictures from TMJ were recorded bilaterally from 24 patients with ADDR and 24 healthy controls by electrovibratography. The total integral of the vibration energy（TI）， the ratio of the integral between frequencies above 300 Hz and below 300 Hz (ratio of >300 Hz/<300 Hz)， peak frequency（FP）， median frequency（MF）， peak amplitude（PA）and distance to centric occlusion position（D）were calculated. Data were analyzed with MannKendall nonparametric test to assess the joint vibration characteristics. Results The values of total integral (P<0.001)， integral<300 Hz(P<0.001)， integral>300 Hz(P<0.001)， peak amplitude(P<0.001) and peak frequency (P=0.002)were significantly higher than those of the control group. The vibration analysis showed that the sensitivity， specificity and accuracy of the disc displacement with reduction were respectively 87.5%， 79.5% and 83.3%. The joint vibration of the ADDR subjects occurred mostly at the beginning of the opening phase and the end of the opening phase， while in normal subjects， the vibration often occurred at the end of the opening phase and the beginning of the closing phase. Conclusion The joint vibration of the ADDR subjects shows higher energy and frequency， which can be used as auxiliary examination. JVA can provide a fast， noninvasive， and repeatable method to record the status of TMJ. Further studies are needed to identify the characteristic waveforms of different subgroups of TMD and to evaluate the possibility of diagnostic value.

Objective The measurement of length， depth， diameter， shape of sella turcica and the incidence of sella turcica bridges on lateral cephalograms were performed to investigate the relationship between the size， morphology and incidence of sella turcica and age and gender， which can provide theoretical information for clinical use. Methods Lateral cephalograms of patients aged 325 from Department of Orthodontics， Hospital of Stomatology， China Medical University， between 2011—2015， were selected. All the patients were divided into 4 groups according to age: 310y group， 1112y group， 1314y group， 1525y group. Every group had 400 cases. There were 1 600 cases in total. Sella structural points were located on cephalometric radiograph by Winceph 8.0 software. The morphology of sella turcica and the types of sella bridging were recorded. The relationship between sella length， depth， diameter and age， gender was analyzed by SPSS 21.0 software. Results With the increasing of the age， the length， depth and diameter of sella increased， which had no significant difference between genders in the same age groups (P>0.05). The length of sella had the largest increase during 1314y， while the depth， diameter of sella had the largest increase during 1112y. It was only slightly different in the increase of the length of sella between genders. The length of the male sella had the largest increase during 1314y， while the length of the female sella had the largest increase during 1112y. The proportion of sellar shapes—the circular， flat， oval was respectively 37.9%， 33.2%， 28.9%. The incidence of sella bridging was 12.2%. There was significant difference in the incidence of sella bridging between genders(P<0.05). Conclusion During the growth and development， the size of the sella increases with age， which has no significant difference between genders in the same age groups. No significant difference is found in the proportion of sellar shapes and genders. Statistically significant difference is found in the incidence of sella bridging between genders. The incidence of sella bridging is higher in the male than in the female.

Objective To investigate the clinical normal values of the whole Ricketts analysis about cephalometry of the Han nationality adolescents with normal occlusion in Changchun area and to compare the craniofacial characteristics between males and females. Methods Students in elementary and middle schools of Changchun were extensively surveyed， and 120 adolescents: 61 males， 59 females with normal occlusion were selected. Cephalometrical films were gathered for each subject. The landmarks and cephalometric planes were determined， measurements for Ricketts were carried out with Dolphin 17.0 software. Data from 65 subjects were statistically analyzed by SPSS17.0 software with average±standard deviation. The differences between males and Females were statistically analyzed by t testing. A level of significance of 5% was assigned and P value was determined. Results The clinical normal values of the whole Ricketts analysis about cephalometry of the Han nationality adolescents with normal occlusion in Changchun area were obtained. Ricketts analysis revealed that except for ANPog、FHNA、XiPm、Anterior Cranial Length， there were no statistical differences in other values between male and female subjects (P<0.05). Conclusion The investigation on the clinical normal values of the whole Ricketts analysis about cephalometry of the Han nationality adolescents with normal occlusion in Changchun area can be used to provide guideline for orthodontic diagnosis， treatment planning and prognosis.

Objective To explore the treatment of patients with chronic periodontitis and periodontal health as well as to obtain a good shortterm prognosis. Methods The patients with mild to moderate chronic periodontitis after periodontal treatment were designed as the experimental group， the periodontal healthy subjects as control group. 1 month and 3 months before planting and after planting saliva of patients was collected， the stability of implants and periodontal status were examined， and saliva was determined by enzymelinked immunosorbent assay (ELISA) in IL-1， IL-17 and TNF-α. Results The expressions of ISQ， IL-1， IL-17 and TNF-α in three examinations were different， and the difference was statistically significant (P<0.05). In experimental group， the expressions of IL-1 beta， IL-17 and TNF-α were higher than those in the control group， and the difference was significant (P<0.05). In further analysis， the results of the experimental group in 3 months showed no statistically significant difference with the initial results of the control group (P>0.05). There was no significant difference in PD and ISQ between the experimental group and the control group (P>0.05). Experimental group and control group showed no statistical difference in initial stability (P>0.05). Conclusion In shorttime observation， after implant treatment the inflammatory factor levels of periodontitis patients decrease， and have good implant stability as the periodontal healthy patients. With occlusal load factors excluded， patients with mild to moderate periodontitis can also get good implant prognosis.

Objective To investigate the clinical application and effect of facial small incision combined with intraoral incision in the treatment of zygomatic complex fracture. Methods A retrospective study was performed on 15 cases of zygomatic complex fractures. They were operated through facial small incision and intraoral incision in our oral and maxillofacial surgery of our hospital. Results 15 cases did not appear related complications postoperatively， and all patients were followed up for 12 months. They had facial symmetry， the normal opening degree， the normal ocular movement and no diplopia. Conclusion The facial small incision and intraoral incision have hidden location. They can get the accurate and reliable fixation and the satisfactory results in the reduction for noncomminuted or nonold zygomatic complex fractures.

The postoperative complications of third molar extraction show aches and swellings. Under the standard tooth extraction steps， the concurrent infection of the mandibular wisdom tooth wound occurs occasionally. Osteomyelitis is a relatively rare complication of dental extractions. In this case， we review the diagnosis and management of two chronic mandibular osteomyelitis that develops from the extraction of a mandibular third molar tooth from Dec 2012 to Apr 2016.

Chronic periodontitis (CP) is a kind of chronic infectious diseases caused by plaque microbial， which can destroy the periodontal tissues and is the main cause of adults tooth loss in our country. It has been a research hotspot to explore the relationship between chronic periodontitis and systemic diseases with the development of periodontal medicine. Alzheimer disease (AD) is one of the most common causes of elderly dementia neural degenerative diseases. The key pathomechanism of CP and AD is inflammatory response triggered by various inflammatory mediators. This article will review the characteristics and the mechanism of the interaction between the two diseases.

The oral cancers are the most common tumors in the head and neck cancers.They can be developed from oral leukoplakia and other oral precancerous lesions. Due to the lack of biomarkers for early detection and risk assessment， more than 50% patients are often diagnosed at the late stage. The discovery of tumor markers for early diagnosis of oral carcinomas is becoming a hot research issue.The analysis method based on the metabolomics technology has the potential to come up with tumorassociated biomarkers. Metabonomics becomes a hot spot in the research of pathological mechanism， clinical diagnosis and prediction of diseases. This paper reviews the theoretical basis and techniques of metabonomics and its application in the metabolomics technology in its way into the biomarker discovery of the oral cancers and oral precancerous lesions.

Tongue has many complex structures， including lingualis， epithelia， taste buds and glands. Different characteristics are shown in different tissues with aging. Appearance， pathophysiology， muscle， and sensation are all degenerated in the tongue retrogression， even dysfunctions come into being. Tongue exercise and neuromuscular electrical stimulation are usually adopted to intervene in clinic. And new breakthroughs have been detected in fundamental research.

Respiration is a fundamental physical function for human beings. As the normal respiratory mode， nasal respiration can be changed into mouth breathing when nasal channels are obstructed. Mouth breathing can modify relevant hard and soft tissues of craniofacial structure， which finally results in craniofacial malformation. Animal models of nasal obstruction have been successfully set up on rats due to its unique advantages in the research on related mechanisms. Based on the theory of “Moss functional matrix”， condylar growth and development can be modified by surrounding micro environment， which is influenced by relevant craniofacial muscles. Postural variation of jaws induced by nasal obstruction can finally lead to craniofacial malformation via muscular mechanical transduction.

Inferior alveolar nerve injury (IAN) is the most common complication after mandibular orthognathic surgery. And it is also the issue that patients and surgeons are all concerned about. Morbidity of IAN injury is reported differently. Influence factors of its occurrence include anatomy and operation ones. As the most famous orthognathic operation， the operative skills of mandibular sagittal split ramus osteotomy have a close relation with IAN injury. The main symptom of IAN injury is anaesthesia of lower lip， chin， and gingiva in affected side. A small number of patients show continuous pain， pressing pain and suffering from occlusal pain or discomfort. This paper reviews pathogenic characteristics， influencing factors， clinical manifestations and therapies of IAN injury after orthognathic surgery and makes a brief summary.