Objective To study the characteristics of apoptosis in the condyles of osteoarthritic temporomandibular joints, and investigate its role in the pathogenesis of the disease. Methods Temporomandibular joint osteoarthrosis model of rabbits were created by partial resection of joint disc. The animal models~sacrificed in the 15^th day, the 1^st, the 2^nd month, the 3^th month, the 4^th month, the 5^th month, and the 6^th month chronologically. Then the pathological condyles were sectioned and detected with TUNEL method to investigate the apoptosis within the tissue. Results In the reactive repairing state of osteoarthmsis, the apoptosis cells mainly located in the superficial fibrous layer of articular cartilage. With the remodeling of articular cartilage and bone, the apoptosis cells gradually appeared in the proliferating layer, especially in the "clusters of chondrocytes" . Accompanied with the severe damage and lose of articular cartilage, the phenomena of apoptosis decreased in the lower zone of cartilage and increased in the hypertrophic and calcified zone.Conclusion There were abundant phenomena of apoptosis within the condylar car tilage of osteoarthritic temporomandibular joint. Abnormal proliferation and abundant apoptosis would disturb the regulation mecha- nism in the cartilage matrix and lead to the osteoarthrosis.

Objective To observe the expression changes of VEGF, iNOS and the level of MVD and NO during the evolution of Golden hamster cheek pouch carcinogenesis. To observe the pathological change during the evolution of Golden hamster cheek pouch carcinogenesis. To study the effect of NO in carcinogenesis in the pouch of hamster, and to investigate the effect of NOS in- hibiter I-NAME in interfering with carcinogenesis. Methods 90 golden hamsters were divided into three groups: 40 in experi- ment group, 40 in control group and 10 in blank group. DMBA was painted on hamsters cheek pouch in experiment and control group, L-NAME was given to hamster in experiment group at the dose of 0.02 ml/g. Hamsters were killed at 6,9, 12 and 16" weeks, respectively. The blank group was killed at the 16" week. SABC immunohistochemistry assay was used to detect the expression of iNOS, VEGF and factor    related antigen. MVD。measured. The level of NO was measured by Spectrophotometry . Results The difference between control group and experiment group at the 12' week and 16" week was observed. The difference of positive expression rate of iNOS in all group was significant and difference between blank group and control group~signifi- cant, The difference of positive expression rate of VEGF in all group was significant and difference between blank group and control group at the 12" and 16"week was significant; there was significant difference in every group MVD from the 6'" week control group to the 160' week control. There were significant difference among the control group, except the 6' week of experiment and control group. Conclusion There is an increased expression of iNOS and the level of N0, as well MVD during the evolution of Golden hamster cheek pouch carcinogenesis from slightly dysplasia to invasive carcinoma. NO plays an important role during the evolution of carcinogenesis, and iNOS inhibitor L-NAME can inhibit the carcinogenesis.

Objective To look for the best carrier for cultivating oral tissue engineered mucosa. Methods A series of mem- brane of scaffold materials of polycleelide-co-plycoclide (PLGA)were studied on their weight and biocompatibilityafter they had been implanted subcutaneously in rabbits for 1, 2 , 3 , 4 weeks respectively. Results PLGAI，II，III degraded completely in rab- bits after 2,3,4 weeks respectively. The other PLGA membrane degraded about 50% after 4 weeks. Histologically, the reactions of PLGAI，II，III with surrounding tissues were normal and membranes had a good biocompatibility. Conclusion The biode- grading rate of PLGA II is suitable for clinic practice. PLGA II~a promising carrier for oral tissue-engineered mucosa due to its excellent biocompatibility and biodegrading rate..

Objective This study~carried out to investigate the effects of insulin-like growth factor- II (IGF- II)and basic fibroblast growth factor (bFGF) on osteoprotegerin (OPG) secretion of periodontal ligament cells(PDLCs).Methods Healthy human premolars extracted for orthodontic reasons from 12一14 years old donators were obtained, and periodontal tissues were col- lected and cultured to obtain PDL cells. Primary or first passage PDLCs were cloned场means of limited dilutions. PDLCs with，- teoblastic phenotypes were characterized as follows; Alkaline phosphatase activity, collagen班production and bone-like nodules formation. IGF- I1 and bFGF~added into culture media and their effects on PDLCs proliferation and OPG secretion were ob- served. The OPG concentrations in cell culture supernatants were detected by sandwich ELISA. Living cell numbers were demon- strated by MTIT test. The average levels of OPG secretion场a single cell were calculated饰dividing OPG concentration with MTT- test result. Results Both IGF- II and bFGF upregulated the mtt values(P<0.05)，but IGF-II downregulated the opg/mtt val- ues(P<0.05)，whereas bFGF had no significant effect on opg/mtt values(P>0.05).Conclusion IGF-II enhances the pro- liferation of PDL cells but prohibits OPG secretion. Although bFGF has the same effect on the proliferation of PDL cells, it has no effect on OPG secretion. Before cytokines were used to enhance periodontal regeneration, their effects on local bone balance should also be studied.

Objective To study the effect of growth hormone (GH) on the proliferation and type II collagen secretion of chon- drocytes of mandibular condyle in rabbit in vitro .Methods Flow cytometry(FCM) and immunohistochemical technique were employed to observe the possible changes. Results 1TThe exogenic GH can enhance the proliferation and synthesis of DNA of the chondrocytes of mandibular condyle in rabbit in vitro.The suitable concentration of GH is 10 pg/ml厂[be synthesis of DNA reach- es the highest level after 12 hours, while the proliferation index (PI) hits the highest after 24 hours.② GH(10 J-g/ml) can stimu- late the secretion of type 1) collagen of the chondrocytes. Conclusion The exogenic GH can enhance the proliferation, the syn- thesis of DNA and the secretion of type n collagen of the chondrocytes of mandibular condyle in rabbit in vitro

Objective To investigate the variety of proliferating ability of umbilical endothelia《UE) transfected场plasmid pBABE-HYGR-hTERT. Methods UE~identified from two aspects: morphology and CD34 labeling technique. The plasmid ~obtained and identified场alkali splitting and gel electrophoresis. Uposomes~used to transfect UE. RT-PCR based telo- meric repeat amplification protocol(TRAP) assay~used to measure the telomerase activity of endothelia. Results LlE arranged as "cobblestone" and were positive of CD34 labeling. Endothelia transfected场pBABE-HYGR-hTERT(HC ) had an raised absor- bance of 0.889. The shape of growth。~of HC was similar to UE. But the absorbance of MTT test and the amount of HC were prior to UE at every measuring time and the amount of HC increased four times within 8 days ( P<0.05).Conclusion The transfection of pBABE-HYGRO-hTERT had greatly improved the prliferating abilities and activated the telemerase of UE.

Objective To explore the biological effects of tetracycline on cultured human periodontal ligament fibroblasts (HP- DLFs ).Methods Increasing concentrations of tetracycline(1,5,20,100,500,2 500卿ml) were added to the medium of cul- tured HPDLFs, respectively. After co-incubated for 2 days, cell morphology~observed under reverse microscope, meanwhile, cell proliferation activity~assayed using M TI', the total amount of protein~detected with Coumassie Bright Blue method and DNA synthesis~measured场3H-TdR. Results Over a concentration range of 1 to 100留ml, cells demonstrated a normal appearance, spindle or fusiform shaped. Moreover, at a concentration range of 20 to 100 pg/ml, tetracycline significantly en- hanced the proliferating act州ty and biosynthesis‘1-II〕I〕 Us(P<0.01).However, higher concentration (2 500 tcg/ml) not only changed cell morphology, but also significantly inhibited cellular activity. Conclusion The results suggested that proper doses of tetracycline could promote proliferation and biosynthesis of HPDLFs while higher concentrations of tetracycline had cytotoxic effect

Objective To compare the treatment effect on the prominence of profile in borderline cases between extraction and non-extraction treatment. Methods The sample consisting of 33 borderline cases based on the judgment of 5 orthodontic special ists was divided into three groups according to the treatment way selected the doctor in charge of the case. Three groups comprised 12 non-extraction cases, 13 four first premolars extraction cases and 8 four second premolars extraction cases. Stricture superimposition was used to measure landmarks displacements which reflect the change of profile prominence before and after orth odontic treatment using pretreatment mplane as a frame of reference. Results Only the prominence of upper and lower incisors showed statistically significance between the extraction and non-extraction treatments. There~no statistically significant differ- ence between the extraction of four first premolars and second premolars. Conclusion The main effect of extraction vs. non-ex- traction on profile of borderline cases is the prominence of upper and lower incisors, while their influences on upper and lower base bone and soft-tissue profile are not obvious.

Objective The purpose of this study was to evaluate the changes of masticatory performance of the cases wearing dentures and relative factors. Methods The changes of masticatory performance of the cases wearing dentures were studied before and after wearing场using the light absorption method and peanuts as test food. Restdts The mastication performance of the expenmental groups was predominantly lower than that of the control groups. The masticatory performance was gradually improved with wearing denture period increasing. Factors relating to the masticatory performance were age, number of occlusal units lost and the kind of denture, and the number of chewing etc. Conclusion The mastication performance of the experimental groups was dominantly lower than that of the control groups, but gradually improved with wearing denture period increasing. Varied factors af fect the masticatory performance of experimental groups.

Obective To determine the efficacy of 2% mepivacaine in conservative dentistry. Methods The patients who needed cavity preparation or access to pulp chamber received local infitration with 2% mepivacaine. Anesthesia time, anesthetic efficacy and cardiovascular system influences were assessed. 3 % lidocaine with epinephrine was served as control. Results In experiment group, the anesthesia effects were quicker and anesthesia duration was longer than that in control group. Doctors highly appreciated the anesthetic efficacy. Tow groups did not show any evident change in blood pressure and heart rate. Conclusion 2% mepivacaine is a safe and efficacious local anesthetic drug in conservative dentistry.

Objective This study aimed to establish the reference value range of healthy teeth mobility in Chinese youth. Methods 200 right side teeth of Han nationality of Chinese youths were measured so as to get the range of the parameters. Results All parameters of 14 teeth were achieved 'Me parameter of TM in mandibular incisor was the highest and in mandibular first molar lowest. Conclusion It is very significant to get and quant沂the healthy teeth's parameter range. Because they can be served as the heal听contrast when dentists diagnose the mobility. It also reflects the fact that lower the TM parameter is, firmer the tooth will be.

Objective To acquire teeth and prosthetic conditions of the elderly. Methods 1 166 patients of over 60 years old had been given prosthetic treatment, and the teeth conditions were analyzed. Results The average number of missing teeth~ 10. 25. The maxillary missing teeth were~than mandibular ones. The rate of missing teeth were as follows: maxillary teeth> mandibular teeth;molars>bicuspids>incisors>cuspid. II20 cases were treated with removable dentures. 59% of the re- movable partial dentures had free-end saddles. 46 cases were treated with fixed bridges. Conclusion The characteristics of pros- thetic patients in the elderly were as follows: a large number of missing teeth and free-end missing teeth, attrition of resident teeth, food impaction, existing-residual root and loosen teeth. Removable denture~the main method of the prosthetic therapy for the elderly patients. Fixed bridge~used when the patient condition was good. The cuspid, treated residual root and the third molar should be used for the retention and support of the prosthesis

Objective To investigate the clinical multimanifestation, diagnosis and treatment of non-Hodgkin's lymphoma in oral, maxillofacial and cervical regions. Methods 58 cases of non-Hodgkin's lymphoma in oral, maxillofacial and cervical re- gions were retrospected in this study. Results The manifestatiomof 58 cases was complicated. Non-Hodgkin's lymphoma treat- merit was synthetical therapy or chemical therapy. Conclusion Nat-Hodgkin s lymphoma in oral, maxillofacial and cervical re- gions had multi-manifestation and higher malignant, The final diagnosis relied on pathological examination. Both of sythetical ther- apy and chemical therapy were effective to non-Hodgkin's lymphoma in oral, maxillofacial and cervical regions.

Objective Cercon all-ceramic system was applied clinically for the first time to make all-ceramic crowns and bridg- es for the patients. The objective of this study~to evaluate the short-term follow-up results of this new system from both techni- cal and clinical aspects. Methods巧units of Cercon all-ceramic crowns and bridges were fabricated and applied to 5 patients, all the cases were followed at 1，3, 6 and 12 months' periods after cementation of the restorations. Results Cercon all-ceramic system demonstrate natural and esthetical appearance. No fracture, broken and color change were found. Conclusion The reli- ability of all-ceramic~and bridges made from Cercon system was greatly improved due to the strengthening effects of the zir- conia copings and substructures, and the indication of this system can be extended to long span posterior bridges. In addition, the better esthetics compared to PFM technique makes it a comparatively ideal all-ceramic system for crowns and bridges.

Objective To compare the fracture resistances of pulpless teeth restored with FRC(Fiber Reinforced Composite) posts and three kinds of resin core material. Methods A total of 42 recently extracted upper incisors were randomly divided into 3 groups. Group A~restored with prefabricated glass-fiber posts and Artglass polymer core;group B with prefabricated glass-fiber posts and Charisma composite resin core; and group C with prefabricated glass-fiber posts and AB composite resin core.In every group, the core material was processed by hot-press and non hot-press respectively. The posts size and shape were identical in the 3 groups. All teeth were fully covered with polycarbonate resin crowns. Fracture resistance was mesasured by applying point force at 130 degrees to the long axis of the teeth on an universal testing machine. Results Mean fracture threshold was 505.4 N 士42.0 N and 564.1 N士41.7 N in group A, 411.3 N土23.3 N and 315.3 N士19.1 N in group B and 358.4 N土36.1 N and 423.4 N土47.5 N in group C. In all groups, there was no posts fracture and polycarbonate resin crowns fragmentation. Condu- lion The composite restoration of FRC posts combined with resin core and resin crown can improve the fracture resistance of the pulpless roots. The strength of resin core material can be increased by hot-press methods.

Objective The purpose of this study is to evaluate the methods of treatment on Class 1)1 malocclusion with mandib- ular deviations, and clarify the principles of expansion and multiloop edgewise arch wire tecbnique.Methods 8 skeletal class IIl with mandibular deviations patients~selected (male 3, female 5, agedl2-18).They were all corrected with maxillary expan- sion and multiloop edgewise arch wire technique. Results In all~，molar relationships were class I, the overbite and the overjet~normal，and the upper and lower midline were harmony. Conclusion Mild and moderate skeletal classmwith man- dibular deviation can be corrected successfully场maxillary expansion and multiloop edgewise arch wire technique.

Objective The aim of this study is to investigate the changes of hard tissue profile in anterior-posterior and vertical direction in bimaxillary protrusion patients after orthodontic treatment. Methods A total of 24 bimaxillary protrusion patients (male 8, female 16)，aged from II. 2 to 29.0 (average 16. 9 years old)， were selected to be treated with standard edgewise tech- nique consisted of 4 first premolars extraction. Cephalometrics were taken before and after treatment. The changes of hard tissue profile were studied using the computer-aid X-ray cephalometric analysis. Results 1.The length of the maxillary and the mandi- ble increased significantly, but the anterior-posterior relationship of the maxillary and the mandible did not change significantly. 2. The anterior and posterior facial height increased significantly, but the ratio of anterior and posterior facial height and the angle of MP-FH which reflected the inclination of the mandible plane did not change significantly. 3. The height of the upper and lower first molar increased significantly along with the increase of the anterior and posterior facial height. 4. The height of the upper inci- ~increased significantly, but the height of the lower incisors decreased significantly. Conclusion The anchorage in anterior- posterior and vertical direction were controlled preferably, the patients did not manifest disadvantageous vertical growth trend.

Objective To evaluate the usage of moir>s interferometre in porcelain-fused-metal interfacial fracture mechanics. Methods Raster was produced on the surface of samples with different thickness of porcelain and metal in 5 groups. The stripes of“field and，field under different load were collected. Then the rupture tenacity Jc~calculated and the extensions of flaws were observed. Results Stress concentration appeared around the flaws under load conditions. The stripe became denser under ~load. The rupture tenacity Jc and the direction of flaw extension of each group were different. Conclusion Moir6 inter- ferometre can be used in the study of porcelain-fused-metal interfacial fracture mechanics and to prognosticate the direction of flaw extension.

Objective To examine the distribution of I1,1 genotypes among the people with Han nationality of different peri- odontal health status and to evaluate if there is an association between the genotype of II,1 and the severity of periodontitis. Meth- ods 271 subjects of Han nationality were selected, among them there~182~of chronic periodontitis and 89 subjects of periodontal healthy control. Full periodontal examinations~taken including full-mouth clinical attachment loss measurements, probing depths and bleeding on probing. DNA samples~obtained with buccal swabbing technique and were further analyzed for ILG1 genotype polymorphisms using PCR-RFLP-based method. Results The results showed a significant increase in the frequency of IL, 1 A-889/Nco I allele 2 , II.1 B+3953/Taq I allele 2, IIr1B-511/Ava I allele 2, IL, 1A-889 plus Ur1B-511 allele 2 and II, 1 B + 3953 plus IL- 1 B-511 allele 2 in patients with severe chronic periodontitis as compared with periodontally healthy controls. Conclusion Findings from this study bring into question the usefulness of the genotypes of allele 2 of II-IA-889, IL-IB-511 and IL- 1B+ 3953 as a method for determining the susceptibility of Chinese patients to chronic periodontitis. There is a possible rule of IIrlgene polymorphisms in the susceptibility to chronic periodontitis for some patients.

Objective To examine the effect of recombinant human bone morphogenetic protein-2(rhBMP-2) on NIH3T3 cells. Methods The NII-UT3 cells~cultured in DMEM with 50 ug/L rhBMP-2. the proliferation ability, alkaline phos- phatase (ALP) activity and osteocalcin (0C) quantity of NIH3T3 cells were investigated. Results The cells showed decreased proliferation ability but enhanced ALP activity and OC quantity. Conclusion 50 1rg/L rhBMP-2 can transform NIH373 fibroblasts to osteo-like cells.

Objective To detect and type human papilloma virus (HPV) in the warts of oral mucosa from HIV-positive patients, and better understand the biological characters of these oral warts. Methods Polymerase chain reaction MR)~used to detect and type HPV infection by concensus HPV primers Gp5+/Gp6+ and specific HPV primers ( HPV6/II，16, 18, 31， 33) in 34 cases of oral mucosa warts from HIV-positive patients. Results The HPV infection rate was 88.2% by consensus HPV primers Gp5十/Gp6十;the HPV infection rate of HPV6/II，16, 18, 31 was respectively 47.06%，11.67 %;2.94%，and 5.88% by specific HPV primers. Conclusion Most lesions of oral warts from HIV-positive patients are associated with the infection of HPV. The low risk HPV6/11 infection is more common than the high risk HPV16, 18, 31.

Objective To investigate the relationship between condylar marrow signal abnormalities and temporomandibular joint internal derangement (TMJID).Methods Oblique sagittal Tl weighted MR imaging at closed and open mouth and Oblique sagittal 12 weighted MR imaging at closed mouth were obtained from 88 joints of 44 patients suffering from TMD. Condylar marrow signal abnormalities were reviewed and classified into bone marrow edema pattern (hypo intense T1，hyperintense 712)，sclerosis pattern (hypointense TI and hypointense 12) and combined edema and sclerosis pattern. Results Of 88) joints，13(14.8%) joints showed condylar marrow signal abnormalities , among which II belonged to edema pattern and, 1 was sclerosis pattern and the other was the combined pattern. Of 13 joints with condylar marrow signal abnormalities, 11(84.6%)had TMJID. Of 75 joints with normal marrow signal, 25(33.3%)joints had TMJID. There was significant correlation between condylar marrow signal ab- normalities and TMJID(P<0.05).Condusion Disc displacement is one of the factors inducing condylar marrow signal abnormalities. The pathological process from disc displacement to osteonecrosis requires further study.

Objective To explore the feasibility of bovine pericardium used as a material for guiding bone regeneration. Methods 1 cm x 1 cm x 0.5 cm defects were created on both buccal sides of the mandibles of II dogs. One side was covered with Gl- utaraldehyde (GA) cross-linking bovine pericardium; no membrane covered side was used as control. The animals were sacrificed in 2 weeks, 4 weeks, 8 weeks and 16 weeks after operation to observe the repair of the bone defects. Results 0Wounds healed well in 10 dogs. Meanwhile, wounds in dogs of 16 weeks group healed badly and severe inflammatory response was found in bovine pericardium treated area.②The pericardium can be maintained in vivo for 16 weeks without absorption, there were only mild infammatory cells invading.③ The bone defects covered with bovine pericardium repaired better than control groups significantly. Conclusion (I)GA bovine pericardium have the effect on guiding bone regeneration in the repair of dog experimental bone defects and it is possible that the bovine pericardium will be used as a new kind of GBR material;②GA bovine pericardium has good biocompatibility.

Objective The aim of this experiment is to know whether active orthopedic appliance is rationale to do presurgical treatment and seek some regularities. Methods Laser scanning confocal microscopy and triple fluorochrome labeling in bone were used to observe and study detailed changes occured in compressed suture systematically. Results Widened suture and broken fibres between the adjoining bones was observed at the 3ed week postoperatively. At the 3th week hyperplasia of organic tissue com- portents was also seen. At the 6 and 9th week there were no apparent differences among all groups no matter whether in control group or experimental groups. Conclusion Retarding injury of compressed suture and surrounding tissue hyperplasia exists. With  growth and development wounded suture will gradually assimilate to control group structurally and functionally.