The popular theory and technique of cleft lip repair has been classified to the theory and technique of cleft lip repaired under functional matrix surgery, the theory and technique of cleft lip repaired under reduction of anatomy marks as well as the theory and technique of cleft lip repaired under analysis result of geometry from previous cleft lip repaired. The characteristic of theory and technique to each class of method has been introduced, which is a new way to understand and hold the method of cleft lip repair.

Objective To investigate the efficacy of S- methylisothiourea（SMT） for treatment of temporomandibular joint osteoarthrosis（TMJOA）of goats. Methods Nine purebred black goats were randomly devided into three groups： Normal control group, control group and experimental group. The upper compartments of both temporomandibular joint of the goats in control group and experimental group were injected with collagenase only once to induce osteoarthrosis. Normal control group received no treatment. The upper compartments of both TMJ were injected with 0.5 mL of normal saline, and experimental group, the upper compartments of both TMJ were injected with 0.5 mL ofSMT. The TMJ of goats was examined with scanning electron microscopy and microscopy after sacrificed. Results Examined in light microscopy and scanning electron microscopy, normal control group showed normal performance, the control group showed severe osteoarthrotic changes in the temporal surface, disk and condyle, while the experimental group showed improvement of different degree. Conclusion On the basis of 3 - month following- up study, repeated intra- articular injection of SMT may play a role in inhibiting TMJOA progression.

Objective To study the expression of inducible nitric oxide synthase（iNOS） in cartilage of temporomandibular joint osteoarthriti（TMJOA）, and to evaluate the role of iNOS in the progression of TMJOA. Methods The goats were used and TMJOA was induced by injection of collagenase in upper joint space. The joints were obtained and were investigated by using immunohistochemistry at 2, 4, 12, 24 weeks after injection. Results Almost no expression of iNOS in normal cartilage of TMJ. In the diseased joints, strong or definite iNOS reactivity was expressed. Conclusion iNOS plays an important role in the progression of TMJOA.

Objective The purpose of this research was to study the genetic diversity of F- ATPase subunit gene uncEBF derived from Streptococcus mutans（S.mutans）clinical isolates, furthermore to investigate the relationship between the genetic diversity of F- ATPase and S.mutans aciduric ability. Methods 38 S.mutans strains included 18 high acid tolerance strains and 20 low acid tolerance strains. Gene uncEBF of these isolates were amplified with specific primers from S.mutans genomic DNA, and the PCR products were analyzed by RFLP and sequenced. SPSS 11.0 statistic software assayed the results. Results It was testified that two genotypes A and B of PCR- RFLP were revealed when digested with AluⅠand DdeⅠdigested fragments of uncEBF displayed two different patterns C and D. Fisher exact two- tail test showed that the distributions of A and B genotype strains with different acidurance were different（P<0.05）, and the proportion of A genotype strains from high acidurance group was higher than that from low acidurance one. Some of these amplified uncEBF genes from different genotype were sequenced and testified that there existed variation of AluⅠand DdeⅠrecognized sites. Conclusion This study indicated that uncEBF gene of S.mutans F- ATPase obviously exhibited genetic diversity.

Objective To investigate the degradation of artificial basement membrane（matrigel） co- cultured with oral carcinoma- associated fibroblasts （CAFs） and its possible mechanism. Methods CAFs and normal fibroblasts （NFs）were incubated on matrigel for 24, 48, 72 h. Equivalent amounts of conditioned medium were collected and assayed for total protein, hydroxyproline and matrix metalloproteinase- 2（MMP- 2）, matrix metalloproteinase- 9（MMP- 9）activity by gelatin zymography. Results Oral CAFs were superior to oral NFs in total protein and hydroxyproline density, CAFs present more pro -MMP - 2 and activated MMP - 2. Conclusion CAFs were superior to NFs in degradation of matrigel. CAFs might play a key role in the reconstitution of extracellular matrix and the progression of tumor.

Objective To establish a salivary sediment malodor system, and to evaluate the effect of several kinds of bacteria dedicated to the halitosis formation，hence to identify halitosis- correlated bacteria. Methods The proportion of the supernatant and sediment, gained from centrifugal whole saliva, was adjusted to establish a salivary sediment malodor system incubated in facultative aerobic environment under 37 ℃ for 7 hours. The halitosis indexes in both gaseous phase and liquid phase were checked by direct sniffing, and volatile sulphur compounds（VSCs） and pH were determined by halimeter and glass electrode respectively between hours to evaluate the malodor formation. The suspended fluid of suspicious halitosis- correlated bacteria and non- halitosis- correlated bacteria and water control were introduced into the salivary sediment system incubated for 1 hour. The five groups were incubated in facultative aerobic environment under 37 ℃ in the residual hours. The halitosis indexes, VSCs and pH changes were recorded between hours. Results The salivary sediment malodor system can simulate the metabolism of halitosis formation to produce halitosis. The odors of the suspicious halitosis - correlated bacteria introduced groups were higher than the non- halitosis- correlated bacteria and water control group. Conclusion With its simple but fundamental manipulations, incubated whole saliva is a powerful model for study of the metabolism of the oral mixed microbial flora, malodor formation, and other oral diseases- related processes.

Objective To evaluate the effects of fluorid on morphology change in enamel and dentin during tooth bleaching. Methods The study population consisted of twelve patients who required the extraction of first premolars for orthodontic reasons. Twelve participants were divided into three groups： bleaching with NaF - treated group， bleaching- treated group and control group. Immediately after bleaching treatment, all teeth were extracted and prepared for scanning electron microscope（SEM）. Morphologic observations were carried out with SEM. Results In the bleaching- treated group, mild demineralization was observed on the surface of enamel and collapse of collagen scaffold was also observed on the longitudinal section of dentine. The diameter of dentinal tubule was not uniform due to peritubular dentine was demineralized. In the bleaching with NaF- treated group, the demineralization of enamel and dentin were reduced and some diameter of dentinal tubule were smaller than bleaching- treated group. Conclusion Fluoride can reduced the demineralization of enamel and dentine obviously, which may be applied as a therapeutic tool for sensitivity induced by tooth bleaching.

Objective To provide experimental evidence for the exploitation of cinnamaldehyde as a kind of root canal disinfectant through studying the effect of cinnamaldehyde on endotoxin in root canals. Methods This experimental model of periapical periodontitis was established with Wistar rats. The 75 rats were divided randomly into 3 groups: Group of cinnamaldehyde, group of formaldehyde cresol formocresol, group of physiological saline. The level of endotoxin was measured by quantitative chromogenic tachypleus amebocyte lysate method before and after sealing the drugs in the root canal. Results The level of endotoxin in the group of cinnamaldehyde and formaldehyde cresol formocresol decreased obviously（P<0.05）, and the difference between them was of no significance（P>0.05）, the group of physiological saline was of no significant difference（P>0.05）. Conclusion Cinnamaldehyde can decrease the level of endotoxin obviously.

Objective To detect the distribution of fimA genotype of P.gingivalis in periodontally healthy adults and chronic periodontitis patients, and to investigate the relationship between the prevalence of fimA genotype of P.gingivalis and periodontal health status. Methods Subgingival plaque samples were collected from 136 periodontally healthy adults and 115 chronic periodontitis patients. The occurrence of P.gingivalis was determined by P.gingivalis 16S rRNA PCR. Distribution of fimA genotype was assessed in P.gingivalis positive samples by PCR using primers pairs homologous to the different fimA genes. Results P.gingivalis was detected in 22.1% of the healthy subjects and 81.7% of chronic periodontitis patients. A single fimA genotype was detected in most subgingival plaque samples. In P.gingivalis- positive healthy adults, the most prevalent fimA genotype of P.gingivalis was type Ⅰ fimA. In contrast, a majority of chronic periodontitis patients carried type Ⅱ fimA, followed by Ⅳ fimA and Ⅰ b fimA. The univariate analysis illustrated that chronic periodontitis was associated with occurrences of typeⅠ fimA（OR= 0.97）, Ⅰb（OR=13.26）, Ⅱ（OR=36.62）, Ⅲ（OR=4.57）, Ⅳ（OR=22.86）, andⅤ（OR=1.19）. Conclusion Ⅱ fimA genotype of P.gingivalis followed by Ⅳ and Ⅰ b were an important virulence factor that may account for the pathogenesis of chronic periodontitis, suggesting an increased pathogenic potential of these types.

Objective To investigate the effects of occlusal rehabilitation on chewing patterns of patients with extensive tooth wear. Methods 29 patients with severe tooth wear were selected and divided into two groups: GroupⅠwith complete posterior tooth support（15 cases）and group Ⅱ with one- side or both side posterior support lost（14 cases）. 15 normal old persons were also selected as control group. The surface electromyography（EMG） of masseter（MM）, anterior temporalis（TA） and posterior temporalis（TP） during chewing movement were recorded in the stage of pre- treatment, 1 month after temporary restoration and 1 month after permanent restoration. The EMG activity, total cycle duration（TCD） and ratio of activation period to relaxation period（AP/RP） of chewing cycles were measured and compared. Results 1）Before treatment, the TCD of these two groups were longer than normal group, but the differences were not significant（P>0.05）. All of the AP/RPs of MM, TA and TP in group Ⅱ were significantly higher than that of normal group（P<0.01）, and EMG activity of TA of group Ⅱ was significantly lower than normal（P<0.05）. 2）After temporary restoration, the TCD of both groups were slightly shortened, while the AP/RP of these two groups were significantly decreased. EMG activities of MM and TP in groupⅠwere both significantly lower than that in pre- treatment stage. 3）After permanent restoration, the TCD of groupⅠwere significantly lower than that in temporary restoration stage（P<0.01）. In group Ⅱ, the TCD was continuously slightly shortened, while the AP/RP were significantly lower（P <0.01） and EMG activities were significantly higher（P<0.01）than that in the temporary restoration stage. Conclusion Occlusal rehabilitation could obviously change the chewing patterns and the EMG activities of patients with severe tooth wear.

Objective To find a way to having higher bond strength on mottled enamel. Methods Sixty mottled enamel first bicuspid teeth extracted from fifteen patients needing orthodontic force were prepared and divided into four groups. Group A was routine acid etched, group B was air abraded, group C was etched by clearfil liner selfetching primer, group D was air abraded and then etched by clearfil liner self- etching primer. Next the bond and resin were used. The shear bond strength was observed and compared. The data were analysed by SPSS 11.5 statistical package. Results The shear bonding strength of group A was（2.247±0.261）MPa, group B was（5.374±0.469）MPa, group C was（4.345±0.401）MPa, group D was（5.791±0.636）MPa. The strengths of four groups were significantly different（ P<0.01）. The adhesive remnant index（ARI） scores of the four groups had no significant difference. Conclusion In clinic, using air abrasion surface preparation technique is an acceptable way to enhancing the shear bond strength before sticking the orthodontic bonding on dental fluorosis.

Objective To localize the gene（s） responsible for autosomal dominant hypocalcified amelogenesis imperfecta in a Chinese family. Methods A Chinese family which was diagnosed as autosomal dominant hypocalcified amelogenesis imperfecta（AI）was studied. Venous blood from nineteen family members was collected and genomic DNA was extracted from the blood. Eight short tandem repeats（STRs） spanning five hereditary AI candidate genes were selected and linkage analysis between the genetic markers and the disease loci was performed. Results Genotype of the eight STRs were acquired, the linkage analysis result can not support that the gene for AI pedigrees was linked to ENAM, AMBN, TUF1, KLK4 or MMP- 20. Conclusion The results can not support all proposed candidate gene regions as causal for autosomal dominant hypocalcified AI in this family. These linkage findings provide further evidence for genetic heterogeneity among families with autosomal dominant AI and indicate that, at least, some forms of autosomal dominant AI are not caused by a gene in the five most commonly reported AI candidate genes.

Objective To evaluate the effect of non- surgical treatment with Florida probe. Methods 100 patients with periodontitis were chosen in the study, who accepted periodontal non- surgical treatment. Pocket depth（PD） and attachment loss（AL） of all patients were recorded with Florida probe before and at the first month after periodontal non- surgical treatment. The detecting sites were mesialbuccal, buccal, distalbuccal and lingual. All teeth were divided into four groups: Anterior teeth group, premolar group, molar group and all teeth group. The therapeutic efficacy of PD and AL of groups, sites and different pocket depths was compared. Results In all four groups, PD, AL before and after one month periodontal non- surgical treatment demonstrated significant differences（P<0.05）. It was found that the short- term effect of periodontal non- surgical treatment resulted in significant resolution of gingival inflammation and pronounced reduction in pocket depth and gain of attachment loss in all patients. Anterior teeth had better therapeutic efficacy than premolar and molar. The PD pronounced reduction and gained a significant difference between PD<5 mm and PD≥5 mm（P<0.05）, but not with AL（P>0.05）. Sites had no significant difference（P>0.05）. Conclusion Florida probe evaluates periodontal conditions accurately and objectively. Periodontal non- surgical treatment allowed for favourable treatment response on periodontitis, anterior teeth had a good therapeutic efficacy, different sites had the equal therapeutic efficacy.

Objective To compare the apical microleakage of Vitapex（calcium hydroxide based paste） with that of AH- plus and zinc oxide eugenol sealer when used with laterally condensed gutta percha obturation technique. Methods One hundred single rooted human anterior teeth were instrumented and randomly divided into three experimental groups（A, B, C） of 30 teeth each and two control groups（D, E） of 5 teeth each. Group A was filled with laterally condensed gutta- percha using Vitapex as sealer. Group B was filled with laterally condensed gutta - percha using AH- plus as sealer. Group C was filled with laterally condensed gutta- percha using zinc oxide eugenol as sealer. Group D was the positive control. Group E was the negative control, which were coated with nail polish to entire root surface. Teeth were then suspended in 2% methylene blue. After this, teeth were demineralized dehydrated  and cleared. Linear dye penetration was determined under stereomicroscope with calibrated eye piece. Results The mean dye penetration for group A, B, C were respectively（0.57±0.56）mm, （0.79 ±0.96）mm and（1.07 ±1.12）mm. Group D demonstrated maximum dye penetration. Group E showed no dye penetration. There was no statistically significant difference between group B and group C（P>0.05）. However, there was statistically significant difference between group A and group B, C（P<0.01）. Conclusion This study showed that Vitapex used as endodontic sealer material are better than AH- plus sealer and zinc oxide eugenol sealer.

Objective To study the clinical effectiveness of implanting miniscrew serving as anchorage instead of molars in treating maxillary dental arch crowding and protrusive patients mandibular molars complete missing. Methods Eight adult patients aged from 22 to 38, whose maxillary dental arch were crowding and protrusion, with mandibular molars missing were chosed. At the missing side, a miniscrew was implanted on the buccal surface, 11- 13 mm away from the distal end of the second premolar. After implanting, a self- made miniscrew traction cap was attached to its supergingival section by keyway retention. Premolars and anterior teeth were tracted in turn to distal end. Intermaxillary traction Ⅱ was made necessarily on the traction cap. Results Successful results were acquired after treating together with normal overbite, overjet and right occlusion relation. It took 24 months in the longest course, 15 months in the shortest course and 20.8 months on average. Conclusion The implanting miniscrew anchorages could be used in maxillary dental arch crowding and protrusive patients with single molars complete missing.

Objective To study the characteristics of thyroglossal tract cyst epidemiology and summarize how to improve the operation therapeutic effect. Methods The clinic appearance, the pathological characteristics and the therapeutic effect of the 60 thyroglossal tract cyst cases were analyzed. Results Thyroglossal tract cyst mostly occurred in children and teenagers. The incidence of female patients was more than that of male patients. Most of thyroglossal tract cyst located in the middle line of the neck and were explored tubular - objects and fibroropes. The histopathological feature was variform. Conclusion The clinical appearance and pathology charaeristic of thyroglossal tract cyst are variform. Thyroglossal tract cyst may be recurred easily if it is not operated well.

Objective To compare the effectiveness of two oral health education program among middle - school students on improving oral health status. Methods Three middle schools randomly chosen from the urban district of Deyang city were divided into three groups: teacher- based group （Group T）, parents- based group （Group P）, and the control group（Group C）. Oral health education sessions were conducted for teachers（Group T） and parents （Group P）of these children. Students obtained oral health knowledge through their teachers（Group T）or their parents （Group P）, brushed their teeth twice daily. No oral health education session was carried out in the control group. The effectiveness of oral health status in three groups were compared after 3 months. Results The debris index （DI）, calculus index（CI） and gingival index（GI） of group T obviously decreased after 3 months（P <0.05）. The decreasing of DI and CI of group P were not significant, and the GI of group P obviously increased after 3 months （P <0.05）. Compared with group P and group C, DI, CI, and GI of group T were statistically lower（P <0.01）. Conclusion Compared with parents- based oral health education, teacher - based oral health education has a better effect on improvement of the oral health status among middle- school students.

Objective To discuss the diagnosis and treatment of condylar resorption of unknown reason. Methods The clinical data including the records of history, physical examination, radiography and laboratory of ten patients were studied. Ten patients consisted of 8 females and 2 males（mean age 24.1 years, range 19- 31 years）had common clinical features including anterior open bite, posterior occlusal prematurities and Class Ⅱ malocclusion. Images demonstrated a small and short condyle with abnormal shape, usually accompanied by the developmental insufficiency of the ramus and condyle. The condylar, even the ramus, showed the black marrow signal on MRI images. Four patients were treated by condylar reconstruction with costochondral graft after condylectomy under the supervision of endoscope. Two patients were treated by reduction and repair of disk. Four patients didn′t accept any treatment. Results Four patients treated by condylar reconstruction with costochondral graft showed structures with the size and shape morphologically similar to normal joint and achieved a stable occlusion after follow- up of 6- 18 months. Two patients treated by reduction and repair of disk didn′t show significant change of open bite and remodeling of condyle after follow- up of 4- 6 months. Conclusion The diagnosis of condylar resorption of unknown reason can be achieved based on the physical examination and radiographical images. The condylar reconstruction with costochondral graft after condylectomy is feasible.

Objective To investigate the treatment of perioperative period on maxillofacial patients with diabetes. Methods The retrospective analysis was taken on clinical data of 24 cases of maxillofacial patients with diabetes. Results All patients recovered without severe complications by controlling blood sugar during whole stage and preventing infection with antibiotics after surgery. The wounds in 21 cases healed in 10- 14 days after the operations and that didn′t in 3 cases. With the treatment on local wounds, the wounds in 3 cases healed in 14- 28 days after the operations. Conclusion It′s the treatment principle of maxillofacial surgical patients with diabetes to monitor the levels of blood glucose on time, to control the levels of blood glucose rigorously at the whole stage and to prevent complication.

Objective To provide content- measuring evidences for establishing the quality criteria of dexamethasone acetate ulcer pasta. Methods Content of dexamethasone acetate was assayed by the isonicotinyl hydrazine（INH） colorimetry. Results The good linear range was 6 - 16 μg/mL（r=0.999 1）. The average recovery of dexamethasone acetate was 98.9%, and relative standard deviation was low than 1%（n=5）. Conclusion It is easy, convenient, accurate and dependable for INH colorimetry to determine the content of dexamethasone acetate.

Objective To study the oral normal bacteria adherence on polymethyl methyacrylate（PMMA）containing silver - supported silicate inorganic antibacterial, and the growth inhibitory concentration of silver - supported silicate inorganic antibacterial to normal oral bacteria were also investigated. Methods A certain volume of normal oral bacteria was inoculated on the BHI plate containing different dilution of silver- supported silicate inorganic antibacterial, then the growth of the bacteria was investigated by light microscope and biochemical methods; the oral bacteria plaque model in vitro was used to evaluate the adherence of 4 species normal oral bacteria mixture on the surface of PMMA which containing silver- supported silicate inorganic antibacterial in the proportion of 5% or 10%. Results The growth of normal oral bacteria was inhibited effectively by silver- supported silicate inorganic antibacterial within the concentration of 8%, and the growth of Porphyromonas gingivalis and Candida albicans were inhibited at concentration from 1.25% to 2.50%，but the PMMA containing silver- supported inorganic antibacterial could not prevent the adherence of bacteria within a period of 16 days. Conclusion Silver- supported silicate inorganic antibacterial has effectiveness on inhibiting the growth of normal oral bacteria，but could not prevent the adherence of oral normal bacteria mixture.

Objective To study the association of transforming growth factor- α（TGF- α） gene polymorphism and environment factors with nonsyndromic cleft lip with or without cleft palate（NSCL/P） in Han nationality. Methods Data related to infection, drug intake and folic acid supplement during pregnancy were gained through investigation of mothers. Polymerase chain reaction combined with restrict enzyme digestion was used to detect the target gene variation in 199 patients with NSCL/P and 203 healthy controls. Analysis was carried on the genotype and infection,drug intake and folic acid supplement. Results The C2 allele frequency in patients with NSCL/P was significantly higher than that in healthy controls. There was a significant increase of patients with NSCL/P in pregnant women exposed to infection, drug intake and folic acid deficiency. There was an interaction between C1C2 genetype and infection, drug intake and folic acid supplement. Conclusion TGF- α gene polymorphism is associated with NSCL/P. Infection, drug intake and folic acid supplement during pregnancy were associated with the occurrence of NSCL/P. Individuals containing C2 allele were more sensitive to infection, drug intake and folic acid deficiency.

Objective To investigate the effects of time varied stress on the proliferation of myoblast in rats and provide the basic experimental data for the remodeling of tissue in functional orthopaedics. Methods Based on the pulsatile mechanical system founded, this study loaded different strain（2.5, 5.0, 10.0 kPa） to the myoblast of lateral pterygoid muscle. The proliferation of myoblast was detected by 3H- TDR. Results After 6 hours under time varied strain, the significant proliferation of myoblast（P <0.05） was observed, and the 5.0 kPa group expressed the best proliferation. After 12 hours under time varied strain, all groups expressed a better proliferation. Meanwhile, the lower frequency（0.40 Hz） had the bigger effect on the proliferation more than in the higher frequency（1.25 Hz） under the same time varied strain. Conclusion The frequency of time varied strain had also the important influence on the proliferation, the lower frequency（0.40 Hz）had the bigger effect on the proliferation more than in the higher frequency （1.25 Hz） under the same time varied strain. In the certain period of time and certain magnitude of time varied strain, the proliferation of myoblasts rised.

Objective To examine the compositions of those adhesion modes between luting cements and canal dentin, and to evaluate the dentin- cement- post interface by Laser- Raman spectroscopy. Methods Three representative luting cements（zinc phosphate, glass ionomer and resin cements）, two kinds of prefabricated posts（titanium and fiber - glass）, six extracted intact human maxillary anterior teeth were used canal dentin after endodontic treatment. Laser- Raman spectroscopy measure of cement, post and canal dentin before and after luting together. Results There are no evident Raman spectra change cross the ZPC/dentin interface and glass ionomer/dentin interface, while cross the resin/dentin interface and resin/glass fiber post interface can be seen special Raman spectra. Conclusion Laser- Raman microspectroscopy is a useful analytical technique for evaluation interface between dentin and luting cements. Resin cement may interact with dentin and glass fiber post.

Objective To evaluate mechanical properties of zirconia toughened composite alumina（ZTCA） ceramic used for dental application, characterize the effect of different zirconia contents on mechanical properties of ZTCA. Methods Dental alumina ceramic powder was prepared by sol- gel method, and four groups of ZTCA powders with different zirconia contents were prepared via surface- induced precipitation method. All five groups of powders were dry- pressed and then sintered to make standard specimens for mechanical tests. The flexural strength and fracture toughness of these specimens were evaluated, and the fractography was characterized by scanning electronic microsc pe （SEM）. Phases of ZTCA were also determined using X- ray diffraction（XRD）. Results It was found that the flexural strength of ZTCA ceramics increases with ZrO2 content up to 30%, and decreases thereafter. ZTCA specimens containing 30% ZrO2 show the highest flexural strength, and the corresponding fracture toughness was 1.85 MPa·m1/2. The XRD results of ZTCA ceramics showed the phase constituents of α- Al2O3, t - ZrO2 and a small amount of m- ZrO2. Conclusion The strengthening and toughening mechanisms of ZTCA depend on ZrO2 content. In the range of 15%～ 30% ZrO2, the stress- induced phase  transformation toughening mechanism is dominant, while microcrack and deflection exist as the additional toughening mechanism when ZrO2 addition amount is above 30%.

Objective To investigate the changes in expression of gelatinase（MMP- 2, MMP- 9） in young rat condylar cartilage during functional mandibular advancement. Methods Sixty male 5- week old SD rats were divided into experimental and control groups. The mimic functional appliances were used in experimental group rats. The animals were sacrificed after 1, 2, 4 weeks. The immunoreactivity of gelatinase was detected by immunohistochemistry. Results In normal mandibular condylar cartilage, the immunoreactivity of MMP- 2 was rather strong, the immunoreactivity of MMP- 9 was very weak. Following functional mandibular advancement, the expression of MMP- 9 was significantly increased（P<0.01）, but immunoreactivity of MMP- 2 had no significant changes. Conclusion Gelatinase plays an important role in the adaptive remondling of young rat condylar cartilage during functional mandibular advancement.

Objective Through orthodontic tooth movement in the pregnant and non- pregnant rats, to investigate the osteopontin（OPN）mRNA expression pattern in the periodontal tissues, and to probe its possible roles in or - thodontic periodontal remodeling. Methods Fixed appliances were used to mesially move the rats′maxillary first molars. In situ hybridization method was used to detect the expression changes of OPN mRNA in periodontal tissues. Results Compared to the non- pregnant rats, the expression of OPN mRNA in periodontal cells of the pregnant rats was more intensive. During the gestational period, the expression intensity had significant difference at different pregnant stages. The highest expressions occurred at the mid- pregnant stage, less at the late- stage and lest at the early- stage. Conclusion Under the pregnant state, the expression of OPN mRNA in periodontal tissues may be up- regulated by increased serum progesterone level.

Systemic thalidomide has good effect on refractory chronic discoid lupus erythematosus（CDLE）whereas topical regimen of it has not been reported previously. In this paper, a case of refractory CDLE cured with topical thalidomide in clinic was reported and the feasibility of topical therapy was reviewed.

Metastasizing pleomorphic adenomas without histological evidence of malignancy have rarely been reported. A case of 30- year- old woman with a mass which showed a benign pleomorphic adenoma appearanced histologically in the left submandibular gland and right supercollarbone respectively was described. Eight years ago, the patient suffered from pleomorphic adenoma of the left submandibular gland. It revealed histopathologic features consistent with the recurrent and metastasizing tumor. The clinic pathological features, possible mechanism and prevention approach of metastasizing pleomorphic adenoma were discussed based on previously reports in the literature.

Proliferative verrucous leukoplakia（PVL） is a particular form of oral leukoplakia clinically characterized by chronic proliferation, multiple occurrence, and intractability. It is seen mostly among elderly women and often involves bucca, palate, gingiva and tongue. Its canceration rate is very high. This article reports a case of a middleaged woman with progressive PVL which became focally malignant who complained about buccal and palatal exophytic white patches, and discusses the possible pathogenic mechanism, diagnosis, treatment, prognosis of PVL and differentiation between PVL and other types of oral leukoplakia by way of reviewing relevant literature.