Objective:To study the masseter motor evoked potential(MEP)in patients with sleep bruxism(SB)and in healthy con-trols.Methods:30 subjects with SB and 30 healthy controls were included.MEPs were obtained by transcranial magnetic stimulation (TMS).Tests were done during daytime when the subjects were awake.The data were statistically analysed.Results:In the patients AMT was 55(52,55)%,latency of c-MEP (6.7 ±1.3)ms,the amplitude of c-MEP 0.19(0.15,0.29)mV,latency of r-MEP (2.3 ±0.4)ms,the central conduction time(CCT)4.4(3.3,5.2)ms.In the control subjects AMT was 52(52,55)%,latency of c-MEP (6.4 ±0.7)ms,the amplitude of c-MEP 0.23(0.17,0.28)mV,latency of r-MEP (2.4 ±0.4)ms,CCT 4.0 (3.4,4.4) ms.No significant difference was found between the 2 groups in the measurements evoked by TMS.Conclusion:The MEP after TMS in patients with SB is similar to that of healthy subjects,indicating that the excitability of the cortical motor system is not changed in bruxism subjects,at least when evaluated by TMS.

Objective:To study the influence of all-trans retinoic acid (atRA)on craniomaxillofacial development of C57 mice. Methods:Pregnant C57BL mice were divided into 4 groups(n =5)at gestation day (GD)1 0.Mice in three atRA-induction groups were given atRA of 60,80 and 1 00 mg/kg,respectively.The mice in control group were given the equivalent volume of corn oil.All pregnant mice were sacrificed at GD1 9 and the embryos were collected.Stereo microscope was used to observe the craniomaxillofacial morphology.Standardized radiographs were taken and cephalometric analysis was performed.Results:The embryonic body length and body mass of control group surpassed those of 80 and 1 00 mg/kg atRA groups(P <0.05,P <0.01 ).atRA induced craniomaxillofacial malformations and maldevelopment.The mice induced by atRA exhibited a shorter mandibular body and more retrusive position of max-illary and mandibular(∠NAK and ∠NBD)when compared with their norm(P <0.01 ).Significant decrease in craniofacial length (Op-Rh)was observed in all atRA-induced groups(P <0.01 ).Decreases in cranial vault height(Fp-Os)and cranial vault length(Pa-Na)dimensions were observed in 80 and 1 00 mg/kg atRA groups(P <0.05,P <0.01 ).Conclusion:Exogenous atRA dose-depend-ently induces retardation of craniomaxillofacial morphology in embryo of C57BL mice by inhibition of the sagital and vertical dimension development of the bone.

OBJECTIVETo investigate the effects of all-trans retinoic acid (atRA) on the function of bone morphogenetic protein receptor 2 (BMPR2) expression in embryonic palate.

METHODSCleft palate mice model was established by atRA. On gestation day (GD) 15 and GD 17, the pregnant mice were killed to obtain the embryos from the uteri. The embryonic palates were stained with hematoxylin-eosin, and the remaining sections were used for the immunohistochemistry of BMPR2 detection. Reverse transcription-polymerase chain reaction was performed to detect the expression levels of Bmpr2 mRNA.

RESULTSIn the atRA-treated group, short extensions and failure to fuse with each other were observed. The positive expression of BMPR2 was detected in developing palatal process from GD 15 to GD 17 in the control group. Compared with those of the control group, BMPR2 protein and Bmpr2 mRNA decreased in the atRA-treated group (P<0.05).

CONCLUSIONThe treatment of pregnant mice with retinoic acid produces small palatal shelves in their fetuses and down-regulates BMPR2 expressions.

Animals ; Bone Morphogenetic Protein 2 ; Cleft Palate ; Disease Models, Animal ; Down-Regulation ; Female ; Mice ; Pregnancy ; RNA, Messenger ; Tretinoin

Objective To explore the related factors that might had effect on orthodontic patients' esthetic evaluation of axial dental midline angulation from three aspects which are ideal value,detectable value and tolerable value.Methods Photographs of a smiling woman was digitally manipulated to produce models with left or right maxillary axial dental midline angulations in 2° increments.These digital photographs models were used to develop an electronic questionnaire in combination with corresponding guidance for each question.The electronic questionnaire was applied to investigate the esthetic evaluation of axial dental midline angulation from 222 orthodontic patients who complied with the inclusion criteria.Esthetic evaluation included three aspects,the ideal value,the detectable value and the tolerable value,which represented the degrees of maxillary axial dental midline angulations the patients considered to be ideal,detectable and tolerable,respectively.The patients' personal information and clinical orthodontic examination results were collected as well.Results The mean detectable value and tolerable value were 4.9° and 9.7°,the median of detectable value and tolerable value were 5°and 9.5°.Logistic regression analysis was applied to explore the influence of seven factors on each evaluator's ideal value,detectable value and tolerable value.The seven factors were gender,marriage condition,education level,orthodontic treatment condition,malocclusion index,dental esthetic rating from others and from themselves.The statistical analysis indicated education level and orthodontic treatment condition were the influential factors of detectable values,while the tolerable values were influenced by the education level and gender.The ideal value converged to 0° and none of the factors had effect on it.Conclusions The education level,orthodontic treatment condition and gender are considered to be the influential factors of the esthetic evaluation of axial dental midline angulation.

Objective To investigate the factors influencing positive and negative affects ot orthodontic patients.Methods 145 orthodontic patients were selected and finished questionnaire survey.The questionnaires included demographic data,psychosocial impact of dental aesthetic questionnaire (PIDAQ),aesthetic content of index of orthodontic treatment need (IOTN-AC),perception of occlusion scale (POS),and positive affect and negative affect scale (PANAS).Mann-Whitney U-test,Kruskal-Walis H-test,and Spearman correlation analysis were used to analyze the relation between impact of dental aesthetics and positive and negative affects in orthodontic patients.Results The scores of adolescent patients were higher than adult patients in negative affect (U =1886.500,P＜0.05).The patients under orthodontic treatment scored higher than those before treatment (U=2228.000,P＜0.05).The subdomains of PIDAQ,such as social impact (x2=ll.794,P＜0.05),aesthetic attitude (x2 =45.853,P＜0.05),and dental confidence (x2 =33.551,P＜0.05) were related with negative affect.The scores of IOTN-AC,PIDAQ,POS demonstrated positive correlation with negative affect (P＜0.05).The scores of social impact showed negative correlation with positive affect (P＜0.05).Conclusions Adult orthodontic patients suffer more negative affect than adolescent patients.Orthodontic treatment could promote patients' positive affect.However,the negative psychosocial impact in dental aesthetics would strengthen the negative affect.

OBJECTIVETo study the short-term effects of nociceptive trigeminal inhibitory tension suppression system (NTI-tss) and occlusal stabilization splint (OS) on sleep bruxism patients.

METHODSTen patients received the two splint treatments in a randomized cross-over fashion: An NTI-tss and an OS for a 1-week period, respectively. Record the bruxism episodes per hour, micro-arousals per hour of the patients before wearing the splints (baseline), the first night and 1 week after wearing the splints with polysomnography. Statistical analysis was performed with SAS 9.1 by means of mixed effect model analysis.

RESULTSThere were no differences among the micro-arousal index of the baseline, the first night and 1 week later with both types of the splints (P>0.05). The NTI-tss was associated with a significant reduction in bruxism index compared with baseline. The bruxism index of baseline, the first night and 1 week later were 7.50 +/- 1.11, 3.45 +/- 1.22, and 3.51 +/- 1.03 per hour(the first night vs baseline, t=26.52, P<0.01; 1 week vs baseline, t=26.12, P<0.01). There were also significant differences in the bruxism index after wearing the OS. The bruxism index of baseline, the first night and 1 week later were 7.44 +/- 1.23, 2.97 +/- 0.91 and 6.43 +/- 1.02 per hour(the first night vs baseline, t=16.79, P<0.01; 1 week vs baseline, t=3.79, P<0.01). Compared with the NTI-tss group, the reduction was much less, especially 1 week later.

CONCLUSIONBoth the NTI-tss and the OS splints can reduce the bruxism index, and have no affect the incidence of micro-arousal. In this short term study, the NTI-tss was more effective than the OS for the treatment of sleep bruxism.

Bruxism ; Humans ; Occlusal Splints ; Polysomnography ; Sleep Bruxism ; Splints

Objective To clone 2-hydroxyacid dehydrogenase (HADH) gene from Ketogulonigenium vulgare(KGV) Y25 and investigate its expression , purification, and enzymatic characterics .Methods The hadh gene was amplified from ketogulonigenium vulgare Y 25 and cloned into the expression plasmid pITG .The recombinant plasmid was transformed into Escherichia coli BL21(DE3).HADH was then successfully expressed with induction .To explore its enzymatic characteris-tics,HADH was purified by Ni +exchange chromatography .Results HADH constituted more than 50% of the total cell proteins analyzed by SDS-PAGE,with a relative molecular mass of about 35 ×103.With 2-keto-gulonic acid(2-KGA) as substrate, the optimal pH of HADH was at 8.0 ,while the optimal temperature of the purified HADH was at 45℃.Mean-while, such metal ions and chelating agents as Cu 2+, Ca2+, Mg2+, EDTA, and DEPC exerted little effect on enzymatic activities.The maximum initial activity of the enzyme towards 2-KGA reached 27 U/mg, and the Km was calculated as 2.6 mmol/L.The results of in vivo enzyme activity assay showed that HADH could metabolize 2-KGA.Conclusion The HADH gene form Y25 is successfully expressed in E.coli BL21 ( DE3 ) and the enzymatic characteristics of HADH are explored, which will facilitate subsequent studies on sorbose metabolic pathways and sugar acid conversion .

Objective To clone the aldehyde dehydrogenase (adhA) gene from Methylovorus glucosotrophus and study its expression,purification and enzymatic characteristics.Methods The adhA gene was amplified and cloned to the expression vector pTIG.The AdhA was successfully expressed with induction in Escherichia coli BL21(DE3).The enzymatic characteristics were investigated by AHMT,and AdhA was purified by Ni+ exchange chromatography.Results AdhA accounted for more than 50% of the total cell proteins,and the purity was about 95%.With methanol as the substrate,the optimal pH of AdhA was 7.0,while the optimal temperature was 30℃.The enzymatic activity of purified AdhA remained about 60% when stored at room temperature for 6 days.Conclusion AdhA from MP688 is expressed in vitro,and methanol is the optimal substrate among all the substrates investigated.

Objective To prepare and characterize specific monoclonal antibodies( McAbs) against the heavy chain of botulinum neurotoxin serotype A ( BoNT/AHc ) .Methods BALB/c mice were immunized with purified BoNT/AHc protein.After the fusion of mouse splenic cells with SP2/0 cells, hybridoma cell lines secreted McAbs against BoNT/AHc. The McAbs obtained were characterized by indirect ELISA, Western blotting and rapid isotypingassay before being used in ELISA to detect interaction sites in McAbs and BoNT/AHc preliminarily.Results Antigen protein BoNT/AHc of high purification was obtained.Four hybridoma cell lines secreting McAbs against BoNT/AHc were screened,named 1A4,3H3, 3H7 and 5H8,respectively.Their titers of McAbs were all above 3.0 ×103 .They were specifically combined with BoNT/AHc protein by Western blotting.The isotype of 1A4 and 3H7 was IgG1(Κ),that of 3H3 was IgM(Κ),and that of 5H8 was IgG2b(Κ).Additive ELISA showed that epitopes recognized by the four McAbs were close.ELISA analysis confirmed the interaction epitopes in McAbs and BoNT/AHc.Conclusion Monoclonal antibodies against BoNT/AHc are prepared and characterized,providing effective tools for studying the neutralizing antibody and antibody epitopes of BoNT/AHc.

OBJECTIVE To investigate the effect and related mechanism of all￣trans retinoic acid (atRA) exposure on osteogenic differentiation of mouse embryonic palate masenchymal cells MEPM. METHODS MEPM were cultured in osteogenic medium (OM) with atRA 0.1 and 1.0 μmol??L-1 for 1, 3,5, 7 and 9 d. MTT assay was performed to measure the cell viability. The alkaline phosphatase (ALP) activity was measured by chemical colorimetry. The cells were stained using the Von￣Kossa technique to detect the formation of mineralization nodules after 21 d of culture. RT￣PCR was performed to determine expression Runx2, osteopontin, bone morphogenetic protein receptor ( Bmpr) 1b, Bmpr2 and Smad5 mRNA. RESULTS The result of MTT on 9 d showed that, compared with normal control group, the cell viability of OM, OM+atRA 0.1 and 1.0 μmol??L-1 groups decreased significantly(P<0.01). Compared with normal control group, ALP activity of OM group increased significantly(P<0.05), while the ALP activity of OM+atRA 0.1 and 1.0 μmol??L-1 groups was lower than OM group(P<0.05). On 21 d, the Von￣Kossa stai￣ning results showed that the percentage of mineralization nodules formation of OM+atRA 1.0 μmol??L-1 group was (3.65±1.24)%, which was significantly lower than that of OM group(10.33±2.29)%(P<0. 05). On 9 d, the relative Run expression of OM group was the highest one in the four groups, while at￣RA 1.0 μmol??L-1 treatment negatively regulated 20% in comparsion with OM group(P<0.05). Compared with normal control group, the mRNA expression of osteopontin of OM, OM+atRA 0.1 and 1.0 μmol??L-1 groups increased significantly(P<0.05); BDNF mRNA expression of OM group was 2.6￣fold to normal control group, while that of OM+atRA 1.0 μmol??L-1 group was 33% to OM group(P<0.05) . The level of Smad5 mRNA of OM+atRA 1.0 μmol??L-1 group was significantly lower than that of OM group(P<0.05). CONCLUSION atRA Might inhibit osteogenic differentiation of MEPM by down￣regulated the expression of Bmpr1b.