Objective:To observe the influence of emotional stress on the temporomandibular joint(TMJ) of SD rats. Methods:Standard animal model of emotional stress was created by emotion communication emergency box technique in 30 SD rats and foot-shocked in another 30. Control rats were 30 without treatment. The microstructure and ultrastructure of the disc surface, condylar surface and external pterygoid muscle were observed 1, 3 and 5 weeks after emotional stress treatment. Results:Obviously pathological changes were observed in the experimental animals, especially at 3 weeks, involving the fissures on the disc and condylar surface, the collagen fibers were disordered. Electron microscopy observation showed that condylar collagen was exposed. The mitochondria edema and vacuolar degeneration in the external pterygoid muscle were found.At 5 weeks, the condylar cartilage started to recover. Conclusion:Long term emotional stress may lead to pathological changes of the temporomandibular system. The changes can be partly recovered after a certain time of adaption of TMJ.

Objective To investigate the repair effect of low intensity ultrasound on radioactive mandibule bone to provide new idea for prevention of osteoradionecrosis of the mandibule after irradiation.Methods The animal models of radioactive mandibular injury were made and treated with low intensity ultrasound.Low intensity ultrasound treatment group ( Group Ⅱ ) and not with low intensity ultrasound treatment group (Group Ⅰ ) were observed by microvessel density detection,micro-CT,ponceau trichrome stain and so on,and compared with control group.Then,the obtained data were statistically analyzed.Results The animal models of radioactive mandibular injury were successfully established.The microvessel density in Group Ⅱ was greater than that in Group Ⅰ.The bone volume fraction,trabecular thickness,bone surface/bone volume and the trabecular number in Group Ⅱ were significantly larger than those in Group Ⅰ (P ＜ 0.05).The ponceau trichrome staining showed that the osteocytes largely disappeared and that the cancellous bone trabecular atrophied in Group Ⅰ,while new bone formation,trabecular and numerous osteoblasts around trabecular were largely observed in Group Ⅱ.Conclusion Low intensity ultrasound has a good recovery effect on bone tissue after irradiation.

Objective To investigate the role of psychological intervention in the prevention of the temporomandibular joint disease (TMD) , through the observation of the relative changes in the rat TMJ under psychological stress after psychological intervention. Methods The rat model of communication box was built to exert the psychological stress. The antianxiety agent was applied before stress, and the stressor was removed after stress. The expression of the proinflammatory cytokines IL-1 and TNF-α in the mandibular condylar chondrocytes in rat TMJ was detected by ELISA and RT-PCR. Results The RT-PCR results showed that the expression of IL-1 mR-NA increased into the peak in the 1st week, weakened in the 3rd week, and returned to normal in the 5th week, while the TNF-αmRNA peaked in the 1st week, returned to normal in the 3rd week. The ELISA results showed that there was no significant difference of the OD value of the serum IL-1 and TNF-α(0. 095 ±0. 006,0. 077 ± 0.007,0.069 ±0.009 ;0.079 ±0.010,0.075 ±0. 009,0.079 ± 0.012) in the antianxiety agent group (0. 107 ± 0.024,0. 101 ±0.005,0.088 ±0.010)and the stressor removal group(0. 090 ±0.016,0. 088 ±0.005,0.089 ± 0.011) , compared with the control group(0.087 ±0.004,0.090 ±0.009,0.089 ±0.010;0.074 ±0.008,0.069 ±0.015,0.068 ±0.011) (P>0.05), while significant differences were observed when compared with the psychological stress group(0.282 ±0.045,0.226 ±0.021,0.092 ±0.002;0. 164 ±0.009,0.123 ±0.013,0.091 ± 0.006) (P<0.05 ). Conclusion Application of the antianxiety agent and stressor removal could effectively counter the influence of psychological stress to TMJ, which provides good experience for the clinical prevention of TMD.

Objective To observe the substance P(SP) and calcitonin gene-related peptide(CGRP) expressions in the temporomandibular joints(TM J) of the rats undergone emotional stress and explore the relationship between emotional stress and temporomandibular joint disorder(TMD). Methods Ninety SD rats were averagely randomly divided into emotional stress ( ES ) group( n = 30 ), electric foot-shocked (FS) group ( n = 30 ) and control (CON) group( n = 30). The emotional stress was induced by communication box. The TMJ tissues in ES and CON groups were removed after 1, 3 and 5 weeks of emotional stress for scanning electron microscope ( SEM ) test and immunohistochemistry test. The SP and CGRP expressions were examined with SABC immunohistochemistry and then analyzed by image analysis system. Results The expressions of SP and CGRP had significant difference after 1 ,3 and 5 weeks emotional stress ( SP: 124.5 ± 16.9,185.6 ± 1.8 and 193.5 ± 3.5, respectively; CGRP: 185.9 ±5.3, 112.5 ±5.2 and 174.3 ±5.3 ,respectively) (P＜0. 05 ). The SEM results showed that there was a series of structural change on the condylar surface after emotional stress. Conclusion The SP and CGRP energy nerve fibers take part in the TMJ pathological process undergone emotional stress.

Objective To investigate the changes of myosin heavy chain ( MyHC) isoforms in rat masseter muscle fibers caused by chronic sleep deprivation ( CSD) and a possible link with the pathogenesis of temporomandibular joint disorders ( TMD ) .Methods Total 180 male rats were randomly divided into three groups( n=60 per group): chronic sleep deprivation group ( CSD),cage control group ( CC),and large-platform control group ( TC ) .Each group was further divided into three subgroups ( n=20 in each group)according to the observation time point(7,14,and 21 days).The expression of MyHC isoforms in mas-seter muscle fibers was investigated by real-time quantitative PCR,Western blotting and immunohistochemi-cal staining.Results The expression of MyHC-Ⅰ,MyHC-ⅡA and MyHC-ⅡB deep and shallow masseter muscle in CSD7d group had differention with the control group(MyHC-Ⅰ:(0.314±0.005,0.134±0.005, P<0.05;MyHC-ⅡA (7.960±0.465,7.090±0.564, P<0.05;MyHC-ⅡB:(2.840±0.054,2.580±0.054, P<0.05) .The expression of MyHC-Ⅰdeep and shallow masseter muscle in CSD 14 d group had differention with the control group(0.284±0.005,0.106±0.015, P<0.05),the same appearance as MyHC-ⅡA deep and shallow masseter muscle(7.030±1.045,6.050±0.976, P<0.05) and MyHC-ⅡB deep and shallow masseter muscle((3.680±0.548,3.850±0.457, P<0.05).CSD groups exhibited increased MyHC-Ⅰexpression in both the deep and shallow muscle fiber layers at 7 days compared with CC and TC groups(P<0.05) ,whereas CSD significantly decreased MyHC-ⅡA and MyHC-ⅡB expression(P<0.05) .The expression of MyHC-Ⅱwas sig-nificantly decreased in CSD 7 d group,while the expression of MyHC-Ⅰwas increased.As the CSD time ex-tended,the MyHC-Ⅱexpression was increased and MyHC-Ⅰexpression was descreased.CSD 21d group ex-hibited significant different from MyHC-Ⅱand MyHC-Ⅰexpression in the deep muscle fiber layer compared with those in CC and TC groups (P<0.05) ,while there was no difference of MyHC-Ⅰor MyHC-Ⅱexpression in the shallow muscle fiber layer between CSD group and CC group (P>0.05) ,and there were no differences between the CC and TC groups at any time point.Conclusion These findings suggest that CSD alters the ex-pression of MyHC isoforms,which may contribute to TMD pathogenesis.

Objective:To observe the effects of low intensity pulsed ultrasound(LIPUS) on the osteogenic differentiation of rat bone marrow mesenchymal stem cells(BMSCs) on titanium surface.Methods:BMSCs from Wistar rat bone marrow were respectively cultured on the flat titanium surface and the large grain blast acid etched(SLA) titanium surface,and induced by mineralization medium.Then,the cells were interfered by LIPUS and a control condition.Alkaline phosphatase(ALP) were quantitative determinated after 3 and 7 d mineralization induction respectively,ALP staining were observed after 14 d induction.Alizarin red staining were observed after 21 d mineralization induction.Osteogenic related protein and gene expressions were detected after mineralization induction.Results:ALP in culture medium of LIPUS group was higher than that of the control group after 3 d and 7 d mineralization induction(P＜0.05).LIPUS group showed stronger ALP staining and alizarin staining,and more mineralized nodules than control group.The expression of osteogenic related proteins,including Runx2,BMP2,OPN in LIPUS group increased.Osteogenic related genes expression,including ALP,Runx2,BMP2,OPN,OCN and Col-1 of the LIPUS group increased.Conclusion:The osteogenic differentiation of BMSCs on the fiat titanium surface or SLA titanium surface can be promoted by LIPUS.

Objective To investigate the possible mechanisms of the attribution of psychological stress to the temporomandibular joint disorder(TMD) ,through the evaluation of the animal model and detection of the proinflammatory cytokines in the TMJ.Methods The animal models of communication box were built to mimic the psychological stress.The concentration of the serum Cor and ACTH was detected in the control group, Psychological Stress group ( PS group), and diazepam ( anti-anxiety drug) group ( PS + DI group).The expression of the proinflammatory cytokines IL-1 and IL-6 in the rat TMJ in the different phases of psychologicalstress was detected by RT-PCR.Results The results of the serum concen- tration of Cor and ACTH showed that there was significant difference between the control group and the PS group(P＜0.01 ) ,while no significant difference between the control group and the PS + DI group(P＞0.05).The expressions of IL-1 and IL-6 were comapared in all group.The expressions of IL-1 in CON group were (0.453± 0.021 ) mg/L, (0.439 ± 0.028 ) mg/L and (0.454 ± 0.023 )mg/L.These values were markedly increased compared with those of the PS group(0.981 ±0.024)mg/L, (0.746±0.017)mg/L and (0.510 ±0.016)mg/L respectively, P＜0.01 ) ,but no significant differences compared with PS + DI group(0.549 ± 0.014 ) mg/L, ( 0.498 ± 0.014 ) mg/L and ( 0.444 ± 0.022 ) mg/L respectively, P ＞ 0.05).Similar changes were observed in expressions of IL-6.The expressions of IL-6 in the CON rats were (0.525 ±0.028)mg/L,(0.515 ±0.028)mg/L and (0.518 ±0.022)mg/L,respectively,while those of PS group were(0.820 ± 0.023 ) mg/L, (0.694 ± 0.019 ) mg/L and (0.579 ± 0.015 ) mg/L, respectively, which were significan- tly higher in the PS groups(P＜ 0.05 ).But there were no significant differences between CON group and PS + DI group( (0.599 ±0.015)mg/L, (0.541 ±0.015)mg/L, (0.487 ±0.008)mg/L respectively, P＞0.05).Conclusion The psychological stress can play important role in the formation of TMD.

Objective To observe the influence of psychological stress and countermeasure implementation upon the temporomandibular joint ( TMJ ) articular disc and external pterygoid muscle in rats,providing experimental and theoretical evidence for clinical treatment of psychological stress-induced temporomandibular disorders (TMD).Methods The animal models treated by psychological stress induced by alternating current box were established.Before and after subjected to psychological stress,rats were given anxiolytic drugs to eliminate stressors.For all the rats in control group,psychological stress group ( PS group),and psychological stress plus anxiolytic drug injection group ( ( PS + DI) group),the microstructure of TMJ articular disc and external pterygoid muscle the changes in RNA expression of interleukin-1 ( 1L-1 ) were investigated by using transmission electron microscope (TEM),scanning electron microscope ( SEM ) and RT-PCR methods,respectively.Statistical analysis was performed upon the obtained test results.Results The TEM showed pathlogical changes in rats'pterygoid muscles of PS group at 1,3 and 5 weeks,including edema,reduction of substrate density and microchondrial cristae.Instead,these structures were all showed normal in the group of PS + DI and recovering group after removal of stressor.For the rats in PS group,SEM observation revealed that partial synovium of articular disc began to disintegrate 1 week after psychological stress.Strip-like wear degenerations were shown in the surface collagenous fiber in articular disc 3 weeks later,and the surface collagenous fibers in articular disc were arrayed in disorder 5 weeks following stress treatment.No significant microstructural changes in articular disc were observed in all stressor-eliminating groups and ( PS + DI) group 1,3,and 5 weeks following stress treatment.Statistical significance was noted in RNA expression level of IL-1 between PS group and PS + DI group (P＜0.05).In addition,there was significant difference in IL-1 expression between PS group and all stressor-eliminating groups.Conclusion The implementation of countermeasures effectively counteracted the influence upon TMJ induced by psychological stress,and provided possible resolutions for the clinical treatment of TMD induced by psychological stress.

Objective: To improve the bioactivity of PEEK by chemical methods. Methods: PEEK samples were treated by polish only (group (1)) ; concentrated sulfuric acid for 5 min (group (2)) ; concentrated sulfuric acid for 10 min (group (3)) ; concentrated sulfuric acid for 5 min, followed by treatment of hydrogen nitrate for 5 min (group (4)) and mineral chameleon and ortho-phosphoric acid (group (5)) respectively (n = 9) . Then, all samples were treated by water at 100 ℃ for 4 h. The sample surface was observed by FE-SEM, the chemical comporent of the samples was analyzed by XPS. BMSCs were cultured on the sample surface for 4 h and observed by SEM. Results: The sample sureface in group (1) was smooth, in group (2), (3) and (4) was with 3 D ethmoidal foramen structure, in group (5) with petal-like from. The sulfur content (Wt％) of the samples of group (1), (2), (3), (4) and (5) was 0, 2. 45 ± 0. 22, 3. 48 ± 0. 16 (vs (1), P= 0. 000), 1. 79 ± 0. 05 (vs (1) P = 0. 002) and 0 respectively. BMSCs cultured on the sample surface of group (2), (3), (4) and (5) were more and with more pseudopod. Conclusion: The bioactivity of PEEK can be enhanced after acid pickling. Water bath and nitric acid treatment can remove the residual acid and further enhance the bioactivity of PEEK.

Objective: To explore the potential role of alpinumisoflavone (AIF) in the treatment of temporomandibular joint osteoarthritis (TMJOA) cell model through network pharmacology and molecular docking and to provide a research basis for AIF in the treatment of TMJOA. Methods: GeneCards, OMIM, DisGeNET, and PharmGKB databases were used to screen TMJOA disease targets, and PharmMapper and HERB were used to retrieve AIF-related targets. The intersection targets of the compounds and diseases were uploaded to the STRING database to obtain the key targets for GO and KEGG enrichment analysis, while the key targets in related signaling pathways were evaluated through molecular docking. Approval was obtained from the Ethics Committee to extract condylar chondrocytes from 3-week-old SD rats. The CCK-8 assay was used to detect AIF cytotoxicity on condylar chondrocytes. Condylar chondrocytes were induced with 10 ng/mL interleukin 1β (IL-1β) for 24 h to construct a TMJOA cell model. The experiment was divided into three groups: control group, comprising condylar chondrocytes cultured in DMEM for 48 h; IL-1β group, comprising condylar chondrocytes pre-cultured in DMEM for 24 h, after which IL-1β was added to the original culture medium to obtain a medium concentration of 10 ng/mL and allowed to culture for 24 h; and the IL-1β+10 μmol/L AIF group, comprising condylar chondrocytes pre-cultured in DMEM medium containing 10 μmol/L AIF for 24 h, after which IL-1β was added to the original culture medium to obtain a medium concentration of 10 ng/mL and allowed to culture for 24 h. The effect of AIF on condylar chondrocyte apoptosis in the TMJOA cell model was detected by flow cytometry. The experiment was divided into four groups: control group, IL-1β group, IL-1β+10 μmol/L AIF group, and IL-1β+30 μmol/L AIF group. The IL-1β+30 μmol/L AIF group was pre-cultured in DMEM containing 30 μmol/L AIF for 24 h, after which IL-1β was added to the original culture medium to obtain a medium concentration of 10 ng/mL and allowed to culture for 24 h. The remaining three groups were cultured in the same manner as before. The mRNA and protein expression of apoptosis-associated B-cell leukemia/lymphoma-2 (Bcl2), cysteinyl aspartate specific protease 3 (caspase-3), matrix degradation-associated a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4), matrix metalloproteinase 3 (MMP3), and matrix metalloproteinase 13 (MMP13) were detected by qPCR and western blot, by AIF in the TMJOA cell model. Results: The PharmMapper and HERB database search yielded 300 AIF compound targets. The GeneCards, OMIM, DisGeNET, and PharmGKB databases yielded 378 TMJOA disease targets. Thirty-three potential common targets were obtained by intersecting compounds with disease targets. The common targets were uploaded into the STRING database to obtain 31 key targets that were mainly associated with apoptosis and extracellular matrix degradation. This process may be associated with the MAPK, estrogen, and TNF signaling pathways. The molecular docking results showed that AIF has good binding activity with extracellular signal-regulated kinase 1/2 (ERK1/2) and estrogen receptor gene 1/2 (ESR1/2), which are key targets in the MAPK and estrogen signaling pathways. The CCK-8 assay showed that AIF had no obvious cytotoxicity to condylar chondrocytes. The cell experiments showed that AIF inhibited apoptosis in the IL-1β+10 μmol/L AIF group compared to the IL-1β group. Compared to the IL-1β group in the IL-1β+10 μmol/L AIF group and the IL-1β+30 μmol/L AIF group, AIF upregulated Bcl2 and downregulated caspase-3 mRNA and protein expression and inhibited ADAMTS4, MMP3, and MMP13 mRNA and protein expression. Conclusion AIF inhibited apoptosis in the TMJOA cell model by upregulating Bcl2 and downregulating caspase-3 mRNA and protein expression, and inhibited extracellular matrix degradation induced by IL-1β, thereby delaying TMJOA progression.